import { byte, DeepMemberOf, KnownKeys } from '../types';
import Apple2IO from '../apple2io';
import CPU6502 from '../cpu6502';
import { debug, toHex } from '../util';

// keycode: [plain, cntl, shift]
const keymap = {
    // Most of these won't happen
    0x00: [0x00, 0x00, 0x00], //
    0x01: [0x01, 0x01, 0x01], //
    0x02: [0x02, 0x02, 0x02], //
    0x03: [0x03, 0x03, 0x03], //
    0x04: [0x04, 0x04, 0x04], //
    0x05: [0x05, 0x05, 0x05], //
    0x06: [0x06, 0x06, 0x06], //
    0x07: [0x07, 0x07, 0x07], //
    0x08: [0x7F, 0x7F, 0x7F], // BS/DELETE
    0x09: [0x09, 0x09, 0x09], // TAB
    0x0A: [0x0A, 0x0A, 0x0A], //
    0x0B: [0x0B, 0x0B, 0x0B], //
    0x0C: [0x0C, 0x0C, 0x0C], //
    0x0D: [0x0D, 0x0D, 0x0D], // CR
    0x0E: [0x0E, 0x0E, 0x0E], //
    0x0F: [0x0F, 0x0F, 0x0F], //

    0x10: [0xff, 0xff, 0xff], // SHIFT
    0x11: [0xff, 0xff, 0xff], // CTRL
    0x12: [0xff, 0xff, 0xff], // ALT/OPTION
    0x13: [0x13, 0x13, 0x13], //
    0x14: [0x14, 0x14, 0x14], //
    0x15: [0x15, 0x15, 0x15], //
    0x16: [0x16, 0x16, 0x16], //
    0x17: [0x17, 0x17, 0x18], //
    0x18: [0x18, 0x18, 0x18], //
    0x19: [0x19, 0x19, 0x19], //
    0x1A: [0x1A, 0x1A, 0x1A], //
    0x1B: [0x1B, 0x1B, 0x1B], // ESC
    0x1C: [0x1C, 0x1C, 0x1C], //
    0x1D: [0x1D, 0x1D, 0x1D], //
    0x1E: [0x1E, 0x1E, 0x1E], //
    0x1F: [0x1F, 0x1F, 0x1F], //

    // Most of these besides space won't happen
    0x20: [0x20, 0x20, 0x20], //
    0x21: [0x21, 0x21, 0x21], //
    0x22: [0x22, 0x22, 0x22], //
    0x23: [0x23, 0x23, 0x23], //
    0x24: [0x24, 0x24, 0x24], //
    0x25: [0x08, 0x08, 0x08], // <- left
    0x26: [0x0B, 0x0B, 0x0B], // ^ up
    0x27: [0x15, 0x15, 0x15], // -> right
    0x28: [0x0A, 0x0A, 0x0A], // v down
    0x29: [0x29, 0x29, 0x29], // )
    0x2A: [0x2A, 0x2A, 0x2A], // *
    0x2B: [0x2B, 0x2B, 0x2B], // +
    0x2C: [0x2C, 0x2C, 0x3C], // , - <
    0x2D: [0x2D, 0x2D, 0x5F], // - - _
    0x2E: [0x2E, 0x2E, 0x3E], // . - >
    0x2F: [0x2F, 0x2F, 0x3F], // / - ?

    0x30: [0x30, 0x30, 0x29], // 0 - )
    0x31: [0x31, 0x31, 0x21], // 1 - !
    0x32: [0x32, 0x00, 0x40], // 2 - @
    0x33: [0x33, 0x33, 0x23], // 3 - #
    0x34: [0x34, 0x34, 0x24], // 4 - $
    0x35: [0x35, 0x35, 0x25], // 5 - %
    0x36: [0x36, 0x36, 0x5E], // 6 - ^
    0x37: [0x37, 0x37, 0x26], // 7 - &
    0x38: [0x38, 0x38, 0x2A], // 8 - *
    0x39: [0x39, 0x39, 0x28], // 9 - (
    0x3A: [0x3A, 0x3A, 0x3A], // :
    0x3B: [0x3B, 0x3B, 0x3A], // ; - :
    0x3C: [0x3C, 0x3C, 0x3C], // <
    0x3D: [0x3D, 0x3D, 0x2B], // = - +
    0x3E: [0x3E, 0x3E, 0x3E], // >
    0x3F: [0x3F, 0x3F, 0x3F], // ?

    // Alpha and control
    0x40: [0x40, 0x00, 0x40], // @
    0x41: [0x61, 0x01, 0x41], // A
    0x42: [0x62, 0x02, 0x42], // B
    0x43: [0x63, 0x03, 0x43], // C - BRK
    0x44: [0x64, 0x04, 0x44], // D
    0x45: [0x65, 0x05, 0x45], // E
    0x46: [0x66, 0x06, 0x46], // F
    0x47: [0x67, 0x07, 0x47], // G - BELL
    0x48: [0x68, 0x08, 0x48], // H
    0x49: [0x69, 0x09, 0x49], // I - TAB
    0x4A: [0x6A, 0x0A, 0x4A], // J - NL
    0x4B: [0x6B, 0x0B, 0x4B], // K - VT
    0x4C: [0x6C, 0x0C, 0x4C], // L
    0x4D: [0x6D, 0x0D, 0x4D], // M - CR
    0x4E: [0x6E, 0x0E, 0x4E], // N
    0x4F: [0x6F, 0x0F, 0x4F], // O

    0x50: [0x70, 0x10, 0x50], // P
    0x51: [0x71, 0x11, 0x51], // Q
    0x52: [0x72, 0x12, 0x52], // R
    0x53: [0x73, 0x13, 0x53], // S
    0x54: [0x74, 0x14, 0x54], // T
    0x55: [0x75, 0x15, 0x55], // U
    0x56: [0x76, 0x16, 0x56], // V
    0x57: [0x77, 0x17, 0x57], // W
    0x58: [0x78, 0x18, 0x58], // X
    0x59: [0x79, 0x19, 0x59], // Y
    0x5A: [0x7A, 0x1A, 0x5A], // Z
    0x5B: [0xFF, 0xFF, 0xFF], // Left window
    0x5C: [0xFF, 0xFF, 0xFF], // Right window
    0x5D: [0xFF, 0xFF, 0xFF], // Select
    0x5E: [0x5E, 0x1E, 0x5E], //
    0x5F: [0x5F, 0x1F, 0x5F], // _

    // Numeric pad
    0x60: [0x30, 0x30, 0x30], // 0
    0x61: [0x31, 0x31, 0x31], // 1
    0x62: [0x32, 0x32, 0x32], // 2
    0x63: [0x33, 0x33, 0x33], // 3
    0x64: [0x34, 0x34, 0x34], // 4
    0x65: [0x35, 0x35, 0x35], // 5
    0x66: [0x36, 0x36, 0x36], // 6
    0x67: [0x37, 0x37, 0x37], // 7
    0x68: [0x38, 0x38, 0x38], // 8
    0x69: [0x39, 0x39, 0x39], // 9

    0x6A: [0x2A, 0x2A, 0x2A], // *
    0x6B: [0x2B, 0x2B, 0x2B], // +
    0x6D: [0x2D, 0x2D, 0x2D], // -
    0x6E: [0x2E, 0x2E, 0x2E], // .
    0x6F: [0x2F, 0x2F, 0x39], // /

    // Stray keys
    0xAD: [0x2D, 0x2D, 0x5F], // - - _
    0xBA: [0x3B, 0x3B, 0x3A], // ; - :
    0xBB: [0x3D, 0x3D, 0x2B], // = - +
    0xBC: [0x2C, 0x2C, 0x3C], // , - <
    0xBD: [0x2D, 0x2D, 0x5F], // - - _
    0xBE: [0x2E, 0x2E, 0x3E], // . - >
    0xBF: [0x2F, 0x2F, 0x3F], // / - ?
    0xC0: [0x60, 0x60, 0x7E], // ` - ~
    0xDB: [0x5B, 0x1B, 0x7B], // [ - {
    0xDC: [0x5C, 0x1C, 0x7C], // \ - |
    0xDD: [0x5D, 0x1D, 0x7D], // ] - }
    0xDE: [0x27, 0x22, 0x22], // ' - '

    0xFF: [0xFF, 0xFF, 0xFF] // No comma line
} as const;

function isKeyboardCode(code: number): code is KnownKeys<typeof keymap> {
    return code in keymap;
}

const uiKitMap = {
    'Dead': 0xFF,
    'UIKeyInputLeftArrow': 0x08,
    'UIKeyInputRightArrow': 0x15,
    'UIKeyInputUpArrow': 0x0B,
    'UIKeyInputDownArrow': 0x0A,
    'UIKeyInputEscape': 0x1B
} as const;


function isUiKitKey(k: string): k is KnownKeys<typeof uiKitMap> {
    return k in uiKitMap;
}

const keys2 = [
    [
        ['1', '2', '3', '4', '5', '6', '7', '8', '9', '0', ':', '-', 'RESET'],
        ['ESC', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', 'REPT', 'RETURN'],
        ['CTRL', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ';', '&larr;', '&rarr;'],
        ['SHIFT', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', ',', '.', '/', 'SHIFT'],
        ['POWER', '&nbsp;']
    ], [
        ['!', '"', '#', '$', '%', '&', '\'', '(', ')', '0', '*', '=', 'RESET'],
        ['ESC', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', '@', 'REPT', 'RETURN'],
        ['CTRL', 'A', 'S', 'D', 'F', 'BELL', 'H', 'J', 'K', 'L', '+', '&larr;', '&rarr;'],
        ['SHIFT', 'Z', 'X', 'C', 'V', 'B', '^', ']', '<', '>', '?', 'SHIFT'],
        ['POWER', '&nbsp;']
    ]
] as const;


type Key2 = DeepMemberOf<typeof keys2>;

const keys2e = [
    [
        ['ESC', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-', '=', 'DELETE'],
        ['TAB', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '[', ']', '\\'],
        ['CTRL', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ';', '"', 'RETURN'],
        ['SHIFT', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', ',', '.', '/', 'SHIFT'],
        ['LOCK', '`', 'POW', 'OPEN_APPLE', '&nbsp;', 'CLOSED_APPLE', '&larr;', '&rarr;', '&darr;', '&uarr;']
    ], [
        ['ESC', '!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '_', '+', 'DELETE'],
        ['TAB', 'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '|'],
        ['CTRL', 'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ':', '\'', 'RETURN'],
        ['SHIFT', 'Z', 'X', 'C', 'V', 'B', 'N', 'M', '<', '>', '?', 'SHIFT'],
        ['CAPS', '~', 'POW', 'OPEN_APPLE', '&nbsp;', 'CLOSED_APPLE', '&larr;', '&rarr;', '&darr;', '&uarr;']
    ]
] as const;

type Key2e = DeepMemberOf<typeof keys2e>;

type Key = Key2 | Key2e;

type KeyFunction = (key: KeyboardEvent) => void;

export default class KeyBoard {
    private kb: HTMLElement;
    private keys;

    private shifted = false;
    private controlled = false;
    private capslocked = true;

    // Initially caps lock on physical keyboard is assumed to be off,
    // but on emulated keyboard it is on.
    private capslockKeyUsed = false;
    private optioned = false;
    private commanded = false;

    private functions: Record<string, KeyFunction> = {};

    constructor(private cpu: CPU6502, private io: Apple2IO, private e: boolean) {
        this.keys = e ? keys2e : keys2;

        window.addEventListener('keydown', this.keydown);
        window.addEventListener('keyup', this.keyup);
    }

    setFunction(key: string, fn: KeyFunction) {
        this.functions[key] = fn;
    }

    mapKeyEvent(evt: KeyboardEvent) {
        const code = evt.keyCode;
        let key: byte = 0xff;

        if (isUiKitKey(evt.key)) {
            key = uiKitMap[evt.key];
        } else if (isKeyboardCode(code)) {
            key = keymap[code][evt.shiftKey ? 2 : (evt.ctrlKey ? 1 : 0)];

            if (code !== 20 && this.capslockKeyUsed) {
                this.capslockKey(evt.getModifierState('CapsLock'));
            }

            if (this.capslocked && key >= 0x61 && key <= 0x7A) {
                key -= 0x20;
            }
        } else {
            debug('Unhandled key = ' + toHex(code));
        }

        if (key === 0x7F && evt.shiftKey && evt.ctrlKey) {
            this.cpu.reset();
            key = 0xff;
        }

        return key;
    }

    shiftKey(down: boolean) {
        const shiftKeys = this.kb.querySelectorAll('.key-SHIFT');
        this.shifted = down;
        if (down) {
            this.io.buttonUp(2);
            shiftKeys.forEach((key) => { key.classList.add('active'); });
        } else {
            this.io.buttonDown(2);
            shiftKeys.forEach((key) => { key.classList.remove('active'); });
        }
    }

    controlKey(down: boolean) {
        const ctrlKey = this.kb.querySelector('.key-CTRL');
        this.controlled = down;
        if (down) {
            ctrlKey!.classList.add('active');
        } else {
            ctrlKey!.classList.remove('active');
        }
    }

    commandKey(down: boolean) {
        const commandKey = this.kb.querySelector('.key-OPEN_APPLE');
        if (!commandKey) {
            return;
        }
        this.commanded = down;
        if (down) {
            this.io.buttonDown(0);
            commandKey.classList.add('active');
        } else {
            this.io.buttonUp(0);
            commandKey.classList.remove('active');
        }
    }

    optionKey(down: boolean) {
        const optionKey = this.kb.querySelector('.key-CLOSED_APPLE');
        if (!optionKey) {
            return;
        }
        this.optioned = down;
        if (down) {
            this.io.buttonDown(1);
            optionKey.classList.add('active');
        } else {
            this.io.buttonUp(1);
            optionKey.classList.remove('active');
        }
    }

    /**
     * Sets the state of the Caps Lock key. It is very complicated.
     * @param down if `true`, Caps Lock is pressed; if `false` Caps Lock is not pressed;
     *     if `undefined`, Caps Lock is toggled and its "used" state is set to false;
     *     if called with no arguments, the state is toggled _if_ it has been used before,
     *     otherwise the used state is set to true.
     */
    capslockKey(down?: boolean | undefined) {
        const capsLock = this.kb.querySelector('.key-LOCK');

        if (arguments.length === 0) {
            if (this.capslockKeyUsed) {
                this.capslocked = !this.capslocked;
            } else {
                this.capslockKeyUsed = true;
            }
        } else if (down === undefined) {
            this.capslocked = !this.capslocked;
            this.capslockKeyUsed = false;
        } else {
            this.capslocked = down;
        }

        if (this.capslocked) {
            capsLock!.classList.add('active');
        } else {
            capsLock!.classList.remove('active');
        }
    }

    reset(event: Event) {
        event.preventDefault();
        event.stopPropagation();
        this.cpu.reset();
    }

    create(el: string) {
        this.kb = document.querySelector(el)!;
        let x, y, row, key, label, label1, label2;

        const buildLabel = (k: string) => {
            const span = document.createElement('span');
            span.innerHTML = k;
            if (k.length > 1 && k.slice(0, 1) !== '&')
                span.classList.add('small');
            return span;
        };

        for (y = 0; y < 5; y++) {
            row = document.createElement('div');
            row.classList.add('row');
            row.classList.add(`row${y}`);
            this.kb.append(row);
            for (x = 0; x < this.keys[0][y].length; x++) {
                const key1 = this.keys[0][y][x];
                const key2 = this.keys[1][y][x];

                label = document.createElement('div');
                label1 = buildLabel(key1);
                label2 = buildLabel(key2);

                key = document.createElement('div');
                key.classList.add('key');
                key.classList.add('key-' + key1.replace(/[&#;]/g, ''));

                if (key1.length > 1) {
                    if (key1 === 'LOCK')
                        key.classList.add('v-center2');
                    else
                        key.classList.add('v-center');
                }
                if (key1 !== key2) {
                    key.classList.add('key-' + key2.replace(/[&;]/g, ''));
                    label.append(label2);
                    label.append(document.createElement('br'));
                }
                if (key1 === 'LOCK') {
                    key.classList.add('active');
                }

                label.append(label1);
                key.append(label);
                key.dataset.key1 = key1;
                key.dataset.key2 = key2;

                const mouseDown = this.genMouseDown(key, key1, key2);
                const mouseUp = this.genMouseUp(key);
                if (window.ontouchstart === undefined) {

                    key.addEventListener('mousedown', mouseDown);
                    key.addEventListener('mouseup', mouseUp);
                    key.addEventListener('mouseleave', mouseUp);
                } else {
                    key.addEventListener('touchstart', mouseDown);
                    key.addEventListener('touchend', mouseUp);
                    key.addEventListener('touchleave', mouseUp);
                }

                row.append(key);
            }
        }
    }

    private genMouseDown(target: HTMLElement, key1: Key, key2: Key) {
        return (ev: MouseEvent) => {
            ev.preventDefault();
            target.classList.add('pressed');

            let key: string = this.shifted ? key2 : key1;
            switch (key) {
                case 'BELL':
                    key = 'G';
                    break;
                case 'RETURN':
                    key = '\r';
                    break;
                case 'TAB':
                    key = '\t';
                    break;
                case 'DELETE':
                    key = '\x7F';
                    break;
                case '&larr;':
                    key = '\x08';
                    break;
                case '&rarr;':
                    key = '\x15';
                    break;
                case '&darr;':
                    key = '\x0A';
                    break;
                case '&uarr;':
                    key = '\x0B';
                    break;
                case '&nbsp;':
                    key = ' ';
                    break;
                case 'ESC':
                    key = '\x1B';
                    break;
                default:
                    break;
            }

            if (key.length > 1) {
                switch (key) {
                    case 'SHIFT':
                        this.shiftKey(!this.shifted);
                        break;
                    case 'CTRL':
                        this.controlKey(!this.controlled);
                        break;
                    case 'CAPS':
                    case 'LOCK':
                        this.capslockKey(undefined);
                        break;
                    case 'POW':
                    case 'POWER':
                        if (window.confirm('Power Cycle?'))
                            window.location.reload();
                        break;
                    case 'RESET':
                        this.cpu.reset();
                        break;
                    case 'OPEN_APPLE':
                        this.commandKey(!this.commanded);
                        break;
                    case 'CLOSED_APPLE':
                        this.optionKey(!this.optioned);
                        break;
                    default:
                        break;
                }
            } else {
                if (this.controlled && key >= '@' && key <= '_') {
                    this.io.keyDown(key.charCodeAt(0) - 0x40);
                } else if (this.e && !this.shifted && !this.capslocked &&
                    key >= 'A' && key <= 'Z') {
                    this.io.keyDown(key.charCodeAt(0) + 0x20);
                } else {
                    this.io.keyDown(key.charCodeAt(0));
                }
            }
        };
    }

    private dialogOpen() {
        return !!document.querySelector('.modal.is-open');
    }

    private genMouseUp(target: HTMLElement) {
        return () => target.classList.remove('pressed');
    }

    private keydown = (evt: KeyboardEvent) => {
        if (!this.dialogOpen() && (!evt.metaKey || evt.ctrlKey || this.e)) {
            evt.preventDefault();

            const key = this.mapKeyEvent(evt);
            if (key !== 0xff) {
                this.io.keyDown(key);
                return;
            }
        }

        if (evt.key === 'Shift') {
            this.shiftKey(true);
        } else if (evt.key === 'CapsLock') {
            this.capslockKey();
        } else if (evt.key === 'Control') {
            this.controlKey(true);
        } else if (evt.key === 'Meta') { // AKA Command
            this.commandKey(true);
        } else if (evt.key === 'Alt') {
            if (evt.location === 1) {
                this.commandKey(true);
            } else {
                this.optionKey(true);
            }
        } else {
            if (evt.key in this.functions) {
                this.functions[evt.key](evt);
                evt.preventDefault();
            }
        }

    };

    private keyup = (evt: KeyboardEvent) => {
        if (!this.dialogOpen()) {
            this.io.keyUp();
        }

        if (evt.key === 'Shift') { // Shift
            this.shiftKey(false);
        } else if (evt.key === 'Control') { // Control
            this.controlKey(false);
        } else if (evt.key === 'Meta') { // AKA Command
            this.commandKey(false);
        } else if (evt.key === 'Alt') { // Alt
            if (evt.location === 1) {
                this.commandKey(false);
            } else {
                this.optionKey(false);
            }
        }
    };
}