#include <curses.h>
#include <dirent.h>
#include <gtk-3.0/gtk/gtk.h>
#include <libgen.h>
#include <stdlib.h>
#include <string.h>

#include "dir.h"

#define TIMEOUT 20
#define ZOOM_FACTOR 0.1

enum scale_mode {
    fit = 0,
    zoomed = 1,
};

GtkWidget *window;
GtkWidget *image;
GdkPixbuf *pixbuf;
GdkPixbuf *curr_pixbuf;
int pixbuf_width, pixbuf_height;
double aspect_ratio;
double curr_zoom = 1.0;
enum scale_mode curr_scale_mod;
GError *error = NULL;

char *curr_file_name;
GDir *dir;
char **file_list;
int curr_file_index, file_list_count;

void print_supported_formats()
{
    GSList *list, *it;
    GdkPixbufFormat *format;
    gchar **extensions;
    gchar *ex;

    list = gdk_pixbuf_get_formats();
    if (list != NULL) {
        for (it = list; it->next != NULL; it = it->next) {
            format = (GdkPixbufFormat *)it->data;
            g_print("%s:", gdk_pixbuf_format_get_description(format));
            extensions = gdk_pixbuf_format_get_extensions(format);
            for (ex = *extensions; *ex; ex++) {
                g_print(" %s", ex);
            }
            g_print("\n");
        }
        g_slist_free(list);
    }
}

void fit_image()
{
    gint win_width, win_height;
    gint new_pixbuf_width, new_pixbuf_height;
    gtk_window_get_size(GTK_WINDOW(window), &win_width, &win_height);

    if (win_width < pixbuf_width && win_height > pixbuf_height) {
        new_pixbuf_width = win_width;
        new_pixbuf_height = (double)new_pixbuf_width / aspect_ratio;
    } else if (win_width > pixbuf_width && win_height < pixbuf_height) {
        new_pixbuf_height = win_height;
        new_pixbuf_width = (double)new_pixbuf_height * aspect_ratio;
    } else if (win_width < pixbuf_width && win_height < pixbuf_height) {
        if (((double)win_width / (double)win_height) > aspect_ratio) {
            new_pixbuf_height = win_height;
            new_pixbuf_width = ((double)new_pixbuf_height * aspect_ratio);
        } else {
            new_pixbuf_width = win_width;
            new_pixbuf_height = (double)new_pixbuf_width / aspect_ratio;
        }
    } else {
        new_pixbuf_width = pixbuf_width;
        new_pixbuf_height = pixbuf_height;
    }

    curr_zoom = (double)new_pixbuf_width / (double)pixbuf_width;
    if (curr_pixbuf != NULL)
        g_object_unref(curr_pixbuf);
    curr_pixbuf =
        gdk_pixbuf_scale_simple(GDK_PIXBUF(pixbuf), new_pixbuf_width,
                                new_pixbuf_height, GDK_INTERP_BILINEAR);
    gtk_image_set_from_pixbuf(GTK_IMAGE(image), GDK_PIXBUF(curr_pixbuf));
}

void next()
{
    if (curr_file_index >= file_list_count - 1) {
        return;
    }
    curr_file_index++;
    curr_file_name = file_list[curr_file_index];
    g_print("qwe2: %s\n", curr_file_name);
    g_object_unref(pixbuf);
    pixbuf = gdk_pixbuf_new_from_file(curr_file_name, &error);
    if (error) {
        g_warning("gdk_pixbuf_new_from_file() failed with error: %s\n",
                  error->message);
        g_clear_error(&error);
        return;
    }
    pixbuf_width = gdk_pixbuf_get_width(GDK_PIXBUF(pixbuf));
    pixbuf_height = gdk_pixbuf_get_height(GDK_PIXBUF(pixbuf));
    aspect_ratio = (double)pixbuf_width / (double)pixbuf_height;
    curr_zoom = 1.0;
    fit_image();
}

void prev()
{
    if (curr_file_index <= 0) {
        return;
    }
    curr_file_index--;
    curr_file_name = file_list[curr_file_index];
    g_print("qwe2: %s\n", curr_file_name);
    g_object_unref(pixbuf);
    pixbuf = gdk_pixbuf_new_from_file(curr_file_name, &error);
    if (error) {
        g_warning("gdk_pixbuf_new_from_file() failed with error: %s\n",
                  error->message);
        g_clear_error(&error);
        return;
    }
    pixbuf_width = gdk_pixbuf_get_width(GDK_PIXBUF(pixbuf));
    pixbuf_height = gdk_pixbuf_get_height(GDK_PIXBUF(pixbuf));
    aspect_ratio = (double)pixbuf_width / (double)pixbuf_height;
    curr_zoom = 1.0;
    fit_image();
}

void zoom(int type)
{
    if (type == 0) {
        if (curr_zoom == 1.0)
            return;
        curr_zoom = (double)1.0;
    } else if (type < 0) {
        if (curr_zoom < 0.2)
            return;
        curr_zoom -= (double)ZOOM_FACTOR;
    } else if (type > 0) {
        if (curr_zoom > 2)
            return;
        curr_zoom += (double)ZOOM_FACTOR;
    }
    if (curr_pixbuf != NULL)
        g_object_unref(curr_pixbuf);
    curr_pixbuf =
        gdk_pixbuf_scale_simple(GDK_PIXBUF(pixbuf), pixbuf_width * curr_zoom,
                                pixbuf_height * curr_zoom, GDK_INTERP_BILINEAR);
    gtk_image_set_from_pixbuf(GTK_IMAGE(image), GDK_PIXBUF(curr_pixbuf));
}

static gboolean key_press(GtkWindow *window, GdkEvent *event, gpointer data)
{
    switch (event->key.keyval) {
    case GDK_KEY_q:
        g_application_quit(
            G_APPLICATION(gtk_window_get_application(GTK_WINDOW(window))));
        return FALSE;
    case GDK_KEY_w:
        curr_scale_mod = fit;
        fit_image();
        return FALSE;
    case GDK_KEY_plus:
        zoom(1);
        return FALSE;
    case GDK_KEY_minus:
        zoom(-1);
        return FALSE;
    case GDK_KEY_equal:
        zoom(0);
        return FALSE;
    case GDK_KEY_n:
    case GDK_KEY_j:
        next();
        return FALSE;
    case GDK_KEY_p:
    case GDK_KEY_k:
        prev();
        return FALSE;
    default:
        return TRUE;
    }
}

gboolean scroll_callback(GtkWindow *window, GdkEvent *event, gpointer data)
{
    GdkModifierType state;
    gdk_event_get_state(event, &state);
    if (state & GDK_CONTROL_MASK && event->scroll.direction == GDK_SCROLL_UP) {
        zoom(1);
        curr_scale_mod = zoomed;
        return FALSE;
    } else if (state & GDK_CONTROL_MASK &&
               event->scroll.direction == GDK_SCROLL_DOWN) {
        zoom(-1);
        curr_scale_mod = zoomed;
        return FALSE;
    }
    return TRUE;
}

gboolean resize_done(gpointer data)
{
    guint *id = data;
    *id = 0;
    fit_image();
    return FALSE;
}

gboolean configure_callback(GtkWindow *window, GdkEvent *event, gpointer data)
{
    if (curr_scale_mod != fit) {
        return FALSE;
    }
    static guint id = 0;
    if (id)
        g_source_remove(id);
    id = g_timeout_add(TIMEOUT, resize_done, &id);
    return FALSE;
}

static void activate(GtkApplication *app, gpointer user_data)
{
    window = gtk_application_window_new(app);
    gtk_window_set_title(GTK_WINDOW(window), "qwe");
    gtk_window_set_default_size(GTK_WINDOW(window), 800, 600);
    g_signal_connect(G_OBJECT(window), "configure-event",
                     G_CALLBACK(configure_callback), NULL);
    g_signal_connect(G_OBJECT(window), "key-press-event", G_CALLBACK(key_press),
                     NULL);
    gtk_widget_add_events(GTK_WIDGET(window), GDK_SCROLL_MASK);
    g_signal_connect(G_OBJECT(window), "scroll-event",
                     G_CALLBACK(scroll_callback), NULL);

    char *curr_filename =
        "/home/nirav/Downloads/Saved Pictures/bash help shortcuts.png";

    curr_file_index = scan(curr_filename, &file_list, &file_list_count);
    printf("num %d %d\n", curr_file_index, file_list_count);
    printf("file %s\n", file_list[curr_file_index]);

    pixbuf = gdk_pixbuf_new_from_file(curr_filename, &error);
    if (error) {
        g_warning("gdk_pixbuf_new_from_file() failed with error: %s\n",
                  error->message);
        g_clear_error(&error);
        return;
    }
    pixbuf_width = gdk_pixbuf_get_width(GDK_PIXBUF(pixbuf));
    pixbuf_height = gdk_pixbuf_get_height(GDK_PIXBUF(pixbuf));
    aspect_ratio = (double)pixbuf_width / (double)pixbuf_height;

    image = gtk_image_new_from_pixbuf(GDK_PIXBUF(pixbuf));
    GtkWidget *scrolled_window = gtk_scrolled_window_new(NULL, NULL);
    gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scrolled_window),
                                   GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
    gtk_container_add(GTK_CONTAINER(scrolled_window), GTK_WIDGET(image));
    gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(scrolled_window));
    gtk_widget_show_all(GTK_WIDGET(window));
}

int main(int argc, char *argv[])
{
    GtkApplication *app;
    int status;
    app = gtk_application_new("org.gtk.qwe", G_APPLICATION_FLAGS_NONE);
    g_signal_connect(app, "activate", G_CALLBACK(activate), NULL);
    status = g_application_run(G_APPLICATION(app), argc, argv);
    g_object_unref(app);
    return status;
}