/*
   Widgets for the Midnight Commander

   Copyright (C) 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003,
   2004, 2005, 2006, 2007, 2009, 2010, 2011, 2012, 2013
   The Free Software Foundation, Inc.

   Authors:
   Radek Doulik, 1994, 1995
   Miguel de Icaza, 1994, 1995
   Jakub Jelinek, 1995
   Andrej Borsenkow, 1996
   Norbert Warmuth, 1997
   Andrew Borodin <aborodin@vmail.ru>, 2009, 2010, 2011, 2012, 2013

   This file is part of the Midnight Commander.

   The Midnight Commander 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.

   The Midnight Commander 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/>.
 */

/** \file history.c
 *  \brief Source: save, load and show history
 */

#include <config.h>

#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "lib/global.h"

#include "lib/tty/tty.h"        /* LINES, COLS */
#include "lib/mcconfig.h"       /* for history loading and saving */
#include "lib/fileloc.h"
#include "lib/strutil.h"
#include "lib/util.h"           /* list_append_unique */
#include "lib/widget.h"

/*** global variables ****************************************************************************/

/* how much history items are used */
int num_history_items_recorded = 60;

/*** file scope macro definitions ****************************************************************/

/*** file scope type declarations ****************************************************************/

typedef struct
{
    Widget *widget;
    size_t count;
    size_t maxlen;
} history_dlg_data;

/*** file scope variables ************************************************************************/

/*** file scope functions ************************************************************************/

static cb_ret_t
history_dlg_reposition (WDialog * dlg_head)
{
    history_dlg_data *data;
    int x = 0, y, he, wi;

    /* guard checks */
    if ((dlg_head == NULL) || (dlg_head->data == NULL))
        return MSG_NOT_HANDLED;

    data = (history_dlg_data *) dlg_head->data;

    y = data->widget->y;
    he = data->count + 2;

    if (he <= y || y > (LINES - 6))
    {
        he = min (he, y - 1);
        y -= he;
    }
    else
    {
        y++;
        he = min (he, LINES - y);
    }

    if (data->widget->x > 2)
        x = data->widget->x - 2;

    wi = data->maxlen + 4;

    if ((wi + x) > COLS)
    {
        wi = min (wi, COLS);
        x = COLS - wi;
    }

    dlg_set_position (dlg_head, y, x, y + he, x + wi);

    return MSG_HANDLED;
}

/* --------------------------------------------------------------------------------------------- */

static cb_ret_t
history_dlg_callback (Widget * w, Widget * sender, widget_msg_t msg, int parm, void *data)
{
    switch (msg)
    {
    case MSG_RESIZE:
        return history_dlg_reposition (DIALOG (w));

    default:
        return dlg_default_callback (w, sender, msg, parm, data);
    }
}

/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */

/**
 * Load the history from the ${XDG_CACHE_HOME}/mc/history file.
 * It is called with the widgets history name and returns the GList list.
 */

GList *
history_get (const char *input_name)
{
    GList *hist = NULL;
    char *profile;
    mc_config_t *cfg;

    if (num_history_items_recorded == 0)        /* this is how to disable */
        return NULL;
    if ((input_name == NULL) || (*input_name == '\0'))
        return NULL;

    profile = mc_config_get_full_path (MC_HISTORY_FILE);
    cfg = mc_config_init (profile, TRUE);

    hist = history_load (cfg, input_name);

    mc_config_deinit (cfg);
    g_free (profile);

    return hist;
}

/* --------------------------------------------------------------------------------------------- */

/**
 * Load history form the mc_config
 */
GList *
history_load (struct mc_config_t * cfg, const char *name)
{
    size_t i;
    GList *hist = NULL;
    char **keys;
    size_t keys_num = 0;
    GIConv conv = INVALID_CONV;
    GString *buffer;

    if (name == NULL || *name == '\0')
        return NULL;

    /* get number of keys */
    keys = mc_config_get_keys (cfg, name, &keys_num);
    g_strfreev (keys);

    /* create charset conversion handler to convert strings
       from utf-8 to system codepage */
    if (!mc_global.utf8_display)
        conv = str_crt_conv_from ("UTF-8");

    buffer = g_string_sized_new (64);

    for (i = 0; i < keys_num; i++)
    {
        char key[BUF_TINY];
        char *this_entry;

        g_snprintf (key, sizeof (key), "%lu", (unsigned long) i);
        this_entry = mc_config_get_string_raw (cfg, name, key, "");

        if (this_entry == NULL)
            continue;

        if (conv == INVALID_CONV)
            hist = list_append_unique (hist, this_entry);
        else
        {
            g_string_set_size (buffer, 0);
            if (str_convert (conv, this_entry, buffer) == ESTR_FAILURE)
                hist = list_append_unique (hist, this_entry);
            else
            {
                hist = list_append_unique (hist, g_strndup (buffer->str, buffer->len));
                g_free (this_entry);
            }
        }
    }

    g_string_free (buffer, TRUE);
    if (conv != INVALID_CONV)
        str_close_conv (conv);

    /* return pointer to the last entry in the list */
    return g_list_last (hist);
}

/* --------------------------------------------------------------------------------------------- */

/**
  * Save history to the mc_config, but don't save config to file
  */
void
history_save (struct mc_config_t *cfg, const char *name, GList * h)
{
    GIConv conv = INVALID_CONV;
    GString *buffer;
    int i;

    if (name == NULL || *name == '\0' || h == NULL)
        return;

    /* go to end of list */
    h = g_list_last (h);

    /* go back 60 places */
    for (i = 0; (i < num_history_items_recorded - 1) && (h->prev != NULL); i++)
        h = g_list_previous (h);

    if (name != NULL)
        mc_config_del_group (cfg, name);

    /* create charset conversion handler to convert strings
       from system codepage to UTF-8 */
    if (!mc_global.utf8_display)
        conv = str_crt_conv_to ("UTF-8");

    buffer = g_string_sized_new (64);
    /* dump history into profile */
    for (i = 0; h != NULL; h = g_list_next (h))
    {
        char key[BUF_TINY];
        char *text = (char *) h->data;

        /* We shouldn't have null entries, but let's be sure */
        if (text == NULL)
            continue;

        g_snprintf (key, sizeof (key), "%d", i++);

        if (conv == INVALID_CONV)
            mc_config_set_string_raw (cfg, name, key, text);
        else
        {
            g_string_set_size (buffer, 0);
            if (str_convert (conv, text, buffer) == ESTR_FAILURE)
                mc_config_set_string_raw (cfg, name, key, text);
            else
                mc_config_set_string_raw (cfg, name, key, buffer->str);
        }
    }

    g_string_free (buffer, TRUE);
    if (conv != INVALID_CONV)
        str_close_conv (conv);
}

/* --------------------------------------------------------------------------------------------- */

char *
history_show (GList ** history, Widget * widget, int current)
{
    GList *z, *hlist = NULL, *hi;
    size_t maxlen, count = 0;
    char *r = NULL;
    WDialog *query_dlg;
    WListbox *query_list;
    history_dlg_data hist_data;

    if (*history == NULL)
        return NULL;

    maxlen = str_term_width1 (_("History")) + 2;

    for (z = *history; z != NULL; z = g_list_previous (z))
    {
        WLEntry *entry;
        size_t i;

        i = str_term_width1 ((char *) z->data);
        maxlen = max (maxlen, i);
        count++;

        entry = g_new0 (WLEntry, 1);
        /* history is being reverted here */
        entry->text = g_strdup ((char *) z->data);
        hlist = g_list_prepend (hlist, entry);
    }

    hist_data.widget = widget;
    hist_data.count = count;
    hist_data.maxlen = maxlen;

    query_dlg =
        dlg_create (TRUE, 0, 0, 4, 4, dialog_colors, history_dlg_callback, NULL,
                    "[History-query]", _("History"), DLG_COMPACT);
    query_dlg->data = &hist_data;

    query_list = listbox_new (1, 1, 2, 2, TRUE, NULL);

    /* this call makes list stick to all sides of dialog, effectively make
       it be resized with dialog */
    add_widget_autopos (query_dlg, query_list, WPOS_KEEP_ALL, NULL);

    /* to avoid diplicating of (calculating sizes in two places)
       code, call dlg_hist_callback function here, to set dialog and
       controls positions.
       The main idea - create 4x4 dialog and add 2x2 list in
       center of it, and let dialog function resize it to needed
       size. */
    send_message (query_dlg, NULL, MSG_RESIZE, 0, NULL);

    if (WIDGET (query_dlg)->y < widget->y)
    {
        /* draw list entries from bottom upto top */
        listbox_set_list (query_list, hlist);
        if (current < 0 || (size_t) current >= count)
            listbox_select_last (query_list);
        else
            listbox_select_entry (query_list, count - 1 - (size_t) current);
    }
    else
    {
        /* draw list entries from top downto bottom */
        /* revert history direction */
        hlist = g_list_reverse (hlist);
        listbox_set_list (query_list, hlist);
        if (current > 0)
            listbox_select_entry (query_list, current);
    }

    if (dlg_run (query_dlg) != B_CANCEL)
    {
        char *q;

        listbox_get_current (query_list, &q, NULL);
        r = g_strdup (q);
    }

    /* get modified history from dialog */
    z = NULL;
    for (hi = query_list->list; hi != NULL; hi = g_list_next (hi))
    {
        WLEntry *entry = LENTRY (hi->data);

        /* history is being reverted here again */
        z = g_list_prepend (z, entry->text);
        entry->text = NULL;
    }

    /* restore history direction */
    if (WIDGET (query_dlg)->y < widget->y)
        z = g_list_reverse (z);

    dlg_destroy (query_dlg);

    g_list_free_full (*history, g_free);
    *history = g_list_last (z);

    return r;
}

/* --------------------------------------------------------------------------------------------- */