#include "xcb.h"

#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xcb/xcb.h>
#include <xcb/xcb_aux.h>
#include <xcb/xcb_ewmh.h>
#include <xcb/xcb_icccm.h>
#include <xcb/xinerama.h>
#include <xcb/xinput.h>
#include <xcb/xproto.h>

#include "app.h"
#include "utils.h"
#include "window.h"
#include "xcb-private.h"

xcb_connection_t *conn = NULL;
xcb_screen_t *screen = NULL;

bool has_other_wm_running(void) {
  conn = xcb_connect(NULL, NULL);
  if (!conn || xcb_connection_has_error(conn)) {
    die("connection:");
  }

  const xcb_setup_t *setup = xcb_get_setup(conn);
  xcb_screen_iterator_t iter = xcb_setup_roots_iterator(setup);
  screen = iter.data;
  printf("screen number: %d\n", iter.rem);
  uint32_t mask = XCB_CW_EVENT_MASK;
  xcb_params_cw_t params = {
    .event_mask = XCB_EVENT_MASK_LEAVE_WINDOW | XCB_EVENT_MASK_ENTER_WINDOW |
                  XCB_EVENT_MASK_POINTER_MOTION |
                  XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT |
                  XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY,
  };
  xcb_void_cookie_t cookie =
    xcb_aux_change_window_attributes(conn, screen->root, mask, &params);
  xcb_generic_error_t *error = xcb_request_check(conn, cookie);
  if (error) {
    xcb_disconnect(conn);
    return true;
  }

  return false;
}

/* xinerama 扩展是否激活 */
static bool xinerama_active(void) {
  const char *name = "XINERAMA";
  xcb_query_extension_cookie_t xinerama_cookie =
    xcb_query_extension(conn, strlen(name), name);
  xcb_query_extension_reply_t *xinerama_reply =
    xcb_query_extension_reply(conn, xinerama_cookie, NULL);

  /* 扩展不存在 */
  if (!xinerama_reply || !xinerama_reply->present) {
    free(xinerama_reply);
    return false;
  }

  xcb_xinerama_is_active_cookie_t active_cookie = xcb_xinerama_is_active(conn);
  xcb_xinerama_is_active_reply_t *active_reply =
    xcb_xinerama_is_active_reply(conn, active_cookie, NULL);
  bool active = active_reply && active_reply->state;
  free(xinerama_reply);
  free(active_reply);
  return active;
}

static monitor_rect_t *detect_monitor_rect_by_xinerama(void) {
  monitor_rect_t *list, *prev;
  xcb_xinerama_query_screens_cookie_t cookie = xcb_xinerama_query_screens(conn);
  xcb_xinerama_query_screens_reply_t *reply =
    xcb_xinerama_query_screens_reply(conn, cookie, NULL);
  xcb_xinerama_screen_info_t *screen_info =
    xcb_xinerama_query_screens_screen_info(reply);

  if (screen_info == NULL) {
    die("no monitor finded");
  }

  int count = xcb_xinerama_query_screens_screen_info_length(reply);
  for (int i = 0; i < count; i++) {
    monitor_rect_t *m = ecalloc(1, sizeof(monitor_rect_t));
    xcb_xinerama_screen_info_t info = screen_info[i];
    m->x = info.x_org;
    m->y = info.y_org;
    m->width = info.width;
    m->height = info.height;
    m->next = NULL;

    if (i == 0) {
      list = m;
    } else {
      prev->next = m;
    }
    prev = m;
  }

  return list;
}

/**
 * 探测屏幕信息
 * @note: 返回值使用完后记得释放其内存
 */
monitor_rect_t *detect_monitor_rect(void) {
  if (xinerama_active()) {
    return detect_monitor_rect_by_xinerama();
  }

  if (!screen) return NULL;

  monitor_rect_t *rect = ecalloc(1, sizeof(monitor_rect_t));
  rect->x = 0;
  rect->y = 0;
  rect->width = screen->width_in_pixels;
  rect->height = screen->height_in_pixels;
  return rect;
}

static xcb_ewmh_connection_t *ewmh = NULL;
static bool ewmh_init_failed = false;
static xcb_window_t wm_check_window = XCB_NONE;
static void init_ewmh_extension(void) {
  if (ewmh || ewmh_init_failed) return;

  ewmh = ecalloc(1, sizeof(xcb_ewmh_connection_t));
  xcb_intern_atom_cookie_t *cookie = xcb_ewmh_init_atoms(conn, ewmh);
  if (!xcb_ewmh_init_atoms_replies(ewmh, cookie, NULL)) {
    free(ewmh);
    ewmh = NULL;
    ewmh_init_failed = true;
    return;
  }

  wm_check_window = xcb_generate_id(conn);
  xcb_create_window(conn, XCB_COPY_FROM_PARENT, wm_check_window, screen->root,
                    0, 0, 1, 1, 0, XCB_WINDOW_CLASS_INPUT_ONLY,
                    screen->root_visual, XCB_NONE, NULL);
  const char *class = APP_NAME "_wm_check";
  set_window_class_instance(wm_check_window, class, class);
  xcb_ewmh_set_wm_name(ewmh, wm_check_window, strlen(APP_NAME), APP_NAME);
  xcb_ewmh_set_supporting_wm_check(ewmh, screen->root, wm_check_window);
  xcb_ewmh_set_supporting_wm_check(ewmh, wm_check_window, wm_check_window);

  uint8_t mode = XCB_PROP_MODE_REPLACE;
  uint8_t format = XCB_INPUT_PROPERTY_FORMAT_32_BITS;
  xcb_atom_t atom = XCB_ATOM_ATOM;
  const xcb_atom_t state[] = {ewmh->_NET_WM_STATE_STICKY};
  const xcb_atom_t supported[] = {
    ewmh->_NET_ACTIVE_WINDOW,
    ewmh->_NET_SUPPORTED,
    ewmh->_NET_WM_NAME,
    ewmh->_NET_WM_STATE,
    ewmh->_NET_SUPPORTING_WM_CHECK,
    ewmh->_NET_WM_STATE_FULLSCREEN,
    ewmh->_NET_WM_WINDOW_TYPE,
    ewmh->_NET_WM_WINDOW_TYPE_DIALOG,
    ewmh->_NET_CLIENT_LIST,
  };
  xcb_change_property(conn, mode, wm_check_window, ewmh->_NET_WM_STATE, atom,
                      format, LENGTH(state), state);
  xcb_change_property(conn, mode, screen->root, ewmh->_NET_SUPPORTED, atom,
                      format, LENGTH(supported), supported);
  xcb_delete_property(conn, screen->root, ewmh->_NET_CLIENT_LIST);
}

/**
 * 扫描窗口列表
 * @returns 若无窗口，返回 NULL，否则返回窗口列表
 * @note: 返回的窗口列表数据使用完后使用 free_window_list 释放
 */
window_list_t *scan_window_list(void) {
  init_ewmh_extension();

  xcb_query_tree_cookie_t cookie = xcb_query_tree(conn, screen->root);
  xcb_query_tree_reply_t *reply = xcb_query_tree_reply(conn, cookie, NULL);
  xcb_window_t *list = xcb_query_tree_children(reply);
  int len = xcb_query_tree_children_length(reply);

  uint32_t count = 0;
  xcb_window_t temp_windoow_array[len];
  for (int i = 0; i < len; i++) {
    xcb_window_t window = list[i];

    xcb_get_window_attributes_cookie_t wa_cookie =
      xcb_get_window_attributes(conn, window);
    xcb_get_window_attributes_reply_t *reply =
      xcb_get_window_attributes_reply(conn, wa_cookie, NULL);
    uint8_t override_redirect = reply->override_redirect;
    uint8_t map_state = reply->map_state;
    free(reply);
    if (override_redirect || map_state != XCB_MAP_STATE_VIEWABLE) continue;

    xcb_window_t transient_for = XCB_NONE;
    xcb_get_property_cookie_t p_cookie =
      xcb_icccm_get_wm_transient_for(conn, window);
    xcb_icccm_get_wm_transient_for_reply(conn, p_cookie, &transient_for, NULL);
    if (transient_for != XCB_NONE) continue;

    temp_windoow_array[count] = window;
    count++;
  }

  if (!count) return NULL;

  xcb_window_t *window_list = ecalloc(count, sizeof(xcb_window_t));
  for (uint32_t i = 0; i < count; i++) window_list[i] = temp_windoow_array[i];

  window_list_t *r = ecalloc(1, sizeof(window_list_t));
  r->count = count;
  r->list = window_list;

  return r;
}

void free_window_list(window_list_t *window_list) {
  if (window_list == NULL) return;
  free(window_list->list);
  free(window_list);
}

void clean_xcb(void) {
  if (wm_check_window != XCB_NONE) {
    xcb_destroy_window(conn, wm_check_window);
    wm_check_window = XCB_NONE;
  }

  if (ewmh) {
    if (!ewmh_init_failed) {
      xcb_ewmh_connection_wipe(ewmh);
    }
    ewmh_init_failed = false;
    ewmh = NULL;
  }

  xcb_disconnect(conn);
  conn = NULL;
  screen = NULL;
}