#include "cache.h"

#include "blob.h"

#include "dir.h"

#include "streaming.h"

#include "submodule.h"

#include "progress.h"

#include "fsmonitor.h"

static void create_directories(const char *path, int path_len,

			       const struct checkout *state)

{

	char *buf = xmallocz(path_len);

	int len = 0;

	while (len < path_len) {

		do {

			buf[len] = path[len];

			len++;

		} while (len < path_len && path[len] != '/');

		if (len >= path_len)

			break;

		buf[len] = 0;

		/*

		 * For 'checkout-index --prefix=<dir>', <dir> is

		 * allowed to be a symlink to an existing directory,

		 * and we set 'state->base_dir_len' below, such that

		 * we test the path components of the prefix with the

		 * stat() function instead of the lstat() function.

		 */

		if (has_dirs_only_path(buf, len, state->base_dir_len))

			continue; /* ok, it is already a directory. */

		/*

		 * If this mkdir() would fail, it could be that there

		 * is already a symlink or something else exists

		 * there, therefore we then try to unlink it and try

		 * one more time to create the directory.

		 */

		if (mkdir(buf, 0777)) {

			if (errno == EEXIST && state->force &&

			    !unlink_or_warn(buf) && !mkdir(buf, 0777))

				continue;

			die_errno("cannot create directory at '%s'", buf);

		}

	}

	free(buf);

}

static void remove_subtree(struct strbuf *path)

{

	DIR *dir = opendir(path->buf);

	struct dirent *de;

	int origlen = path->len;

	if (!dir)

		die_errno("cannot opendir '%s'", path->buf);

	while ((de = readdir(dir)) != NULL) {

		struct stat st;

		if (is_dot_or_dotdot(de->d_name))

			continue;

		strbuf_addch(path, '/');

		strbuf_addstr(path, de->d_name);

		if (lstat(path->buf, &st))

			die_errno("cannot lstat '%s'", path->buf);

		if (S_ISDIR(st.st_mode))

			remove_subtree(path);

		else if (unlink(path->buf))

			die_errno("cannot unlink '%s'", path->buf);

		strbuf_setlen(path, origlen);

	}

	closedir(dir);

	if (rmdir(path->buf))

		die_errno("cannot rmdir '%s'", path->buf);

}

static int create_file(const char *path, unsigned int mode)

{

	mode = (mode & 0100) ? 0777 : 0666;

	return open(path, O_WRONLY | O_CREAT | O_EXCL, mode);

}

static void *read_blob_entry(const struct cache_entry *ce, unsigned long *size)

{

	enum object_type type;

	void *blob_data = read_object_file(&ce->oid, &type, size);

	if (blob_data) {

		if (type == OBJ_BLOB)

			return blob_data;

		free(blob_data);

	}

	return NULL;

}

static int open_output_fd(char *path, const struct cache_entry *ce, int to_tempfile)

{

	int symlink = (ce->ce_mode & S_IFMT) != S_IFREG;

	if (to_tempfile) {

		xsnprintf(path, TEMPORARY_FILENAME_LENGTH, "%s",

			  symlink ? ".merge_link_XXXXXX" : ".merge_file_XXXXXX");

		return mkstemp(path);

	} else {

		return create_file(path, !symlink ? ce->ce_mode : 0666);

	}

}

static int fstat_output(int fd, const struct checkout *state, struct stat *st)

{

	/* use fstat() only when path == ce->name */

	if (fstat_is_reliable() &&

	    state->refresh_cache && !state->base_dir_len) {

		fstat(fd, st);

		return 1;

	}

	return 0;

}

static int streaming_write_entry(const struct cache_entry *ce, char *path,

				 struct stream_filter *filter,

				 const struct checkout *state, int to_tempfile,

				 int *fstat_done, struct stat *statbuf)

{

	int result = 0;

	int fd;

	fd = open_output_fd(path, ce, to_tempfile);

	if (fd < 0)

		return -1;

	result |= stream_blob_to_fd(fd, &ce->oid, filter, 1);

	*fstat_done = fstat_output(fd, state, statbuf);

	result |= close(fd);

	if (result)

		unlink(path);

	return result;

}

void enable_delayed_checkout(struct checkout *state)

{

	if (!state->delayed_checkout) {

		state->delayed_checkout = xmalloc(sizeof(*state->delayed_checkout));

		state->delayed_checkout->state = CE_CAN_DELAY;

		string_list_init(&state->delayed_checkout->filters, 0);

		string_list_init(&state->delayed_checkout->paths, 0);

	}

}

static int remove_available_paths(struct string_list_item *item, void *cb_data)

{

	struct string_list *available_paths = cb_data;

	struct string_list_item *available;

	available = string_list_lookup(available_paths, item->string);

	if (available)

		available->util = (void *)item->string;

	return !available;

}

int finish_delayed_checkout(struct checkout *state)

{

	int errs = 0;

	unsigned delayed_object_count;

	off_t filtered_bytes = 0;

	struct string_list_item *filter, *path;

	struct progress *progress;

	struct delayed_checkout *dco = state->delayed_checkout;

	if (!state->delayed_checkout)

		return errs;

	dco->state = CE_RETRY;

	delayed_object_count = dco->paths.nr;

	progress = start_delayed_progress(_("Filtering content"), delayed_object_count);

	while (dco->filters.nr > 0) {

		for_each_string_list_item(filter, &dco->filters) {

			struct string_list available_paths = STRING_LIST_INIT_NODUP;

			display_progress(progress, delayed_object_count - dco->paths.nr);

			if (!async_query_available_blobs(filter->string, &available_paths)) {

				/* Filter reported an error */

				errs = 1;

				filter->string = "";

				continue;

			}

			if (available_paths.nr <= 0) {

				/*

				 * Filter responded with no entries. That means

				 * the filter is done and we can remove the

				 * filter from the list (see

				 * "string_list_remove_empty_items" call below).

				 */

				filter->string = "";

				continue;

			}

			/*

			 * In dco->paths we store a list of all delayed paths.

			 * The filter just send us a list of available paths.

			 * Remove them from the list.

			 */

			filter_string_list(&dco->paths, 0,

				&remove_available_paths, &available_paths);

			for_each_string_list_item(path, &available_paths) {

				struct cache_entry* ce;

				if (!path->util) {

					error("external filter '%s' signaled that '%s' "

					      "is now available although it has not been "

					      "delayed earlier",

					      filter->string, path->string);

					errs |= 1;

					/*

					 * Do not ask the filter for available blobs,

					 * again, as the filter is likely buggy.

					 */

					filter->string = "";

					continue;

				}

				ce = index_file_exists(state->istate, path->string,

						       strlen(path->string), 0);

				if (ce) {

					errs |= checkout_entry(ce, state, NULL);

					filtered_bytes += ce->ce_stat_data.sd_size;

					display_throughput(progress, filtered_bytes);

				} else

					errs = 1;

			}

		}

		string_list_remove_empty_items(&dco->filters, 0);

	}

	stop_progress(&progress);

	string_list_clear(&dco->filters, 0);

	/* At this point we should not have any delayed paths anymore. */

	errs |= dco->paths.nr;

	for_each_string_list_item(path, &dco->paths) {

		error("'%s' was not filtered properly", path->string);

	}

	string_list_clear(&dco->paths, 0);

	free(dco);

	state->delayed_checkout = NULL;

	return errs;

}

static int write_entry(struct cache_entry *ce,

		       char *path, const struct checkout *state, int to_tempfile)

{

	unsigned int ce_mode_s_ifmt = ce->ce_mode & S_IFMT;

	struct delayed_checkout *dco = state->delayed_checkout;

	int fd, ret, fstat_done = 0;

	char *new_blob;

	struct strbuf buf = STRBUF_INIT;

	unsigned long size;

	ssize_t wrote;

	size_t newsize = 0;

	struct stat st;

	const struct submodule *sub;

	if (ce_mode_s_ifmt == S_IFREG) {

		struct stream_filter *filter = get_stream_filter(ce->name,

								 &ce->oid);

		if (filter &&

		    !streaming_write_entry(ce, path, filter,

					   state, to_tempfile,

					   &fstat_done, &st))

			goto finish;

	}

	switch (ce_mode_s_ifmt) {

	case S_IFLNK:

		new_blob = read_blob_entry(ce, &size);

		if (!new_blob)

			return error("unable to read sha1 file of %s (%s)",

				     path, oid_to_hex(&ce->oid));

		/*

		 * We can't make a real symlink; write out a regular file entry

		 * with the symlink destination as its contents.

		 */

		if (!has_symlinks || to_tempfile)

			goto write_file_entry;

		ret = symlink(new_blob, path);

		free(new_blob);

		if (ret)

			return error_errno("unable to create symlink %s", path);

		break;

	case S_IFREG:

		/*

		 * We do not send the blob in case of a retry, so do not

		 * bother reading it at all.

		 */

		if (dco && dco->state == CE_RETRY) {

			new_blob = NULL;

			size = 0;

		} else {

			new_blob = read_blob_entry(ce, &size);

			if (!new_blob)

				return error("unable to read sha1 file of %s (%s)",

					     path, oid_to_hex(&ce->oid));

		}

		/*

		 * Convert from git internal format to working tree format

		 */

		if (dco && dco->state != CE_NO_DELAY) {

			ret = async_convert_to_working_tree(ce->name, new_blob,

							    size, &buf, dco);

			if (ret && string_list_has_string(&dco->paths, ce->name)) {

				free(new_blob);

				goto delayed;

			}

		} else

			ret = convert_to_working_tree(ce->name, new_blob, size, &buf;;

		if (ret) {

			free(new_blob);

			new_blob = strbuf_detach(&buf, &newsize);

			size = newsize;

		}

		/*

		 * No "else" here as errors from convert are OK at this

		 * point. If the error would have been fatal (e.g.

		 * filter is required), then we would have died already.

		 */

	write_file_entry:

		fd = open_output_fd(path, ce, to_tempfile);

		if (fd < 0) {

			free(new_blob);

			return error_errno("unable to create file %s", path);

		}

		wrote = write_in_full(fd, new_blob, size);

		if (!to_tempfile)

			fstat_done = fstat_output(fd, state, &st);

		close(fd);

		free(new_blob);

		if (wrote < 0)

			return error("unable to write file %s", path);

		break;

	case S_IFGITLINK:

		if (to_tempfile)

			return error("cannot create temporary submodule %s", path);

		if (mkdir(path, 0777) < 0)

			return error("cannot create submodule directory %s", path);

		sub = submodule_from_ce(ce);

		if (sub)

			return submodule_move_head(ce->name,

				NULL, oid_to_hex(&ce->oid),

				state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);

		break;

	default:

		return error("unknown file mode for %s in index", path);

	}

finish:

	if (state->refresh_cache) {

		assert(state->istate);

		if (!fstat_done)

			if (lstat(ce->name, &st) < 0)

				return error_errno("unable to stat just-written file %s",

						   ce->name);

		fill_stat_cache_info(ce, &st);

		ce->ce_flags |= CE_UPDATE_IN_BASE;

		mark_fsmonitor_invalid(state->istate, ce);

		state->istate->cache_changed |= CE_ENTRY_CHANGED;

	}

delayed:

	return 0;

}

/*

 * This is like 'lstat()', except it refuses to follow symlinks

 * in the path, after skipping "skiplen".

 */

static int check_path(const char *path, int len, struct stat *st, int skiplen)

{

	const char *slash = path + len;

	while (path < slash && *slash != '/')

		slash--;

	if (!has_dirs_only_path(path, slash - path, skiplen)) {

		errno = ENOENT;

		return -1;

	}

	return lstat(path, st);

}

/*

 * Write the contents from ce out to the working tree.

 *

 * When topath[] is not NULL, instead of writing to the working tree

 * file named by ce, a temporary file is created by this function and

 * its name is returned in topath[], which must be able to hold at

 * least TEMPORARY_FILENAME_LENGTH bytes long.

 */

int checkout_entry(struct cache_entry *ce,

		   const struct checkout *state, char *topath)

{

	static struct strbuf path = STRBUF_INIT;

	struct stat st;

	if (topath)

		return write_entry(ce, topath, state, 1);

	strbuf_reset(&path);

	strbuf_add(&path, state->base_dir, state->base_dir_len);

	strbuf_add(&path, ce->name, ce_namelen(ce));

	if (!check_path(path.buf, path.len, &st, state->base_dir_len)) {

		const struct submodule *sub;

		unsigned changed = ce_match_stat(ce, &st, CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE);

		/*

		 * Needs to be checked before !changed returns early,

		 * as the possibly empty directory was not changed

		 */

		sub = submodule_from_ce(ce);

		if (sub) {

			int err;

			if (!is_submodule_populated_gently(ce->name, &err)) {

				struct stat sb;

				if (lstat(ce->name, &sb))

					die(_("could not stat file '%s'"), ce->name);

				if (!(st.st_mode & S_IFDIR))

					unlink_or_warn(ce->name);

				return submodule_move_head(ce->name,

					NULL, oid_to_hex(&ce->oid), 0);

			} else

				return submodule_move_head(ce->name,

					"HEAD", oid_to_hex(&ce->oid),

					state->force ? SUBMODULE_MOVE_HEAD_FORCE : 0);

		}

		if (!changed)

			return 0;

		if (!state->force) {

			if (!state->quiet)

				fprintf(stderr,

					"%s already exists, no checkout\n",

					path.buf);

			return -1;

		}

		/*

		 * We unlink the old file, to get the new one with the

		 * right permissions (including umask, which is nasty

		 * to emulate by hand - much easier to let the system

		 * just do the right thing)

		 */

		if (S_ISDIR(st.st_mode)) {

			/* If it is a gitlink, leave it alone! */

			if (S_ISGITLINK(ce->ce_mode))

				return 0;

			if (!state->force)

				return error("%s is a directory", path.buf);

			remove_subtree(&path);

		} else if (unlink(path.buf))

			return error_errno("unable to unlink old '%s'", path.buf);

	} else if (state->not_new)

		return 0;

	create_directories(path.buf, path.len, state);

	return write_entry(ce, path.buf, state, 0);

}