xianyan/lib/core/providers/split_view_provider.dart

/// ============================================================
/// 闲言APP — 宽屏分屏状态管理
/// 创建时间: 2026-05-29
/// 更新时间: 2026-05-29
/// 作用: 管理分屏比例、右侧面板内容、导航栏位置、分屏开关
/// 上次更新: 新增三栏布局状态(thirdPanelContent/thirdPanelArgs/setThirdPanel)
/// ============================================================

import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:freezed_annotation/freezed_annotation.dart';
import 'package:xianyan/core/storage/kv_storage.dart';

part 'split_view_provider.freezed.dart';

/// 导航栏停靠位置
enum NavBarPosition {
  left,
  right,
  top,
  bottom;

  String get label => switch (this) {
    left => '左侧',
    right => '右侧',
    top => '顶部',
    bottom => '底部',
  };

  String get emoji => switch (this) {
    left => '⬅️',
    right => '➡️',
    top => '⬆️',
    bottom => '⬇️',
  };
}

/// 分屏比例选项
class SplitRatioOption {
  const SplitRatioOption(this.value, this.label);
  final double value;
  final String label;

  static const List<SplitRatioOption> options = [
    SplitRatioOption(0.30, '30:70'),
    SplitRatioOption(0.35, '35:65'),
    SplitRatioOption(0.40, '40:60'),
    SplitRatioOption(0.45, '45:55'),
    SplitRatioOption(0.50, '50:50'),
    SplitRatioOption(0.55, '55:45'),
    SplitRatioOption(0.60, '60:40'),
  ];

  static SplitRatioOption? findByValue(double v) =>
      options.where((o) => o.value == v).firstOrNull;

  static int indexOfValue(double v) {
    final idx = options.indexWhere((o) => o.value == v);
    return idx >= 0 ? idx : 2;
  }
}

const String _kSplitRatio = 'split_view_ratio';
const String _kNavBarPosition = 'nav_bar_position';
const String _kSplitViewEnabled = 'split_view_enabled';

/// 三栏布局断点：宽度 >= 1400px 进入三栏模式
const double kTripleColumnBreakpoint = 1400.0;

/// 分屏视图状态（freezed不可变数据类）
@freezed
sealed class SplitViewState with _$SplitViewState {
  const SplitViewState._();
  const factory SplitViewState({
    @Default(0.4) double splitRatio,
    String? rightPanelContent,
    Map<String, dynamic>? rightPanelArgs,
    @Default(NavBarPosition.left) NavBarPosition navBarPosition,
    @Default(true) bool splitViewEnabled,
    String? homeRightPanel,
    String? discoverRightPanel,
    String? profileRightPanel,
    @Default(0) int currentTab,
    String? thirdPanelContent,
    Map<String, dynamic>? thirdPanelArgs,
  }) = _SplitViewState;

  String? get activeRightPanel => switch (currentTab) {
    0 => homeRightPanel,
    1 => discoverRightPanel,
    2 => profileRightPanel,
    _ => null,
  };
}

/// 分屏视图状态管理Notifier
class SplitViewNotifier extends Notifier<SplitViewState> {
  @override
  SplitViewState build() {
    final savedIndex = KvStorage.getInt(_kNavBarPosition) ?? 0;
    const positions = NavBarPosition.values;
    return SplitViewState(
      splitRatio: KvStorage.getDouble(_kSplitRatio) ?? 0.4,
      navBarPosition: (savedIndex >= 0 && savedIndex < positions.length)
          ? positions[savedIndex]
          : NavBarPosition.left,
      splitViewEnabled: KvStorage.getBool(_kSplitViewEnabled) ?? true,
    );
  }

  void setSplitRatio(double value) {
    KvStorage.setDouble(_kSplitRatio, value);
    state = state.copyWith(splitRatio: value);
  }

  void setRightPanelContent(String? content, {Map<String, dynamic>? args}) {
    state = state.copyWith(rightPanelContent: content, rightPanelArgs: args);
  }

  void setNavBarPosition(NavBarPosition position) {
    KvStorage.setInt(_kNavBarPosition, position.index);
    state = state.copyWith(navBarPosition: position);
  }

  void setSplitViewEnabled(bool enabled) {
    KvStorage.setBool(_kSplitViewEnabled, enabled);
    state = state.copyWith(splitViewEnabled: enabled);
  }

  void setHomeRightPanel(String? panelId, {Map<String, dynamic>? args}) {
    state = state.copyWith(homeRightPanel: panelId, rightPanelArgs: args);
  }

  void setDiscoverRightPanel(String? panelId, {Map<String, dynamic>? args}) {
    state = state.copyWith(discoverRightPanel: panelId, rightPanelArgs: args);
  }

  void setProfileRightPanel(String? panelId, {Map<String, dynamic>? args}) {
    state = state.copyWith(profileRightPanel: panelId, rightPanelArgs: args);
  }

  void setCurrentTab(int index) {
    state = state.copyWith(currentTab: index);
  }

  /// 设置第三栏面板内容
  void setThirdPanel(String? panelId, {Map<String, dynamic>? args}) {
    state = state.copyWith(thirdPanelContent: panelId, thirdPanelArgs: args);
  }

  void clearActivePanel() {
    final tab = state.currentTab;
    switch (tab) {
      case 0:
        state = state.copyWith(homeRightPanel: null);
      case 1:
        state = state.copyWith(discoverRightPanel: null);
      case 2:
        state = state.copyWith(profileRightPanel: null);
    }
  }
}

/// 分屏视图Provider
final splitViewProvider = NotifierProvider<SplitViewNotifier, SplitViewState>(
  SplitViewNotifier.new,
);