/* 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 <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "notmuch-client.h"

#define DEFAULT_TAG_ARRAY_SIZE 2
/* for qsort */
static int scmp( const void *sp1, const void *sp2 )
{
    return( strcmp(*(const char **)sp1, *(const char **)sp2) );
}
int
notmuch_restore_command (unused (void *ctx), int argc, char *argv[])
{
    notmuch_config_t *config;
    notmuch_database_t *notmuch;
    FILE *input;
    char *line = NULL;
    size_t line_size;
    ssize_t line_len;
    regex_t regex;
    int rerr;
    char **tag_array=NULL;
    int tag_array_size=DEFAULT_TAG_ARRAY_SIZE;


    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;

    if (argc) {
	input = fopen (argv[0], "r");
	if (input == NULL) {
	    fprintf (stderr, "Error opening %s for reading: %s\n",
		     argv[0], strerror (errno));
	    return 1;
	}
    } else {
	printf ("No filename given. Reading dump from stdin.\n");
	input = stdin;
    }

    /* 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 ')'. */
    xregcomp (&regex,
	      "^([^ ]+) \\(([^)]*)\\)$",
	      REG_EXTENDED);

    /* Make an array of pointers to point to individual tokens */
    tag_array=calloc(tag_array_size,sizeof(char*));

    while ((line_len = getline (&line, &line_size, input)) != -1) {
	regmatch_t match[3];
	char *message_id, *tags,  *next;
	notmuch_message_t *message;
	notmuch_status_t status;
	int tag_count;

	notmuch_tags_t *tag_list;
	int i;

	chomp_newline (line);

	rerr = xregexec (&regex, line, 3, match, 0);
	if (rerr == REG_NOMATCH)
	{
	    fprintf (stderr, "Warning: Ignoring invalid input line: %s\n",
		     line);
	    continue;
	}

	message_id = xstrndup (line + match[1].rm_so,
			       match[1].rm_eo - match[1].rm_so);
	tags = xstrndup (line + match[2].rm_so,
			 match[2].rm_eo - match[2].rm_so);

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

	next=tags;
	tag_count=0;
	while(*next){
	  while(*next && isspace(*next))
	    next++;
	  if (*next) {
	    while (tag_count>= tag_array_size){
	      tag_array_size*=2;
	      tag_array=realloc(tag_array,tag_array_size*sizeof(char *));
	    }
	    tag_array[tag_count]=next;
	    tag_count++;
	  }
	  while (*next && !isspace(*next))
	    next++;
	  if (*next){
	    *next='\0';
	    next++;
	  }
	}

	qsort(tag_array,tag_count,sizeof(char*),scmp);
	
	tag_list = notmuch_message_get_tags (message);
	i=0;
	while (notmuch_tags_has_more (tag_list) && i<tag_count &&
	       (strcmp(notmuch_tags_get (tag_list),tag_array[i])==0)){
	  notmuch_tags_advance (tag_list);
	  i++;
	}

	/* the only success condition is for the tag list comparison is to run
	   off the end of both lists at the same time */
	if (notmuch_tags_has_more (tag_list) || i<tag_count ){
	  notmuch_message_freeze (message);
	  notmuch_message_remove_all_tags (message);

	  for (i=0; i<tag_count; i++) {
	    status = notmuch_message_add_tag (message, tag_array[i]);
	    if (status) {
		fprintf (stderr,
			 "Error applying tag %s to message %s:\n",
			 tag_array[i], message_id);
		fprintf (stderr, "%s\n",
			 notmuch_status_to_string (status));
	    }
	  }
	  notmuch_message_thaw (message);
	}
	notmuch_message_destroy (message);
      NEXT_LINE:
	free (message_id);
	free (tags);
    }

    regfree (&regex);

    if (line)
	free (line);

    if (tag_array)
      free (tag_array);

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

    return 0;
}