/********************************************************************\
 * datecell-gnome.c -- implement date cell handler in gnome         *
 *                                                                  *
 * 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, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
 *                                                                  *
\********************************************************************/

/*
 * FILE: datecell-gnome.c
 *
 * FUNCTION: Implement gnome portion of datecell widget
 *           embedded in a table cell.
 *
 * HISTORY:
 * Copyright (c) 2000 Dave Peticolas <dave@krondo.com>
 * Copyright (c) 2017 Aaron Laws
 */

#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <glib/gi18n.h>
#include <gdk/gdkkeysyms.h>

#include "datecell.h"
#include "dialog-utils.h"
#include "gnc-ui.h"
#include "gnc-ui-util.h"
#include "gnucash-date-picker.h"
#include "gnucash-item-edit.h"
#include "gnucash-sheet.h"
#include "gnucash-sheetP.h"


#define DATE_BUF (MAX_DATE_LENGTH+1)

typedef struct _PopBox
{
    GnucashSheet  *sheet;
    GncItemEdit   *item_edit;
    GNCDatePicker *date_picker;

    gboolean signals_connected; /* date picker signals connected? */
    gboolean calendar_popped;   /* calendar is popped up? */
    gboolean in_date_select;

    struct tm date;
} PopBox;


static void block_picker_signals (DateCell *cell);
static void unblock_picker_signals (DateCell *cell);
static void gnc_date_cell_realize (BasicCell *bcell, gpointer w);
static void gnc_date_cell_set_value_internal (BasicCell *bcell,
        const char *value);
static void gnc_date_cell_move (BasicCell *bcell);
static void gnc_date_cell_gui_destroy (BasicCell *bcell);
static void gnc_date_cell_destroy (BasicCell *bcell);
static void gnc_date_cell_modify_verify (BasicCell *_cell,
        const char *change,
        int change_len,
        const char *newval,
        int newval_len,
        int *cursor_position,
        int *start_selection,
        int *end_selection);
static gboolean gnc_date_cell_direct_update (BasicCell *bcell,
        int *cursor_position,
        int *start_selection,
        int *end_selection,
        void *gui_data);
static gboolean gnc_date_cell_enter (BasicCell *bcell,
                                     int *cursor_position,
                                     int *start_selection,
                                     int *end_selection);
static void gnc_date_cell_leave (BasicCell *bcell);

static gboolean
check_readonly_threshold (const gchar *datestr, GDate *d, gboolean warn)
{
    GDate *readonly_threshold = qof_book_get_autoreadonly_gdate(gnc_get_current_book());
    if (g_date_compare(d, readonly_threshold) < 0)
    {
        if (warn)
        {
            gchar *dialog_msg = _("The entered date of the transaction is "
                          "older than the \"Read-Only Threshold\" set for "
                          "this book. This setting can be changed in "
                          "File->Properties->Accounts, resetting to the threshold.");
            gchar *dialog_title = _("Cannot store a transaction at this date");
            GtkWidget *dialog = gtk_message_dialog_new(gnc_ui_get_main_window (NULL),
                                   0,
                                   GTK_MESSAGE_ERROR,
                                   GTK_BUTTONS_OK,
                                   "%s", dialog_title);
            gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG(dialog),
                                 "%s", dialog_msg);
            gtk_dialog_run (GTK_DIALOG(dialog));
            gtk_widget_destroy (dialog);

//        g_warning("Entered date %s is before the \"auto-read-only threshold\";"
//              " resetting to the threshold.", datestr);
        }
        // Reset the date to the threshold date
        g_date_set_julian (d, g_date_get_julian (readonly_threshold));
        g_date_free (readonly_threshold);
        return TRUE;
    }
    g_date_free (readonly_threshold);
    return FALSE;
}

static void
gnc_parse_date (struct tm *parsed, const char * datestr, gboolean warn)
{
    int day, month, year;
    gboolean use_autoreadonly = qof_book_uses_autoreadonly(gnc_get_current_book());
    GDate *test_date;

    if (!parsed) return;
    if (!datestr) return;

    if (!qof_scan_date (datestr, &day, &month, &year))
    {
        // Couldn't parse date, use today
        struct tm tm_today;

        memset (&tm_today, 0, sizeof (struct tm));
        gnc_tm_get_today_start (&tm_today);
        day = tm_today.tm_mday;
        month = tm_today.tm_mon + 1;
        year = tm_today.tm_year + 1900;
    }

    test_date = g_date_new_dmy (day, month, year);

    if (!gnc_gdate_in_valid_range (test_date, warn))
    {
        struct tm tm_today;
        memset (&tm_today, 0, sizeof (struct tm));
        gnc_tm_get_today_start (&tm_today);
        year = tm_today.tm_year + 1900;
    }

    // If we have an auto-read-only threshold, do not accept a date that is
    // older than the threshold.
    if (use_autoreadonly)
    {
        g_date_set_dmy (test_date, day, month, year);
        if (check_readonly_threshold (datestr, test_date, warn))
        {
            day = g_date_get_day (test_date);
            month = g_date_get_month (test_date);
            year = g_date_get_year (test_date);
        }
    }
    g_date_free (test_date);

    parsed->tm_mday = day;
    parsed->tm_mon  = month - 1;
    parsed->tm_year = year - 1900;

    gnc_tm_set_day_start(parsed);
    /* Using gnc_mktime purely for its side effect of filling in the
     * rest of parsed and to check that it's valid.
     */
    if (gnc_mktime (parsed) == -1)
        gnc_tm_get_today_start (parsed);
    gnc_mktime (parsed);
}

static void
gnc_date_cell_print_date (DateCell *cell, char *buff)
{
    PopBox *box = cell->cell.gui_private;

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH,
                             box->date.tm_mday,
                             box->date.tm_mon + 1,
                             box->date.tm_year + 1900);
}

static void
gnc_date_cell_init (DateCell *cell)
{
    PopBox *box;
    time64 secs;
    char buff[DATE_BUF];

    gnc_basic_cell_init (&(cell->cell));

    cell->cell.is_popup = TRUE;

    cell->cell.destroy = gnc_date_cell_destroy;

    cell->cell.gui_realize = gnc_date_cell_realize;
    cell->cell.gui_destroy = gnc_date_cell_gui_destroy;
    cell->cell.modify_verify = gnc_date_cell_modify_verify;
    cell->cell.direct_update = gnc_date_cell_direct_update;
    cell->cell.set_value = gnc_date_cell_set_value_internal;

    box = g_new0 (PopBox, 1);

    box->sheet = NULL;
    box->item_edit = NULL;
    box->date_picker = NULL;

    box->signals_connected = FALSE;
    box->calendar_popped = FALSE;
    box->in_date_select = FALSE;

    cell->cell.gui_private = box;

    /* default value is today's date */
    gnc_time (&secs);
    gnc_localtime_r (&secs, &(box->date));
    gnc_date_cell_print_date (cell, buff);

    gnc_basic_cell_set_value_internal (&cell->cell, buff);
}

BasicCell *
gnc_date_cell_new (void)
{
    DateCell *cell;

    cell = g_new0 (DateCell, 1);

    gnc_date_cell_init (cell);

    return &cell->cell;
}

static void
date_picked_cb (GNCDatePicker *gdp, gpointer data)
{
    DateCell *cell = data;
    PopBox *box = cell->cell.gui_private;
    guint day, month, year;
    char buffer[DATE_BUF];

    gtk_calendar_get_date (gdp->calendar, &year, &month, &day);

    qof_print_date_dmy_buff (buffer, MAX_DATE_LENGTH, day, month + 1, year);

    box->in_date_select = TRUE;
    gnucash_sheet_modify_current_cell (box->sheet, buffer);
    box->in_date_select = FALSE;

    gnc_item_edit_hide_popup (box->item_edit);
    box->calendar_popped = FALSE;
}

static void
date_selected_cb (GNCDatePicker *gdp, gpointer data)
{
    DateCell *cell = data;
    PopBox *box = cell->cell.gui_private;
    guint day, month, year;
    char buffer[DATE_BUF];

    gtk_calendar_get_date (gdp->calendar, &year, &month, &day);

    qof_print_date_dmy_buff (buffer, MAX_DATE_LENGTH, day, month + 1, year);

    box->in_date_select = TRUE;
    gnucash_sheet_modify_current_cell (box->sheet, buffer);
    box->in_date_select = FALSE;
}

static void
key_press_item_cb (GNCDatePicker *gdp, GdkEventKey *event, gpointer data)
{
    DateCell *cell = data;
    PopBox *box = cell->cell.gui_private;

    switch (event->keyval)
    {
    case GDK_KEY_Escape:
        gnc_item_edit_hide_popup (box->item_edit);
        box->calendar_popped = FALSE;
        break;

    default:
        gtk_widget_event(GTK_WIDGET (box->sheet), (GdkEvent *) event);
        break;
    }
}

static void
date_picker_disconnect_signals (DateCell *cell)
{
    PopBox *box = cell->cell.gui_private;

    if (!box->signals_connected)
        return;

    g_signal_handlers_disconnect_matched (box->date_picker, G_SIGNAL_MATCH_DATA,
                                          0, 0, NULL, NULL, cell);

    box->signals_connected = FALSE;
}

static void
date_picker_connect_signals (DateCell *cell)
{
    PopBox *box = cell->cell.gui_private;

    if (box->signals_connected)
        return;

    g_signal_connect (box->date_picker, "date_selected",
                      G_CALLBACK(date_selected_cb), cell);

    g_signal_connect(box->date_picker, "date_picked",
                     G_CALLBACK(date_picked_cb), cell);

    g_signal_connect(box->date_picker, "key_press_event",
                     G_CALLBACK(key_press_item_cb), cell);

    box->signals_connected = TRUE;
}

static void
block_picker_signals (DateCell *cell)
{
    PopBox *box = cell->cell.gui_private;

    if (!box->signals_connected)
        return;

    g_signal_handlers_block_matched (box->date_picker, G_SIGNAL_MATCH_DATA,
                                     0, 0, NULL, NULL, cell);
}

static void
unblock_picker_signals (DateCell *cell)
{
    PopBox *box = cell->cell.gui_private;

    if (!box->signals_connected)
        return;

    g_signal_handlers_unblock_matched (box->date_picker, G_SIGNAL_MATCH_DATA,
                                       0, 0, NULL, NULL, cell);
}

static void
gnc_date_cell_gui_destroy (BasicCell *bcell)
{
    PopBox *box = bcell->gui_private;
    DateCell *cell = (DateCell *) bcell;

    if (cell->cell.gui_realize == NULL)
    {
        if (box != NULL && box->date_picker != NULL)
        {
            date_picker_disconnect_signals (cell);
            g_object_unref (box->date_picker);
            box->date_picker = NULL;
        }

        /* allow the widget to be shown again */
        cell->cell.gui_realize = gnc_date_cell_realize;
        cell->cell.gui_move = NULL;
        cell->cell.enter_cell = NULL;
        cell->cell.leave_cell = NULL;
        cell->cell.gui_destroy = NULL;
    }
}

static void
gnc_date_cell_destroy (BasicCell *bcell)
{
    DateCell *cell = (DateCell *) bcell;
    PopBox *box = cell->cell.gui_private;

    gnc_date_cell_gui_destroy (&(cell->cell));

    g_free (box);

    cell->cell.gui_private = NULL;
    cell->cell.gui_realize = NULL;
}

void
gnc_date_cell_set_value (DateCell *cell, int day, int mon, int year)
{
    PopBox *box = cell->cell.gui_private;
    struct tm dada;
    char buff[DATE_BUF];

    dada.tm_mday = day;
    dada.tm_mon  = mon - 1;
    dada.tm_year = year - 1900;

    gnc_tm_set_day_start(&dada);
    gnc_mktime (&dada);

    box->date.tm_mday = dada.tm_mday;
    box->date.tm_mon  = dada.tm_mon;
    box->date.tm_year = dada.tm_year;

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH, dada.tm_mday, dada.tm_mon + 1, dada.tm_year + 1900);

    gnc_basic_cell_set_value_internal (&cell->cell, buff);

    if (!box->date_picker)
        return;

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker, day, mon - 1, year);
    unblock_picker_signals (cell);
}

void
gnc_date_cell_set_value_secs (DateCell *cell, time64 secs)
{
    PopBox *box = cell->cell.gui_private;
    char buff[DATE_BUF];

    gnc_localtime_r (&secs, &(box->date));

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH,
                             box->date.tm_mday,
                             box->date.tm_mon + 1,
                             box->date.tm_year + 1900);

    gnc_basic_cell_set_value_internal (&cell->cell, buff);

    if (!box->date_picker)
        return;

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker,
                              box->date.tm_mday,
                              box->date.tm_mon,
                              box->date.tm_year + 1900);
    unblock_picker_signals (cell);
}

void
gnc_date_cell_commit (DateCell *cell)
{
    PopBox *box = cell->cell.gui_private;
    char buff[DATE_BUF];

    if (!cell)
        return;

    gnc_parse_date (&(box->date), cell->cell.value, FALSE);

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH,
                             box->date.tm_mday,
                             box->date.tm_mon + 1,
                             box->date.tm_year + 1900);

    gnc_basic_cell_set_value_internal (&cell->cell, buff);

    if (!box->date_picker)
        return;

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker,
                              box->date.tm_mday,
                              box->date.tm_mon,
                              box->date.tm_year + 1900);
    unblock_picker_signals (cell);
}

static gboolean
gnc_date_cell_direct_update (BasicCell *bcell,
                             int *cursor_position,
                             int *start_selection,
                             int *end_selection,
                             void *gui_data)
{
    DateCell *cell = (DateCell *) bcell;
    PopBox *box = cell->cell.gui_private;
    GdkEventKey *event = gui_data;
    char buff[DATE_BUF];

    if (!gnc_handle_date_accelerator (event, &(box->date), bcell->value))
        return FALSE;

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH,
                             box->date.tm_mday,
                             box->date.tm_mon + 1,
                             box->date.tm_year + 1900);

    gnc_basic_cell_set_value_internal (&cell->cell, buff);

    *start_selection = 0;
    *end_selection = -1;

    if (!box->date_picker)
        return TRUE;

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker,
                              box->date.tm_mday,
                              box->date.tm_mon,
                              box->date.tm_year + 1900);
    unblock_picker_signals (cell);

    return TRUE;
}

static void
gnc_date_cell_modify_verify (BasicCell *_cell,
                             const char *change,
                             int change_len,
                             const char *newval,
                             int newval_len,
                             int *cursor_position,
                             int *start_selection,
                             int *end_selection)
{
    DateCell *cell = (DateCell *) _cell;
    PopBox *box = cell->cell.gui_private;
    gboolean accept = FALSE;

    if (box->in_date_select)
    {
        gnc_basic_cell_set_value (_cell, newval);
        return;
    }

    /* if user hit backspace, accept the change */
    if (change == NULL)
        accept = TRUE;
    else if (change_len == 0)
        accept = TRUE;
    else
    {
        int count = 0;
        unsigned char separator = dateSeparator ();
        gboolean ok = TRUE;
        const gchar *c;
        gunichar uc;

        /* accept only numbers or a date separator. Note that the
         * separator of '-' (for DATE_FORMAT_ISO) takes precedence
         * over the accelerator below! */
        c = change;
        while (*c)
        {
            uc = g_utf8_get_char (c);

            if (!g_unichar_isdigit (uc) && (separator != uc))
                ok = FALSE;

            if (separator == uc)
                count++;

            c = g_utf8_next_char (c);
        }

        c = _cell->value;
        while (*c)
        {
            uc = g_utf8_get_char (c);

            if (separator == uc)
                count++;

            c = g_utf8_next_char (c);
        }

        if (2 < count)
            ok = FALSE;

        if (ok)
            accept = TRUE;
    }

    /* keep a copy of the new value */
    if (accept)
    {
        gnc_basic_cell_set_value_internal (&cell->cell, newval);
        gnc_parse_date (&(box->date), newval, FALSE);
        *end_selection = *start_selection = *cursor_position;

        if (!box->date_picker)
            return;

        block_picker_signals (cell);
        gnc_date_picker_set_date (box->date_picker,
                                  box->date.tm_mday,
                                  box->date.tm_mon,
                                  box->date.tm_year + 1900);
        unblock_picker_signals (cell);
    }
}

static void
gnc_date_cell_realize (BasicCell *bcell, gpointer data)
{
    GnucashSheet *sheet = data;
    GncItemEdit *item_edit = gnucash_sheet_get_item_edit (sheet);
    DateCell *cell = (DateCell *) bcell;
    PopBox *box = cell->cell.gui_private;

    /* initialize gui-specific, private data */
    box->sheet = sheet;
    box->item_edit = item_edit;
    box->date_picker = GNC_DATE_PICKER (gnc_date_picker_new ());
    gtk_widget_show_all (GTK_WIDGET(box->date_picker));
    g_object_ref_sink(box->date_picker);

    /* to mark cell as realized, remove the realize method */
    cell->cell.gui_realize = NULL;
    cell->cell.gui_move = gnc_date_cell_move;
    cell->cell.enter_cell = gnc_date_cell_enter;
    cell->cell.leave_cell = gnc_date_cell_leave;
}

static void
gnc_date_cell_move (BasicCell *bcell)
{
    PopBox *box = bcell->gui_private;

    date_picker_disconnect_signals ((DateCell *) bcell);

    gnc_item_edit_set_popup (box->item_edit, NULL, NULL,
                             NULL, NULL, NULL, NULL, NULL);

    box->calendar_popped = FALSE;
}

static int
popup_get_height (GtkWidget *widget,
                  G_GNUC_UNUSED int space_available,
                  G_GNUC_UNUSED int row_height,
                  G_GNUC_UNUSED gpointer user_data)
{
    GtkWidget *cal = GTK_WIDGET (GNC_DATE_PICKER (widget)->calendar);
    GtkRequisition req;

    req.height = 0;
    req.width = 0;

    gtk_widget_get_preferred_size (cal, &req, NULL);

    return req.height;
}

static void
popup_set_focus (GtkWidget *widget,
                 G_GNUC_UNUSED gpointer user_data)
{
    gtk_widget_grab_focus (GTK_WIDGET (GNC_DATE_PICKER (widget)->calendar));
}

static gboolean
gnc_date_cell_enter (BasicCell *bcell,
                     G_GNUC_UNUSED int *cursor_position,
                     int *start_selection,
                     int *end_selection)
{
    DateCell *cell = (DateCell *) bcell;
    PopBox *box = bcell->gui_private;

    gnc_item_edit_set_popup (box->item_edit, GTK_WIDGET (box->date_picker),
                             popup_get_height, NULL, popup_set_focus,
                             NULL, NULL, NULL);

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker,
                              box->date.tm_mday,
                              box->date.tm_mon,
                              box->date.tm_year + 1900);
    unblock_picker_signals (cell);

    date_picker_connect_signals ((DateCell *) bcell);

    *start_selection = 0;
    *end_selection = -1;

    return TRUE;
}

static void
gnc_date_cell_leave (BasicCell *bcell)
{
    time64 time;
    PopBox *box = bcell->gui_private;

    date_picker_disconnect_signals ((DateCell *) bcell);

    gnc_item_edit_set_popup (box->item_edit, NULL, NULL,
                             NULL, NULL, NULL, NULL, NULL);

    box->calendar_popped = FALSE;

    /* Refresh the date to expand any shortcuts. */
    gnc_date_cell_get_date ((DateCell *)bcell, &time, TRUE);
    gnc_date_cell_set_value_secs ((DateCell *)bcell, time);
}

void
gnc_date_cell_get_date (DateCell *cell, time64 *time, gboolean warn)
{
    PopBox *box = cell->cell.gui_private;
    if (!cell || !time)
        return;

    gnc_parse_date (&(box->date), cell->cell.value, warn);
    *time = gnc_mktime (&box->date);
}

static void
gnc_date_cell_set_value_internal (BasicCell *_cell, const char *str)
{
    DateCell *cell = (DateCell *) _cell;
    PopBox *box = cell->cell.gui_private;
    char buff[DATE_BUF];

    gnc_parse_date (&(box->date), str, FALSE);

    qof_print_date_dmy_buff (buff, MAX_DATE_LENGTH,
                             box->date.tm_mday,
                             box->date.tm_mon + 1,
                             box->date.tm_year + 1900);

    gnc_basic_cell_set_value_internal (_cell, buff);

    if (!box->date_picker)
        return;

    block_picker_signals (cell);
    gnc_date_picker_set_date (box->date_picker,
                              box->date.tm_mday,
                              box->date.tm_mon,
                              box->date.tm_year + 1900);
    unblock_picker_signals (cell);
}