import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:xterm/xterm.dart';
import '../core/app_controller.dart';
import '../l10n/strings.dart';
import 'adaptive.dart';
import 'common.dart';
import 'theme.dart';

// xterm's default palette on the desktop terminal background.
const _terminalTheme = TerminalTheme(
  cursor: Color(0xccecf5ff),
  selection: Color(0x6642a5ff),
  foreground: Color(0xffdce8f5),
  background: Brand.terminal,
  black: Color(0xff000000),
  red: Color(0xffcd3131),
  green: Color(0xff0dbc79),
  yellow: Color(0xffe5e510),
  blue: Color(0xff2472c8),
  magenta: Color(0xffbc3fbc),
  cyan: Color(0xff11a8cd),
  white: Color(0xffe5e5e5),
  brightBlack: Color(0xff666666),
  brightRed: Color(0xfff14c4c),
  brightGreen: Color(0xff23d18b),
  brightYellow: Color(0xfff5f543),
  brightBlue: Color(0xff3b8eea),
  brightMagenta: Color(0xffd670d6),
  brightCyan: Color(0xff29b8db),
  brightWhite: Color(0xffffffff),
  searchHitBackground: Color(0xffffff2b),
  searchHitBackgroundCurrent: Color(0xff31ff26),
  searchHitForeground: Color(0xff000000),
);

class TerminalPage extends StatefulWidget {
  final AppController controller;
  const TerminalPage(this.controller, {super.key});
  @override
  State<TerminalPage> createState() => _TerminalPageState();
}

class _TerminalPageState extends State<TerminalPage> {
  final selection = TerminalController();
  final focus = FocusNode();
  bool ctrl = false, alt = false;
  @override
  void initState() {
    super.initState();
    // The keyboard button offers show or hide depending on focus.
    focus.addListener(_focusChanged);
  }

  void _focusChanged() {
    if (mounted) setState(() {});
  }

  @override
  void dispose() {
    focus.removeListener(_focusChanged);
    selection.dispose();
    focus.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final c = widget.controller;
    if (!c.ssh.connected) {
      return const PageMessage('selectServer', icon: Icons.terminal);
    }
    final terminal = c.ssh.terminal;
    // Key bar plus at least a few terminal rows; shorter space scrolls.
    return MinHeight(
      minHeight: 120,
      child: Column(
        children: [
          Expanded(
            child: Focus(
              onKeyEvent: (_, _) {
                c.activity();
                return KeyEventResult.ignored;
              },
              // xterm paints lines without clipping; scrolled-out lines
              // would otherwise draw over the status row and app bar.
              child: ClipRect(
                child: ColoredBox(
                  color: Brand.terminal,
                  child: TerminalView(
                    terminal,
                    controller: selection,
                    focusNode: focus,
                    theme: _terminalTheme,
                    // Desktop terminal insets; narrower on compact phones.
                    padding: MediaQuery.sizeOf(context).width < 600
                        ? const EdgeInsets.fromLTRB(8, 6, 4, 4)
                        : const EdgeInsets.fromLTRB(14, 12, 8, 8),
                    // Soft keyboards (iOS, many Android IMEs) send no backspace
                    // key event on an empty input buffer; this detects deletion.
                    deleteDetection:
                        defaultTargetPlatform == TargetPlatform.iOS ||
                        defaultTargetPlatform == TargetPlatform.android,
                    textStyle: TerminalStyle(
                      fontSize: 14 * MediaQuery.textScalerOf(context).scale(1),
                    ),
                    onKeyEvent: (_, key) {
                      c.activity();
                      return KeyEventResult.ignored;
                    },
                  ),
                ),
              ),
            ),
          ),
          // Key bar styled like the desktop terminal toolbar.
          DecoratedBox(
            decoration: BoxDecoration(
              color: Theme.of(context).navigationBarTheme.backgroundColor,
              border: Border(
                top: BorderSide(color: Theme.of(context).dividerColor),
              ),
            ),
            child: SingleChildScrollView(
              scrollDirection: Axis.horizontal,
              padding: const EdgeInsets.symmetric(horizontal: 4),
              child: Row(
                children: [
                  for (final entry in {
                    'ESC': TerminalKey.escape,
                    'TAB': TerminalKey.tab,
                    '↑': TerminalKey.arrowUp,
                    '↓': TerminalKey.arrowDown,
                    '←': TerminalKey.arrowLeft,
                    '→': TerminalKey.arrowRight,
                  }.entries)
                    TextButton(
                      onPressed: () {
                        c.activity();
                        terminal.keyInput(entry.value);
                      },
                      child: Text(entry.key),
                    ),
                  FilterChip(
                    label: const Text('CTRL'),
                    selected: c.ssh.ctrlNext,
                    onSelected: (v) => setState(() => c.ssh.ctrlNext = v),
                  ),
                  const SizedBox(width: 6),
                  FilterChip(
                    label: const Text('ALT'),
                    selected: c.ssh.altNext,
                    onSelected: (v) => setState(() => c.ssh.altNext = v),
                  ),
                  IconButton(
                    tooltip: context.tr(
                      focus.hasFocus ? 'hideKeyboard' : 'keyboard',
                    ),
                    icon: Icon(
                      focus.hasFocus ? Icons.keyboard_hide : Icons.keyboard,
                    ),
                    onPressed: () =>
                        focus.hasFocus ? focus.unfocus() : focus.requestFocus(),
                  ),
                  IconButton(
                    tooltip: context.tr('copy'),
                    icon: const Icon(Icons.copy),
                    onPressed: () {
                      if (selection.selection != null) {
                        Clipboard.setData(
                          ClipboardData(
                            text: terminal.buffer.getText(selection.selection),
                          ),
                        );
                      }
                    },
                  ),
                  IconButton(
                    tooltip: context.tr('paste'),
                    icon: const Icon(Icons.paste),
                    onPressed: () async {
                      final data = await Clipboard.getData(
                        Clipboard.kTextPlain,
                      );
                      if (c.ssh.connected &&
                          c.vault.unlocked &&
                          data?.text != null) {
                        terminal.paste(data!.text!);
                      }
                    },
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}