#include "builtin.h"
#include "config.h"
#include "dir.h"
#include "lockfile.h"
#include "parse-options.h"
#include "repository.h"
#include "commit-graph.h"
#include "object-store.h"
#include "progress.h"
#include "tag.h"

static char const * const builtin_commit_graph_usage[] = {
	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
	N_("git commit-graph write [--object-dir <objdir>] [--append] "
	   "[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] "
	   "[--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress] "
	   "<split options>"),
	NULL
};

static const char * const builtin_commit_graph_verify_usage[] = {
	N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
	NULL
};

static const char * const builtin_commit_graph_write_usage[] = {
	N_("git commit-graph write [--object-dir <objdir>] [--append] "
	   "[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] "
	   "[--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress] "
	   "<split options>"),
	NULL
};

static struct opts_commit_graph {
	const char *obj_dir;
	int reachable;
	int stdin_packs;
	int stdin_commits;
	int append;
	int split;
	int shallow;
	int progress;
	int enable_changed_paths;
} opts;

static struct object_directory *find_odb(struct repository *r,
					 const char *obj_dir)
{
	struct object_directory *odb;
	char *obj_dir_real = real_pathdup(obj_dir, 1);
	struct strbuf odb_path_real = STRBUF_INIT;

	prepare_alt_odb(r);
	for (odb = r->objects->odb; odb; odb = odb->next) {
		strbuf_realpath(&odb_path_real, odb->path, 1);
		if (!strcmp(obj_dir_real, odb_path_real.buf))
			break;
	}

	free(obj_dir_real);
	strbuf_release(&odb_path_real);

	if (!odb)
		die(_("could not find object directory matching %s"), obj_dir);
	return odb;
}

static int graph_verify(int argc, const char **argv)
{
	struct commit_graph *graph = NULL;
	struct object_directory *odb = NULL;
	char *graph_name;
	int open_ok;
	int fd;
	struct stat st;
	int flags = 0;

	static struct option builtin_commit_graph_verify_options[] = {
		OPT_STRING(0, "object-dir", &opts.obj_dir,
			   N_("dir"),
			   N_("The object directory to store the graph")),
		OPT_BOOL(0, "shallow", &opts.shallow,
			 N_("if the commit-graph is split, only verify the tip file")),
		OPT_BOOL(0, "progress", &opts.progress, N_("force progress reporting")),
		OPT_END(),
	};

	trace2_cmd_mode("verify");

	opts.progress = isatty(2);
	argc = parse_options(argc, argv, NULL,
			     builtin_commit_graph_verify_options,
			     builtin_commit_graph_verify_usage, 0);

	if (!opts.obj_dir)
		opts.obj_dir = get_object_directory();
	if (opts.shallow)
		flags |= COMMIT_GRAPH_VERIFY_SHALLOW;
	if (opts.progress)
		flags |= COMMIT_GRAPH_WRITE_PROGRESS;

	odb = find_odb(the_repository, opts.obj_dir);
	graph_name = get_commit_graph_filename(odb);
	open_ok = open_commit_graph(graph_name, &fd, &st);
	if (!open_ok && errno != ENOENT)
		die_errno(_("Could not open commit-graph '%s'"), graph_name);

	FREE_AND_NULL(graph_name);

	if (open_ok)
		graph = load_commit_graph_one_fd_st(the_repository, fd, &st, odb);
	else
		graph = read_commit_graph_one(the_repository, odb);

	/* Return failure if open_ok predicted success */
	if (!graph)
		return !!open_ok;

	UNLEAK(graph);
	return verify_commit_graph(the_repository, graph, flags);
}

extern int read_replace_refs;
static struct commit_graph_opts write_opts;

static int write_option_parse_split(const struct option *opt, const char *arg,
				    int unset)
{
	enum commit_graph_split_flags *flags = opt->value;

	opts.split = 1;
	if (!arg)
		return 0;

	if (!strcmp(arg, "no-merge"))
		*flags = COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED;
	else if (!strcmp(arg, "replace"))
		*flags = COMMIT_GRAPH_SPLIT_REPLACE;
	else
		die(_("unrecognized --split argument, %s"), arg);

	return 0;
}

static int read_one_commit(struct oidset *commits, struct progress *progress,
			   const char *hash)
{
	struct object *result;
	struct object_id oid;
	const char *end;

	if (parse_oid_hex(hash, &oid, &end))
		return error(_("unexpected non-hex object ID: %s"), hash);

	result = deref_tag(the_repository, parse_object(the_repository, &oid),
			   NULL, 0);
	if (!result)
		return error(_("invalid object: %s"), hash);
	else if (object_as_type(result, OBJ_COMMIT, 1))
		oidset_insert(commits, &result->oid);

	display_progress(progress, oidset_size(commits));

	return 0;
}

static int write_option_max_new_filters(const struct option *opt,
					const char *arg,
					int unset)
{
	int *to = opt->value;
	if (unset)
		*to = -1;
	else {
		const char *s;
		*to = strtol(arg, (char **)&s, 10);
		if (*s)
			return error(_("%s expects a numerical value"),
				     optname(opt, opt->flags));
	}
	return 0;
}

static int git_commit_graph_write_config(const char *var, const char *value,
					 void *cb)
{
	if (!strcmp(var, "commitgraph.maxnewfilters"))
		write_opts.max_new_filters = git_config_int(var, value);
	/*
	 * No need to fall-back to 'git_default_config', since this was already
	 * called in 'cmd_commit_graph()'.
	 */
	return 0;
}

static int graph_write(int argc, const char **argv)
{
	struct string_list pack_indexes = STRING_LIST_INIT_NODUP;
	struct strbuf buf = STRBUF_INIT;
	struct oidset commits = OIDSET_INIT;
	struct object_directory *odb = NULL;
	int result = 0;
	enum commit_graph_write_flags flags = 0;
	struct progress *progress = NULL;

	static struct option builtin_commit_graph_write_options[] = {
		OPT_STRING(0, "object-dir", &opts.obj_dir,
			N_("dir"),
			N_("The object directory to store the graph")),
		OPT_BOOL(0, "reachable", &opts.reachable,
			N_("start walk at all refs")),
		OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
			N_("scan pack-indexes listed by stdin for commits")),
		OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
			N_("start walk at commits listed by stdin")),
		OPT_BOOL(0, "append", &opts.append,
			N_("include all commits already in the commit-graph file")),
		OPT_BOOL(0, "changed-paths", &opts.enable_changed_paths,
			N_("enable computation for changed paths")),
		OPT_BOOL(0, "progress", &opts.progress, N_("force progress reporting")),
		OPT_CALLBACK_F(0, "split", &write_opts.split_flags, NULL,
			N_("allow writing an incremental commit-graph file"),
			PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
			write_option_parse_split),
		OPT_INTEGER(0, "max-commits", &write_opts.max_commits,
			N_("maximum number of commits in a non-base split commit-graph")),
		OPT_INTEGER(0, "size-multiple", &write_opts.size_multiple,
			N_("maximum ratio between two levels of a split commit-graph")),
		OPT_EXPIRY_DATE(0, "expire-time", &write_opts.expire_time,
			N_("only expire files older than a given date-time")),
		OPT_CALLBACK_F(0, "max-new-filters", &write_opts.max_new_filters,
			NULL, N_("maximum number of changed-path Bloom filters to compute"),
			0, write_option_max_new_filters),
		OPT_END(),
	};

	opts.progress = isatty(2);
	opts.enable_changed_paths = -1;
	write_opts.size_multiple = 2;
	write_opts.max_commits = 0;
	write_opts.expire_time = 0;
	write_opts.max_new_filters = -1;

	trace2_cmd_mode("write");

	git_config(git_commit_graph_write_config, &opts);

	argc = parse_options(argc, argv, NULL,
			     builtin_commit_graph_write_options,
			     builtin_commit_graph_write_usage, 0);

	if (opts.reachable + opts.stdin_packs + opts.stdin_commits > 1)
		die(_("use at most one of --reachable, --stdin-commits, or --stdin-packs"));
	if (!opts.obj_dir)
		opts.obj_dir = get_object_directory();
	if (opts.append)
		flags |= COMMIT_GRAPH_WRITE_APPEND;
	if (opts.split)
		flags |= COMMIT_GRAPH_WRITE_SPLIT;
	if (opts.progress)
		flags |= COMMIT_GRAPH_WRITE_PROGRESS;
	if (!opts.enable_changed_paths)
		flags |= COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS;
	if (opts.enable_changed_paths == 1 ||
	    git_env_bool(GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS, 0))
		flags |= COMMIT_GRAPH_WRITE_BLOOM_FILTERS;

	read_replace_refs = 0;
	odb = find_odb(the_repository, opts.obj_dir);

	if (opts.reachable) {
		if (write_commit_graph_reachable(odb, flags, &write_opts))
			return 1;
		return 0;
	}

	if (opts.stdin_packs) {
		while (strbuf_getline(&buf, stdin) != EOF)
			string_list_append(&pack_indexes,
					   strbuf_detach(&buf, NULL));
	} else if (opts.stdin_commits) {
		oidset_init(&commits, 0);
		if (opts.progress)
			progress = start_delayed_progress(
				_("Collecting commits from input"), 0);

		while (strbuf_getline(&buf, stdin) != EOF) {
			if (read_one_commit(&commits, progress, buf.buf)) {
				result = 1;
				goto cleanup;
			}
		}

		stop_progress(&progress);
	}

	if (write_commit_graph(odb,
			       opts.stdin_packs ? &pack_indexes : NULL,
			       opts.stdin_commits ? &commits : NULL,
			       flags,
			       &write_opts))
		result = 1;

cleanup:
	string_list_clear(&pack_indexes, 0);
	strbuf_release(&buf);
	return result;
}

int cmd_commit_graph(int argc, const char **argv, const char *prefix)
{
	static struct option builtin_commit_graph_options[] = {
		OPT_STRING(0, "object-dir", &opts.obj_dir,
			N_("dir"),
			N_("The object directory to store the graph")),
		OPT_END(),
	};

	if (argc == 2 && !strcmp(argv[1], "-h"))
		usage_with_options(builtin_commit_graph_usage,
				   builtin_commit_graph_options);

	git_config(git_default_config, NULL);
	argc = parse_options(argc, argv, prefix,
			     builtin_commit_graph_options,
			     builtin_commit_graph_usage,
			     PARSE_OPT_STOP_AT_NON_OPTION);

	save_commit_buffer = 0;

	if (argc > 0) {
		if (!strcmp(argv[0], "verify"))
			return graph_verify(argc, argv);
		if (!strcmp(argv[0], "write"))
			return graph_write(argc, argv);
	}

	usage_with_options(builtin_commit_graph_usage,
			   builtin_commit_graph_options);
}