/*  time-admin 
*   Copyright (C) 2018  zhuyaliang https://github.com/zhuyaliang/
*
*   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 <https://www.gnu.org/licenses/>.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "time-map.h"
#include <math.h>

#define PIN_HOT_POINT_X 8
#define PIN_HOT_POINT_Y 15

typedef struct
{
    gdouble offset;
    guchar red;
    guchar green;
    guchar blue;
    guchar alpha;
}TimezoneMapOffset; 
enum
{
    LOCATION_CHANGED,
    LAST_SIGNAL
};
 
G_DEFINE_TYPE (TimezoneMap, timezone_map, GTK_TYPE_WIDGET)
static guint signals[LAST_SIGNAL];
static TimezoneMapOffset color_codes[] =
{
    {-11.0, 43, 0, 0, 255 },
    {-10.0, 85, 0, 0, 255 },
    {-9.5, 102, 255, 0, 255 },
    {-9.0, 128, 0, 0, 255 },
    {-8.0, 170, 0, 0, 255 },
    {-7.0, 212, 0, 0, 255 },
    {-6.0, 255, 0, 1, 255 }, // north
    {-6.0, 255, 0, 0, 255 }, // south
    {-5.0, 255, 42, 42, 255 },
    {-4.5, 192, 255, 0, 255 },
    {-4.0, 255, 85, 85, 255 },
    {-3.5, 0, 255, 0, 255 },
    {-3.0, 255, 128, 128, 255 },
    {-2.0, 255, 170, 170, 255 },
    {-1.0, 255, 213, 213, 255 },
    {0.0, 43, 17, 0, 255 },
    {1.0, 85, 34, 0, 255 },
    {2.0, 128, 51, 0, 255 },
    {3.0, 170, 68, 0, 255 },
    {3.5, 0, 255, 102, 255 },
    {4.0, 212, 85, 0, 255 },
    {4.5, 0, 204, 255, 255 },
    {5.0, 255, 102, 0, 255 },
    {5.5, 0, 102, 255, 255 },
    {5.75, 0, 238, 207, 247 },
    {6.0, 255, 127, 42, 255 },
    {6.5, 204, 0, 254, 254 },
    {7.0, 255, 153, 85, 255 },
    {8.0, 255, 179, 128, 255 },
    {9.0, 255, 204, 170, 255 },
    {9.5, 170, 0, 68, 250 },
    {10.0, 255, 230, 213, 255 },
    {10.5, 212, 124, 21, 250 },
    {11.0, 212, 170, 0, 255 },
    {11.5, 249, 25, 87, 253 },
    {12.0, 255, 204, 0, 255 },
    {12.75, 254, 74, 100, 248 },
    {13.0, 255, 85, 153, 250 },
    {-100, 0, 0, 0, 0 }
};
static void
cc_timezone_map_dispose (GObject *object)
{
    TimezoneMap *self = TIMEZONEMAP (object);

    g_clear_object (&self->orig_background);
    g_clear_object (&self->orig_background_dim);
    g_clear_object (&self->orig_color_map);
    g_clear_object (&self->background);
    g_clear_object (&self->pin);
    g_clear_pointer (&self->bubble_text, g_free);

    if (self->color_map)
    {
        g_clear_object (&self->color_map);

        self->visible_map_pixels = NULL;
        self->visible_map_rowstride = 0;
    }

    G_OBJECT_CLASS (timezone_map_parent_class)->dispose (object);
}
static void
timezone_map_finalize (GObject *object)
{
    TimezoneMap *self = TIMEZONEMAP (object);

    g_clear_pointer (&self->tzdb, TimeZoneDateBaseFree);

    G_OBJECT_CLASS (timezone_map_parent_class)->finalize (object);
}
static void
cc_timezone_map_get_preferred_width (GtkWidget *widget,
                                     gint      *minimum,
                                     gint      *natural)
{
    TimezoneMap *map = TIMEZONEMAP (widget);
    gint size;

    size = gdk_pixbuf_get_width (map->orig_background);

    if (minimum != NULL)
        *minimum = size;
    if (natural != NULL)
        *natural = size;
}

static void
cc_timezone_map_get_preferred_height (GtkWidget *widget,
                                      gint      *minimum,
                                      gint      *natural)
{
    TimezoneMap *map = TIMEZONEMAP (widget);
    gint size;

    size = gdk_pixbuf_get_height (map->orig_background);

    if (minimum != NULL)
        *minimum = size;
    if (natural != NULL)
        *natural = size;
}
static void
cc_timezone_map_size_allocate (GtkWidget     *widget,
                               GtkAllocation *allocation)
{
    TimezoneMap *map = TIMEZONEMAP (widget);
    GdkPixbuf *pixbuf;

    if (map->background)
        g_object_unref (map->background);

    if (!gtk_widget_is_sensitive (widget))
        pixbuf = map->orig_background_dim;
    else
        pixbuf = map->orig_background;

    map->background = gdk_pixbuf_scale_simple (pixbuf,
                                               allocation->width,
                                               allocation->height,
                                               GDK_INTERP_BILINEAR);

    if (map->color_map)
        g_object_unref (map->color_map);

    map->color_map = gdk_pixbuf_scale_simple (map->orig_color_map,
                                              allocation->width,
                                              allocation->height,
                                              GDK_INTERP_BILINEAR);

    map->visible_map_pixels = gdk_pixbuf_get_pixels (map->color_map);
    map->visible_map_rowstride = gdk_pixbuf_get_rowstride (map->color_map);
    GTK_WIDGET_CLASS (timezone_map_parent_class)->size_allocate (widget,
                                                                 allocation);
}

static void
cc_timezone_map_realize (GtkWidget *widget)
{
    GdkWindowAttr attr = { 0, };
    GtkAllocation allocation;
    GdkWindow *window;

    gtk_widget_get_allocation (widget, &allocation);

    gtk_widget_set_realized (widget, TRUE);

    attr.window_type = GDK_WINDOW_CHILD;
    attr.wclass = GDK_INPUT_OUTPUT;
    attr.width = allocation.width;
    attr.height = allocation.height;
    attr.x = allocation.x;
    attr.y = allocation.y;
    attr.event_mask = gtk_widget_get_events (widget)
                                 | GDK_EXPOSURE_MASK | GDK_BUTTON_PRESS_MASK;

    window = gdk_window_new (gtk_widget_get_parent_window (widget), &attr,
                             GDK_WA_X | GDK_WA_Y);

    gdk_window_set_user_data (window, widget);
    gtk_widget_set_window (widget, window);
}
static gdouble
convert_longitude_to_x (gdouble longitude, gint map_width)
{
    const gdouble xdeg_offset = -6;
    gdouble x;

    x = (map_width * (180.0 + longitude) / 360.0)
        + (map_width * xdeg_offset / 180.0);

    return x;
}

static gdouble
radians (gdouble degrees)
{
    return (degrees / 360.0) * G_PI * 2;
}

static gdouble
convert_latitude_to_y (gdouble latitude, gdouble map_height)
{
    gdouble bottom_lat = -59;
    gdouble top_lat = 81;
    gdouble top_per, y, full_range, top_offset, map_range;

    top_per = top_lat / 180.0;
    y = 1.25 * log (tan (G_PI_4 + 0.4 * radians (latitude)));
    full_range = 4.6068250867599998;
    top_offset = full_range * top_per;
    map_range = fabs (1.25 * log (tan (G_PI_4 + 0.4 * radians (bottom_lat))) - top_offset);
    y = fabs (y - top_offset);
    y = y / map_range;
    y = y * map_height;
    return y;
}


static void
draw_text_bubble (cairo_t *cr,
                  GtkWidget *widget,
                  gdouble pointx,
                  gdouble pointy)
{
    static const double corner_radius = 9.0;
    static const double margin_top = 12.0;
    static const double margin_bottom = 12.0;
    static const double margin_left = 24.0;
    static const double margin_right = 24.0;

    TimezoneMap *map = TIMEZONEMAP (widget);
    GtkAllocation alloc;
    PangoLayout *layout;
    PangoRectangle text_rect;
    double x;
    double y;
    double width;
    double height;

    if (!map->bubble_text)
        return;

    gtk_widget_get_allocation (widget, &alloc);
    layout = gtk_widget_create_pango_layout (widget, NULL);
    /* Layout the text */
    pango_layout_set_alignment (layout, PANGO_ALIGN_CENTER);
    pango_layout_set_spacing (layout, 3);
    pango_layout_set_markup (layout, map->bubble_text, -1);

    pango_layout_get_pixel_extents (layout, NULL, &text_rect);

    /* Calculate the bubble size based on the text layout size */
    width = text_rect.width + margin_left + margin_right;
    height = text_rect.height + margin_top + margin_bottom;

    if (pointx < alloc.width / 2)
        x = pointx + 25;
    else
        x = pointx - width - 25;

    y = pointy - height / 2;

    /* Make sure it fits in the visible area */
    x = CLAMP (x, 0, alloc.width - width);
    y = CLAMP (y, 0, alloc.height - height);

    cairo_save (cr);
    cairo_translate (cr, x, y);

    /* Draw the bubble */
    cairo_new_sub_path (cr);
    cairo_arc (cr, width - corner_radius, corner_radius, corner_radius, radians (-90), radians (0));
    cairo_arc (cr, width - corner_radius, height - corner_radius, corner_radius, radians (0), radians (90));
    cairo_arc (cr, corner_radius, height - corner_radius, corner_radius, radians (90), radians (180));
    cairo_arc (cr, corner_radius, corner_radius, corner_radius, radians (180), radians (270));
    cairo_close_path (cr);

    cairo_set_source_rgba (cr, 0.2, 0.2, 0.2, 0.7);
    cairo_fill (cr);

    /* And finally draw the text */
    cairo_set_source_rgb (cr, 1, 1, 1);
    cairo_move_to (cr, margin_left, margin_top);
    pango_cairo_show_layout (cr, layout);

    g_object_unref (layout);
    cairo_restore (cr);
}

static gboolean
cc_timezone_map_draw (GtkWidget *widget,
                      cairo_t   *cr)
{
    TimezoneMap *map = TIMEZONEMAP (widget);
    g_autoptr(GdkPixbuf) orig_hilight = NULL;
    GtkAllocation alloc;
    g_autofree gchar *file = NULL;
    g_autoptr(GError) err = NULL;
    gdouble pointx, pointy;
    char buf[16];

    gtk_widget_get_allocation (widget, &alloc);

    /* paint background */
    gdk_cairo_set_source_pixbuf (cr, map->background, 0, 0);
    cairo_paint (cr);

    /* paint hilight */
    if (gtk_widget_is_sensitive (widget))
    {
        file = g_strdup_printf (TIMPZONEDIR"timezone_%s.png",
                                g_ascii_formatd (buf, sizeof (buf),
                               "%g", map->selected_offset));
    }
    else
    {
        file = g_strdup_printf (TIMPZONEDIR"timezone_%s_dim.png",
                                g_ascii_formatd (buf, sizeof (buf),
                               "%g", map->selected_offset));
    }

    orig_hilight = gdk_pixbuf_new_from_file (file, &err);

    if (!orig_hilight)
    {
        g_warning ("Could not load hilight: %s",
                   (err) ? err->message : "Unknown Error");
    }
    else
    {
        g_autoptr(GdkPixbuf) hilight = NULL;

        hilight = gdk_pixbuf_scale_simple (orig_hilight, alloc.width,
                                           alloc.height, GDK_INTERP_BILINEAR);
        gdk_cairo_set_source_pixbuf (cr, hilight, 0, 0);

        cairo_paint (cr);
    }

    if (map->location)
    {
        pointx = convert_longitude_to_x (map->location->longitude, alloc.width);
        pointy = convert_latitude_to_y (map->location->latitude, alloc.height);

        pointx = CLAMP (floor (pointx), 0, alloc.width);
        pointy = CLAMP (floor (pointy), 0, alloc.height);

        draw_text_bubble (cr, widget, pointx, pointy);
        if (map->pin)
        {
            gdk_cairo_set_source_pixbuf (cr, map->pin,
                                         pointx - PIN_HOT_POINT_X,
                                         pointy - PIN_HOT_POINT_Y);
            cairo_paint (cr);
        }
    }

    return TRUE;
}
static void
update_cursor (GtkWidget *widget)
{
    GdkWindow *window;
    g_autoptr(GdkCursor) cursor = NULL;

    if (!gtk_widget_get_realized (widget))
        return;

    if (gtk_widget_is_sensitive (widget))
    {
        GdkDisplay *display;
        display = gtk_widget_get_display (widget);
        cursor = gdk_cursor_new_for_display (display, GDK_HAND2);
    }

    window = gtk_widget_get_window (widget);
    gdk_window_set_cursor (window, cursor);
}

static void
cc_timezone_map_state_flags_changed (GtkWidget     *widget,
                                     GtkStateFlags  prev_state)
{
    update_cursor (widget);

    if (GTK_WIDGET_CLASS (timezone_map_parent_class)->state_flags_changed)
        GTK_WIDGET_CLASS (timezone_map_parent_class)->state_flags_changed (widget, prev_state);
}
static gint sort_locations (TzLocation *a,
                            TzLocation *b)
{
    if (a->dist > b->dist)
        return 1;

    if (a->dist < b->dist)
        return -1;

    return 0;
}

static void
set_location (TimezoneMap   *map,
              TzLocation    *location)
{
    g_autoptr(TzInfo) info = NULL;
    
    map->location = location;
    info = tz_info_from_location (map->location);
    map->selected_offset = tz_location_get_utc_offset (map->location)
                                                      / (60.0*60.0) + 
                                                      ((info->daylight) ? -1.0 : 0.0);
    
    g_signal_emit (map, signals[LOCATION_CHANGED], 0, map->location,NULL);
}

static gboolean
button_press_event (TimezoneMap    *map,
                    GdkEventButton *event)
{
    gint x, y;
    guchar r, g, b, a;
    guchar *pixels;
    gint rowstride;
    guint i;

    const GPtrArray *array;
    gint width, height;
    GList *distances = NULL;
    GtkAllocation alloc;

    x = event->x;
    y = event->y;


    rowstride = map->visible_map_rowstride;
    pixels = map->visible_map_pixels;

    r = pixels[(rowstride * y + x * 4)];
    g = pixels[(rowstride * y + x * 4) + 1];
    b = pixels[(rowstride * y + x * 4) + 2];
    a = pixels[(rowstride * y + x * 4) + 3];


    for (i = 0; color_codes[i].offset != -100; i++)
    {
        if (color_codes[i].red == r && color_codes[i].green == g
           && color_codes[i].blue == b && color_codes[i].alpha == a)
        {
            map->selected_offset = color_codes[i].offset;
        }
    }

    gtk_widget_queue_draw (GTK_WIDGET (map));

  /* work out the co-ordinates */

    array = tz_get_locations (map->tzdb);

    gtk_widget_get_allocation (GTK_WIDGET (map), &alloc);
    width = alloc.width;
    height = alloc.height;

    for (i = 0; i < array->len; i++)
    {
        gdouble pointx, pointy, dx, dy;
        TzLocation *loc = array->pdata[i];

        pointx = convert_longitude_to_x (loc->longitude, width);
        pointy = convert_latitude_to_y (loc->latitude, height);

        dx = pointx - x;
        dy = pointy - y;

        loc->dist = dx * dx + dy * dy;
        distances = g_list_prepend (distances, loc);

    }
    distances = g_list_sort (distances, (GCompareFunc) sort_locations);

    set_location (map, (TzLocation*) distances->data);

    g_list_free (distances);

    return TRUE;
}

static void
timezone_map_class_init (TimezoneMapClass *klass)
{
    GObjectClass *object_class = G_OBJECT_CLASS (klass);
    GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (klass);

    object_class->dispose = cc_timezone_map_dispose;
    object_class->finalize = timezone_map_finalize;

    widget_class->get_preferred_width = cc_timezone_map_get_preferred_width;
    widget_class->get_preferred_height = cc_timezone_map_get_preferred_height;
    widget_class->size_allocate = cc_timezone_map_size_allocate;
    widget_class->realize = cc_timezone_map_realize;
    widget_class->draw = cc_timezone_map_draw;
    widget_class->state_flags_changed = cc_timezone_map_state_flags_changed;
    
    
    signals[LOCATION_CHANGED] = g_signal_new ("location-changed",
                                               TYPE_TIMEZONE_MAP,
                                               G_SIGNAL_RUN_FIRST,
                                               0,
                                               NULL,
                                               NULL,
                                               g_cclosure_marshal_VOID__POINTER,
                                               G_TYPE_NONE, 1,
                                               G_TYPE_POINTER);
}

static void
timezone_map_init (TimezoneMap *map)
{
    GError *err = NULL;
    
    map->orig_background = gdk_pixbuf_new_from_file (TIMPZONEDIR"bg.png",&err);
    if (!map->orig_background)
    {   
        g_warning ("Could not load background image: %s",
                   (err) ? err->message : "Unknown error");
        g_clear_error (&err);
    }
    map->orig_background_dim = gdk_pixbuf_new_from_file(TIMPZONEDIR"bg_dim.png",&err);
    if (!map->orig_background_dim)
    {
        g_warning ("Could not load background image: %s",
                 (err) ? err->message : "Unknown error");
        g_clear_error (&err);
    }

    map->orig_color_map = gdk_pixbuf_new_from_file (TIMPZONEDIR"cc.png",&err);
    if (!map->orig_color_map)
    {
        g_warning ("Could not load background image: %s",
                  (err) ? err->message : "Unknown error");
        g_clear_error (&err);
    }

    map->pin = gdk_pixbuf_new_from_file (TIMPZONEDIR"pin.png",&err);
    if (!map->pin)
    {
        g_warning ("Could not load pin icon: %s",
                  (err) ? err->message : "Unknown error");
        g_clear_error (&err);
    }

    map->tzdb = tz_load_db ();

    g_signal_connect_object (map, 
                            "button-press-event", 
                             G_CALLBACK (button_press_event), 
                             map, 
                             G_CONNECT_SWAPPED);
}
gboolean timezone_map_set_timezone (TimezoneMap *map,
                                    const gchar *timezone)
{
    GPtrArray *locations;
    guint i;
    g_autofree gchar *real_tz = NULL;
    gboolean ret;
    
    real_tz = tz_info_get_clean_name (map->tzdb, timezone);

    locations = tz_get_locations (map->tzdb);
    ret = FALSE;

    for (i = 0; i < locations->len; i++)
    {
        TzLocation *loc = locations->pdata[i];

        if (!g_strcmp0 (loc->zone, real_tz ? real_tz : timezone))
        {
            set_location (map, loc);
            ret = TRUE;
            break;
        }
    }

    if (ret)
        gtk_widget_queue_draw (GTK_WIDGET (map));

    return ret;
}
TzLocation *timezone_map_get_location (TimezoneMap *map)
{  
    return map->location;
}
void timezone_map_set_bubble_text (TimezoneMap *map,
                                   const gchar *text)
{
    g_free (map->bubble_text);
    map->bubble_text = g_strdup (text);
    gtk_widget_queue_draw (GTK_WIDGET (map));
}

TimezoneMap * timezone_map_new (void)
{  
    return g_object_new (TYPE_TIMEZONE_MAP, NULL);
}