import 'package:flutter/material.dart';
import 'package:supabase_flutter/supabase_flutter.dart';

import 'api.dart';
import 'theme.dart';

String creditLine(AdminTrack t) => t.singerNames.isEmpty ? 'No singer yet' : t.singerNames;

String formatDuration(Duration d) {
  final s = d.inSeconds;
  return '${s ~/ 60}:${(s % 60).toString().padLeft(2, '0')}';
}

String formatDate(DateTime d) {
  const months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
  final l = d.toLocal();
  return '${l.day} ${months[l.month - 1]} ${l.year}';
}

String errorText(Object e) => switch (e) {
      PostgrestException(:final message) => message,
      AuthException(:final message) => message,
      StorageException(:final message) => message,
      _ => '$e',
    };

void showMessage(BuildContext context, String text) =>
    ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(text)));

void showError(BuildContext context, Object e) => ScaffoldMessenger.of(context)
    .showSnackBar(SnackBar(content: Text(errorText(e)), backgroundColor: NkColors.roofRed));

Future<bool> confirm(BuildContext context, String title, String body,
    {String action = 'OK', bool danger = false}) async {
  final ok = await showDialog<bool>(
    context: context,
    builder: (context) => AlertDialog(
      title: Text(title),
      content: ConstrainedBox(constraints: const BoxConstraints(maxWidth: 420), child: Text(body)),
      actions: [
        TextButton(onPressed: () => Navigator.pop(context, false), child: const Text('Cancel')),
        FilledButton(
          style: danger ? FilledButton.styleFrom(backgroundColor: NkColors.roofRed, foregroundColor: NkColors.cream) : null,
          onPressed: () => Navigator.pop(context, true),
          child: Text(action),
        ),
      ],
    ),
  );
  return ok ?? false;
}

/// Title row at the top of each page.
class PageHeader extends StatelessWidget {
  const PageHeader(this.title, {super.key, this.subtitle, this.actions = const []});

  final String title;
  final String? subtitle;
  final List<Widget> actions;

  @override
  Widget build(BuildContext context) => Padding(
        padding: const EdgeInsets.fromLTRB(24, 24, 24, 12),
        child: Wrap(
          alignment: WrapAlignment.spaceBetween,
          crossAxisAlignment: WrapCrossAlignment.center,
          spacing: 16,
          runSpacing: 12,
          children: [
            Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              mainAxisSize: MainAxisSize.min,
              children: [
                Text(title, style: Theme.of(context).textTheme.headlineSmall),
                if (subtitle != null) ...[
                  const SizedBox(height: 4),
                  Text(subtitle!, style: Theme.of(context).textTheme.bodySmall),
                ],
              ],
            ),
            Wrap(spacing: 8, runSpacing: 8, children: actions),
          ],
        ),
      );
}

class StatusChip extends StatelessWidget {
  const StatusChip(this.status, {super.key});

  final SongStatus status;

  @override
  Widget build(BuildContext context) {
    final color = switch (status) {
      SongStatus.approved => NkColors.teaLeaf,
      SongStatus.pending => NkColors.sun,
      SongStatus.needsChanges => NkColors.info,
      SongStatus.draft => NkColors.muted,
      SongStatus.rejected || SongStatus.takenDown => NkColors.roofRed,
    };
    return Tag(status.label, color: color);
  }
}

class Tag extends StatelessWidget {
  const Tag(this.text, {super.key, this.color = NkColors.muted});

  final String text;
  final Color color;

  @override
  Widget build(BuildContext context) => Container(
        padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 3),
        decoration: BoxDecoration(
          color: color.withValues(alpha: 0.16),
          borderRadius: BorderRadius.circular(99),
          border: Border.all(color: color.withValues(alpha: 0.5)),
        ),
        child: Text(text, style: TextStyle(color: color, fontSize: 12, fontWeight: FontWeight.w700)),
      );
}

/// Shows a spinner, an error with a retry button, or the loaded data.
class Loader<T> extends StatelessWidget {
  const Loader({super.key, required this.future, required this.onRetry, required this.builder});

  final Future<T>? future;
  final VoidCallback onRetry;
  final Widget Function(BuildContext context, T data) builder;

  @override
  Widget build(BuildContext context) => FutureBuilder<T>(
        future: future,
        builder: (context, snap) {
          if (snap.hasError) {
            return Center(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  const Icon(Icons.cloud_off, color: NkColors.muted, size: 40),
                  const SizedBox(height: 12),
                  Text(errorText(snap.error!), textAlign: TextAlign.center),
                  const SizedBox(height: 12),
                  OutlinedButton(onPressed: onRetry, child: const Text('Try again')),
                ],
              ),
            );
          }
          if (!snap.hasData) return const Center(child: CircularProgressIndicator());
          return builder(context, snap.data as T);
        },
      );
}

class EmptyState extends StatelessWidget {
  const EmptyState(this.text, {super.key, this.icon = Icons.inbox_outlined});

  final String text;
  final IconData icon;

  @override
  Widget build(BuildContext context) => Center(
        child: Padding(
          padding: const EdgeInsets.all(32),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              Icon(icon, color: NkColors.muted, size: 40),
              const SizedBox(height: 12),
              Text(text, textAlign: TextAlign.center, style: const TextStyle(color: NkColors.muted)),
            ],
          ),
        ),
      );
}

/// Search box that reports its text after a short pause in typing.
class SearchField extends StatefulWidget {
  const SearchField({super.key, required this.hint, required this.onChanged, this.initial = '', this.width = 320});

  final String hint;
  final String initial;
  final double width;
  final ValueChanged<String> onChanged;

  @override
  State<SearchField> createState() => _SearchFieldState();
}

class _SearchFieldState extends State<SearchField> {
  late final _text = TextEditingController(text: widget.initial);
  int _typing = 0;

  @override
  void dispose() {
    _text.dispose();
    super.dispose();
  }

  void _changed(String v) {
    final n = ++_typing;
    Future.delayed(const Duration(milliseconds: 350), () {
      if (mounted && n == _typing) widget.onChanged(v.trim());
    });
  }

  @override
  Widget build(BuildContext context) => SizedBox(
        width: widget.width,
        child: TextField(
          controller: _text,
          onChanged: _changed,
          onSubmitted: (v) => widget.onChanged(v.trim()),
          decoration: InputDecoration(
            hintText: widget.hint,
            prefixIcon: const Icon(Icons.search, color: NkColors.muted),
            suffixIcon: ListenableBuilder(
              listenable: _text,
              builder: (context, _) => _text.text.isEmpty
                  ? const SizedBox.shrink()
                  : IconButton(
                      tooltip: 'Clear',
                      icon: const Icon(Icons.close, size: 18),
                      onPressed: () {
                        _text.clear();
                        widget.onChanged('');
                      },
                    ),
            ),
          ),
        ),
      );
}

/// A dialog body with a fixed width that scrolls when tall.
class DialogBody extends StatelessWidget {
  const DialogBody({super.key, required this.children, this.width = 520});

  final List<Widget> children;
  final double width;

  @override
  Widget build(BuildContext context) => SizedBox(
        width: width,
        child: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              for (final (i, c) in children.indexed) ...[if (i > 0) const SizedBox(height: 14), c],
            ],
          ),
        ),
      );
}

String? trimmedOrNull(String s) => s.trim().isEmpty ? null : s.trim();