import 'package:flutter/foundation.dart' show defaultTargetPlatform, TargetPlatform;
import 'package:flutter/material.dart';
import 'package:signals/signals_flutter.dart' show SignalBuilder;

import '../../application/pages/mews_urls.dart';
import '../app.dart';

/// The single-field address bar. The left icon opens the hub and, on pointer
/// platforms, carries the back and forward buttons; the right icons reload,
/// subscribe (only when the page offers something to subscribe to) and
/// bookmark the current page.
class AddressBar extends StatefulWidget {
  const AddressBar({super.key});

  @override
  State<AddressBar> createState() => _AddressBarState();
}

class _AddressBarState extends State<AddressBar> {
  final _controller = TextEditingController();
  final _focus = FocusNode();
  bool _focused = false;

  @override
  void initState() {
    super.initState();
    _focus.addListener(() {
      if (_focus.hasFocus != _focused) {
        setState(() => _focused = _focus.hasFocus);
        if (_focused) {
          _controller.selection =
              TextSelection(baseOffset: 0, extentOffset: _controller.text.length);
        }
      }
    });
  }

  @override
  void dispose() {
    _focus.dispose();
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final deps = AppScope.of(context).deps;
    final strings = AppScope.of(context).strings;

    return SignalBuilder(builder: (context) {
      final page = deps.browser.currentPage.value;
      final url = page?.url;
      if (url != null && !_focused) {
        _controller.text = url;
      }

      // Touch devices navigate with swipes; desktops get buttons.
      final hasButtons = switch (defaultTargetPlatform) {
        TargetPlatform.linux ||
        TargetPlatform.windows ||
        TargetPlatform.macOS => true,
        _ => false,
      };

      // Only pages with dated entry links or an Atom feed can be subscribed
      // to (mews spec, section 6).
      final canSubscribe = page != null &&
          !MewsUrls.isInternal(page.url) &&
          (page.atomFeedHref != null || page.entries.isNotEmpty);
      final canBookmark = page != null && !MewsUrls.isInternal(page.url);

      // One button, two layouts: on pointer platforms it sits beside the
      // back and forward buttons.
      final hubButton = IconButton(
        icon: const Icon(Icons.menu),
        tooltip: strings.t('reader-open-hub'),
        onPressed: () => deps.browser.open(MewsUrls.hub),
      );

      return Padding(
        padding: const EdgeInsets.fromLTRB(8, 8, 8, 4),
        child: TextField(
          controller: _controller,
          focusNode: _focus,
          autofocus: false,
          keyboardType: TextInputType.url,
          textInputAction: TextInputAction.go,
          autocorrect: false,
          enableSuggestions: false,
          onSubmitted: (value) {
            _focus.unfocus();
            deps.browser.open(value);
          },
          decoration: InputDecoration(
            hintText: strings.t('reader-address-placeholder'),
            labelText: strings.t('reader-address-label'),
            isDense: true,
            border: const OutlineInputBorder(),
            prefixIcon: hasButtons
                ? Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      hubButton,
                      IconButton(
                        icon: const Icon(Icons.arrow_back),
                        tooltip: strings.t('reader-back'),
                        onPressed: deps.browser.canGoBack
                            ? deps.browser.back
                            : null,
                      ),
                      IconButton(
                        icon: const Icon(Icons.arrow_forward),
                        tooltip: strings.t('reader-forward'),
                        onPressed: deps.browser.canGoForward
                            ? deps.browser.forward
                            : null,
                      ),
                    ],
                  )
                : hubButton,
            prefixIconConstraints: hasButtons
                ? const BoxConstraints(minWidth: 138, minHeight: 48)
                : null,
            suffixIcon: Row(
              mainAxisSize: MainAxisSize.min,
              children: [
                IconButton(
                  icon: const Icon(Icons.refresh),
                  tooltip: strings.t('reader-reload'),
                  onPressed: () => deps.browser.reload(),
                ),
                if (canSubscribe)
                  IconButton(
                    icon: Icon(
                      deps.library.isSubscribed(page.url)
                          ? Icons.notifications_active
                          : Icons.notifications_outlined,
                    ),
                    tooltip: deps.library.isSubscribed(page.url)
                        ? strings.t('reader-unsubscribe')
                        : strings.t('reader-subscribe'),
                    onPressed: () => deps.library
                        .toggleSubscription(page.url, page.title, page.entries),
                  ),
                if (canBookmark)
                  IconButton(
                    icon: Icon(
                      deps.library.isBookmarked(page.url)
                          ? Icons.star
                          : Icons.star_border,
                    ),
                    tooltip: deps.library.isBookmarked(page.url)
                        ? strings.t('reader-bookmark-remove')
                        : strings.t('reader-bookmark-add'),
                    onPressed: () =>
                        deps.library.toggleBookmark(page.url, page.title),
                  ),
              ],
            ),
          ),
        ),
      );
    });
  }
}