/* Atlus — Custom on-screen keyboard for terminal */
(function () {
    'use strict';

    const MODES = {
        keys: 'Keys',
        fn: 'Fn',
        nav: 'Nav',
        sym: 'Sym',
    };

    const QUICK_KEYS = ['$', '#', '>', '-', '_', '.', '/', '|', '~'];

    const QWERTY_ROWS = [
        ['1','2','3','4','5','6','7','8','9','0'],
        ['q','w','e','r','t','y','u','i','o','p'],
        ['a','s','d','f','g','h','j','k','l'],
        ['z','x','c','v','b','n','m'],
    ];

    const SYM_ROWS = [
        ['!','@','#','$','%','^','&','*','(',')'],
        ['-','_','=','+','[',']','{','}','\\','|'],
        [';',':','\'','"',',','.','/','?','`','~'],
        ['<','>','©','®','…','§','±','×'],
    ];

    const FN_KEYS = ['F1','F2','F3','F4','F5','F6','F7','F8','F9','F10','F11','F12'];

    const NAV_KEYS = [
        {label: '↑', seq: '\x1b[A'},
        {label: '↓', seq: '\x1b[B'},
        {label: '←', seq: '\x1b[D'},
        {label: '→', seq: '\x1b[C'},
        {label: 'Home', seq: '\x1b[H'},
        {label: 'End', seq: '\x1b[F'},
        {label: 'PgUp', seq: '\x1b[5~'},
        {label: 'PgDn', seq: '\x1b[6~'},
        {label: 'Del', seq: '\x1b[3~'},
        {label: 'Ins', seq: '\x1b[2~'},
    ];

    class OnScreenKeyboard {
        constructor() {
            this.el = null;
            this.terminal = null;  // set by terminal app
            this.mode = 'keys';
            this.shift = false;
            this.ctrl = false;
            this.alt = false;
            // States: null=off, 'armed'=one-shot, 'locked'=persistent
            this.ctrlState = null;
            this.altState = null;
            this.shiftState = null;
            this.visible = true;
        }

        create() {
            this.el = document.createElement('div');
            this.el.className = 'osk';
            this._render();
            return this.el;
        }

        toggle() {
            this.visible = !this.visible;
            if (this.el) this.el.classList.toggle('hidden', !this.visible);
        }

        setTerminal(term) {
            this.terminal = term;
        }

        _send(data) {
            if (!this.terminal) return;

            let out = data;

            // Apply modifiers
            if (this.ctrlState && data.length === 1) {
                const code = data.toLowerCase().charCodeAt(0);
                if (code >= 97 && code <= 122) {
                    out = String.fromCharCode(code - 96);
                }
            } else if (this.altState && data.length === 1) {
                out = '\x1b' + data;
            }

            if (this.shiftState && data.length === 1 && data >= 'a' && data <= 'z') {
                out = data.toUpperCase();
            }

            this.terminal.input(out);

            // Clear armed (one-shot) modifiers
            if (this.ctrlState === 'armed') { this.ctrlState = null; }
            if (this.altState === 'armed') { this.altState = null; }
            if (this.shiftState === 'armed') { this.shiftState = null; }
            this._updateModifiers();
        }

        _toggleMod(mod) {
            const key = mod + 'State';
            if (this[key] === null) {
                this[key] = 'armed';
            } else if (this[key] === 'armed') {
                this[key] = 'locked';
            } else {
                this[key] = null;
            }
            this._updateModifiers();
        }

        _updateModifiers() {
            if (!this.el) return;
            this.el.querySelectorAll('.osk-key.mod').forEach(key => {
                const mod = key.dataset.mod;
                if (!mod) return;
                const state = this[mod + 'State'];
                key.classList.toggle('armed', state === 'armed');
                key.classList.toggle('locked', state === 'locked');
            });
        }

        _render() {
            this.el.innerHTML = '';

            // Quick row
            const quick = document.createElement('div');
            quick.className = 'osk-quick';
            QUICK_KEYS.forEach(k => {
                const btn = this._makeKey(k, () => this._send(k));
                quick.appendChild(btn);
            });
            this.el.appendChild(quick);

            // Mode tabs
            const modes = document.createElement('div');
            modes.className = 'osk-modes';
            for (const [id, label] of Object.entries(MODES)) {
                const tab = document.createElement('button');
                tab.className = 'osk-mode-tab' + (id === this.mode ? ' active' : '');
                tab.textContent = label;
                tab.addEventListener('click', () => {
                    this.mode = id;
                    this._render();
                });
                modes.appendChild(tab);
            }
            this.el.appendChild(modes);

            // Mode content
            if (this.mode === 'keys') this._renderQwerty();
            else if (this.mode === 'fn') this._renderFn();
            else if (this.mode === 'nav') this._renderNav();
            else if (this.mode === 'sym') this._renderSym();
        }

        _makeKey(label, handler, className = '') {
            const btn = document.createElement('button');
            btn.className = 'osk-key ' + className;
            btn.textContent = label;
            let touchFired = false;
            btn.addEventListener('touchstart', (e) => {
                e.preventDefault();
                touchFired = true;
                handler();
            });
            btn.addEventListener('click', (e) => {
                e.preventDefault();
                if (touchFired) { touchFired = false; return; }
                handler();
            });
            return btn;
        }

        _renderQwerty() {
            // Modifier row
            const modRow = document.createElement('div');
            modRow.className = 'osk-row';
            modRow.appendChild(this._makeKey('Esc', () => this._send('\x1b'), 'mod'));
            modRow.appendChild(this._makeKey('Tab', () => this._send('\t'), 'mod'));

            const ctrlKey = this._makeKey('Ctrl', () => this._toggleMod('ctrl'), 'mod');
            ctrlKey.dataset.mod = 'ctrl';
            modRow.appendChild(ctrlKey);

            const altKey = this._makeKey('Alt', () => this._toggleMod('alt'), 'mod');
            altKey.dataset.mod = 'alt';
            modRow.appendChild(altKey);

            this.el.appendChild(modRow);

            // QWERTY rows
            QWERTY_ROWS.forEach((row, i) => {
                const rowEl = document.createElement('div');
                rowEl.className = 'osk-row';

                if (i === 3) {
                    // Shift key
                    const shiftKey = this._makeKey('Shift', () => this._toggleMod('shift'), 'mod wide');
                    shiftKey.dataset.mod = 'shift';
                    rowEl.appendChild(shiftKey);
                }

                row.forEach(k => {
                    rowEl.appendChild(this._makeKey(k, () => this._send(k)));
                });

                if (i === 3) {
                    rowEl.appendChild(this._makeKey('⌫', () => this._send('\x7f'), 'wide'));
                }

                this.el.appendChild(rowEl);
            });

            // Space row
            const spaceRow = document.createElement('div');
            spaceRow.className = 'osk-row';
            spaceRow.appendChild(this._makeKey('Paste', () => this._paste(), 'mod'));
            spaceRow.appendChild(this._makeKey('Space', () => this._send(' '), 'space'));
            spaceRow.appendChild(this._makeKey('Enter', () => this._send('\r'), 'wide'));
            this.el.appendChild(spaceRow);

            this._updateModifiers();
        }

        _renderSym() {
            SYM_ROWS.forEach(row => {
                const rowEl = document.createElement('div');
                rowEl.className = 'osk-row';
                row.forEach(k => {
                    rowEl.appendChild(this._makeKey(k, () => this._send(k)));
                });
                this.el.appendChild(rowEl);
            });
        }

        _renderFn() {
            const scroll = document.createElement('div');
            scroll.className = 'osk-fn-scroll';
            FN_KEYS.forEach((k, i) => {
                const seq = `\x1bO${String.fromCharCode(80 + i)}`;
                // F1-F4 use \x1bOP-S, F5+ use \x1b[15~, etc.
                const seqs = [
                    '\x1bOP','\x1bOQ','\x1bOR','\x1bOS',
                    '\x1b[15~','\x1b[17~','\x1b[18~','\x1b[19~',
                    '\x1b[20~','\x1b[21~','\x1b[23~','\x1b[24~',
                ];
                scroll.appendChild(this._makeKey(k, () => this._send(seqs[i])));
            });
            this.el.appendChild(scroll);

            // Common ctrl combos
            const combos = document.createElement('div');
            combos.className = 'osk-row';
            const ctrlKeys = [
                {label: 'Ctrl+C', seq: '\x03'},
                {label: 'Ctrl+D', seq: '\x04'},
                {label: 'Ctrl+Z', seq: '\x1a'},
                {label: 'Ctrl+A', seq: '\x01'},
                {label: 'Ctrl+L', seq: '\x0c'},
                {label: 'Ctrl+R', seq: '\x12'},
            ];
            ctrlKeys.forEach(k => {
                combos.appendChild(this._makeKey(k.label, () => this._send(k.seq), 'mod'));
            });
            this.el.appendChild(combos);
        }

        _renderNav() {
            const nav = document.createElement('div');
            nav.className = 'osk-nav';
            NAV_KEYS.forEach(k => {
                nav.appendChild(this._makeKey(k.label, () => this._send(k.seq)));
            });
            this.el.appendChild(nav);
        }

        async _paste() {
            try {
                const text = await navigator.clipboard.readText();
                if (text && this.terminal) {
                    this.terminal.input(text);
                }
            } catch (e) {
                // Clipboard access denied
            }
        }
    }

    window.Atlus.keyboard = new OnScreenKeyboard();
})();