// @flow
import { keyboardKeys } from './keyboard-keys';
import { ALT_SYM, CTRL_SYM, isMac, META_SYM, SHIFT_SYM } from './constants';

/**
 * The readable definition of a hotkey.
 * The {@code id} the hotkey's reference id.
 */
export type HotKeyDefinition = {
  id: string,
  description: string,
};

/**
 * The combination of key presses that will activate a hotkey if pressed.
 */
export type KeyCombination = {
  ctrl: boolean,
  alt: boolean,
  shift: boolean,
  meta: boolean,
  keyCode: number,
};

/**
 * The collection of a hotkey's key combinations for each platforms.
 */
export type KeyBindings = {
  macKeys: Array<KeyCombination>,
  // The key combinations for both Windows and Linux.
  winLinuxKeys: Array<KeyCombination>,
};

/**
 * The collection of defined hotkeys.
 * The registry maps a hotkey by its reference id to its key bindings.
 */
export type HotKeyRegistry = {
  [refId: string]: KeyBindings,
};

function defineHotKey(id: string, description: string): HotKeyDefinition {
  return {
    id: id,
    description: description,
  };
}

function keyComb(
  ctrl: boolean,
  alt: boolean,
  shift: boolean,
  meta: boolean,
  keyCode: number,
): KeyCombination {
  return {
    ctrl: ctrl,
    alt: alt,
    shift: shift,
    meta: meta,
    keyCode: keyCode,
  };
}

function keyBinds(
  mac: KeyCombination | Array<KeyCombination>,
  winLinux: KeyCombination | Array<KeyCombination>,
): KeyBindings {
  if (!Array.isArray(mac)) {
    mac = [mac];
  }

  if (!Array.isArray(winLinux)) {
    winLinux = [winLinux];
  }

  return {
    macKeys: mac,
    winLinuxKeys: winLinux,
  };
}

/**
 * The collection of available hotkeys' and their definitions.
 */
// Not using dot, because NeDB prohibits field names to contain dots.
export const hotKeyRefs = {
  WORKSPACE_SHOW_SETTINGS: defineHotKey('workspace_showSettings', 'Show Workspace Settings'),

  REQUEST_SHOW_SETTINGS: defineHotKey('request_showSettings', 'Show Request Settings'),

  PREFERENCES_SHOW_KEYBOARD_SHORTCUTS: defineHotKey(
    'preferences_showKeyboardShortcuts',
    'Show Keyboard Shortcuts',
  ),

  PREFERENCES_SHOW_GENERAL: defineHotKey('preferences_showGeneral', 'Show App Preferences'),

  TOGGLE_MAIN_MENU: defineHotKey('toggleMainMenu', 'Toggle Main Menu'),

  REQUEST_QUICK_SWITCH: defineHotKey('request_quickSwitch', 'Switch Requests'),

  SHOW_RECENT_REQUESTS: defineHotKey('request_showRecent', 'Show Recent Requests'),

  SHOW_RECENT_REQUESTS_PREVIOUS: defineHotKey(
    'request_showRecentPrevious',
    'Show Recent Requests (Previous)',
  ),

  PLUGIN_RELOAD: defineHotKey('plugin_reload', 'Reload Plugins'),

  SHOW_AUTOCOMPLETE: defineHotKey('showAutocomplete', 'Show Autocomplete'),

  REQUEST_SEND: defineHotKey('request_send', 'Send Request'),

  REQUEST_SHOW_OPTIONS: defineHotKey('request_showOptions', 'Send Request (Options)'),

  ENVIRONMENT_SHOW_EDITOR: defineHotKey('environment_showEditor', 'Show Environment Editor'),

  ENVIRONMENT_SHOW_SWITCH_MENU: defineHotKey('environment_showSwitchMenu', 'Switch Environments'),

  REQUEST_TOGGLE_HTTP_METHOD_MENU: defineHotKey(
    'request_toggleHttpMethodMenu',
    'Change HTTP Method',
  ),

  REQUEST_TOGGLE_HISTORY: defineHotKey('request_toggleHistory', 'Show Request History'),

  REQUEST_FOCUS_URL: defineHotKey('request_focusUrl', 'Focus URL'),

  REQUEST_SHOW_GENERATE_CODE_EDITOR: defineHotKey(
    'request_showGenerateCodeEditor',
    'Generate Code',
  ),

  SIDEBAR_FOCUS_FILTER: defineHotKey('sidebar_focusFilter', 'Filter Sidebar'),

  SIDEBAR_TOGGLE: defineHotKey('sidebar_toggle', 'Toggle Sidebar'),

  RESPONSE_FOCUS: defineHotKey('response_focus', 'Focus Response'),

  SHOW_COOKIES_EDITOR: defineHotKey('showCookiesEditor', 'Edit Cookies'),

  REQUEST_SHOW_CREATE: defineHotKey('request_showCreate', 'Create Request'),

  REQUEST_QUICK_CREATE: defineHotKey('request_quickCreate', 'Create Request (Quick)'),

  REQUEST_SHOW_DELETE: defineHotKey('request_showDelete', 'Delete Request'),

  REQUEST_SHOW_CREATE_FOLDER: defineHotKey('request_showCreateFolder', 'Create Folder'),

  REQUEST_SHOW_DUPLICATE: defineHotKey('request_showDuplicate', 'Duplicate Request'),

  REQUEST_TOGGLE_PIN: defineHotKey('request_togglePin', 'Pin/Unpin Request'),

  CLOSE_DROPDOWN: defineHotKey('closeDropdown', 'Close Dropdown'),

  CLOSE_MODAL: defineHotKey('closeModal', 'Close Modal'),

  ENVIRONMENT_UNCOVER_VARIABLES: defineHotKey('environment_uncoverVariables', 'Uncover Variables'),
};

/**
 * The default key bindings values of all available hotkeys.
 */
const defaultRegistry: HotKeyRegistry = {
  [hotKeyRefs.WORKSPACE_SHOW_SETTINGS.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.comma.keyCode),
    keyComb(true, false, true, false, keyboardKeys.comma.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_SETTINGS.id]: keyBinds(
    keyComb(false, true, true, true, keyboardKeys.comma.keyCode),
    keyComb(true, true, true, false, keyboardKeys.comma.keyCode),
  ),

  [hotKeyRefs.PREFERENCES_SHOW_KEYBOARD_SHORTCUTS.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.forwardslash.keyCode),
    keyComb(true, false, true, false, keyboardKeys.forwardslash.keyCode),
  ),

  [hotKeyRefs.PREFERENCES_SHOW_GENERAL.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.comma.keyCode),
    keyComb(true, false, false, false, keyboardKeys.comma.keyCode),
  ),

  [hotKeyRefs.TOGGLE_MAIN_MENU.id]: keyBinds(
    keyComb(false, true, false, true, keyboardKeys.comma.keyCode),
    keyComb(true, true, false, false, keyboardKeys.comma.keyCode),
  ),

  [hotKeyRefs.REQUEST_QUICK_SWITCH.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.p.keyCode),
    keyComb(true, false, false, false, keyboardKeys.p.keyCode),
  ),

  [hotKeyRefs.SHOW_RECENT_REQUESTS.id]: keyBinds(
    keyComb(true, false, false, false, keyboardKeys.tab.keyCode),
    keyComb(true, false, false, false, keyboardKeys.tab.keyCode),
  ),

  [hotKeyRefs.SHOW_RECENT_REQUESTS_PREVIOUS.id]: keyBinds(
    keyComb(true, false, true, false, keyboardKeys.tab.keyCode),
    keyComb(true, false, true, false, keyboardKeys.tab.keyCode),
  ),

  [hotKeyRefs.PLUGIN_RELOAD.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.r.keyCode),
    keyComb(true, false, true, false, keyboardKeys.r.keyCode),
  ),

  [hotKeyRefs.SHOW_AUTOCOMPLETE.id]: keyBinds(
    keyComb(true, false, false, false, keyboardKeys.space.keyCode),
    keyComb(true, false, false, false, keyboardKeys.space.keyCode),
  ),

  [hotKeyRefs.REQUEST_SEND.id]: keyBinds(
    [
      keyComb(false, false, false, true, keyboardKeys.enter.keyCode),
      keyComb(false, false, false, true, keyboardKeys.r.keyCode),
      keyComb(false, false, false, false, keyboardKeys.f5.keyCode),
    ],
    [
      keyComb(true, false, false, false, keyboardKeys.enter.keyCode),
      keyComb(true, false, false, false, keyboardKeys.r.keyCode),
      keyComb(false, false, false, false, keyboardKeys.f5.keyCode),
    ],
  ),

  [hotKeyRefs.REQUEST_SHOW_OPTIONS.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.enter.keyCode),
    keyComb(true, false, true, false, keyboardKeys.enter.keyCode),
  ),

  [hotKeyRefs.ENVIRONMENT_SHOW_EDITOR.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.e.keyCode),
    keyComb(true, false, false, false, keyboardKeys.e.keyCode),
  ),

  [hotKeyRefs.ENVIRONMENT_SHOW_SWITCH_MENU.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.e.keyCode),
    keyComb(true, false, true, false, keyboardKeys.e.keyCode),
  ),

  [hotKeyRefs.REQUEST_TOGGLE_HTTP_METHOD_MENU.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.l.keyCode),
    keyComb(true, false, true, false, keyboardKeys.l.keyCode),
  ),

  [hotKeyRefs.REQUEST_TOGGLE_HISTORY.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.h.keyCode),
    keyComb(true, false, true, false, keyboardKeys.h.keyCode),
  ),

  [hotKeyRefs.REQUEST_FOCUS_URL.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.l.keyCode),
    keyComb(true, false, false, false, keyboardKeys.l.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_GENERATE_CODE_EDITOR.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.g.keyCode),
    keyComb(true, false, true, false, keyboardKeys.g.keyCode),
  ),

  [hotKeyRefs.SIDEBAR_FOCUS_FILTER.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.f.keyCode),
    keyComb(true, false, true, false, keyboardKeys.f.keyCode),
  ),

  [hotKeyRefs.SIDEBAR_TOGGLE.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.backslash.keyCode),
    keyComb(true, false, false, false, keyboardKeys.backslash.keyCode),
  ),

  [hotKeyRefs.RESPONSE_FOCUS.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.singlequote.keyCode),
    keyComb(true, false, false, false, keyboardKeys.singlequote.keyCode),
  ),

  [hotKeyRefs.SHOW_COOKIES_EDITOR.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.k.keyCode),
    keyComb(true, false, false, false, keyboardKeys.k.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_CREATE.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.n.keyCode),
    keyComb(true, false, false, false, keyboardKeys.n.keyCode),
  ),

  [hotKeyRefs.REQUEST_QUICK_CREATE.id]: keyBinds(
    keyComb(false, true, false, true, keyboardKeys.n.keyCode),
    keyComb(true, true, false, false, keyboardKeys.n.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_DELETE.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.delete.keyCode),
    keyComb(true, false, true, false, keyboardKeys.delete.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_CREATE_FOLDER.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.n.keyCode),
    keyComb(true, false, true, false, keyboardKeys.n.keyCode),
  ),

  [hotKeyRefs.REQUEST_SHOW_DUPLICATE.id]: keyBinds(
    keyComb(false, false, false, true, keyboardKeys.d.keyCode),
    keyComb(true, false, false, false, keyboardKeys.d.keyCode),
  ),

  [hotKeyRefs.REQUEST_TOGGLE_PIN.id]: keyBinds(
    keyComb(false, false, true, true, keyboardKeys.p.keyCode),
    keyComb(true, false, true, false, keyboardKeys.p.keyCode),
  ),

  [hotKeyRefs.CLOSE_DROPDOWN.id]: keyBinds(
    keyComb(false, false, false, false, keyboardKeys.esc.keyCode),
    keyComb(false, false, false, false, keyboardKeys.esc.keyCode),
  ),

  [hotKeyRefs.CLOSE_MODAL.id]: keyBinds(
    keyComb(false, false, false, false, keyboardKeys.esc.keyCode),
    keyComb(false, false, false, false, keyboardKeys.esc.keyCode),
  ),

  [hotKeyRefs.ENVIRONMENT_UNCOVER_VARIABLES.id]: keyBinds(
    keyComb(false, true, true, false, keyboardKeys.u.keyCode),
    keyComb(false, true, true, false, keyboardKeys.u.keyCode),
  ),
};

function copyKeyCombs(sources: Array<KeyCombination>): Array<KeyCombination> {
  let targets: Array<KeyCombination> = [];
  sources.forEach(keyComb => {
    targets.push(Object.assign({}, keyComb));
  });
  return targets;
}

/**
 * Get a new copy of key bindings with default key combinations.
 * @param hotKeyRefId
 * @returns {KeyBindings}
 */
export function newDefaultKeyBindings(hotKeyRefId: string): KeyBindings {
  const keyBindings: KeyBindings = defaultRegistry[hotKeyRefId];
  return {
    macKeys: copyKeyCombs(keyBindings.macKeys),
    winLinuxKeys: copyKeyCombs(keyBindings.winLinuxKeys),
  };
}

/**
 * Get a new copy of hotkey registry with default values.
 * @returns {HotKeyRegistry}
 */
export function newDefaultRegistry(): HotKeyRegistry {
  let newDefaults: HotKeyRegistry = {};
  for (const refId in defaultRegistry) {
    if (!defaultRegistry.hasOwnProperty(refId)) {
      continue;
    }
    newDefaults[refId] = newDefaultKeyBindings(refId);
  }
  return newDefaults;
}

/**
 * Get the key combinations based on the current platform.
 * @param bindings
 * @returns {Array<KeyCombination>}
 */
export function getPlatformKeyCombinations(bindings: KeyBindings): Array<KeyCombination> {
  if (isMac()) {
    return bindings.macKeys;
  }
  return bindings.winLinuxKeys;
}

/**
 * Determine whether two key combinations are the same by comparing each of their keys.
 * @param keyComb1
 * @param keyComb2
 * @returns {boolean}
 */
export function areSameKeyCombinations(
  keyComb1: KeyCombination,
  keyComb2: KeyCombination,
): boolean {
  return (
    keyComb1.alt === keyComb2.alt &&
    keyComb1.shift === keyComb2.shift &&
    keyComb1.ctrl === keyComb2.ctrl &&
    keyComb1.meta === keyComb2.meta &&
    keyComb1.keyCode === keyComb2.keyCode
  );
}

/**
 * Checks whether the given key bindings is the same as the default one,
 * identified with hot key reference id.
 * @param hotKeyRefId refers to the default key bindings to check.
 * @param keyBinds to check with the default ones.
 * @returns {boolean}
 */
export function areKeyBindingsSameAsDefault(hotKeyRefId: string, keyBinds: KeyBindings): boolean {
  const keyCombs = getPlatformKeyCombinations(keyBinds);
  const defaultKeyCombs = getPlatformKeyCombinations(defaultRegistry[hotKeyRefId]);
  if (keyCombs.length !== defaultKeyCombs.length) {
    return false;
  }
  for (const keyComb of keyCombs) {
    const found = defaultKeyCombs.find(defKeyComb => {
      if (areSameKeyCombinations(keyComb, defKeyComb)) {
        return true;
      }
    });
    if (found == null) {
      return false;
    }
  }
  return true;
}

/**
 * Gets the displayed text of a key code.
 * @param keyCode
 * @returns {string}
 */
export function getChar(keyCode: number): string {
  let char;
  const key = Object.keys(keyboardKeys).find(k => keyboardKeys[k].keyCode === keyCode);

  if (!key) {
    console.error('Invalid key code', keyCode);
  } else {
    char = keyboardKeys[key].label;
  }

  return char || 'unknown';
}

function joinHotKeys(mustUsePlus: boolean, keys: Array<string>): string {
  if (!mustUsePlus && isMac()) {
    return keys.join('');
  }
  return keys.join('+');
}

/**
 * Check whether key code is a modifier key, i.e., alt, shift, ctrl, or meta.
 * @param keyCode
 * @returns {boolean}
 */
export function isModifierKeyCode(keyCode: number): boolean {
  return (
    keyCode === keyboardKeys.alt.keyCode ||
    keyCode === keyboardKeys.shift.keyCode ||
    keyCode === keyboardKeys.ctrl.keyCode ||
    // Meta keys.
    keyCode === keyboardKeys.leftwindowkey.keyCode ||
    keyCode === keyboardKeys.rightwindowkey.keyCode ||
    keyCode === keyboardKeys.selectkey.keyCode
  );
}

/**
 * Construct the display string of a key combination based on platform.
 * For example, the display of alt in Windows or Linux would be "Alt";
 * while in Mac would be "⌥".
 * @param keyComb
 * @param mustUsePlus if true will join the characters with "+" for all platforms;
 * otherwise if the platform is Mac, the characters will be next to each other.
 * @returns the constructed string, if keyCode is null and the characters are joint with "+",
 * it will have a dangling "+" as the last character, e.g., "Alt+Ctrl+".
 */
export function constructKeyCombinationDisplay(
  keyComb: KeyCombination,
  mustUsePlus: boolean,
): string {
  const { ctrl, alt, shift, meta, keyCode } = keyComb;
  const chars = [];

  alt && chars.push(ALT_SYM);
  shift && chars.push(SHIFT_SYM);
  ctrl && chars.push(CTRL_SYM);
  meta && chars.push(META_SYM);
  if (keyCode != null && !isModifierKeyCode(keyCode)) {
    chars.push(getChar(keyCode));
  }

  let joint = joinHotKeys(mustUsePlus, chars);
  if (mustUsePlus && isModifierKeyCode(keyCode)) {
    joint += '+';
  }
  return joint;
}

/**
 * Construct the display string for a key combination
 *
 * @param hotKeyDef
 * @param hotKeyRegistry
 * @param mustUsePlus
 * @returns {string} – key combination as string or empty string if not found
 */
export function getHotKeyDisplay(
  hotKeyDef: HotKeyDefinition,
  hotKeyRegistry: HotKeyRegistry,
  mustUsePlus: boolean,
) {
  const hotKey: ?KeyBindings = hotKeyRegistry[hotKeyDef.id];
  if (!hotKey) {
    return '';
  }

  const keyCombs: Array<KeyCombination> = getPlatformKeyCombinations(hotKey);
  if (keyCombs.length === 0) {
    return '';
  }

  return constructKeyCombinationDisplay(keyCombs[0], mustUsePlus);
}