// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/global_keyboard_shortcuts_mac.h"

#import <AppKit/AppKit.h>

#include "base/logging.h"
#include "base/macros.h"
#include "chrome/app/chrome_command_ids.h"
#import "chrome/browser/ui/cocoa/nsmenuitem_additions.h"

namespace {

// Returns the menu item associated with |key| in |menu|, or nil if not found.
NSMenuItem* FindMenuItem(NSEvent* key, NSMenu* menu) {
  NSMenuItem* result = nil;

  for (NSMenuItem* item in [menu itemArray]) {
    NSMenu* submenu = [item submenu];
    if (submenu) {
      if (submenu != [NSApp servicesMenu])
        result = FindMenuItem(key, submenu);
    } else if ([item cr_firesForKeyEventIfEnabled:key]) {
      result = item;
    }

    if (result)
      break;
  }

  return result;
}

bool MatchesEventForKeyboardShortcut(const KeyboardShortcutData& shortcut,
                                     bool command_key,
                                     bool shift_key,
                                     bool cntrl_key,
                                     bool opt_key,
                                     int vkey_code,
                                     unichar key_char) {
  // Expects that one of |key_char| or |vkey_code| is 0.
  DCHECK((shortcut.key_char == 0) ^ (shortcut.vkey_code == 0));
  if (shortcut.key_char) {
    // Shortcuts that have a |key_char| and have |opt_key| set are mistakes,
    // since |opt_key| is not checked when there is a |key_char|.
    DCHECK(!shortcut.opt_key);
    // The given shortcut key is to be matched by a keyboard character.
    // In this case we ignore shift and opt (alt) key modifiers, because
    // the character may be generated by a combination with those keys.
    if (shortcut.command_key == command_key &&
        shortcut.cntrl_key == cntrl_key &&
        shortcut.key_char == key_char)
      return true;
  } else if (shortcut.vkey_code) {
    // The given shortcut key is to be matched by a virtual key code.
    if (shortcut.command_key == command_key &&
        shortcut.shift_key == shift_key &&
        shortcut.cntrl_key == cntrl_key &&
        shortcut.opt_key == opt_key &&
        shortcut.vkey_code == vkey_code)
      return true;
  } else {
    NOTREACHED();  // Shouldn't happen.
  }
  return false;
}

int CommandForKeyboardShortcut(const std::vector<KeyboardShortcutData>& table,
                               bool command_key,
                               bool shift_key,
                               bool cntrl_key,
                               bool opt_key,
                               int vkey_code,
                               unichar key_char) {
  // Scan through keycodes and see if it corresponds to one of the global
  // shortcuts on file.
  //
  // TODO(jeremy): Change this into a hash table once we get enough
  // entries in the array to make a difference.
  // (When turning this into a hash table, note that the current behavior
  // relies on the order of the table (see the comment for '{' / '}' above).
  for (const auto& shortcut : table) {
    if (MatchesEventForKeyboardShortcut(shortcut, command_key, shift_key,
                                        cntrl_key, opt_key, vkey_code,
                                        key_char))
      return shortcut.chrome_command;
  }

  return -1;
}

}  // namespace

int CommandForWindowKeyboardShortcut(
    bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
    int vkey_code, unichar key_char) {
  return CommandForKeyboardShortcut(GetWindowKeyboardShortcutTable(),
                                    command_key, shift_key,
                                    cntrl_key, opt_key, vkey_code,
                                    key_char);
}

int CommandForDelayedWindowKeyboardShortcut(
    bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
    int vkey_code, unichar key_char) {
  return CommandForKeyboardShortcut(GetDelayedWindowKeyboardShortcutTable(),
                                    command_key, shift_key,
                                    cntrl_key, opt_key, vkey_code,
                                    key_char);
}

int CommandForBrowserKeyboardShortcut(
    bool command_key, bool shift_key, bool cntrl_key, bool opt_key,
    int vkey_code, unichar key_char) {
  return CommandForKeyboardShortcut(GetBrowserKeyboardShortcutTable(),
                                    command_key, shift_key,
                                    cntrl_key, opt_key, vkey_code,
                                    key_char);
}

int CommandForKeyEvent(NSEvent* event) {
  if ([event type] != NSKeyDown)
    return -1;

  // Look in menu.
  NSMenuItem* item = FindMenuItem(event, [NSApp mainMenu]);
  if (item && [item action] == @selector(commandDispatch:) && [item tag] > 0)
    return [item tag];

  // "Close window" doesn't use the |commandDispatch:| mechanism. Menu items
  // that do not correspond to IDC_ constants need no special treatment however,
  // as they can't be blacklisted in
  // |BrowserCommandController::IsReservedCommandOrKey()| anyhow.
  if (item && [item action] == @selector(performClose:))
    return IDC_CLOSE_WINDOW;

  // "Exit" doesn't use the |commandDispatch:| mechanism either.
  if (item && [item action] == @selector(terminate:))
    return IDC_EXIT;

  // Look in secondary keyboard shortcuts.
  NSUInteger modifiers = [event modifierFlags];
  const bool cmdKey = (modifiers & NSCommandKeyMask) != 0;
  const bool shiftKey = (modifiers & NSShiftKeyMask) != 0;
  const bool cntrlKey = (modifiers & NSControlKeyMask) != 0;
  const bool optKey = (modifiers & NSAlternateKeyMask) != 0;
  const int keyCode = [event keyCode];
  const unichar keyChar = KeyCharacterForEvent(event);

  int cmdNum = CommandForWindowKeyboardShortcut(
      cmdKey, shiftKey, cntrlKey, optKey, keyCode, keyChar);
  if (cmdNum != -1)
    return cmdNum;

  cmdNum = CommandForBrowserKeyboardShortcut(
      cmdKey, shiftKey, cntrlKey, optKey, keyCode, keyChar);
  if (cmdNum != -1)
    return cmdNum;

  return -1;
}

unichar KeyCharacterForEvent(NSEvent* event) {
  NSString* eventString = [event charactersIgnoringModifiers];
  NSString* characters = [event characters];

  if ([eventString length] != 1)
    return 0;

  if ([characters length] != 1)
    return [eventString characterAtIndex:0];

  // Some characters are BiDi mirrored.  The mirroring is different
  // for different OS versions.  Instead of having a mirror table, map
  // raw/processed pairs to desired outputs.
  const struct {
    unichar rawChar;
    unichar unmodChar;
    unichar targetChar;
  } kCharMapping[] = {
    // OSX 10.8 mirrors certain chars.
    {'{', '}', '{'},
    {'}', '{', '}'},
    {'(', ')', '('},
    {')', '(', ')'},

    // OSX 10.9 has the unshifted raw char.
    {'[', '}', '{'},
    {']', '{', '}'},
    {'9', ')', '('},
    {'0', '(', ')'},

    // These are the same either way.
    {'[', ']', '['},
    {']', '[', ']'},
  };

  unichar noModifiersChar = [eventString characterAtIndex:0];
  unichar rawChar = [characters characterAtIndex:0];

  // Only apply transformation table for ascii.
  if (isascii(noModifiersChar) && isascii(rawChar)) {
    // Alphabetic characters aren't mirrored, go with the raw character.
    // [A previous partial comment said something about Dvorak?]
    if (isalpha(rawChar))
      return rawChar;

    // http://crbug.com/42517
    // http://crbug.com/315379
    // In RTL keyboard layouts, Cocoa mirrors characters in the string
    // returned by [event charactersIgnoringModifiers].  In this case, return
    // the raw (unmirrored) char.
    for (size_t i = 0; i < arraysize(kCharMapping); ++i) {
      if (rawChar == kCharMapping[i].rawChar &&
          noModifiersChar == kCharMapping[i].unmodChar) {
        return kCharMapping[i].targetChar;
      }
    }

    // opt/alt modifier is set (e.g. on german layout we want '{' for opt-8).
    if ([event modifierFlags] & NSAlternateKeyMask)
      return rawChar;
  }

  return noModifiersChar;
}