/**
 * Project Store - Zustand
 * =======================
 */

import { create } from 'zustand';
import { immer } from 'zustand/middleware/immer';
import { persist } from 'zustand/middleware';
import { localProjectApi, generateProjectId, getCurrentProjectId, setCurrentProjectId } from '../api/modules/localStorage';
import type { ProjectState, ScriptShot, MetaOverrides } from '../types/project';
import { buildProjectMeta, migrateMeta, BLANK_META_OVERRIDES } from '../utils/projectMeta';

export type { ScriptShot } from '../types/project';

interface ProjectActions {
  // 分镜操作
  updateSegment: (_id: number, _data: Partial<ScriptShot>) => void;
  setSegments: (_segments: ScriptShot[]) => void;

  // 其他操作
  setTopic: (_topic: string) => void;
  setTitle: (_title: string) => void;
  setCurrentStep: (_step: number) => void;
  setAvatarMaterial: (_path?: string, _name?: string, _duration?: number) => void;
  setSelectedVoiceId: (_voiceId: string) => void;
  setFinalVideoPath: (_path: string | undefined) => void;
  setCoverPath: (_path: string | undefined) => void;
  setCoverConfig: (_config: ProjectState['coverConfig']) => void;
  setExportedAt: (_timestamp: number | undefined) => void;
  setDubbingAudioDuration: (_duration: number | undefined) => void;
  setVoiceSpeed: (_speed: number) => void;
  setVoiceVolume: (_volume: number) => void;
  setBgmMusic: (_id: number | undefined, _title: string | undefined, _path: string | undefined) => void;
  setBgmVolume: (_volume: number) => void;
  setCategoryCode: (_code: string) => void;
  setFilename: (_filename: string) => void;
  setIsLoading: (_loading: boolean) => void;
  setHasHydrated: (_hydrated: boolean) => void;
  markStepsDirty: (_fromStep: number) => void;
  clearStepDirty: (_stepId: number) => void;
  reset: () => void;
}
 

interface ProjectGetters {
  hasHydrated: boolean;
}

type ProjectStore = ProjectState &
  ProjectActions &
  ProjectGetters;

const initialState: Omit<
  ProjectStore,
  keyof ProjectActions | keyof ProjectGetters
> = {
  id: '',
  title: '',
  status: 'draft',
  segments: [],
  currentStep: 1,
  createdAt: 0,
  updatedAt: 0,
  version: 1,
  _isLoading: false,
  voiceSpeed: 1.0,
  voiceVolume: 0,
  _hasHydrated: false,
};

// 元数据保存队列（避免并发覆盖）
let metaSavePromise: Promise<void> = Promise.resolve();

/**
 * 立即保存项目元数据（不防抖，不保存 segments）
 * 用于 coverPath / finalVideoPath / exportedAt 等关键字段的持久化
 *
 * 实现细节：
 * 1. 先读取磁盘上的现有 meta.json，避免覆盖其他字段
 * 2. 只覆盖传入的 overrides 字段（显式传 undefined 表示清除）
 * 3. 通过 Promise 链串行化，避免并发写导致数据丢失
 */
export async function saveMetaToLocalFile(overrides: MetaOverrides = {}) {
  const projectId = getCurrentProjectId();
  if (!projectId) {
    console.error('[ProjectStore] Cannot save meta: no project ID');
    return;
  }

  const task = async () => {
    try {
      const rawExisting = await localProjectApi.loadMeta(projectId);
      const existing = rawExisting ? migrateMeta(rawExisting) : null;

      // 核心：buildProjectMeta 自动合并所有字段，无需逐个判断
      const meta = buildProjectMeta(projectId, existing, overrides);

      await localProjectApi.saveMeta(projectId, meta);
    } catch (err) {
      console.error('[ProjectStore] Save meta failed:', err);
    }
  };

  metaSavePromise = metaSavePromise.then(task).catch((err) => {
    console.error('[ProjectStore] Save meta failed:', err);
    throw err;
  });
  await metaSavePromise;
}

// 当前项目 ID（内存中）
let currentProjectId: string = getCurrentProjectId();

export const useProjectStore = create<ProjectStore>()(
  immer(
    persist(
      (set, get) => ({
        ...initialState,

        get hasHydrated() {
          return get()._hasHydrated;
        },

        // 获取当前项目 ID
        get currentProjectId() {
          return currentProjectId;
        },

        setIsLoading: (loading: boolean) =>
          set(state => {
            state._isLoading = loading;
          }),

        setHasHydrated: (hydrated: boolean) =>
          set(state => {
            state._hasHydrated = hydrated;
          }),

        updateSegment: (id, data) =>
          set(state => {
            const shotIndex = state.segments.findIndex(s => s.id === id);
            if (shotIndex !== -1) {
              // 直接修改 draft 属性，让 Immer 正确追踪数组元素变化
              Object.assign(state.segments[shotIndex], data);
              state.updatedAt = Date.now();
            } else {
              // no-op: 分镜不存在时不处理
            }
            // 自动保存已移除，数据将在点击下一步时统一落盘
          }),

        setSegments: segments =>
          set(state => {
            state.segments = segments;
            state.updatedAt = Date.now();
            // 自动保存已移除，数据将在点击下一步时统一落盘
          }),

        setTopic: topic =>
          set(state => {
            state.topic = topic;
          }),
        setTitle: title =>
          set(state => {
            state.title = title;
            state.updatedAt = Date.now();
          }),

        setCurrentStep: step =>
          set(state => {
            state.currentStep = step;
          }),

        setAvatarMaterial: (path, name, duration) => {
          set(state => {
            state.avatarMaterialPath = path;
            state.avatarMaterialName = name;
            state.avatarMaterialDuration = duration;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ avatarMaterialPath: path, avatarMaterialName: name, avatarMaterialDuration: duration });
        },
        setSelectedVoiceId: voiceId => {
          set(state => {
            state.selectedVoiceId = voiceId;
            state.updatedAt = Date.now();
          });
        },
        setFinalVideoPath: path => {
          set(state => {
            state.finalVideoPath = path;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ finalVideoPath: path });
        },
        setCoverPath: path => {
          set(state => {
            state.coverPath = path;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ coverPath: path });
        },
        setCoverConfig: config => {
          set(state => {
            state.coverConfig = config;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ coverConfig: config });
        },
        setExportedAt: timestamp => {
          set(state => {
            state.exportedAt = timestamp;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ exportedAt: timestamp });
        },
        setDubbingAudioDuration: duration => {
          set(state => {
            state.dubbingAudioDuration = duration;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ dubbingAudioDuration: duration });
        },
        setVoiceSpeed: speed =>
          set(state => {
            state.voiceSpeed = speed;
            state.updatedAt = Date.now();
          }),
        setVoiceVolume: volume =>
          set(state => {
            state.voiceVolume = volume;
            state.updatedAt = Date.now();
          }),
        setBgmMusic: (id, title, path) => {
          set(state => {
            state.bgmMusicId = id;
            state.bgmMusicTitle = title;
            state.bgmMusicPath = path;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ bgmMusicId: id, bgmMusicTitle: title, bgmMusicPath: path });
        },
        setBgmVolume: volume => {
          set(state => {
            state.bgmVolume = volume;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ bgmVolume: volume });
        },
        setCategoryCode: code => {
          set(state => {
            state.categoryCode = code;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ categoryCode: code });
        },
        setFilename: filename => {
          set(state => {
            state.filename = filename;
            state.updatedAt = Date.now();
          });
          saveMetaToLocalFile({ filename });
        },

        markStepsDirty: (fromStep: number) => {
          set(state => {
            if (!state.stepDirtyFlags) {
              state.stepDirtyFlags = {};
            }
            for (let i = fromStep + 1; i <= 6; i++) {
              state.stepDirtyFlags[i] = true;
            }
            state.updatedAt = Date.now();
          });
          const flags = get().stepDirtyFlags || {};
          const newFlags: Record<number, boolean> = {};
          for (let i = fromStep + 1; i <= 6; i++) {
            newFlags[i] = true;
          }
          saveMetaToLocalFile({ stepDirtyFlags: { ...flags, ...newFlags } });
        },

        clearStepDirty: (stepId: number) => {
          set(state => {
            if (state.stepDirtyFlags) {
              state.stepDirtyFlags[stepId] = false;
            }
            state.updatedAt = Date.now();
          });
          const flags = get().stepDirtyFlags || {};
          saveMetaToLocalFile({ stepDirtyFlags: { ...flags, [stepId]: false } });
        },

        reset: () => {
          currentProjectId = '';
          setCurrentProjectId('');
          set({
            ...initialState,
            ...BLANK_META_OVERRIDES,
            segments: [],
            _hasHydrated: true,
          });
        },

      }),
      {
        name: 'ai-video-project-config',
        // 只保存配置，不保存项目数据（项目数据存文件）
        partialize: (state) => ({
          // 只保存 UI 状态，不保存项目业务数据
          _isLoading: state._isLoading,
          // 不保存: segments, finalVideoPath, coverPath 等
        }),
        onRehydrateStorage: () => state => {
          if (state) {
            state.setHasHydrated(true);
          }
        },
      }
    )
  )
);

// 注：移除自动保存，改为在"进入第二步"时手动创建项目
// 符合文档逻辑：第一步完成进入第二步时创建项目文件

/**
 * 初始化加载项目
 * 应用启动时调用
 */
export async function initProjectStore(projectId?: string): Promise<void> {
  const id = projectId || getCurrentProjectId();
  currentProjectId = id;
  setCurrentProjectId(id);


  const { meta: rawMeta, segments } = await localProjectApi.loadProject(id);

  if (rawMeta || segments.length > 0) {
    const meta = rawMeta ? migrateMeta(rawMeta) : null;

    // 先清空旧数据，再加载新项目数据，防止字段残留
    useProjectStore.setState({
      ...BLANK_META_OVERRIDES,
      segments: segments as ScriptShot[],
      ...(meta || {}),
      _hasHydrated: true,
    });
  } else {
    // 新项目
    useProjectStore.setState({
      ...BLANK_META_OVERRIDES,
      segments: [],
      _hasHydrated: true,
    });
  }
}

/**
 * 创建新项目
 * @param topic 创作灵感主题，用于生成标题
 * @param segments 可选的初始分镜数据（从第一步带入第二步时）
 */
export async function createNewProject(topic?: string, segments?: ScriptShot[]): Promise<string> {
  const newId = generateProjectId();
  currentProjectId = newId;
  setCurrentProjectId(newId);

  // 彻底重置 Store，防止旧项目数据残留
  useProjectStore.setState({
    ...initialState,
    ...BLANK_META_OVERRIDES,
    segments: segments || [],
    _hasHydrated: true,
  });

  // 使用 buildProjectMeta 自动构建 meta（包含 title 生成逻辑）
  const meta = buildProjectMeta(newId, null, { topic });
  await localProjectApi.saveMeta(newId, meta);

  return newId;
}

/**
 * 切换项目
 */
export async function switchProject(projectId: string): Promise<void> {
  // 切换项目 ID
  currentProjectId = projectId;
  setCurrentProjectId(projectId);

  // 加载新项目
  await initProjectStore(projectId);
}