contrib/fast-import/git-p4

#!/usr/bin/env python
#
# git-p4.py -- A tool for bidirectional operation between a Perforce depot and git.
#
# Author: Simon Hausmann <simon@lst.de>
# Copyright: 2007 Simon Hausmann <simon@lst.de>
#            2007 Trolltech ASA
# License: MIT <http://www.opensource.org/licenses/mit-license.php>
#

import optparse, sys, os, marshal, popen2, subprocess, shelve
import tempfile, getopt, sha, os.path, time, platform
import re

from sets import Set;

verbose = False

def die(msg):
    if verbose:
        raise Exception(msg)
    else:
        sys.stderr.write(msg + "\n")
        sys.exit(1)

def write_pipe(c, str):
    if verbose:
        sys.stderr.write('Writing pipe: %s\n' % c)

    pipe = os.popen(c, 'w')
    val = pipe.write(str)
    if pipe.close():
        die('Command failed: %s' % c)

    return val

def read_pipe(c, ignore_error=False):
    if verbose:
        sys.stderr.write('Reading pipe: %s\n' % c)

    pipe = os.popen(c, 'rb')
    val = pipe.read()
    if pipe.close() and not ignore_error:
        die('Command failed: %s' % c)

    return val


def read_pipe_lines(c):
    if verbose:
        sys.stderr.write('Reading pipe: %s\n' % c)
    ## todo: check return status
    pipe = os.popen(c, 'rb')
    val = pipe.readlines()
    if pipe.close():
        die('Command failed: %s' % c)

    return val

def system(cmd):
    if verbose:
        sys.stderr.write("executing %s\n" % cmd)
    if os.system(cmd) != 0:
        die("command failed: %s" % cmd)

def p4CmdList(cmd, stdin=None, stdin_mode='w+b'):
    cmd = "p4 -G %s" % cmd
    if verbose:
        sys.stderr.write("Opening pipe: %s\n" % cmd)

    # Use a temporary file to avoid deadlocks without
    # subprocess.communicate(), which would put another copy
    # of stdout into memory.
    stdin_file = None
    if stdin is not None:
        stdin_file = tempfile.TemporaryFile(prefix='p4-stdin', mode=stdin_mode)
        stdin_file.write(stdin)
        stdin_file.flush()
        stdin_file.seek(0)

    p4 = subprocess.Popen(cmd, shell=True,
                          stdin=stdin_file,
                          stdout=subprocess.PIPE)

    result = []
    try:
        while True:
            entry = marshal.load(p4.stdout)
            result.append(entry)
    except EOFError:
        pass
    exitCode = p4.wait()
    if exitCode != 0:
        entry = {}
        entry["p4ExitCode"] = exitCode
        result.append(entry)

    return result

def p4Cmd(cmd):
    list = p4CmdList(cmd)
    result = {}
    for entry in list:
        result.update(entry)
    return result;

def p4Where(depotPath):
    if not depotPath.endswith("/"):
        depotPath += "/"
    output = p4Cmd("where %s..." % depotPath)
    if output["code"] == "error":
        return ""
    clientPath = ""
    if "path" in output:
        clientPath = output.get("path")
    elif "data" in output:
        data = output.get("data")
        lastSpace = data.rfind(" ")
        clientPath = data[lastSpace + 1:]

    if clientPath.endswith("..."):
        clientPath = clientPath[:-3]
    return clientPath

def currentGitBranch():
    return read_pipe("git name-rev HEAD").split(" ")[1].strip()

def isValidGitDir(path):
    if (os.path.exists(path + "/HEAD")
        and os.path.exists(path + "/refs") and os.path.exists(path + "/objects")):
        return True;
    return False

def parseRevision(ref):
    return read_pipe("git rev-parse %s" % ref).strip()

def extractLogMessageFromGitCommit(commit):
    logMessage = ""

    ## fixme: title is first line of commit, not 1st paragraph.
    foundTitle = False
    for log in read_pipe_lines("git cat-file commit %s" % commit):
       if not foundTitle:
           if len(log) == 1:
               foundTitle = True
           continue

       logMessage += log
    return logMessage

def extractSettingsGitLog(log):
    values = {}
    for line in log.split("\n"):
        line = line.strip()
        m = re.search (r"^ *\[git-p4: (.*)\]$", line)
        if not m:
            continue

        assignments = m.group(1).split (':')
        for a in assignments:
            vals = a.split ('=')
            key = vals[0].strip()
            val = ('='.join (vals[1:])).strip()
            if val.endswith ('\"') and val.startswith('"'):
                val = val[1:-1]

            values[key] = val

    paths = values.get("depot-paths")
    if not paths:
        paths = values.get("depot-path")
    if paths:
        values['depot-paths'] = paths.split(',')
    return values

def gitBranchExists(branch):
    proc = subprocess.Popen(["git", "rev-parse", branch],
                            stderr=subprocess.PIPE, stdout=subprocess.PIPE);
    return proc.wait() == 0;

def gitConfig(key):
    return read_pipe("git config %s" % key, ignore_error=True).strip()

def p4BranchesInGit(branchesAreInRemotes = True):
    branches = {}

    cmdline = "git rev-parse --symbolic "
    if branchesAreInRemotes:
        cmdline += " --remotes"
    else:
        cmdline += " --branches"

    for line in read_pipe_lines(cmdline):
        line = line.strip()

        ## only import to p4/
        if not line.startswith('p4/') or line == "p4/HEAD":
            continue
        branch = line

        # strip off p4
        branch = re.sub ("^p4/", "", line)

        branches[branch] = parseRevision(line)
    return branches

def findUpstreamBranchPoint(head = "HEAD"):
    branches = p4BranchesInGit()
    # map from depot-path to branch name
    branchByDepotPath = {}
    for branch in branches.keys():
        tip = branches[branch]
        log = extractLogMessageFromGitCommit(tip)
        settings = extractSettingsGitLog(log)
        if settings.has_key("depot-paths"):
            paths = ",".join(settings["depot-paths"])
            branchByDepotPath[paths] = "remotes/p4/" + branch

    settings = None
    parent = 0
    while parent < 65535:
        commit = head + "~%s" % parent
        log = extractLogMessageFromGitCommit(commit)
        settings = extractSettingsGitLog(log)
        if settings.has_key("depot-paths"):
            paths = ",".join(settings["depot-paths"])
            if branchByDepotPath.has_key(paths):
                return [branchByDepotPath[paths], settings]

        parent = parent + 1

    return ["", settings]

class Command:
    def __init__(self):
        self.usage = "usage: %prog [options]"
        self.needsGit = True

class P4Debug(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [
            optparse.make_option("--verbose", dest="verbose", action="store_true",
                                 default=False),
            ]
        self.description = "A tool to debug the output of p4 -G."
        self.needsGit = False
        self.verbose = False

    def run(self, args):
        j = 0
        for output in p4CmdList(" ".join(args)):
            print 'Element: %d' % j
            j += 1
            print output
        return True

class P4RollBack(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [
            optparse.make_option("--verbose", dest="verbose", action="store_true"),
            optparse.make_option("--local", dest="rollbackLocalBranches", action="store_true")
        ]
        self.description = "A tool to debug the multi-branch import. Don't use :)"
        self.verbose = False
        self.rollbackLocalBranches = False

    def run(self, args):
        if len(args) != 1:
            return False
        maxChange = int(args[0])

        if "p4ExitCode" in p4Cmd("changes -m 1"):
            die("Problems executing p4");

        if self.rollbackLocalBranches:
            refPrefix = "refs/heads/"
            lines = read_pipe_lines("git rev-parse --symbolic --branches")
        else:
            refPrefix = "refs/remotes/"
            lines = read_pipe_lines("git rev-parse --symbolic --remotes")

        for line in lines:
            if self.rollbackLocalBranches or (line.startswith("p4/") and line != "p4/HEAD\n"):
                line = line.strip()
                ref = refPrefix + line
                log = extractLogMessageFromGitCommit(ref)
                settings = extractSettingsGitLog(log)

                depotPaths = settings['depot-paths']
                change = settings['change']

                changed = False

                if len(p4Cmd("changes -m 1 "  + ' '.join (['%s...@%s' % (p, maxChange)
                                                           for p in depotPaths]))) == 0:
                    print "Branch %s did not exist at change %s, deleting." % (ref, maxChange)
                    system("git update-ref -d %s `git rev-parse %s`" % (ref, ref))
                    continue

                while change and int(change) > maxChange:
                    changed = True
                    if self.verbose:
                        print "%s is at %s ; rewinding towards %s" % (ref, change, maxChange)
                    system("git update-ref %s \"%s^\"" % (ref, ref))
                    log = extractLogMessageFromGitCommit(ref)
                    settings =  extractSettingsGitLog(log)


                    depotPaths = settings['depot-paths']
                    change = settings['change']

                if changed:
                    print "%s rewound to %s" % (ref, change)

        return True

class P4Submit(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [
                optparse.make_option("--continue", action="store_false", dest="firstTime"),
                optparse.make_option("--verbose", dest="verbose", action="store_true"),
                optparse.make_option("--origin", dest="origin"),
                optparse.make_option("--reset", action="store_true", dest="reset"),
                optparse.make_option("--log-substitutions", dest="substFile"),
                optparse.make_option("--dry-run", action="store_true"),
                optparse.make_option("--direct", dest="directSubmit", action="store_true"),
                optparse.make_option("--trust-me-like-a-fool", dest="trustMeLikeAFool", action="store_true"),
        ]
        self.description = "Submit changes from git to the perforce depot."
        self.usage += " [name of git branch to submit into perforce depot]"
        self.firstTime = True
        self.reset = False
        self.interactive = True
        self.dryRun = False
        self.substFile = ""
        self.firstTime = True
        self.origin = ""
        self.directSubmit = False
        self.trustMeLikeAFool = False
        self.verbose = False
        self.isWindows = (platform.system() == "Windows")

        self.logSubstitutions = {}
        self.logSubstitutions["<enter description here>"] = "%log%"
        self.logSubstitutions["\tDetails:"] = "\tDetails:  %log%"

    def check(self):
        if len(p4CmdList("opened ...")) > 0:
            die("You have files opened with perforce! Close them before starting the sync.")

    def start(self):
        if len(self.config) > 0 and not self.reset:
            die("Cannot start sync. Previous sync config found at %s\n"
                "If you want to start submitting again from scratch "
                "maybe you want to call git-p4 submit --reset" % self.configFile)

        commits = []
        if self.directSubmit:
            commits.append("0")
        else:
            for line in read_pipe_lines("git rev-list --no-merges %s..%s" % (self.origin, self.master)):
                commits.append(line.strip())
            commits.reverse()

        self.config["commits"] = commits

    def prepareLogMessage(self, template, message):
        result = ""

        for line in template.split("\n"):
            if line.startswith("#"):
                result += line + "\n"
                continue

            substituted = False
            for key in self.logSubstitutions.keys():
                if line.find(key) != -1:
                    value = self.logSubstitutions[key]
                    value = value.replace("%log%", message)
                    if value != "@remove@":
                        result += line.replace(key, value) + "\n"
                    substituted = True
                    break

            if not substituted:
                result += line + "\n"

        return result

    def applyCommit(self, id):
        if self.directSubmit:
            print "Applying local change in working directory/index"
            diff = self.diffStatus
        else:
            print "Applying %s" % (read_pipe("git log --max-count=1 --pretty=oneline %s" % id))
            diff = read_pipe_lines("git diff-tree -r --name-status \"%s^\" \"%s\"" % (id, id))
        filesToAdd = set()
        filesToDelete = set()
        editedFiles = set()
        for line in diff:
            modifier = line[0]
            path = line[1:].strip()
            if modifier == "M":
                system("p4 edit \"%s\"" % path)
                editedFiles.add(path)
            elif modifier == "A":
                filesToAdd.add(path)
                if path in filesToDelete:
                    filesToDelete.remove(path)
            elif modifier == "D":
                filesToDelete.add(path)
                if path in filesToAdd:
                    filesToAdd.remove(path)
            else:
                die("unknown modifier %s for %s" % (modifier, path))

        if self.directSubmit:
            diffcmd = "cat \"%s\"" % self.diffFile
        else:
            diffcmd = "git format-patch -k --stdout \"%s^\"..\"%s\"" % (id, id)
        patchcmd = diffcmd + " | git apply "
        tryPatchCmd = patchcmd + "--check -"
        applyPatchCmd = patchcmd + "--check --apply -"

        if os.system(tryPatchCmd) != 0:
            print "Unfortunately applying the change failed!"
            print "What do you want to do?"
            response = "x"
            while response != "s" and response != "a" and response != "w":
                response = raw_input("[s]kip this patch / [a]pply the patch forcibly "
                                     "and with .rej files / [w]rite the patch to a file (patch.txt) ")
            if response == "s":
                print "Skipping! Good luck with the next patches..."
                return
            elif response == "a":
                os.system(applyPatchCmd)
                if len(filesToAdd) > 0:
                    print "You may also want to call p4 add on the following files:"
                    print " ".join(filesToAdd)
                if len(filesToDelete):
                    print "The following files should be scheduled for deletion with p4 delete:"
                    print " ".join(filesToDelete)
                die("Please resolve and submit the conflict manually and "
                    + "continue afterwards with git-p4 submit --continue")
            elif response == "w":
                system(diffcmd + " > patch.txt")
                print "Patch saved to patch.txt in %s !" % self.clientPath
                die("Please resolve and submit the conflict manually and "
                    "continue afterwards with git-p4 submit --continue")

        system(applyPatchCmd)

        for f in filesToAdd:
            system("p4 add \"%s\"" % f)
        for f in filesToDelete:
            system("p4 revert \"%s\"" % f)
            system("p4 delete \"%s\"" % f)

        logMessage = ""
        if not self.directSubmit:
            logMessage = extractLogMessageFromGitCommit(id)
            logMessage = logMessage.replace("\n", "\n\t")
            if self.isWindows:
                logMessage = logMessage.replace("\n", "\r\n")
            logMessage = logMessage.strip()

        template = read_pipe("p4 change -o")

        if self.interactive:
            submitTemplate = self.prepareLogMessage(template, logMessage)
            diff = read_pipe("p4 diff -du ...")

            for newFile in filesToAdd:
                diff += "==== new file ====\n"
                diff += "--- /dev/null\n"
                diff += "+++ %s\n" % newFile
                f = open(newFile, "r")
                for line in f.readlines():
                    diff += "+" + line
                f.close()

            separatorLine = "######## everything below this line is just the diff #######"
            if platform.system() == "Windows":
                separatorLine += "\r"
            separatorLine += "\n"

            response = "e"
            if self.trustMeLikeAFool:
                response = "y"

            firstIteration = True
            while response == "e":
                if not firstIteration:
                    response = raw_input("Do you want to submit this change? [y]es/[e]dit/[n]o/[s]kip ")
                firstIteration = False
                if response == "e":
                    [handle, fileName] = tempfile.mkstemp()
                    tmpFile = os.fdopen(handle, "w+")
                    tmpFile.write(submitTemplate + separatorLine + diff)
                    tmpFile.close()
                    defaultEditor = "vi"
                    if platform.system() == "Windows":
                        defaultEditor = "notepad"
                    editor = os.environ.get("EDITOR", defaultEditor);
                    system(editor + " " + fileName)
                    tmpFile = open(fileName, "rb")
                    message = tmpFile.read()
                    tmpFile.close()
                    os.remove(fileName)
                    submitTemplate = message[:message.index(separatorLine)]
                    if self.isWindows:
                        submitTemplate = submitTemplate.replace("\r\n", "\n")

            if response == "y" or response == "yes":
               if self.dryRun:
                   print submitTemplate
                   raw_input("Press return to continue...")
               else:
                   if self.directSubmit:
                       print "Submitting to git first"
                       os.chdir(self.oldWorkingDirectory)
                       write_pipe("git commit -a -F -", submitTemplate)
                       os.chdir(self.clientPath)

                   write_pipe("p4 submit -i", submitTemplate)
            elif response == "s":
                for f in editedFiles:
                    system("p4 revert \"%s\"" % f);
                for f in filesToAdd:
                    system("p4 revert \"%s\"" % f);
                    system("rm %s" %f)
                for f in filesToDelete:
                    system("p4 delete \"%s\"" % f);
                return
            else:
                print "Not submitting!"
                self.interactive = False
        else:
            fileName = "submit.txt"
            file = open(fileName, "w+")
            file.write(self.prepareLogMessage(template, logMessage))
            file.close()
            print ("Perforce submit template written as %s. "
                   + "Please review/edit and then use p4 submit -i < %s to submit directly!"
                   % (fileName, fileName))

    def run(self, args):
        if len(args) == 0:
            self.master = currentGitBranch()
            if len(self.master) == 0 or not gitBranchExists("refs/heads/%s" % self.master):
                die("Detecting current git branch failed!")
        elif len(args) == 1:
            self.master = args[0]
        else:
            return False

        [upstream, settings] = findUpstreamBranchPoint()
        depotPath = settings['depot-paths'][0]
        if len(self.origin) == 0:
            self.origin = upstream

        if self.verbose:
            print "Origin branch is " + self.origin

        if len(depotPath) == 0:
            print "Internal error: cannot locate perforce depot path from existing branches"
            sys.exit(128)

        self.clientPath = p4Where(depotPath)

        if len(self.clientPath) == 0:
            print "Error: Cannot locate perforce checkout of %s in client view" % depotPath
            sys.exit(128)

        print "Perforce checkout for depot path %s located at %s" % (depotPath, self.clientPath)
        self.oldWorkingDirectory = os.getcwd()

        if self.directSubmit:
            self.diffStatus = read_pipe_lines("git diff -r --name-status HEAD")
            if len(self.diffStatus) == 0:
                print "No changes in working directory to submit."
                return True
            patch = read_pipe("git diff -p --binary --diff-filter=ACMRTUXB HEAD")
            self.diffFile = self.gitdir + "/p4-git-diff"
            f = open(self.diffFile, "wb")
            f.write(patch)
            f.close();

        os.chdir(self.clientPath)
        response = raw_input("Do you want to sync %s with p4 sync? [y]es/[n]o " % self.clientPath)
        if response == "y" or response == "yes":
            system("p4 sync ...")

        if self.reset:
            self.firstTime = True

        if len(self.substFile) > 0:
            for line in open(self.substFile, "r").readlines():
                tokens = line.strip().split("=")
                self.logSubstitutions[tokens[0]] = tokens[1]

        self.check()
        self.configFile = self.gitdir + "/p4-git-sync.cfg"
        self.config = shelve.open(self.configFile, writeback=True)

        if self.firstTime:
            self.start()

        commits = self.config.get("commits", [])

        while len(commits) > 0:
            self.firstTime = False
            commit = commits[0]
            commits = commits[1:]
            self.config["commits"] = commits
            self.applyCommit(commit)
            if not self.interactive:
                break

        self.config.close()

        if self.directSubmit:
            os.remove(self.diffFile)

        if len(commits) == 0:
            if self.firstTime:
                print "No changes found to apply between %s and current HEAD" % self.origin
            else:
                print "All changes applied!"
                os.chdir(self.oldWorkingDirectory)
                response = raw_input("Do you want to sync from Perforce now using git-p4 rebase? [y]es/[n]o ")
                if response == "y" or response == "yes":
                    rebase = P4Rebase()
                    rebase.run([])
            os.remove(self.configFile)

        return True

class P4Sync(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [
                optparse.make_option("--branch", dest="branch"),
                optparse.make_option("--detect-branches", dest="detectBranches", action="store_true"),
                optparse.make_option("--changesfile", dest="changesFile"),
                optparse.make_option("--silent", dest="silent", action="store_true"),
                optparse.make_option("--detect-labels", dest="detectLabels", action="store_true"),
                optparse.make_option("--verbose", dest="verbose", action="store_true"),
                optparse.make_option("--import-local", dest="importIntoRemotes", action="store_false",
                                     help="Import into refs/heads/ , not refs/remotes"),
                optparse.make_option("--max-changes", dest="maxChanges"),
                optparse.make_option("--keep-path", dest="keepRepoPath", action='store_true',
                                     help="Keep entire BRANCH/DIR/SUBDIR prefix during import")
        ]
        self.description = """Imports from Perforce into a git repository.\n
    example:
    //depot/my/project/ -- to import the current head
    //depot/my/project/@all -- to import everything
    //depot/my/project/@1,6 -- to import only from revision 1 to 6

    (a ... is not needed in the path p4 specification, it's added implicitly)"""

        self.usage += " //depot/path[@revRange]"
        self.silent = False
        self.createdBranches = Set()
        self.committedChanges = Set()
        self.branch = ""
        self.detectBranches = False
        self.detectLabels = False
        self.changesFile = ""
        self.syncWithOrigin = True
        self.verbose = False
        self.importIntoRemotes = True
        self.maxChanges = ""
        self.isWindows = (platform.system() == "Windows")
        self.keepRepoPath = False
        self.depotPaths = None
        self.p4BranchesInGit = []

        if gitConfig("git-p4.syncFromOrigin") == "false":
            self.syncWithOrigin = False

    def extractFilesFromCommit(self, commit):
        files = []
        fnum = 0
        while commit.has_key("depotFile%s" % fnum):
            path =  commit["depotFile%s" % fnum]

            found = [p for p in self.depotPaths
                     if path.startswith (p)]
            if not found:
                fnum = fnum + 1
                continue

            file = {}
            file["path"] = path
            file["rev"] = commit["rev%s" % fnum]
            file["action"] = commit["action%s" % fnum]
            file["type"] = commit["type%s" % fnum]
            files.append(file)
            fnum = fnum + 1
        return files

    def stripRepoPath(self, path, prefixes):
        if self.keepRepoPath:
            prefixes = [re.sub("^(//[^/]+/).*", r'\1', prefixes[0])]

        for p in prefixes:
            if path.startswith(p):
                path = path[len(p):]

        return path

    def splitFilesIntoBranches(self, commit):
        branches = {}
        fnum = 0
        while commit.has_key("depotFile%s" % fnum):
            path =  commit["depotFile%s" % fnum]
            found = [p for p in self.depotPaths
                     if path.startswith (p)]
            if not found:
                fnum = fnum + 1
                continue

            file = {}
            file["path"] = path
            file["rev"] = commit["rev%s" % fnum]
            file["action"] = commit["action%s" % fnum]
            file["type"] = commit["type%s" % fnum]
            fnum = fnum + 1

            relPath = self.stripRepoPath(path, self.depotPaths)

            for branch in self.knownBranches.keys():

                # add a trailing slash so that a commit into qt/4.2foo doesn't end up in qt/4.2
                if relPath.startswith(branch + "/"):
                    if branch not in branches:
                        branches[branch] = []
                    branches[branch].append(file)
                    break

        return branches

    ## Should move this out, doesn't use SELF.
    def readP4Files(self, files):
        files = [f for f in files
                 if f['action'] != 'delete']

        if not files:
            return

        filedata = p4CmdList('-x - print',
                             stdin='\n'.join(['%s#%s' % (f['path'], f['rev'])
                                              for f in files]),
                             stdin_mode='w+')
        if "p4ExitCode" in filedata[0]:
            die("Problems executing p4. Error: [%d]."
                % (filedata[0]['p4ExitCode']));

        j = 0;
        contents = {}
        while j < len(filedata):
            stat = filedata[j]
            j += 1
            text = ''
            while j < len(filedata) and filedata[j]['code'] in ('text',
                                                                'binary'):
                text += filedata[j]['data']
                j += 1


            if not stat.has_key('depotFile'):
                sys.stderr.write("p4 print fails with: %s\n" % repr(stat))
                continue

            contents[stat['depotFile']] = text

        for f in files:
            assert not f.has_key('data')
            f['data'] = contents[f['path']]

    def commit(self, details, files, branch, branchPrefixes, parent = ""):
        epoch = details["time"]
        author = details["user"]

        if self.verbose:
            print "commit into %s" % branch

        # start with reading files; if that fails, we should not
        # create a commit.
        new_files = []
        for f in files:
            if [p for p in branchPrefixes if f['path'].startswith(p)]:
                new_files.append (f)
            else:
                sys.stderr.write("Ignoring file outside of prefix: %s\n" % path)
        files = new_files
        self.readP4Files(files)




        self.gitStream.write("commit %s\n" % branch)
#        gitStream.write("mark :%s\n" % details["change"])
        self.committedChanges.add(int(details["change"]))
        committer = ""
        if author not in self.users:
            self.getUserMapFromPerforceServer()
        if author in self.users:
            committer = "%s %s %s" % (self.users[author], epoch, self.tz)
        else:
            committer = "%s <a@b> %s %s" % (author, epoch, self.tz)

        self.gitStream.write("committer %s\n" % committer)

        self.gitStream.write("data <<EOT\n")
        self.gitStream.write(details["desc"])
        self.gitStream.write("\n[git-p4: depot-paths = \"%s\": change = %s"
                             % (','.join (branchPrefixes), details["change"]))
        if len(details['options']) > 0:
            self.gitStream.write(": options = %s" % details['options'])
        self.gitStream.write("]\nEOT\n\n")

        if len(parent) > 0:
            if self.verbose:
                print "parent %s" % parent
            self.gitStream.write("from %s\n" % parent)

        for file in files:
            if file["type"] == "apple":
                print "\nfile %s is a strange apple file that forks. Ignoring!" % file['path']
                continue

            relPath = self.stripRepoPath(file['path'], branchPrefixes)
            if file["action"] == "delete":
                self.gitStream.write("D %s\n" % relPath)
            else:
                mode = 644
                if file["type"].startswith("x"):
                    mode = 755

                data = file['data']

                if self.isWindows and file["type"].endswith("text"):
                    data = data.replace("\r\n", "\n")

                self.gitStream.write("M %d inline %s\n" % (mode, relPath))
                self.gitStream.write("data %s\n" % len(data))
                self.gitStream.write(data)
                self.gitStream.write("\n")

        self.gitStream.write("\n")

        change = int(details["change"])

        if self.labels.has_key(change):
            label = self.labels[change]
            labelDetails = label[0]
            labelRevisions = label[1]
            if self.verbose:
                print "Change %s is labelled %s" % (change, labelDetails)

            files = p4CmdList("files " + ' '.join (["%s...@%s" % (p, change)
                                                    for p in branchPrefixes]))

            if len(files) == len(labelRevisions):

                cleanedFiles = {}
                for info in files:
                    if info["action"] == "delete":
                        continue
                    cleanedFiles[info["depotFile"]] = info["rev"]

                if cleanedFiles == labelRevisions:
                    self.gitStream.write("tag tag_%s\n" % labelDetails["label"])
                    self.gitStream.write("from %s\n" % branch)

                    owner = labelDetails["Owner"]
                    tagger = ""
                    if author in self.users:
                        tagger = "%s %s %s" % (self.users[owner], epoch, self.tz)
                    else:
                        tagger = "%s <a@b> %s %s" % (owner, epoch, self.tz)
                    self.gitStream.write("tagger %s\n" % tagger)
                    self.gitStream.write("data <<EOT\n")
                    self.gitStream.write(labelDetails["Description"])
                    self.gitStream.write("EOT\n\n")

                else:
                    if not self.silent:
                        print ("Tag %s does not match with change %s: files do not match."
                               % (labelDetails["label"], change))

            else:
                if not self.silent:
                    print ("Tag %s does not match with change %s: file count is different."
                           % (labelDetails["label"], change))

    def getUserCacheFilename(self):
        home = os.environ.get("HOME", os.environ.get("USERPROFILE"))
        return home + "/.gitp4-usercache.txt"

    def getUserMapFromPerforceServer(self):
        if self.userMapFromPerforceServer:
            return
        self.users = {}

        for output in p4CmdList("users"):
            if not output.has_key("User"):
                continue
            self.users[output["User"]] = output["FullName"] + " <" + output["Email"] + ">"


        s = ''
        for (key, val) in self.users.items():
            s += "%s\t%s\n" % (key, val)

        open(self.getUserCacheFilename(), "wb").write(s)
        self.userMapFromPerforceServer = True

    def loadUserMapFromCache(self):
        self.users = {}
        self.userMapFromPerforceServer = False
        try:
            cache = open(self.getUserCacheFilename(), "rb")
            lines = cache.readlines()
            cache.close()
            for line in lines:
                entry = line.strip().split("\t")
                self.users[entry[0]] = entry[1]
        except IOError:
            self.getUserMapFromPerforceServer()

    def getLabels(self):
        self.labels = {}

        l = p4CmdList("labels %s..." % ' '.join (self.depotPaths))
        if len(l) > 0 and not self.silent:
            print "Finding files belonging to labels in %s" % `self.depotPath`

        for output in l:
            label = output["label"]
            revisions = {}
            newestChange = 0
            if self.verbose:
                print "Querying files for label %s" % label
            for file in p4CmdList("files "
                                  +  ' '.join (["%s...@%s" % (p, label)
                                                for p in self.depotPaths])):
                revisions[file["depotFile"]] = file["rev"]
                change = int(file["change"])
                if change > newestChange:
                    newestChange = change

            self.labels[newestChange] = [output, revisions]

        if self.verbose:
            print "Label changes: %s" % self.labels.keys()

    def guessProjectName(self):
        for p in self.depotPaths:
            if p.endswith("/"):
                p = p[:-1]
            p = p[p.strip().rfind("/") + 1:]
            if not p.endswith("/"):
               p += "/"
            return p

    def getBranchMapping(self):
        lostAndFoundBranches = set()

        for info in p4CmdList("branches"):
            details = p4Cmd("branch -o %s" % info["branch"])
            viewIdx = 0
            while details.has_key("View%s" % viewIdx):
                paths = details["View%s" % viewIdx].split(" ")
                viewIdx = viewIdx + 1
                # require standard //depot/foo/... //depot/bar/... mapping
                if len(paths) != 2 or not paths[0].endswith("/...") or not paths[1].endswith("/..."):
                    continue
                source = paths[0]
                destination = paths[1]
                ## HACK
                if source.startswith(self.depotPaths[0]) and destination.startswith(self.depotPaths[0]):
                    source = source[len(self.depotPaths[0]):-4]
                    destination = destination[len(self.depotPaths[0]):-4]

                    if destination in self.knownBranches:
                        if not self.silent:
                            print "p4 branch %s defines a mapping from %s to %s" % (info["branch"], source, destination)
                            print "but there exists another mapping from %s to %s already!" % (self.knownBranches[destination], destination)
                        continue

                    self.knownBranches[destination] = source

                    lostAndFoundBranches.discard(destination)

                    if source not in self.knownBranches:
                        lostAndFoundBranches.add(source)


        for branch in lostAndFoundBranches:
            self.knownBranches[branch] = branch

    def listExistingP4GitBranches(self):
        # branches holds mapping from name to commit
        branches = p4BranchesInGit(self.importIntoRemotes)
        self.p4BranchesInGit = branches.keys()
        for branch in branches.keys():
            self.initialParents[self.refPrefix + branch] = branches[branch]

    def createOrUpdateBranchesFromOrigin(self):
        if not self.silent:
            print ("Creating/updating branch(es) in %s based on origin branch(es)"
                   % self.refPrefix)

        originPrefix = "origin/p4/"

        for line in read_pipe_lines("git rev-parse --symbolic --remotes"):
            line = line.strip()
            if (not line.startswith(originPrefix)) or line.endswith("HEAD"):
                continue

            headName = line[len(originPrefix):]
            remoteHead = self.refPrefix + headName
            originHead = line

            original = extractSettingsGitLog(extractLogMessageFromGitCommit(originHead))
            if (not original.has_key('depot-paths')
                or not original.has_key('change')):
                continue

            update = False
            if not gitBranchExists(remoteHead):
                if self.verbose:
                    print "creating %s" % remoteHead
                update = True
            else:
                settings = extractSettingsGitLog(extractLogMessageFromGitCommit(remoteHead))
                if settings.has_key('change') > 0:
                    if settings['depot-paths'] == original['depot-paths']:
                        originP4Change = int(original['change'])
                        p4Change = int(settings['change'])
                        if originP4Change > p4Change:
                            print ("%s (%s) is newer than %s (%s). "
                                   "Updating p4 branch from origin."
                                   % (originHead, originP4Change,
                                      remoteHead, p4Change))
                            update = True
                    else:
                        print ("Ignoring: %s was imported from %s while "
                               "%s was imported from %s"
                               % (originHead, ','.join(original['depot-paths']),
                                  remoteHead, ','.join(settings['depot-paths'])))

            if update:
                system("git update-ref %s %s" % (remoteHead, originHead))

    def updateOptionDict(self, d):
        option_keys = {}
        if self.keepRepoPath:
            option_keys['keepRepoPath'] = 1

        d["options"] = ' '.join(sorted(option_keys.keys()))

    def readOptions(self, d):
        self.keepRepoPath = (d.has_key('options')
                             and ('keepRepoPath' in d['options']))

    def run(self, args):
        self.depotPaths = []
        self.changeRange = ""
        self.initialParent = ""
        self.previousDepotPaths = []

        # map from branch depot path to parent branch
        self.knownBranches = {}
        self.initialParents = {}
        self.hasOrigin = gitBranchExists("origin") or gitBranchExists("origin/p4") or gitBranchExists("origin/p4/master")
        if not self.syncWithOrigin:
            self.hasOrigin = False

        if self.importIntoRemotes:
            self.refPrefix = "refs/remotes/p4/"
        else:
            self.refPrefix = "refs/heads/p4/"

        if self.syncWithOrigin and self.hasOrigin:
            if not self.silent:
                print "Syncing with origin first by calling git fetch origin"
            system("git fetch origin")

        if len(self.branch) == 0:
            self.branch = self.refPrefix + "master"
            if gitBranchExists("refs/heads/p4") and self.importIntoRemotes:
                system("git update-ref %s refs/heads/p4" % self.branch)
                system("git branch -D p4");
            # create it /after/ importing, when master exists
            if not gitBranchExists(self.refPrefix + "HEAD") and self.importIntoRemotes:
                system("git symbolic-ref %sHEAD %s" % (self.refPrefix, self.branch))

        # TODO: should always look at previous commits,
        # merge with previous imports, if possible.
        if args == []:
            if self.hasOrigin:
                self.createOrUpdateBranchesFromOrigin()
            self.listExistingP4GitBranches()

            if len(self.p4BranchesInGit) > 1:
                if not self.silent:
                    print "Importing from/into multiple branches"
                self.detectBranches = True

            if self.verbose:
                print "branches: %s" % self.p4BranchesInGit

            p4Change = 0
            for branch in self.p4BranchesInGit:
                logMsg =  extractLogMessageFromGitCommit(self.refPrefix + branch)

                settings = extractSettingsGitLog(logMsg)

                self.readOptions(settings)
                if (settings.has_key('depot-paths')
                    and settings.has_key ('change')):
                    change = int(settings['change']) + 1
                    p4Change = max(p4Change, change)

                    depotPaths = sorted(settings['depot-paths'])
                    if self.previousDepotPaths == []:
                        self.previousDepotPaths = depotPaths
                    else:
                        paths = []
                        for (prev, cur) in zip(self.previousDepotPaths, depotPaths):
                            for i in range(0, min(len(cur), len(prev))):
                                if cur[i] <> prev[i]:
                                    i = i - 1
                                    break

                            paths.append (cur[:i + 1])

                        self.previousDepotPaths = paths

            if p4Change > 0:
                self.depotPaths = sorted(self.previousDepotPaths)
                self.changeRange = "@%s,#head" % p4Change
                if not self.detectBranches:
                    self.initialParent = parseRevision(self.branch)
                if not self.silent and not self.detectBranches:
                    print "Performing incremental import into %s git branch" % self.branch

        if not self.branch.startswith("refs/"):
            self.branch = "refs/heads/" + self.branch

        if len(args) == 0 and self.depotPaths:
            if not self.silent:
                print "Depot paths: %s" % ' '.join(self.depotPaths)
        else:
            if self.depotPaths and self.depotPaths != args:
                print ("previous import used depot path %s and now %s was specified. "
                       "This doesn't work!" % (' '.join (self.depotPaths),
                                               ' '.join (args)))
                sys.exit(1)

            self.depotPaths = sorted(args)

        self.revision = ""
        self.users = {}

        newPaths = []
        for p in self.depotPaths:
            if p.find("@") != -1:
                atIdx = p.index("@")
                self.changeRange = p[atIdx:]
                if self.changeRange == "@all":
                    self.changeRange = ""
                elif ',' not in self.changeRange:
                    self.revision = self.changeRange
                    self.changeRange = ""
                p = p[:atIdx]
            elif p.find("#") != -1:
                hashIdx = p.index("#")
                self.revision = p[hashIdx:]
                p = p[:hashIdx]
            elif self.previousDepotPaths == []:
                self.revision = "#head"

            p = re.sub ("\.\.\.$", "", p)
            if not p.endswith("/"):
                p += "/"

            newPaths.append(p)

        self.depotPaths = newPaths


        self.loadUserMapFromCache()
        self.labels = {}
        if self.detectLabels:
            self.getLabels();

        if self.detectBranches:
            ## FIXME - what's a P4 projectName ?
            self.projectName = self.guessProjectName()

            if not self.hasOrigin:
                self.getBranchMapping();
            if self.verbose:
                print "p4-git branches: %s" % self.p4BranchesInGit
                print "initial parents: %s" % self.initialParents
            for b in self.p4BranchesInGit:
                if b != "master":

                    ## FIXME
                    b = b[len(self.projectName):]
                self.createdBranches.add(b)

        self.tz = "%+03d%02d" % (- time.timezone / 3600, ((- time.timezone % 3600) / 60))

        importProcess = subprocess.Popen(["git", "fast-import"],
                                         stdin=subprocess.PIPE, stdout=subprocess.PIPE,
                                         stderr=subprocess.PIPE);
        self.gitOutput = importProcess.stdout
        self.gitStream = importProcess.stdin
        self.gitError = importProcess.stderr

        if self.revision:
            print "Doing initial import of %s from revision %s into %s" % (' '.join(self.depotPaths), self.revision, self.branch)

            details = { "user" : "git perforce import user", "time" : int(time.time()) }
            details["desc"] = ("Initial import of %s from the state at revision %s"
                               % (' '.join(self.depotPaths), self.revision))
            details["change"] = self.revision
            newestRevision = 0

            fileCnt = 0
            for info in p4CmdList("files "
                                  +  ' '.join(["%s...%s"
                                               % (p, self.revision)
                                               for p in self.depotPaths])):

                if info['code'] == 'error':
                    sys.stderr.write("p4 returned an error: %s\n"
                                     % info['data'])
                    sys.exit(1)


                change = int(info["change"])
                if change > newestRevision:
                    newestRevision = change

                if info["action"] == "delete":
                    # don't increase the file cnt, otherwise details["depotFile123"] will have gaps!
                    #fileCnt = fileCnt + 1
                    continue

                for prop in ["depotFile", "rev", "action", "type" ]:
                    details["%s%s" % (prop, fileCnt)] = info[prop]

                fileCnt = fileCnt + 1

            details["change"] = newestRevision
            self.updateOptionDict(details)
            try:
                self.commit(details, self.extractFilesFromCommit(details), self.branch, self.depotPaths)
            except IOError:
                print "IO error with git fast-import. Is your git version recent enough?"
                print self.gitError.read()

        else:
            changes = []

            if len(self.changesFile) > 0:
                output = open(self.changesFile).readlines()
                changeSet = Set()
                for line in output:
                    changeSet.add(int(line))

                for change in changeSet:
                    changes.append(change)

                changes.sort()
            else:
                if self.verbose:
                    print "Getting p4 changes for %s...%s" % (', '.join(self.depotPaths),
                                                              self.changeRange)
                assert self.depotPaths
                output = read_pipe_lines("p4 changes " + ' '.join (["%s...%s" % (p, self.changeRange)
                                                                    for p in self.depotPaths]))

                for line in output:
                    changeNum = line.split(" ")[1]
                    changes.append(changeNum)

                changes.sort()

                if len(self.maxChanges) > 0:
                    changes = changes[:min(int(self.maxChanges), len(changes))]

            if len(changes) == 0:
                if not self.silent:
                    print "No changes to import!"
                return True

            if not self.silent and not self.detectBranches:
                print "Import destination: %s" % self.branch

            self.updatedBranches = set()

            cnt = 1
            for change in changes:
                description = p4Cmd("describe %s" % change)
                self.updateOptionDict(description)

                if not self.silent:
                    sys.stdout.write("\rImporting revision %s (%s%%)" % (change, cnt * 100 / len(changes)))
                    sys.stdout.flush()
                cnt = cnt + 1

                try:
                    if self.detectBranches:
                        branches = self.splitFilesIntoBranches(description)
                        for branch in branches.keys():
                            ## HACK  --hwn
                            branchPrefix = self.depotPaths[0] + branch + "/"

                            parent = ""

                            filesForCommit = branches[branch]

                            if self.verbose:
                                print "branch is %s" % branch

                            self.updatedBranches.add(branch)

                            if branch not in self.createdBranches:
                                self.createdBranches.add(branch)
                                parent = self.knownBranches[branch]
                                if parent == branch:
                                    parent = ""
                                elif self.verbose:
                                    print "parent determined through known branches: %s" % parent

                            # main branch? use master
                            if branch == "main":
                                branch = "master"
                            else:

                                ## FIXME
                                branch = self.projectName + branch

                            if parent == "main":
                                parent = "master"
                            elif len(parent) > 0:
                                ## FIXME
                                parent = self.projectName + parent

                            branch = self.refPrefix + branch
                            if len(parent) > 0:
                                parent = self.refPrefix + parent

                            if self.verbose:
                                print "looking for initial parent for %s; current parent is %s" % (branch, parent)

                            if len(parent) == 0 and branch in self.initialParents:
                                parent = self.initialParents[branch]
                                del self.initialParents[branch]

                            self.commit(description, filesForCommit, branch, [branchPrefix], parent)
                    else:
                        files = self.extractFilesFromCommit(description)
                        self.commit(description, files, self.branch, self.depotPaths,
                                    self.initialParent)
                        self.initialParent = ""
                except IOError:
                    print self.gitError.read()
                    sys.exit(1)

            if not self.silent:
                print ""
                if len(self.updatedBranches) > 0:
                    sys.stdout.write("Updated branches: ")
                    for b in self.updatedBranches:
                        sys.stdout.write("%s " % b)
                    sys.stdout.write("\n")


        self.gitStream.close()
        if importProcess.wait() != 0:
            die("fast-import failed: %s" % self.gitError.read())
        self.gitOutput.close()
        self.gitError.close()

        return True

class P4Rebase(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [ ]
        self.description = ("Fetches the latest revision from perforce and "
                            + "rebases the current work (branch) against it")
        self.verbose = False

    def run(self, args):
        sync = P4Sync()
        sync.run([])

        [upstream, settings] = findUpstreamBranchPoint()
        if len(upstream) == 0:
            die("Cannot find upstream branchpoint for rebase")

        # the branchpoint may be p4/foo~3, so strip off the parent
        upstream = re.sub("~[0-9]+$", "", upstream)

        print "Rebasing the current branch onto %s" % upstream
        oldHead = read_pipe("git rev-parse HEAD").strip()
        system("git rebase %s" % upstream)
        system("git diff-tree --stat --summary -M %s HEAD" % oldHead)
        return True

class P4Clone(P4Sync):
    def __init__(self):
        P4Sync.__init__(self)
        self.description = "Creates a new git repository and imports from Perforce into it"
        self.usage = "usage: %prog [options] //depot/path[@revRange]"
        self.options.append(
            optparse.make_option("--destination", dest="cloneDestination",
                                 action='store', default=None,
                                 help="where to leave result of the clone"))
        self.cloneDestination = None
        self.needsGit = False

    def defaultDestination(self, args):
        ## TODO: use common prefix of args?
        depotPath = args[0]
        depotDir = re.sub("(@[^@]*)$", "", depotPath)
        depotDir = re.sub("(#[^#]*)$", "", depotDir)
        depotDir = re.sub(r"\.\.\.$,", "", depotDir)
        depotDir = re.sub(r"/$", "", depotDir)
        return os.path.split(depotDir)[1]

    def run(self, args):
        if len(args) < 1:
            return False

        if self.keepRepoPath and not self.cloneDestination:
            sys.stderr.write("Must specify destination for --keep-path\n")
            sys.exit(1)

        depotPaths = args

        if not self.cloneDestination and len(depotPaths) > 1:
            self.cloneDestination = depotPaths[-1]
            depotPaths = depotPaths[:-1]

        for p in depotPaths:
            if not p.startswith("//"):
                return False

        if not self.cloneDestination:
            self.cloneDestination = self.defaultDestination(args)

        print "Importing from %s into %s" % (', '.join(depotPaths), self.cloneDestination)
        if not os.path.exists(self.cloneDestination):
            os.makedirs(self.cloneDestination)
        os.chdir(self.cloneDestination)
        system("git init")
        self.gitdir = os.getcwd() + "/.git"
        if not P4Sync.run(self, depotPaths):
            return False
        if self.branch != "master":
            if gitBranchExists("refs/remotes/p4/master"):
                system("git branch master refs/remotes/p4/master")
                system("git checkout -f")
            else:
                print "Could not detect main branch. No checkout/master branch created."

        return True

class P4Branches(Command):
    def __init__(self):
        Command.__init__(self)
        self.options = [ ]
        self.description = ("Shows the git branches that hold imports and their "
                            + "corresponding perforce depot paths")
        self.verbose = False

    def run(self, args):
        cmdline = "git rev-parse --symbolic "
        cmdline += " --remotes"

        for line in read_pipe_lines(cmdline):
            line = line.strip()

            if not line.startswith('p4/') or line == "p4/HEAD":
                continue
            branch = line

            log = extractLogMessageFromGitCommit("refs/remotes/%s" % branch)
            settings = extractSettingsGitLog(log)

            print "%s <= %s (%s)" % (branch, ",".join(settings["depot-paths"]), settings["change"])
        return True

class HelpFormatter(optparse.IndentedHelpFormatter):
    def __init__(self):
        optparse.IndentedHelpFormatter.__init__(self)

    def format_description(self, description):
        if description:
            return description + "\n"
        else:
            return ""

def printUsage(commands):
    print "usage: %s <command> [options]" % sys.argv[0]
    print ""
    print "valid commands: %s" % ", ".join(commands)
    print ""
    print "Try %s <command> --help for command specific help." % sys.argv[0]
    print ""

commands = {
    "debug" : P4Debug,
    "submit" : P4Submit,
    "sync" : P4Sync,
    "rebase" : P4Rebase,
    "clone" : P4Clone,
    "rollback" : P4RollBack,
    "branches" : P4Branches
}


def main():
    if len(sys.argv[1:]) == 0:
        printUsage(commands.keys())
        sys.exit(2)

    cmd = ""
    cmdName = sys.argv[1]
    try:
        klass = commands[cmdName]
        cmd = klass()
    except KeyError:
        print "unknown command %s" % cmdName
        print ""
        printUsage(commands.keys())
        sys.exit(2)

    options = cmd.options
    cmd.gitdir = os.environ.get("GIT_DIR", None)

    args = sys.argv[2:]

    if len(options) > 0:
        options.append(optparse.make_option("--git-dir", dest="gitdir"))

        parser = optparse.OptionParser(cmd.usage.replace("%prog", "%prog " + cmdName),
                                       options,
                                       description = cmd.description,
                                       formatter = HelpFormatter())

        (cmd, args) = parser.parse_args(sys.argv[2:], cmd);
    global verbose
    verbose = cmd.verbose
    if cmd.needsGit:
        if cmd.gitdir == None:
            cmd.gitdir = os.path.abspath(".git")
            if not isValidGitDir(cmd.gitdir):
                cmd.gitdir = read_pipe("git rev-parse --git-dir").strip()
                if os.path.exists(cmd.gitdir):
                    cdup = read_pipe("git rev-parse --show-cdup").strip()
                    if len(cdup) > 0:
                        os.chdir(cdup);

        if not isValidGitDir(cmd.gitdir):
            if isValidGitDir(cmd.gitdir + "/.git"):
                cmd.gitdir += "/.git"
            else:
                die("fatal: cannot locate git repository at %s" % cmd.gitdir)

        os.environ["GIT_DIR"] = cmd.gitdir

    if not cmd.run(args):
        parser.print_help()


if __name__ == '__main__':
    main()