/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

"use strict";

import nls = require('vs/nls');
import Platform = require('vs/base/common/platform');

/**
 * Virtual Key Codes, the value does not hold any inherent meaning.
 * Inspired somewhat from https://msdn.microsoft.com/en-us/library/windows/desktop/dd375731(v=vs.85).aspx
 * But these are "more general", as they should work across browsers & OS`s
 */
export enum KeyCode {
	/**
	 * Placed first to cover the 0 value of the enum
	 */
	Unknown,

	Backspace,
	Tab,
	Enter,
	Shift,
	Ctrl,
	Alt,
	PauseBreak,
	CapsLock,
	Escape,
	Space,
	PageUp,
	PageDown,
	End,
	Home,
	LeftArrow,
	UpArrow,
	RightArrow,
	DownArrow,
	Insert,
	Delete,

	KEY_0,
	KEY_1,
	KEY_2,
	KEY_3,
	KEY_4,
	KEY_5,
	KEY_6,
	KEY_7,
	KEY_8,
	KEY_9,

	KEY_A,
	KEY_B,
	KEY_C,
	KEY_D,
	KEY_E,
	KEY_F,
	KEY_G,
	KEY_H,
	KEY_I,
	KEY_J,
	KEY_K,
	KEY_L,
	KEY_M,
	KEY_N,
	KEY_O,
	KEY_P,
	KEY_Q,
	KEY_R,
	KEY_S,
	KEY_T,
	KEY_U,
	KEY_V,
	KEY_W,
	KEY_X,
	KEY_Y,
	KEY_Z,

	Meta,
	ContextMenu,

	F1,
	F2,
	F3,
	F4,
	F5,
	F6,
	F7,
	F8,
	F9,
	F10,
	F11,
	F12,

	NumLock,
	ScrollLock,

	/**
	 * For the US standard keyboard, the ';:' key
	 */
	US_SEMICOLON,
	/**
	 * For the US standard keyboard, the '=+' key
	 */
	US_EQUAL,
	/**
	 * For the US standard keyboard, the ',<' key
	 */
	US_COMMA,
	/**
	 * For the US standard keyboard, the '-_' key
	 */
	US_MINUS,
	/**
	 * For the US standard keyboard, the '.>' key
	 */
	US_DOT,
	/**
	 * For the US standard keyboard, the '/?' key
	 */
	US_SLASH,
	/**
	 * For the US standard keyboard, the '`~' key
	 */
	US_BACKTICK,
	/**
	 * For the US standard keyboard, the '[{' key
	 */
	US_OPEN_SQUARE_BRACKET,
	/**
	 * For the US standard keyboard, the '\|' key
	 */
	US_BACKSLASH,
	/**
	 * For the US standard keyboard, the ']}' key
	 */
	US_CLOSE_SQUARE_BRACKET,
	/**
	 * For the US standard keyboard, the ''"' key
	 */
	US_QUOTE
}

let TO_STRING_MAP: string[] = [];
(function() {
	TO_STRING_MAP[KeyCode.Unknown] 		= 'unknown';

	TO_STRING_MAP[KeyCode.Backspace] 	= 'Backspace';
	TO_STRING_MAP[KeyCode.Tab] 			= 'Tab';
	TO_STRING_MAP[KeyCode.Enter] 		= 'Enter';
	TO_STRING_MAP[KeyCode.Shift] 		= 'Shift';
	TO_STRING_MAP[KeyCode.Ctrl] 		= 'Ctrl';
	TO_STRING_MAP[KeyCode.Alt] 			= 'Alt';
	TO_STRING_MAP[KeyCode.PauseBreak] 	= 'PauseBreak';
	TO_STRING_MAP[KeyCode.CapsLock] 	= 'CapsLock';
	TO_STRING_MAP[KeyCode.Escape] 		= 'Escape';
	TO_STRING_MAP[KeyCode.Space] 		= 'Space';
	TO_STRING_MAP[KeyCode.PageUp] 		= 'PageUp';
	TO_STRING_MAP[KeyCode.PageDown] 	= 'PageDown';
	TO_STRING_MAP[KeyCode.End] 			= 'End';
	TO_STRING_MAP[KeyCode.Home] 		= 'Home';
	TO_STRING_MAP[KeyCode.LeftArrow] 	= 'LeftArrow';
	TO_STRING_MAP[KeyCode.UpArrow] 		= 'UpArrow';
	TO_STRING_MAP[KeyCode.RightArrow] 	= 'RightArrow';
	TO_STRING_MAP[KeyCode.DownArrow] 	= 'DownArrow';
	TO_STRING_MAP[KeyCode.Insert] 		= 'Insert';
	TO_STRING_MAP[KeyCode.Delete] 		= 'Delete';

	TO_STRING_MAP[KeyCode.KEY_0] = '0';
	TO_STRING_MAP[KeyCode.KEY_1] = '1';
	TO_STRING_MAP[KeyCode.KEY_2] = '2';
	TO_STRING_MAP[KeyCode.KEY_3] = '3';
	TO_STRING_MAP[KeyCode.KEY_4] = '4';
	TO_STRING_MAP[KeyCode.KEY_5] = '5';
	TO_STRING_MAP[KeyCode.KEY_6] = '6';
	TO_STRING_MAP[KeyCode.KEY_7] = '7';
	TO_STRING_MAP[KeyCode.KEY_8] = '8';
	TO_STRING_MAP[KeyCode.KEY_9] = '9';

	TO_STRING_MAP[KeyCode.KEY_A] = 'A';
	TO_STRING_MAP[KeyCode.KEY_B] = 'B';
	TO_STRING_MAP[KeyCode.KEY_C] = 'C';
	TO_STRING_MAP[KeyCode.KEY_D] = 'D';
	TO_STRING_MAP[KeyCode.KEY_E] = 'E';
	TO_STRING_MAP[KeyCode.KEY_F] = 'F';
	TO_STRING_MAP[KeyCode.KEY_G] = 'G';
	TO_STRING_MAP[KeyCode.KEY_H] = 'H';
	TO_STRING_MAP[KeyCode.KEY_I] = 'I';
	TO_STRING_MAP[KeyCode.KEY_J] = 'J';
	TO_STRING_MAP[KeyCode.KEY_K] = 'K';
	TO_STRING_MAP[KeyCode.KEY_L] = 'L';
	TO_STRING_MAP[KeyCode.KEY_M] = 'M';
	TO_STRING_MAP[KeyCode.KEY_N] = 'N';
	TO_STRING_MAP[KeyCode.KEY_O] = 'O';
	TO_STRING_MAP[KeyCode.KEY_P] = 'P';
	TO_STRING_MAP[KeyCode.KEY_Q] = 'Q';
	TO_STRING_MAP[KeyCode.KEY_R] = 'R';
	TO_STRING_MAP[KeyCode.KEY_S] = 'S';
	TO_STRING_MAP[KeyCode.KEY_T] = 'T';
	TO_STRING_MAP[KeyCode.KEY_U] = 'U';
	TO_STRING_MAP[KeyCode.KEY_V] = 'V';
	TO_STRING_MAP[KeyCode.KEY_W] = 'W';
	TO_STRING_MAP[KeyCode.KEY_X] = 'X';
	TO_STRING_MAP[KeyCode.KEY_Y] = 'Y';
	TO_STRING_MAP[KeyCode.KEY_Z] = 'Z';

	TO_STRING_MAP[KeyCode.ContextMenu] = 'ContextMenu';

	TO_STRING_MAP[KeyCode.F1] = 'F1';
	TO_STRING_MAP[KeyCode.F2] = 'F2';
	TO_STRING_MAP[KeyCode.F3] = 'F3';
	TO_STRING_MAP[KeyCode.F4] = 'F4';
	TO_STRING_MAP[KeyCode.F5] = 'F5';
	TO_STRING_MAP[KeyCode.F6] = 'F6';
	TO_STRING_MAP[KeyCode.F7] = 'F7';
	TO_STRING_MAP[KeyCode.F8] = 'F8';
	TO_STRING_MAP[KeyCode.F9] = 'F9';
	TO_STRING_MAP[KeyCode.F10] = 'F10';
	TO_STRING_MAP[KeyCode.F11] = 'F11';
	TO_STRING_MAP[KeyCode.F12] = 'F12';

	TO_STRING_MAP[KeyCode.NumLock] 		= 'NumLock';
	TO_STRING_MAP[KeyCode.ScrollLock] 	= 'ScrollLock';

	TO_STRING_MAP[KeyCode.US_SEMICOLON] 			= ';';
	TO_STRING_MAP[KeyCode.US_EQUAL] 				= '=';
	TO_STRING_MAP[KeyCode.US_COMMA] 				= ',';
	TO_STRING_MAP[KeyCode.US_MINUS] 				= '-';
	TO_STRING_MAP[KeyCode.US_DOT] 					= '.';
	TO_STRING_MAP[KeyCode.US_SLASH] 				= '/';
	TO_STRING_MAP[KeyCode.US_BACKTICK] 				= '`';
	TO_STRING_MAP[KeyCode.US_OPEN_SQUARE_BRACKET] 	= '[';
	TO_STRING_MAP[KeyCode.US_BACKSLASH] 			= '\\';
	TO_STRING_MAP[KeyCode.US_CLOSE_SQUARE_BRACKET] 	= ']';
	TO_STRING_MAP[KeyCode.US_QUOTE]					= '\'';
})();

let FROM_STRING_MAP: {[str:string]:KeyCode;} = {};
FROM_STRING_MAP['\r'] = KeyCode.Enter;
(function() {
	for (let i = 0, len = TO_STRING_MAP.length; i < len; i++) {
		FROM_STRING_MAP[TO_STRING_MAP[i]] = i;
	}
})();

export namespace KeyCode {
	export function toString(key:KeyCode): string {
		return TO_STRING_MAP[key];
	}
	export function fromString(key:string): KeyCode {
		if (FROM_STRING_MAP.hasOwnProperty(key)) {
			return FROM_STRING_MAP[key];
		}
		return KeyCode.Unknown;
	}
}

// Binary encoding strategy:
// 15:  1 bit for ctrlCmd
// 14:  1 bit for shift
// 13:  1 bit for alt
// 12:  1 bit for winCtrl
//  0: 12 bits for keyCode (up to a maximum keyCode of 4096. Given we have 83 at this point thats good enough)

const BIN_CTRLCMD_MASK = 1 << 15;
const BIN_SHIFT_MASK = 1 << 14;
const BIN_ALT_MASK = 1 << 13;
const BIN_WINCTRL_MASK = 1 << 12;
const BIN_KEYCODE_MASK = 0x00000fff;

export class BinaryKeybindings {

	public static extractFirstPart(keybinding:number): number {
		return keybinding & 0x0000ffff;
	}

	public static extractChordPart(keybinding:number): number {
		return (keybinding >> 16) & 0x0000ffff;
	}

	public static hasChord(keybinding:number): boolean {
		return (this.extractChordPart(keybinding) !== 0);
	}

	public static hasCtrlCmd(keybinding:number): boolean {
		return (keybinding & BIN_CTRLCMD_MASK ? true : false);
	}

	public static hasShift(keybinding:number): boolean {
		return (keybinding & BIN_SHIFT_MASK ? true : false);
	}

	public static hasAlt(keybinding:number): boolean {
		return (keybinding & BIN_ALT_MASK ? true : false);
	}

	public static hasWinCtrl(keybinding:number): boolean {
		return (keybinding & BIN_WINCTRL_MASK ? true : false);
	}

	public static extractKeyCode(keybinding:number): KeyCode {
		return (keybinding & BIN_KEYCODE_MASK);
	}
}



export class KeyMod {
	public static CtrlCmd = BIN_CTRLCMD_MASK;
	public static Shift = BIN_SHIFT_MASK;
	public static Alt = BIN_ALT_MASK;
	public static WinCtrl = BIN_WINCTRL_MASK;

	public static chord(firstPart:number, secondPart:number): number {
		return firstPart | ((secondPart & 0x0000ffff) << 16);
	}
}

/**
 * A set of usual keybindings that can be reused in code
 */
export class CommonKeybindings {

	public static ENTER: number = KeyCode.Enter;
	public static SHIFT_ENTER: number = KeyMod.Shift | KeyCode.Enter;
	public static CTRLCMD_ENTER: number = KeyMod.CtrlCmd | KeyCode.Enter;
	public static WINCTRL_ENTER: number = KeyMod.WinCtrl | KeyCode.Enter;

	public static TAB: number = KeyCode.Tab;
	public static ESCAPE: number = KeyCode.Escape;
	public static SPACE: number = KeyCode.Space;
	public static DELETE: number = KeyCode.Delete;
	public static SHIFT_DELETE: number = KeyMod.Shift | KeyCode.Delete;
	public static CTRLCMD_BACKSPACE: number = KeyMod.CtrlCmd | KeyCode.Backspace;

	public static UP_ARROW: number = KeyCode.UpArrow;
	public static SHIFT_UP_ARROW: number = KeyMod.Shift | KeyCode.UpArrow;
	public static CTRLCMD_UP_ARROW: number = KeyMod.CtrlCmd | KeyCode.UpArrow;

	public static DOWN_ARROW: number = KeyCode.DownArrow;
	public static SHIFT_DOWN_ARROW: number = KeyMod.Shift | KeyCode.DownArrow;
	public static CTRLCMD_DOWN_ARROW: number = KeyMod.CtrlCmd | KeyCode.DownArrow;

	public static LEFT_ARROW: number = KeyCode.LeftArrow;

	public static RIGHT_ARROW: number = KeyCode.RightArrow;

	public static PAGE_UP: number = KeyCode.PageUp;
	public static SHIFT_PAGE_UP: number = KeyMod.Shift | KeyCode.PageUp;

	public static PAGE_DOWN: number = KeyCode.PageDown;
	public static SHIFT_PAGE_DOWN: number = KeyMod.Shift | KeyCode.PageDown;

	public static F2: number = KeyCode.F2;

	public static CTRLCMD_S: number = KeyMod.CtrlCmd | KeyCode.KEY_S;
	public static CTRLCMD_C: number = KeyMod.CtrlCmd | KeyCode.KEY_C;
	public static CTRLCMD_V: number = KeyMod.CtrlCmd | KeyCode.KEY_V;
}

export class Keybinding {

	/**
	 * Format the binding to a format appropiate for rendering in the UI
	 */
	public static toLabel(value:number): string {
		return _asString(value, (Platform.isMacintosh ? MacUIKeyLabelProvider.INSTANCE : ClassicUIKeyLabelProvider.INSTANCE));
	}

	/**
	 * This prints the binding in a format suitable for electron's accelerators.
	 * See https://github.com/atom/electron/blob/master/docs/api/accelerator.md
	 */
	public static toElectronAccelerator(value:number): string {
		if (BinaryKeybindings.hasChord(value)) {
			// Electron cannot handle chords
			return null;
		}
		return _asString(value, ElectronAcceleratorLabelProvider.INSTANCE);
	}

	/**
	 * Format the binding to a format appropiate for the user settings file.
	 */
	public static toUserSettingsLabel(value:number): string {
		return _asString(value, UserSettingsKeyLabelProvider.INSTANCE);
	}

	public value:number;

	constructor(keybinding:number) {
		this.value = keybinding;
	}

	public hasCtrlCmd(): boolean {
		return BinaryKeybindings.hasCtrlCmd(this.value);
	}

	public hasShift(): boolean {
		return BinaryKeybindings.hasShift(this.value);
	}

	public hasAlt(): boolean {
		return BinaryKeybindings.hasAlt(this.value);
	}

	public hasWinCtrl(): boolean {
		return BinaryKeybindings.hasWinCtrl(this.value);
	}

	public extractKeyCode(): KeyCode {
		return BinaryKeybindings.extractKeyCode(this.value);
	}

	/**
	 * Format the binding to a format appropiate for rendering in the UI
	 */
	public toLabel(): string {
		return Keybinding.toLabel(this.value);
	}

	/**
	 * This prints the binding in a format suitable for electron's accelerators.
	 * See https://github.com/atom/electron/blob/master/docs/api/accelerator.md
	 */
	public toElectronAccelerator(): string {
		return Keybinding.toElectronAccelerator(this.value);
	}

	/**
	 * Format the binding to a format appropiate for the user settings file.
	 */
	public toUserSettingsLabel(): string {
		return Keybinding.toUserSettingsLabel(this.value);
	}

}

interface IKeyBindingLabelProvider {
	ctrlKeyLabel:string;
	shiftKeyLabel:string;
	altKeyLabel:string;
	cmdKeyLabel:string;
	windowsKeyLabel:string;
	modifierSeparator:string;
	getLabelForKey(keyCode:KeyCode): string;
}

/**
 * Print for Electron
 */
class ElectronAcceleratorLabelProvider implements IKeyBindingLabelProvider {
	public static INSTANCE = new ElectronAcceleratorLabelProvider();

	public ctrlKeyLabel = 'Ctrl';
	public shiftKeyLabel = 'Shift';
	public altKeyLabel = 'Alt';
	public cmdKeyLabel = 'Cmd';
	public windowsKeyLabel = 'Super';
	public modifierSeparator = '+';

	public getLabelForKey(keyCode:KeyCode): string {
		switch (keyCode) {
			case KeyCode.UpArrow:
				return 'Up';
			case KeyCode.DownArrow:
				return 'Down';
			case KeyCode.LeftArrow:
				return 'Left';
			case KeyCode.RightArrow:
				return 'Right';
		}

		return KeyCode.toString(keyCode);
	}
}

/**
 * Print for Mac UI
 */
class MacUIKeyLabelProvider implements IKeyBindingLabelProvider {
	public static INSTANCE = new MacUIKeyLabelProvider();

	private static leftArrowUnicodeLabel = String.fromCharCode(8592);
	private static upArrowUnicodeLabel = String.fromCharCode(8593);
	private static rightArrowUnicodeLabel = String.fromCharCode(8594);
	private static downArrowUnicodeLabel = String.fromCharCode(8595);

	public ctrlKeyLabel = '\u2303';
	public shiftKeyLabel = '\u21E7';
	public altKeyLabel = '\u2325';
	public cmdKeyLabel = '\u2318';
	public windowsKeyLabel = nls.localize('windowsKey', "Windows");
	public modifierSeparator = '';

	public getLabelForKey(keyCode:KeyCode): string {
		switch (keyCode) {
			case KeyCode.LeftArrow:
				return MacUIKeyLabelProvider.leftArrowUnicodeLabel;
			case KeyCode.UpArrow:
				return MacUIKeyLabelProvider.upArrowUnicodeLabel;
			case KeyCode.RightArrow:
				return MacUIKeyLabelProvider.rightArrowUnicodeLabel;
			case KeyCode.DownArrow:
				return MacUIKeyLabelProvider.downArrowUnicodeLabel;
		}

		return KeyCode.toString(keyCode);
	}
}

/**
 * Print for Windows, Linux UI
 */
class ClassicUIKeyLabelProvider implements IKeyBindingLabelProvider {
	public static INSTANCE = new ClassicUIKeyLabelProvider();

	public ctrlKeyLabel = nls.localize('ctrlKey', "Ctrl");
	public shiftKeyLabel = nls.localize('shiftKey', "Shift");
	public altKeyLabel = nls.localize('altKey', "Alt");
	public cmdKeyLabel = nls.localize('cmdKey', "Command");
	public windowsKeyLabel = nls.localize('windowsKey', "Windows");
	public modifierSeparator = '+';

	public getLabelForKey(keyCode:KeyCode): string {
		return KeyCode.toString(keyCode);
	}
}

/**
 * Print for the user settings file.
 */
class UserSettingsKeyLabelProvider implements IKeyBindingLabelProvider {
	public static INSTANCE = new UserSettingsKeyLabelProvider();

	public ctrlKeyLabel = 'Ctrl';
	public shiftKeyLabel = 'Shift';
	public altKeyLabel = 'Alt';
	public cmdKeyLabel = 'Meta';
	public windowsKeyLabel = 'Meta';

	public modifierSeparator = '+';

	public getLabelForKey(keyCode:KeyCode): string {
		return KeyCode.toString(keyCode);
	}
}

function _asString(keybinding:number, labelProvider:IKeyBindingLabelProvider): string {
	let result:string[] = [],
		ctrlCmd = BinaryKeybindings.hasCtrlCmd(keybinding),
		shift = BinaryKeybindings.hasShift(keybinding),
		alt = BinaryKeybindings.hasAlt(keybinding),
		winCtrl = BinaryKeybindings.hasWinCtrl(keybinding),
		keyCode = BinaryKeybindings.extractKeyCode(keybinding);

	// translate modifier keys: Ctrl-Shift-Alt-Meta
	if ((ctrlCmd && !Platform.isMacintosh) || (winCtrl && Platform.isMacintosh)) {
		result.push(labelProvider.ctrlKeyLabel);
	}

	if (shift) {
		result.push(labelProvider.shiftKeyLabel);
	}

	if (alt) {
		result.push(labelProvider.altKeyLabel);
	}

	if (ctrlCmd && Platform.isMacintosh) {
		result.push(labelProvider.cmdKeyLabel);
	}

	if (winCtrl && !Platform.isMacintosh) {
		result.push(labelProvider.windowsKeyLabel);
	}

	// the actual key
	result.push(labelProvider.getLabelForKey(keyCode));

	var actualResult = result.join(labelProvider.modifierSeparator);

	if (BinaryKeybindings.hasChord(keybinding)) {
		return actualResult + ' ' + _asString(BinaryKeybindings.extractChordPart(keybinding), labelProvider);
	}

	return actualResult;
}