/*
 * Copyright (C) 2001, 2002, 2003, 2004 Philip Blundell <philb@gnu.org>
 *               2006 Florian Boor <florian.boor@kernelconcepts.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sqlite.h>

#include <gpe/errorbox.h>

#include "gpe/pim-categories.h"

#include "internal.h"

#define _(x) (x)

#define DB_NAME "/.gpe/categories"

static const char *schema_old_tmp_str = "create temporary table old_category (id INTEGER PRIMARY KEY, description TEXT);";
static const char *schema_str = "create table category (id INTEGER PRIMARY KEY, description TEXT, colour TEXT);";

static GSList *categories;
static sqlite *db;

static int
load_one (void *arg, int argc, char **argv, char **names)
{
  if (argc == 3)
    {
      GSList **list = (GSList **) arg;
      struct gpe_pim_category *c = g_malloc0 (sizeof (c));

      c->id = atoi (argv[0]);
      c->name = g_strdup (argv[1]);
      if (argv[2] && strcmp (argv[2], "(NULL)"))
        c->colour = g_strdup (argv[2]);
      *list = g_slist_prepend (*list, c);
    }

  return 0;
}

/* check categories table and update to new scheme if necessary */
static void
check_table_update (void)
{
  gint r;
  gchar *err = NULL;
  GSList *entries = NULL, *iter = NULL;

  /* check if we have the colour field */
  r = sqlite_exec (db, "select colour from category", NULL, NULL, &err);

  if (r) /* r > 0 indicates a failure, need to recreate that table with new schema */
    {
      g_free (err);
      r = sqlite_exec (db, "begin transaction", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, schema_old_tmp_str, NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, "insert into old_category select id,description from category", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, "drop table category", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, schema_str, NULL, NULL, NULL);
      if (r)
       goto error;
      r = sqlite_exec (db, "insert into category select id,description,NULL from old_category", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, "drop table old_category", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, "commit transaction", NULL, NULL, &err);
      if (r)
        goto error;
      r = sqlite_exec (db, "vacuum", NULL, NULL, &err);
      if (r)
        goto error;

      return;

    error:
      {
        gpe_error_box_fmt ("Couldn't convert database data to new format: %s",
                           err);
        g_free (err);
        sqlite_exec (db, "rollback transaction", NULL, NULL, &err);
      }
    }
}

gboolean 
gpe_pim_categories_init (void)
{
  static int run_once;

  if (run_once)
    return TRUE;
  run_once = TRUE;

  gchar *err;
  gchar *buf;
  size_t len;
  gchar *home = getenv ("HOME");
  if (home == NULL)
    home = "";
  
  len = strlen (home) + strlen (DB_NAME) + 1;
  buf = g_malloc (len);
  strcpy (buf, home);
  strcat (buf, DB_NAME);
  
  db = sqlite_open (buf, 0, &err);
  g_free (buf);
	
  if (db == NULL) 
    {
      gpe_error_box (err);
      free (err);
      return FALSE;
    }
  
  /* make sure table exists */
  sqlite_exec (db, schema_str, NULL, NULL, NULL);
  
  /* update table layout if necessary */
  check_table_update ();

  if (sqlite_exec (db, "select id,description,colour from category",
                   load_one, &categories, &err))
    {
      gpe_error_box (err);
      free (err);
      return FALSE;
    }
  
  return TRUE;
}

GSList *
gpe_pim_categories_list (void)
{
  return g_slist_copy (categories);
}

const gchar *
gpe_pim_category_name (gint id)
{
  GSList *iter;

  for (iter = categories; iter; iter = iter->next)
    {
      struct gpe_pim_category *c = iter->data;

      if (c->id == id)
        return c->name;
    }

  return NULL;
}

/**
 * gpe_pim_category_colour:
 * @id: Category id
 *
 * Get the colour assigned to the given category.
 *
 * Returns: Colour string.
 */
const gchar *
gpe_pim_category_colour (gint id)
{
  GSList *iter;

  for (iter = categories; iter; iter = iter->next)
    {
      struct gpe_pim_category *c = iter->data;

      if (c->id == id)
        return c->colour;
    }

  return NULL;
}

gboolean
gpe_pim_category_new (const gchar *name, gint *id)
{
  gchar *err;
  gint r;
  struct gpe_pim_category *c;
  
  r = sqlite_exec_printf (db, "insert into category values (NULL, '%q', NULL)",
                          NULL, NULL, &err, name);
  if (r)
    {
      gpe_error_box (err);
      free (err);
      return FALSE;
    }
  
  *id = sqlite_last_insert_rowid (db);

  c = g_malloc0 (sizeof (c));

  c->id = *id;
  c->name = g_strdup (name);

  categories = g_slist_prepend (categories, c);
      
  return TRUE;
}

/**
 * gpe_pim_category_delete:
 * @c: Pim category to become deleted.
 *
 * Delete a PIM category. The category to delete is isentified by the id 
 * field in the given category.
 */
void 
gpe_pim_category_delete (struct gpe_pim_category *c)
{
  sqlite_exec_printf (db, "delete from category where id='%d'", NULL, NULL, NULL, c->id);

  categories = g_slist_remove (categories, c);
}

/**
 * gpe_pim_category_rename:
 * @id: Category id
 * @new_name: String
 *
 * Rename an existing category.
 *
 * Returns: %TRUE on success, %FALSE otherwise.
 */
gboolean
gpe_pim_category_rename (gint id, gchar *new_name)
{
  gchar *err;
  gint r;

  r = sqlite_exec_printf (db,
                          "update category set description = '%q' where id =%d",
                          NULL, NULL, &err, new_name, id);

  if (r)
    {
      gpe_error_box (err);
      g_free (err);
      return FALSE;
    }
  return TRUE;
}

/**
 * gpe_pim_category_set_colour:
 * @id: Category id
 * @new_colour: Colour description.
 *
 * Set the colour descrition for a category. Valid strings are 
 * symbolic names like 'green' or HTML-like RGB values e.g. <quote>#11FF11</quote>
 *
 * Returns: %TRUE on success, %FALSE otherwise.
 */
gboolean
gpe_pim_category_set_colour (gint id, const gchar *new_colour)
{
  gchar *err;
  gint r;

  r = sqlite_exec_printf (db,
                          "update category set colour = '%q' where id =%d",
                          NULL, NULL, &err, new_colour, id);

  if (r)
    {
      gpe_error_box (err);
      g_free (err);
      return FALSE;
    }
  return TRUE;
}