/*	$calcurse: todo.c,v 1.32 2009/06/26 21:44:12 culot Exp $	*/

/*
 * Calcurse - text-based organizer
 * Copyright (c) 2004-2009 Frederic Culot
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Send your feedback or comments to : calcurse@culot.org
 * Calcurse home page : http://culot.org/calcurse
 *
 */

#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "utils.h"
#include "custom.h"
#include "keys.h"
#include "i18n.h"
#include "mem.h"
#include "todo.h"

struct todo_s *todolist;
static int hilt = 0;
static int todos = 0;
static int first = 1;
static char *msgsav;

/* Returns a structure containing the selected item. */
static struct todo_s *
todo_get_item (int item_number)
{
  struct todo_s *o;
  int i;

  o = todolist;
  for (i = 1; i < item_number; i++)
    {
      o = o->next;
    }
  return (o);
}

/* Sets which todo is highlighted. */
void
todo_hilt_set (int highlighted)
{
  hilt = highlighted;
}

void
todo_hilt_decrease (void)
{
  hilt--;
}

void
todo_hilt_increase (void)
{
  hilt++;
}

/* Return which todo is highlighted. */
int
todo_hilt (void)
{
  return (hilt);
}

/* Return the number of todos. */
int
todo_nb (void)
{
  return (todos);
}

/* Set the number of todos. */
void
todo_set_nb (int nb)
{
  todos = nb;
}

/* Set which one is the first todo to be displayed. */
void
todo_set_first (int nb)
{
  first = nb;
}

void
todo_first_increase (void)
{
  first++;
}

void
todo_first_decrease (void)
{
  first--;
}

/* 
 * Return the position of the hilghlighted item, relative to the first one
 * displayed. 
 */
int
todo_hilt_pos (void)
{
  return (hilt - first);
}

/* Return the last visited todo. */
char *
todo_saved_mesg (void)
{
  return (msgsav);
}

/* Request user to enter a new todo item. */
void
todo_new_item (void)
{
  int ch = 0;
  char *mesg = _("Enter the new ToDo item : ");
  char *mesg_id = _("Enter the ToDo priority [1 (highest) - 9 (lowest)] :");
  char todo_input[BUFSIZ] = "";

  status_mesg (mesg, "");
  if (getstring (win[STA].p, todo_input, BUFSIZ, 0, 1) == GETSTRING_VALID)
    {
      while ((ch < '1') || (ch > '9'))
	{
	  status_mesg (mesg_id, "");
	  ch = wgetch (win[STA].p);
	}
      todo_add (todo_input, ch - '0', NULL);
      todos++;
    }
}

/*
 * Add an item in the todo linked list.
 */
struct todo_s *
todo_add (char *mesg, int id, char *note)
{
  struct todo_s *o, **i;
  int absid;
  
  o = (struct todo_s *) mem_malloc (sizeof (struct todo_s));
  o->mesg = mem_strdup (mesg);
  o->id = id;
  o->note = (note != NULL && note[0] != '\0') ? mem_strdup (note) : NULL;
  i = &todolist;

  /*
   * As of version 2.6, todo items can have a negative id, which means they
   * were completed. To keep them sorted, we need to consider the absolute id
   * value.
   */
  absid = abs (id);
  for (;;)
    {
      if (*i == 0 || abs ((*i)->id) > absid)
	{
	  o->next = *i;
	  *i = o;
	  break;
	}
      i = &(*i)->next;
    }
  return (o);
}

/* Delete a note previously attached to a todo item. */
static void
todo_delete_note_bynum (unsigned num)
{
  unsigned n;
  struct todo_s *i, **iptr;

  n = 0;
  iptr = &todolist;
  for (i = todolist; i != 0; i = i->next)
    {
      if (n == num)
	{
	  if (i->note == NULL)
            EXIT (_("no note attached"));
	  erase_note (&i->note, ERASE_FORCE_ONLY_NOTE);
	  return;
	}
      iptr = &i->next;
      n++;
    }
  /* NOTREACHED */
  EXIT (_("no such todo"));
}

/* Delete an item from the todo linked list. */
static void
todo_delete_bynum (unsigned num, erase_flag_e flag)
{
  unsigned n;
  struct todo_s *i, **iptr;

  n = 0;
  iptr = &todolist;
  for (i = todolist; i != 0; i = i->next)
    {
      if (n == num)
	{
	  *iptr = i->next;
	  mem_free (i->mesg);
	  if (i->note != NULL)
	    erase_note (&i->note, flag);
	  mem_free (i);
	  return;
	}
      iptr = &i->next;
      n++;
    }
  /* NOTREACHED */
  EXIT (_("no such todo"));
}

/*
 * Flag a todo item (for now on, only the 'completed' state is available).
 * Internally, a completed item keeps its priority, but it becomes negative.
 * This way, it is easy to retrive its original priority if the user decides
 * that in fact it was not completed.
 */
void
todo_flag (void)
{
  struct todo_s *t;

  t = todo_get_item (hilt);
  t->id = -t->id;
}

/* Delete an item from the ToDo list. */
void
todo_delete (conf_t *conf)
{
  char *choices = "[y/n] ";
  char *del_todo_str = _("Do you really want to delete this task ?");
  char *erase_warning =
      _("This item has a note attached to it. "
	"Delete (t)odo or just its (n)ote ?");
  char *erase_choice = _("[t/n] ");
  bool go_for_todo_del = false;
  int answer, has_note;

  if (conf->confirm_delete)
    {
      status_mesg (del_todo_str, choices);
      answer = wgetch (win[STA].p);
      if ((answer == 'y') && (todos > 0))
	{
	  go_for_todo_del = true;
	}
      else
	{
	  wins_erase_status_bar ();
	  return;
	}
    }
  else if (todos > 0)
    go_for_todo_del = true;

  if (go_for_todo_del == false)
    {
      wins_erase_status_bar ();
      return;
    }

  answer = -1;
  has_note = (todo_get_item (hilt)->note != NULL) ? 1 : 0;
  if (has_note == 0)
    answer = 't';

  while (answer != 't' && answer != 'n' && answer != KEY_GENERIC_CANCEL)
    {
      status_mesg (erase_warning, erase_choice);
      answer = wgetch (win[STA].p);
    }

  switch (answer)
    {
    case 't':
      todo_delete_bynum (hilt - 1, ERASE_FORCE);
      todos--;
      if (hilt > 1)
	hilt--;
      if (todos == 0)
	hilt = 0;
      if (hilt - first < 0)
	first--;
      break;
    case 'n':
      todo_delete_note_bynum (hilt - 1);
      break;
    default:
      wins_erase_status_bar ();
      return;
    }
}

/* 
 * Returns the position into the linked list corresponding to the
 * given todo_s item.
 */
static int
todo_get_position (struct todo_s *i)
{
  struct todo_s *o;
  int n = 1, found = 0;

  for (o = todolist; o; o = o->next)
    {
      if (o == i)
	{
	  found = 1;
	  break;
	}
      n++;
    }
  if (found)
    {
      return (n);
    }
  else
    {
      EXIT (_("todo not found"));
      return -1; /* avoid compiler warnings */
    }
}

/* Change an item priority by pressing '+' or '-' inside TODO panel. */
void
todo_chg_priority (int action)
{
  struct todo_s *backup;
  char backup_mesg[BUFSIZ];
  int backup_id;
  char backup_note[NOTESIZ + 1];
  int do_chg = 1;

  backup = todo_get_item (hilt);
  (void)strncpy (backup_mesg, backup->mesg, strlen (backup->mesg) + 1);
  backup_id = backup->id;
  if (backup->note)
    (void)strncpy (backup_note, backup->note, NOTESIZ + 1);
  else
    backup_note[0] = '\0';
  switch (action)
    {
    case KEY_RAISE_PRIORITY:
      (backup_id > 1) ? backup_id-- : do_chg--;
      break;
    case KEY_LOWER_PRIORITY:
      (backup_id > 0 && backup_id < 9) ? backup_id++ : do_chg--;
      break;
    default:
      EXIT (_("no such action"));
      /* NOTREACHED */
    }
  if (do_chg)
    {
      todo_delete_bynum (hilt - 1, ERASE_FORCE_KEEP_NOTE);
      backup = todo_add (backup_mesg, backup_id, backup_note);
      hilt = todo_get_position (backup);
    }
}

/* Edit the description of an already existing todo item. */
void
todo_edit_item (void)
{
  struct todo_s *i;
  char *mesg = _("Enter the new ToDo description :");

  status_mesg (mesg, "");
  i = todo_get_item (hilt);
  updatestring (win[STA].p, &i->mesg, 0, 1);
}

/* Display todo items in the corresponding panel. */
static void
display_todo_item (int incolor, char *msg, int prio, int note, int len, int y,
		   int x)
{
  WINDOW *w;
  int ch_note;
  char buf[len], priostr[2];

  w = win[TOD].p;
  ch_note = (note) ? '>' : '.';
  if (prio > 0)
    snprintf (priostr, sizeof priostr, "%d", prio);
  else
    snprintf (priostr, sizeof priostr, "X");
    
  if (incolor == 0)
    custom_apply_attr (w, ATTR_HIGHEST);
  if (strlen (msg) < len)
    mvwprintw (w, y, x, "%s%c %s", priostr, ch_note, msg);
  else
    {
      (void)strncpy (buf, msg, len - 1);
      buf[len - 1] = '\0';
      mvwprintw (w, y, x, "%s%c %s...", priostr, ch_note, buf);
    }
  if (incolor == 0)
    custom_remove_attr (w, ATTR_HIGHEST);
}

/* Updates the ToDo panel. */
void
todo_update_panel (int which_pan)
{
  struct todo_s *i;
  int len = win[TOD].w - 8;
  int num_todo = 0;
  int y_offset = 3, x_offset = 1;
  int t_realpos = -1;
  int title_lines = 3;
  int todo_lines = 1;
  int max_items = win[TOD].h - 4;
  int incolor = -1;

  /* Print todo item in the panel. */
  erase_window_part (win[TOD].p, 1, title_lines, win[TOD].w - 2,
                     win[TOD].h - 2);
  for (i = todolist; i != 0; i = i->next)
    {
      num_todo++;
      t_realpos = num_todo - first;
      incolor = num_todo - hilt;
      if (incolor == 0)
	msgsav = i->mesg;
      if (t_realpos >= 0 && t_realpos < max_items)
	{
	  display_todo_item (incolor, i->mesg, i->id,
			     (i->note != NULL) ? 1 : 0, len, y_offset,
			     x_offset);
	  y_offset = y_offset + todo_lines;
	}
    }

  /* Draw the scrollbar if necessary. */
  if (todos > max_items)
    {
      float ratio = ((float) max_items) / ((float) todos);
      int sbar_length = (int) (ratio * (max_items + 1));
      int highend = (int) (ratio * first);
      bool hilt_bar = (which_pan == TOD) ? true : false;
      int sbar_top = highend + title_lines;

      if ((sbar_top + sbar_length) > win[TOD].h - 1)
	sbar_length = win[TOD].h - 1 - sbar_top;
      draw_scrollbar (win[TOD].p, sbar_top, win[TOD].w - 2,
		      sbar_length, title_lines, win[TOD].h - 1, hilt_bar);
    }

  wnoutrefresh (win[TOD].p);
}

/* Attach a note to a todo */
void
todo_edit_note (char *editor)
{
  struct todo_s *i;
  char fullname[BUFSIZ];
  char *filename;

  i = todo_get_item (hilt);
  if (i->note == NULL)
    {
      if ((filename = new_tempfile (path_notes, NOTESIZ)) != NULL)
	i->note = filename;
      else
	return;
    }
  (void)snprintf (fullname, BUFSIZ, "%s%s", path_notes, i->note);
  wins_launch_external (fullname, editor);
}

/* View a note previously attached to a todo */
void
todo_view_note (char *pager)
{
  struct todo_s *i;
  char fullname[BUFSIZ];

  i = todo_get_item (hilt);
  if (i->note == NULL)
    return;
  (void)snprintf (fullname, BUFSIZ, "%s%s", path_notes, i->note);
  wins_launch_external (fullname, pager);
}

void
todo_free_list (void)
{
  struct todo_s *o, **i;

  i = &todolist;
  while (*i)
    {
      o = *i;
      *i = o->next;
      mem_free (o->mesg);
      if (o->note != 0)
        erase_note (&o->note, ERASE_FORCE_KEEP_NOTE);
      mem_free (o);
    }
  if (todolist)
    mem_free (todolist);
}