'use client';

import { create } from 'zustand';
import type { Requirement, RequirementStatus, Effort, DictItem, SourceType, SourceTarget } from '@/lib/requirement';
import type { Priority } from '@/lib/derive';
import {
  createRequirementByProductId,
  deleteRequirementByProductId,
  updateRequirementByProductId,
  updateRequirementStatusByProductId,
} from '@/lib/domain-api';
import { scheduleSaveWithOptimisticRollback } from '@/lib/optimistic-persistence';
import { loadServerData, saveServerData, SERVER_DATA_CACHE_MS } from '@/lib/server-data';

interface RequirementState {
  requirements: Requirement[];
  sourceTargets: SourceTarget[];
  types: DictItem[];
  platforms: DictItem[];
  loading: boolean;
  loaded: boolean;
  fetchRequirements: (options?: { force?: boolean }) => Promise<void>;
  createRequirement: (data: Omit<Requirement, 'id' | 'code' | 'createdAt'>) => void;
  updateRequirement: (id: string, data: Partial<Requirement>) => void;
  deleteRequirement: (id: string, productId?: string) => void;
  addSourceTarget: (name: string, sourceType: SourceType) => void;
  updateSourceTarget: (id: string, name: string) => void;
  deleteSourceTarget: (id: string) => void;
  addType: (name: string) => void;
  updateType: (id: string, name: string) => void;
  deleteType: (id: string) => void;
  addPlatform: (name: string) => void;
  updatePlatform: (id: string, name: string) => void;
  deletePlatform: (id: string) => void;
}

// --- Preset dictionaries ---

const PRESET_SOURCE_TARGETS: SourceTarget[] = [];

const PRESET_TYPES: DictItem[] = [
  { id: 'type-1', name: '新功能', createdAt: '2024-01-01' },
  { id: 'type-2', name: 'BUG修复', createdAt: '2024-01-01' },
  { id: 'type-3', name: '数据需求/埋点需求', createdAt: '2024-01-01' },
  { id: 'type-4', name: '优化需求', createdAt: '2024-01-01' },
  { id: 'type-5', name: '模块重构', createdAt: '2024-01-01' },
  { id: 'type-6', name: '缺陷修复', createdAt: '2024-01-01' },
  { id: 'type-7', name: '功能优化', createdAt: '2024-01-01' },
  { id: 'type-8', name: '插单/紧急需求', createdAt: '2024-01-01' },
];

const PRESET_PLATFORMS: DictItem[] = [
  { id: 'platform-1', name: 'Web', createdAt: '2024-01-01' },
  { id: 'platform-2', name: 'App(iOS)', createdAt: '2024-01-01' },
  { id: 'platform-3', name: 'App(Android)', createdAt: '2024-01-01' },
  { id: 'platform-4', name: '小程序', createdAt: '2024-01-01' },
  { id: 'platform-5', name: 'H5', createdAt: '2024-01-01' },
];

// --- Mock requirements ---

const MOCK_REQUIREMENTS: Requirement[] = [];
let lastRequirementsFetchAt = 0;

async function loadStored(): Promise<{ requirements: Requirement[]; sourceTargets: SourceTarget[]; types: DictItem[]; platforms: DictItem[] } | null> {
  try {
    return await loadServerData<{ requirements: Requirement[]; sourceTargets: SourceTarget[]; types: DictItem[]; platforms: DictItem[] }>('requirements');
  } catch {}
  return null;
}

// --- Store ---

export const useRequirementStore = create<RequirementState>((set, get) => {
  return {
    requirements: MOCK_REQUIREMENTS,
    sourceTargets: PRESET_SOURCE_TARGETS,
    types: PRESET_TYPES,
    platforms: PRESET_PLATFORMS,
    loading: false,
    loaded: false,

    fetchRequirements: async (options) => {
      if (!options?.force && get().loaded && Date.now() - lastRequirementsFetchAt < SERVER_DATA_CACHE_MS) return;
      const cached = await loadStored();
      if (!options?.force && get().loaded && Date.now() - lastRequirementsFetchAt < SERVER_DATA_CACHE_MS) return;
      lastRequirementsFetchAt = Date.now();
      if (cached) {
        set({ requirements: cached.requirements, sourceTargets: cached.sourceTargets, types: cached.types, platforms: cached.platforms, loaded: true });
      } else {
        set({ loaded: true });
      }
    },

    createRequirement: (data) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const code = `REQ-${String(requirements.length + 1).padStart(3, '0')}`;
      const newReq: Requirement = {
        ...data,
        status: data.status ?? 'pending_review',
        id: `req-${Date.now()}`,
        code,
        createdAt: new Date().toISOString(),
      };
      const updated = [...requirements, newReq];
      set({ requirements: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: async () => {
          try {
            const created = await createRequirementByProductId(newReq.productId, newReq);
            set({
              requirements: get().requirements.map((item) => (
                item.id === newReq.id ? { ...created, creator: newReq.creator || created.creator } : item
              )),
              loaded: true,
            });
          } catch {
            await saveRequirementsFallback({ requirements: updated, sourceTargets, types, platforms });
          }
        },
        expected: updated,
        getCurrent: () => get().requirements,
        rollback: () => set({ requirements, loaded: true }),
      });
    },

    updateRequirement: (id, data) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const current = requirements.find((r) => r.id === id);
      const productId = data.productId ?? current?.productId;
      const updated = requirements.map((r) => (r.id === id ? { ...r, ...data } : r));
      set({ requirements: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: async () => {
          try {
            if (!productId) throw new Error('missing requirement productId');
            const domainPatch = { ...data };
            const status = domainPatch.status;
            delete domainPatch.status;
            delete domainPatch.productId;
            delete domainPatch.productOwner;
            delete domainPatch.addedToVersionBy;
            if (hasDomainPatch(domainPatch)) {
              await updateRequirementByProductId(productId, id, domainPatch);
            }
            if (status) {
              await updateRequirementStatusByProductId(productId, id, status);
            }
          } catch {
            await saveRequirementsFallback({ requirements: updated, sourceTargets, types, platforms });
          }
        },
        expected: updated,
        getCurrent: () => get().requirements,
        rollback: () => set({ requirements, loaded: true }),
      });
    },

    deleteRequirement: (id, scopedProductId) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const productId = scopedProductId ?? requirements.find((r) => r.id === id)?.productId;
      const updated = requirements.filter((r) => r.id !== id);
      set({ requirements: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: async () => {
          try {
            if (!productId) throw new Error('missing requirement productId');
            await deleteRequirementByProductId(productId, id);
          } catch {
            await saveRequirementsFallback({ requirements: updated, sourceTargets, types, platforms });
          }
        },
        expected: updated,
        getCurrent: () => get().requirements,
        rollback: () => set({ requirements, loaded: true }),
      });
    },

    // --- SourceTarget dict ---
    addSourceTarget: (name, sourceType) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const item: SourceTarget = { id: `st-${Date.now()}`, name, sourceType, createdAt: new Date().toISOString().slice(0, 10) };
      const updated = [...sourceTargets, item];
      set({ sourceTargets: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets: updated, types, platforms }),
        expected: updated,
        getCurrent: () => get().sourceTargets,
        rollback: () => set({ sourceTargets, loaded: true }),
      });
    },

    updateSourceTarget: (id, name) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = sourceTargets.map((s) => (s.id === id ? { ...s, name } : s));
      set({ sourceTargets: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets: updated, types, platforms }),
        expected: updated,
        getCurrent: () => get().sourceTargets,
        rollback: () => set({ sourceTargets, loaded: true }),
      });
    },

    deleteSourceTarget: (id) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = sourceTargets.filter((s) => s.id !== id);
      set({ sourceTargets: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets: updated, types, platforms }),
        expected: updated,
        getCurrent: () => get().sourceTargets,
        rollback: () => set({ sourceTargets, loaded: true }),
      });
    },

    // --- Type dict ---
    addType: (name) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const item: DictItem = { id: `type-${Date.now()}`, name, createdAt: new Date().toISOString().slice(0, 10) };
      const updated = [...types, item];
      set({ types: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types: updated, platforms }),
        expected: updated,
        getCurrent: () => get().types,
        rollback: () => set({ types, loaded: true }),
      });
    },

    updateType: (id, name) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = types.map((t) => (t.id === id ? { ...t, name } : t));
      set({ types: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types: updated, platforms }),
        expected: updated,
        getCurrent: () => get().types,
        rollback: () => set({ types, loaded: true }),
      });
    },

    deleteType: (id) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = types.filter((t) => t.id !== id);
      set({ types: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types: updated, platforms }),
        expected: updated,
        getCurrent: () => get().types,
        rollback: () => set({ types, loaded: true }),
      });
    },

    // --- Platform dict ---
    addPlatform: (name) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const item: DictItem = { id: `platform-${Date.now()}`, name, createdAt: new Date().toISOString().slice(0, 10) };
      const updated = [...platforms, item];
      set({ platforms: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types, platforms: updated }),
        expected: updated,
        getCurrent: () => get().platforms,
        rollback: () => set({ platforms, loaded: true }),
      });
    },

    updatePlatform: (id, name) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = platforms.map((p) => (p.id === id ? { ...p, name } : p));
      set({ platforms: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types, platforms: updated }),
        expected: updated,
        getCurrent: () => get().platforms,
        rollback: () => set({ platforms, loaded: true }),
      });
    },

    deletePlatform: (id) => {
      const { requirements, sourceTargets, types, platforms } = get();
      const updated = platforms.filter((p) => p.id !== id);
      set({ platforms: updated, loaded: true });
      scheduleSaveWithOptimisticRollback({
        save: () => saveServerData('requirements', { requirements, sourceTargets, types, platforms: updated }),
        expected: updated,
        getCurrent: () => get().platforms,
        rollback: () => set({ platforms, loaded: true }),
      });
    },
  };
});

async function saveRequirementsFallback(data: {
  requirements: Requirement[];
  sourceTargets: SourceTarget[];
  types: DictItem[];
  platforms: DictItem[];
}) {
  await saveServerData('requirements', data);
}

function hasDomainPatch(data: Partial<Requirement>) {
  return Object.values(data).some((value) => value !== undefined);
}