#include "cache.h"
#include "config.h"
#include "json-writer.h"
#include "run-command.h"
#include "version.h"
#include "trace2/tr2_dst.h"
#include "trace2/tr2_tbuf.h"
#include "trace2/tr2_sid.h"
#include "trace2/tr2_tgt.h"
#include "trace2/tr2_tls.h"

static struct tr2_dst tr2dst_event = { "GIT_TR2_EVENT", 0, 0, 0 };

/*
 * The version number of the JSON data generated by the EVENT target
 * in this source file.  Update this if you make a significant change
 * to the JSON fields or message structure.  You probably do not need
 * to update this if you just add another call to one of the existing
 * TRACE2 API methods.
 */
#define TR2_EVENT_VERSION "1"

/*
 * Region nesting limit for messages written to the event target.
 *
 * The "region_enter" and "region_leave" messages (especially recursive
 * messages such as those produced while diving the worktree or index)
 * are primarily intended for the performance target during debugging.
 *
 * Some of the outer-most messages, however, may be of interest to the
 * event target.  Set this environment variable to a larger integer for
 * more detail in the event target.
 */
#define TR2_ENVVAR_EVENT_NESTING "GIT_TR2_EVENT_NESTING"
static int tr2env_event_nesting_wanted = 2;

/*
 * Set this environment variable to true to omit the <time>, <file>, and
 * <line> fields from most events.
 */
#define TR2_ENVVAR_EVENT_BRIEF "GIT_TR2_EVENT_BRIEF"
static int tr2env_event_brief;

static int fn_init(void)
{
	int want = tr2_dst_trace_want(&tr2dst_event);
	int want_nesting;
	int want_brief;
	char *nesting;
	char *brief;

	if (!want)
		return want;

	nesting = getenv(TR2_ENVVAR_EVENT_NESTING);
	if (nesting && ((want_nesting = atoi(nesting)) > 0))
		tr2env_event_nesting_wanted = want_nesting;

	brief = getenv(TR2_ENVVAR_EVENT_BRIEF);
	if (brief && ((want_brief = atoi(brief)) > 0))
		tr2env_event_brief = want_brief;

	return want;
}

static void fn_term(void)
{
	tr2_dst_trace_disable(&tr2dst_event);
}

/*
 * Append common key-value pairs to the currently open JSON object.
 *     "event:"<event_name>"
 *      "sid":"<sid>"
 *   "thread":"<thread_name>"
 *     "time":"<time>"
 *     "file":"<filename>"
 *     "line":<line_number>
 *     "repo":<repo_id>
 */
static void event_fmt_prepare(const char *event_name, const char *file,
			      int line, const struct repository *repo,
			      struct json_writer *jw)
{
	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
	struct tr2_tbuf tb_now;

	jw_object_string(jw, "event", event_name);
	jw_object_string(jw, "sid", tr2_sid_get());
	jw_object_string(jw, "thread", ctx->thread_name.buf);

	/*
	 * In brief mode, only emit <time> on these 2 event types.
	 */
	if (!tr2env_event_brief || !strcmp(event_name, "version") ||
	    !strcmp(event_name, "atexit")) {
		tr2_tbuf_utc_time(&tb_now);
		jw_object_string(jw, "time", tb_now.buf);
	}

	if (!tr2env_event_brief && file && *file) {
		jw_object_string(jw, "file", file);
		jw_object_intmax(jw, "line", line);
	}

	if (repo)
		jw_object_intmax(jw, "repo", repo->trace2_repo_id);
}

static void fn_version_fl(const char *file, int line)
{
	const char *event_name = "version";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "evt", TR2_EVENT_VERSION);
	jw_object_string(&jw, "exe", git_version_string);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_start_fl(const char *file, int line, const char **argv)
{
	const char *event_name = "start";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_inline_begin_array(&jw, "argv");
	jw_array_argv(&jw, argv);
	jw_end(&jw);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_exit_fl(const char *file, int line, uint64_t us_elapsed_absolute,
		       int code)
{
	const char *event_name = "exit";
	struct json_writer jw = JSON_WRITER_INIT;
	double t_abs = (double)us_elapsed_absolute / 1000000.0;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_double(&jw, "t_abs", 6, t_abs);
	jw_object_intmax(&jw, "code", code);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_signal(uint64_t us_elapsed_absolute, int signo)
{
	const char *event_name = "signal";
	struct json_writer jw = JSON_WRITER_INIT;
	double t_abs = (double)us_elapsed_absolute / 1000000.0;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
	jw_object_double(&jw, "t_abs", 6, t_abs);
	jw_object_intmax(&jw, "signo", signo);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_atexit(uint64_t us_elapsed_absolute, int code)
{
	const char *event_name = "atexit";
	struct json_writer jw = JSON_WRITER_INIT;
	double t_abs = (double)us_elapsed_absolute / 1000000.0;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, __FILE__, __LINE__, NULL, &jw);
	jw_object_double(&jw, "t_abs", 6, t_abs);
	jw_object_intmax(&jw, "code", code);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void maybe_add_string_va(struct json_writer *jw, const char *field_name,
				const char *fmt, va_list ap)
{
	if (fmt && *fmt) {
		va_list copy_ap;
		struct strbuf buf = STRBUF_INIT;

		va_copy(copy_ap, ap);
		strbuf_vaddf(&buf, fmt, copy_ap);
		va_end(copy_ap);

		jw_object_string(jw, field_name, buf.buf);
		strbuf_release(&buf);
		return;
	}

	if (fmt && *fmt) {
		jw_object_string(jw, field_name, fmt);
		return;
	}
}

static void fn_error_va_fl(const char *file, int line, const char *fmt,
			   va_list ap)
{
	const char *event_name = "error";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	maybe_add_string_va(&jw, "msg", fmt, ap);
	/*
	 * Also emit the format string as a field in case
	 * post-processors want to aggregate common error
	 * messages by type without argument fields (such
	 * as pathnames or branch names) cluttering it up.
	 */
	if (fmt && *fmt)
		jw_object_string(&jw, "fmt", fmt);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_command_path_fl(const char *file, int line, const char *pathname)
{
	const char *event_name = "cmd_path";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "path", pathname);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_command_name_fl(const char *file, int line, const char *name,
			       const char *hierarchy)
{
	const char *event_name = "cmd_name";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "name", name);
	if (hierarchy && *hierarchy)
		jw_object_string(&jw, "hierarchy", hierarchy);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_command_mode_fl(const char *file, int line, const char *mode)
{
	const char *event_name = "cmd_mode";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "name", mode);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_alias_fl(const char *file, int line, const char *alias,
			const char **argv)
{
	const char *event_name = "alias";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "alias", alias);
	jw_object_inline_begin_array(&jw, "argv");
	jw_array_argv(&jw, argv);
	jw_end(&jw);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_child_start_fl(const char *file, int line,
			      uint64_t us_elapsed_absolute,
			      const struct child_process *cmd)
{
	const char *event_name = "child_start";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_intmax(&jw, "child_id", cmd->trace2_child_id);
	if (cmd->trace2_hook_name) {
		jw_object_string(&jw, "child_class", "hook");
		jw_object_string(&jw, "hook_name", cmd->trace2_hook_name);
	} else {
		const char *child_class =
			cmd->trace2_child_class ? cmd->trace2_child_class : "?";
		jw_object_string(&jw, "child_class", child_class);
	}
	if (cmd->dir)
		jw_object_string(&jw, "cd", cmd->dir);
	jw_object_bool(&jw, "use_shell", cmd->use_shell);
	jw_object_inline_begin_array(&jw, "argv");
	if (cmd->git_cmd)
		jw_array_string(&jw, "git");
	jw_array_argv(&jw, cmd->argv);
	jw_end(&jw);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_child_exit_fl(const char *file, int line,
			     uint64_t us_elapsed_absolute, int cid, int pid,
			     int code, uint64_t us_elapsed_child)
{
	const char *event_name = "child_exit";
	struct json_writer jw = JSON_WRITER_INIT;
	double t_rel = (double)us_elapsed_child / 1000000.0;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_intmax(&jw, "child_id", cid);
	jw_object_intmax(&jw, "pid", pid);
	jw_object_intmax(&jw, "code", code);
	jw_object_double(&jw, "t_rel", 6, t_rel);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);

	jw_release(&jw);
}

static void fn_thread_start_fl(const char *file, int line,
			       uint64_t us_elapsed_absolute)
{
	const char *event_name = "thread_start";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_thread_exit_fl(const char *file, int line,
			      uint64_t us_elapsed_absolute,
			      uint64_t us_elapsed_thread)
{
	const char *event_name = "thread_exit";
	struct json_writer jw = JSON_WRITER_INIT;
	double t_rel = (double)us_elapsed_thread / 1000000.0;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_double(&jw, "t_rel", 6, t_rel);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_exec_fl(const char *file, int line, uint64_t us_elapsed_absolute,
		       int exec_id, const char *exe, const char **argv)
{
	const char *event_name = "exec";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_intmax(&jw, "exec_id", exec_id);
	if (exe)
		jw_object_string(&jw, "exe", exe);
	jw_object_inline_begin_array(&jw, "argv");
	jw_array_argv(&jw, argv);
	jw_end(&jw);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_exec_result_fl(const char *file, int line,
			      uint64_t us_elapsed_absolute, int exec_id,
			      int code)
{
	const char *event_name = "exec_result";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_intmax(&jw, "exec_id", exec_id);
	jw_object_intmax(&jw, "code", code);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_param_fl(const char *file, int line, const char *param,
			const char *value)
{
	const char *event_name = "def_param";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, NULL, &jw);
	jw_object_string(&jw, "param", param);
	jw_object_string(&jw, "value", value);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_repo_fl(const char *file, int line,
		       const struct repository *repo)
{
	const char *event_name = "def_repo";
	struct json_writer jw = JSON_WRITER_INIT;

	jw_object_begin(&jw, 0);
	event_fmt_prepare(event_name, file, line, repo, &jw);
	jw_object_string(&jw, "worktree", repo->worktree);
	jw_end(&jw);

	tr2_dst_write_line(&tr2dst_event, &jw.json);
	jw_release(&jw);
}

static void fn_region_enter_printf_va_fl(const char *file, int line,
					 uint64_t us_elapsed_absolute,
					 const char *category,
					 const char *label,
					 const struct repository *repo,
					 const char *fmt, va_list ap)
{
	const char *event_name = "region_enter";
	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
		struct json_writer jw = JSON_WRITER_INIT;

		jw_object_begin(&jw, 0);
		event_fmt_prepare(event_name, file, line, repo, &jw);
		jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
		if (category)
			jw_object_string(&jw, "category", category);
		if (label)
			jw_object_string(&jw, "label", label);
		maybe_add_string_va(&jw, "msg", fmt, ap);
		jw_end(&jw);

		tr2_dst_write_line(&tr2dst_event, &jw.json);
		jw_release(&jw);
	}
}

static void fn_region_leave_printf_va_fl(
	const char *file, int line, uint64_t us_elapsed_absolute,
	uint64_t us_elapsed_region, const char *category, const char *label,
	const struct repository *repo, const char *fmt, va_list ap)
{
	const char *event_name = "region_leave";
	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
		struct json_writer jw = JSON_WRITER_INIT;
		double t_rel = (double)us_elapsed_region / 1000000.0;

		jw_object_begin(&jw, 0);
		event_fmt_prepare(event_name, file, line, repo, &jw);
		jw_object_double(&jw, "t_rel", 6, t_rel);
		jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
		if (category)
			jw_object_string(&jw, "category", category);
		if (label)
			jw_object_string(&jw, "label", label);
		maybe_add_string_va(&jw, "msg", fmt, ap);
		jw_end(&jw);

		tr2_dst_write_line(&tr2dst_event, &jw.json);
		jw_release(&jw);
	}
}

static void fn_data_fl(const char *file, int line, uint64_t us_elapsed_absolute,
		       uint64_t us_elapsed_region, const char *category,
		       const struct repository *repo, const char *key,
		       const char *value)
{
	const char *event_name = "data";
	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
		struct json_writer jw = JSON_WRITER_INIT;
		double t_abs = (double)us_elapsed_absolute / 1000000.0;
		double t_rel = (double)us_elapsed_region / 1000000.0;

		jw_object_begin(&jw, 0);
		event_fmt_prepare(event_name, file, line, repo, &jw);
		jw_object_double(&jw, "t_abs", 6, t_abs);
		jw_object_double(&jw, "t_rel", 6, t_rel);
		jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
		jw_object_string(&jw, "category", category);
		jw_object_string(&jw, "key", key);
		jw_object_string(&jw, "value", value);
		jw_end(&jw);

		tr2_dst_write_line(&tr2dst_event, &jw.json);
		jw_release(&jw);
	}
}

static void fn_data_json_fl(const char *file, int line,
			    uint64_t us_elapsed_absolute,
			    uint64_t us_elapsed_region, const char *category,
			    const struct repository *repo, const char *key,
			    const struct json_writer *value)
{
	const char *event_name = "data_json";
	struct tr2tls_thread_ctx *ctx = tr2tls_get_self();
	if (ctx->nr_open_regions <= tr2env_event_nesting_wanted) {
		struct json_writer jw = JSON_WRITER_INIT;
		double t_abs = (double)us_elapsed_absolute / 1000000.0;
		double t_rel = (double)us_elapsed_region / 1000000.0;

		jw_object_begin(&jw, 0);
		event_fmt_prepare(event_name, file, line, repo, &jw);
		jw_object_double(&jw, "t_abs", 6, t_abs);
		jw_object_double(&jw, "t_rel", 6, t_rel);
		jw_object_intmax(&jw, "nesting", ctx->nr_open_regions);
		jw_object_string(&jw, "category", category);
		jw_object_string(&jw, "key", key);
		jw_object_sub_jw(&jw, "value", value);
		jw_end(&jw);

		tr2_dst_write_line(&tr2dst_event, &jw.json);
		jw_release(&jw);
	}
}

struct tr2_tgt tr2_tgt_event = {
	&tr2dst_event,

	fn_init,
	fn_term,

	fn_version_fl,
	fn_start_fl,
	fn_exit_fl,
	fn_signal,
	fn_atexit,
	fn_error_va_fl,
	fn_command_path_fl,
	fn_command_name_fl,
	fn_command_mode_fl,
	fn_alias_fl,
	fn_child_start_fl,
	fn_child_exit_fl,
	fn_thread_start_fl,
	fn_thread_exit_fl,
	fn_exec_fl,
	fn_exec_result_fl,
	fn_param_fl,
	fn_repo_fl,
	fn_region_enter_printf_va_fl,
	fn_region_leave_printf_va_fl,
	fn_data_fl,
	fn_data_json_fl,
	NULL, /* printf */
};