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

import 'widgets/manual_entry_tab.dart';
import 'widgets/ocr_tab.dart';

/// 记账页内部 Tab：0=手动记账 1=OCR识别
class AddTabNotifier extends Notifier<int> {
  @override
  int build() => 0;

  void set(int index) => state = index;
}

final addTabProvider = NotifierProvider<AddTabNotifier, int>(AddTabNotifier.new);

/// 记账页：手动记账 / OCR识别 双 Tab（复刻 uniApp pages/add/add.vue）
class AddPage extends ConsumerWidget {
  const AddPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final tabIndex = ref.watch(addTabProvider);
    return Scaffold(
      appBar: AppBar(title: const Text('添加账单')),
      body: Container(
        decoration: const BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topLeft,
            end: Alignment.bottomRight,
            colors: [Color(0xFFFFE5CC), Color(0xFFFFD4A8), Color(0xFFFFC08A)],
          ),
        ),
        child: Column(
          children: [
            const SizedBox(height: 12),
            _buildTabs(tabIndex, ref),
            Expanded(
              child: tabIndex == 0 ? const ManualEntryTab() : const OcrTab(),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildTabs(int tabIndex, WidgetRef ref) {
    void setTab(int index) => ref.read(addTabProvider.notifier).set(index);
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 16),
      padding: const EdgeInsets.all(4),
      decoration: BoxDecoration(
        color: Colors.white.withValues(alpha: 0.9),
        borderRadius: BorderRadius.circular(14),
        border: Border.all(color: const Color(0xFFC8956E)),
      ),
      child: Row(
        children: [
          _tab('手动记账', 0, tabIndex, setTab),
          _tab('OCR识别', 1, tabIndex, setTab),
        ],
      ),
    );
  }

  Widget _tab(String text, int index, int tabIndex, void Function(int) setTab) {
    final active = tabIndex == index;
    return Expanded(
      child: GestureDetector(
        onTap: () => setTab(index),
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 200),
          padding: const EdgeInsets.symmetric(vertical: 10),
          decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(10),
            gradient: active
                ? const LinearGradient(colors: [Color(0xFFC8956E), Color(0xFFF5D59E)])
                : null,
          ),
          child: Center(
            child: Text(
              text,
              style: TextStyle(
                fontSize: 15,
                fontWeight: FontWeight.w600,
                color: active ? const Color(0xFF5D4037) : const Color(0xFF8D6E63),
              ),
            ),
          ),
        ),
      ),
    );
  }
}