/* notmuch - Not much of an email program, (just index and search)
 *
 * Copyright © 2009 Carl Worth
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see http://www.gnu.org/licenses/ .
 *
 * Author: Carl Worth <cworth@cworth.org>
 */

#include "notmuch-client.h"
#include "dump-restore-private.h"

int
notmuch_restore_command (unused (void *ctx), int argc, char *argv[])
{
    notmuch_config_t *config;
    notmuch_database_t *notmuch;
    notmuch_bool_t synchronize_flags;
    notmuch_bool_t accumulate = FALSE;
    char *input_file_name = NULL;
    FILE *input = stdin;
    char *line = NULL;
    size_t line_size;
    ssize_t line_len;
    regex_t regex;
    int rerr;
    int opt_index;
    int input_format = DUMP_FORMAT_SUP;

    config = notmuch_config_open (ctx, NULL, NULL);
    if (config == NULL)
	return 1;

    notmuch = notmuch_database_open (notmuch_config_get_database_path (config),
				     NOTMUCH_DATABASE_MODE_READ_WRITE);
    if (notmuch == NULL)
	return 1;

    synchronize_flags = notmuch_config_get_maildir_synchronize_flags (config);

    notmuch_opt_desc_t options[] = {
	FORMAT_DESC (input_format),
	{ NOTMUCH_OPT_POSITION, &input_file_name, 0, 0, 0 },
	{ NOTMUCH_OPT_BOOLEAN,  &accumulate, "accumulate", 'a', 0 },
	{ 0, 0, 0, 0, 0 }
    };

    opt_index = parse_arguments (argc, argv, options, 1);

    if (opt_index < 0) {
	/* diagnostics already printed */
	return 1;
    }

    if (input_file_name) {
	input = fopen (input_file_name, "r");
	if (input == NULL) {
	    fprintf (stderr, "Error opening %s for reading: %s\n",
		     input_file_name, strerror (errno));
	    return 1;
	}
	optind++;
    }

    if (opt_index < argc) {
	fprintf (stderr,
	 "Cannot read dump from more than one file: %s\n",
		 argv[optind]);
	return 1;
    }

    /* Dump output is one line per message. We match a sequence of
     * non-space characters for the message-id, then one or more
     * spaces, then a list of space-separated tags as a sequence of
     * characters within literal '(' and ')'. */
    if (input_format == DUMP_FORMAT_SUP) {
	if ( xregcomp (&regex,
		       "^([^ ]+) \\(([^)]*)\\)$",
		       REG_EXTENDED) )
	    INTERNAL_ERROR("compile time constant regex failed.");
    }


    /* These are out here to re-use the buffers with hex_decode */

    char *message_id = NULL;
    size_t message_id_size=0;
    char *tag = NULL;
    size_t tag_size=0;

    while ((line_len = getline (&line, &line_size, input)) != -1) {
	regmatch_t match[3];
	char  *file_tags, *next;
	notmuch_message_t *message = NULL;

	notmuch_status_t status;
	notmuch_tags_t *db_tags;
	char *db_tags_str;

	chomp_newline (line);

	/* Silently ignore blank lines */

	if (line[0] == '\0') {
		continue;
	}

	if (input_format == DUMP_FORMAT_SUP) {
	    rerr = xregexec (&regex, line, 3, match, 0);
	    if (rerr == REG_NOMATCH)
	    {
		fprintf (stderr, "Warning: Ignoring invalid input line: %s\n",
			 line);
		continue;
	    }
	    message_id = talloc_strndup (notmuch, line + match[1].rm_so,
					 match[1].rm_eo - match[1].rm_so);
	    file_tags = talloc_strndup (notmuch, line + match[2].rm_so,
					match[2].rm_eo - match[2].rm_so);
	} else {
	    char *p = line;
	    char *raw_mid;

	    raw_mid = strsep (&p, " \t");

	    if (hex_decode (notmuch, raw_mid,
			    &message_id, &message_id_size) != HEX_SUCCESS)
		return 1;

	    file_tags = xstrdup (p);
	}


	status = notmuch_database_find_message (notmuch, message_id, &message);
	if (status || message == NULL) {
	    fprintf (stderr, "Warning: Cannot apply tags to %smessage: %s\n",
		     message ? "" : "missing ", message_id);
	    if (status)
		fprintf (stderr, "%s\n",
			 notmuch_status_to_string(status));
	    goto NEXT_LINE;
	}

	/* In order to detect missing messages, this check/optimization is
	 * intentionally done *after* first finding the message.  */
	if (accumulate && (file_tags == NULL || *file_tags == '\0'))
	{
	    goto NEXT_LINE;
	}

	db_tags_str = NULL;
	for (db_tags = notmuch_message_get_tags (message);
	     notmuch_tags_valid (db_tags);
	     notmuch_tags_move_to_next (db_tags))
	{
	    const char *tag = notmuch_tags_get (db_tags);

	    if (db_tags_str)
		db_tags_str = talloc_asprintf_append (db_tags_str, " %s", tag);
	    else
		db_tags_str = talloc_strdup (message, tag);
	}

	if (((file_tags == NULL || *file_tags == '\0') &&
	     (db_tags_str == NULL || *db_tags_str == '\0')) ||
	    (file_tags && db_tags_str && strcmp (file_tags, db_tags_str) == 0))
	{
	    goto NEXT_LINE;
	}

	notmuch_message_freeze (message);

	if (!accumulate)
	    notmuch_message_remove_all_tags (message);

	next = file_tags;
	while (next) {
	    char *raw_tag = strsep (&next, " ");

	    if (input_format == DUMP_FORMAT_NOTMUCH) {
		if (hex_decode (notmuch, raw_tag,
			    &tag, &tag_size) != HEX_SUCCESS)
		    return 1;
	    } else {
		tag = talloc_strdup(notmuch, raw_tag);
	    }

	    if (*tag == '\0')
		continue;
	    status = notmuch_message_add_tag (message, tag);
	    if (status) {
		fprintf (stderr,
			 "Error applying tag %s to message %s:\n",
			 tag, message_id);
		fprintf (stderr, "%s\n",
			 notmuch_status_to_string (status));
	    }
	}

	notmuch_message_thaw (message);

	if (synchronize_flags)
	    notmuch_message_tags_to_maildir_flags (message);

      NEXT_LINE:
	if (message)
	    notmuch_message_destroy (message);
	message = NULL;
	if (input_format == DUMP_FORMAT_SUP) {
	    talloc_free (message_id);
	    talloc_free (file_tags);
	}
    }

    if (input_format == DUMP_FORMAT_SUP)
	regfree (&regex);

    if (line)
	free (line);

    notmuch_database_close (notmuch);
    if (input != stdin)
	fclose (input);

    return 0;
}