import { Model } from '../types/models';
import { authService } from './authService';

// API Base URL - nginx 反代模式下为空字符串（走相对路径 /api/）
const API_BASE_URL = import.meta.env.VITE_API_BASE_URL ?? '';

// API 响应类型定义
export interface ApiResponse<T> {
  code: number;
  message: string;
  data: T;
}

// 后端API响应类型（对应新表 models_new）
export interface BackendModelResponse {
  id: number;
  model_code: string;
  display_name: string | null;
  img: string | null;
  tag1: string | null;
  tag2: string | null;
  description: string | null;
  custom_description: string | null;
  keyword: string | null;
  keywords: string | null;
  categories: number[];
  category: number;
  supplier: string;
  is_featured: boolean;
  is_api_enabled: boolean;
  is_show_enabled: boolean;
  created_at: string;
  updated_at: string;
  // 前端兼容字段（后端 model_service 里有映射）
  title: string;
  name: string;
  time: string | null;
  price_id: number | null;
  pricing_mode: string | null;
  input_price: string | null;
  output_price: string | null;
  price_unit: string | null;
  price_currency: string | null;
  price_tiers: any[];
}

// 精选模型列表响应类型
export interface FeaturedModelsResponse {
  items: BackendModelResponse[];
}

export interface ParsedPricingResponse {
  model_code: string;
  model_intro?: string | null;
  model_tags?: string[] | null;
  model_capabilities?: any | null;
  model_pricing?: any | null;
  tool_call_pricing?: any | null;
  model_limits?: any | null;
  api_examples?: any | null;
  is_api_enabled?: boolean;
  categories?: number[];
}

export interface ParsedPricingMappingItem {
  source_key: string;
  normalized_key: string;
  model_code: string;
}

export interface ParsedPricingMappingResponse {
  items: ParsedPricingMappingItem[];
}

export interface BackendPaginatedResponse {
  total: number;
  page: number;
  page_size: number;
  items: BackendModelResponse[];
}

export interface Pagination {
  page: number;
  pageSize: number;
  total: number;
  totalPages: number;
}

export interface ModelListResponse {
  list: Model[];
  pagination: Pagination;
}

export interface ModelDetailResponse extends Model {
  apiEndpoint?: string;
  apiDocumentation?: string;
  pricing?: {
    type: string;
    unit: string;
    price: number;
  };
  capabilities?: string[];
  limitations?: string[];
}

// 请求参数接口
export interface GetModelsParams {
  keyword?: string;
  page?: number;
  pageSize?: number;
  category?: string;
  supplier?: string;           // 供应商筛选（对应后端 supplier 参数）
  group_name?: string;         // 模型分组筛选（对应后端 group_name 参数）
  filter_keyword?: string;     // 关键字筛选（对应后端 filter_keyword 参数）
  filter_tag?: string;         // 标签筛选（对应后端 filter_tag 参数）
  is_api_enabled?: boolean;    // 是否支持API调用筛选
  // 以下为前端本地筛选参数
  isNew?: boolean;
  isHot?: boolean;
  sortBy?: string;
  order?: 'asc' | 'desc';
}

// 模型分类映射到分类字符串（支持多分类，取优先级最高的）
const CATEGORY_NAMES: Record<number, string> = {
  0: '语言模型', 1: '多模态模型', 2: 'TTS模型', 3: 'STT模型',
  4: '生图模型', 5: '生视频模型', 6: '图像编辑', 7: 'Embedding', 8: 'Rerank'
};

const getModelCategory = (categories: number[], category?: number): string => {
  const cats = categories?.length ? categories : (category !== undefined ? [category] : [0]);
  const priority = [6, 5, 4, 3, 2, 8, 7, 1, 0];
  const main = priority.find(c => cats.includes(c)) ?? cats[0] ?? 0;
  return CATEGORY_NAMES[main] || '语言模型';
};

// 前端分类名称映射到后端 category 数值
const categoryNameToNumber: Record<string, number> = {
  '语言模型': 0, '多模态模型': 1, 'TTS模型': 2, 'STT模型': 3,
  '生图模型': 4, '生视频模型': 5, '图像编辑': 6, 'Embedding': 7, 'Rerank': 8
};

// 将后端模型数据转换为前端Model格式（字段与 Model 类型对齐）
function convertBackendModelToModel(backendModel: BackendModelResponse): Model {
  const cats = backendModel.categories?.length ? backendModel.categories : [backendModel.category ?? 0];
  return {
    id: backendModel.id,
    title: backendModel.model_code,
    img: backendModel.img || '',
    name: backendModel.display_name || backendModel.model_code,
    tag1: backendModel.tag1,
    description: backendModel.custom_description || backendModel.description,
    keyword: backendModel.keywords || backendModel.keyword,
    time: null,
    tag2: backendModel.tag2,
    category: cats[0],
    categories: cats,
    supplier: backendModel.supplier,
    price_id: null,
    is_featured: backendModel.is_featured,
    is_api_enabled: backendModel.is_api_enabled,
    created_at: backendModel.created_at,
    updated_at: backendModel.updated_at,
    pricing_mode: null,
    input_price: null,
    output_price: null,
    price_unit: null,
    price_currency: null,
    price_tiers: [],
  };
}

// 真实 API 调用
class ModelApiService {
  private baseUrl = `${API_BASE_URL}/api/models`;

  /**
   * 获取请求头（包含鉴权信息）
   * @returns 请求头对象
   */
  private getHeaders(): Record<string, string> {
    const headers: Record<string, string> = {
      'Content-Type': 'application/json'
    };

    // 始终添加 Authorization header（如果有token）
    const authHeader = authService.getAuthHeader();
    if (authHeader) {
      headers['Authorization'] = authHeader;
    }

    return headers;
  }

  /**
   * 处理 API 响应，检查鉴权错误
   * @param response 响应对象
   */
  private handleAuthError(response: ApiResponse<any>): void {
    if (response.code === 401) {
      // Token 过期或无效，清除本地存储并重定向到登录页
      authService.logout();
      // 实际项目中可以触发路由跳转到登录页
      if (typeof window !== 'undefined') {
        console.warn('Token 已过期，请重新登录');
        // window.location.href = '/login';
      }
    }
  }

  /**
   * 发送HTTP请求
   * @param url 请求URL
   * @param options 请求选项
   * @returns Promise<Response>
   */
  private async fetchApi(url: string, options: RequestInit = {}): Promise<Response> {
    const response = await fetch(url, {
      ...options,
      headers: {
        'Content-Type': 'application/json',
        ...options.headers,
      },
    });

    if (!response.ok) {
      if (response.status === 401) {
        authService.logout();
        throw new Error('未授权：请先登录');
      }
      if (response.status === 404) {
        throw new Error('资源不存在');
      }
      throw new Error(`HTTP错误: ${response.status}`);
    }

    return response;
  }

  /**
   * 获取模型列表
   * API: GET /api/models
   * @param params 查询参数
   */
  async getModels(params: GetModelsParams = {}): Promise<ApiResponse<ModelListResponse>> {
    try {
      // 构建查询参数 - 使用后端API支持的参数
      const queryParams = new URLSearchParams();
      if (params.page) {
        queryParams.append('page', params.page.toString());
      }
      if (params.pageSize) {
        queryParams.append('page_size', params.pageSize.toString());
      }
      if (params.keyword) {
        queryParams.append('keyword', params.keyword);
      }
      // 分类筛选 - 直接传给后端处理
      if (params.category && params.category !== '全部') {
        queryParams.append('category', params.category);
      }
      // 供应商筛选 - 后端支持精确匹配
      if (params.supplier) {
        queryParams.append('supplier', params.supplier);
      }
      // 模型分组筛选 - 后端支持精确匹配
      if (params.group_name) {
        queryParams.append('group_name', params.group_name);
      }
      // 关键字筛选 - 后端支持精确匹配 keyword 字段
      if (params.filter_keyword) {
        queryParams.append('filter_keyword', params.filter_keyword);
      }
      // 标签筛选 - 后端支持在 tag1 或 tag2 中精确匹配
      if (params.filter_tag) {
        queryParams.append('filter_tag', params.filter_tag);
      }
      // API支持筛选
      if (params.is_api_enabled !== undefined) {
        queryParams.append('is_api_enabled', params.is_api_enabled.toString());
      }

      const url = `${this.baseUrl}?${queryParams.toString()}`;
      const headers = this.getHeaders();
      
      const response = await this.fetchApi(url, {
        method: 'GET',
        headers,
      });

      const apiResponse: ApiResponse<BackendPaginatedResponse> = await response.json();

      // 检查鉴权错误
      this.handleAuthError(apiResponse);

      if (apiResponse.code !== 200) {
        throw new Error(apiResponse.message || '获取模型列表失败');
      }

      // 转换后端数据格式为前端格式
      const convertedModels = apiResponse.data.items.map(convertBackendModelToModel);

      // 前端本地筛选（后端不支持的筛选条件）
      let filteredModels = [...convertedModels];

      // 最新模型筛选：基于 tag1 / tag2 推断
      if (params.isNew !== undefined) {
        filteredModels = filteredModels.filter(m => 
          params.isNew 
            ? (m.tag1 === 'New' || m.tag2 === 'New')
            : !(m.tag1 === 'New' || m.tag2 === 'New')
        );
      }

      // 热门模型筛选：基于 is_featured 字段
      if (params.isHot !== undefined) {
        filteredModels = filteredModels.filter(m => 
          params.isHot ? m.is_featured : !m.is_featured
        );
      }

      // 排序
      const sortBy = params.sortBy || 'createdAt';
      const order = params.order || 'desc';
      
      filteredModels.sort((a, b) => {
        if (sortBy === 'name') {
          return order === 'asc' 
            ? a.name.localeCompare(b.name)
            : b.name.localeCompare(a.name);
        }
        // 默认按创建时间排序
        return order === 'asc'
          ? new Date(a.created_at).getTime() - new Date(b.created_at).getTime()
          : new Date(b.created_at).getTime() - new Date(a.created_at).getTime();
      });

      // 使用后端返回的分页信息
      const page = apiResponse.data.page;
      const pageSize = apiResponse.data.page_size;
      // 如果有前端本地筛选，需要重新计算 total
      const hasLocalFilter = params.isNew !== undefined || params.isHot !== undefined;
      const total = hasLocalFilter ? filteredModels.length : apiResponse.data.total;
      const totalPages = Math.ceil(total / pageSize);
      
      // 如果进行了前端本地筛选，需要重新分页
      let paginatedModels = filteredModels;
      if (hasLocalFilter) {
        const startIndex = (page - 1) * pageSize;
        const endIndex = startIndex + pageSize;
        paginatedModels = filteredModels.slice(startIndex, endIndex);
      }

      return {
        code: 200,
        message: 'success',
        data: {
          list: paginatedModels,
          pagination: {
            page,
            pageSize,
            total,
            totalPages
          }
        }
      };
    } catch (error) {
      console.error('Failed to fetch models:', error);
      throw error;
    }
  }

  /**
   * 获取 parsed_json 中的模型定价信息
   * API: GET /api/models/pricing/{model_code}
   * @param modelCode 模型代码
   */
  async getParsedPricing(modelCode: string): Promise<ApiResponse<ParsedPricingResponse>> {
    const url = `${this.baseUrl}/pricing/${encodeURIComponent(modelCode)}`;
    const response = await this.fetchApi(url, {
      method: 'GET',
      headers: this.getHeaders()
    });
    const data = await response.json();
    this.handleAuthError(data);
    return data;
  }

  /**
   * 获取模型定价映射关系
   * API: GET /api/models/pricing/mapping
   */
  async getParsedPricingMapping(): Promise<ApiResponse<ParsedPricingMappingResponse>> {
    const url = `${this.baseUrl}/pricing/mapping`;
    const response = await this.fetchApi(url, {
      method: 'GET',
      headers: this.getHeaders()
    });
    const data = await response.json();
    this.handleAuthError(data);
    return data;
  }

  /**
   * 获取模型详情
   * API: GET /api/models/{modelId}
   * @param modelId 模型 ID（数字ID）
   */
  async getModelDetail(modelId: number): Promise<ApiResponse<ModelDetailResponse>> {
    try {
      const url = `${this.baseUrl}/${modelId}`;
      const headers = this.getHeaders();
      
      const response = await this.fetchApi(url, {
        method: 'GET',
        headers,
      });

      const apiResponse: ApiResponse<BackendModelResponse> = await response.json();

      // 检查鉴权错误
      this.handleAuthError(apiResponse);

      if (apiResponse.code !== 200) {
        throw new Error(apiResponse.message || '获取模型详情失败');
      }

      // 转换后端数据格式为前端格式
      const model = convertBackendModelToModel(apiResponse.data);
      const category = getModelCategory(model.category);

      // 扩展模型详情信息
      const detail: ModelDetailResponse = {
        ...model,
        apiEndpoint: `${API_BASE_URL}/api/models/${modelId}`,
        apiDocumentation: `${API_BASE_URL}/docs`,
        pricing: {
          type: 'usage',
          unit: 'token',
          price: 0.001
        },
        capabilities: [
          `${category}生成`,
          `${category}理解`,
          '多语言支持'
        ],
        limitations: [
          '最大上下文长度：128K tokens',
          '不支持图像输入'
        ]
      };

      return {
        code: 200,
        message: 'success',
        data: detail
      };
    } catch (error) {
      console.error('Failed to fetch model detail:', error);
      throw error;
    }
  }

  /**
   * 获取模型分类统计
   * 通过获取所有模型并统计分类
   */
  async getCategoryStatistics(): Promise<ApiResponse<Record<string, number>>> {
    try {
      // 获取所有模型（使用较大的page_size）
      const response = await this.getModels({ page: 1, pageSize: 1000 });
      
      const allModels = response.data.list;
      const hasCategory = (m: Model, c: number) => {
        const cats: number[] = (m as any).categories?.length ? (m as any).categories : [m.category];
        return cats.includes(c);
      };
      const statistics: Record<string, number> = {
        '全部': response.data.pagination.total,
        '语言模型': allModels.filter(m => hasCategory(m, 0)).length,
        '多模态模型': allModels.filter(m => hasCategory(m, 1)).length,
        'TTS模型': allModels.filter(m => hasCategory(m, 2)).length,
        'STT模型': allModels.filter(m => hasCategory(m, 3)).length,
        '生图模型': allModels.filter(m => hasCategory(m, 4)).length,
        '生视频模型': allModels.filter(m => hasCategory(m, 5)).length,
        '图像编辑': allModels.filter(m => hasCategory(m, 6)).length,
        'Embedding': allModels.filter(m => hasCategory(m, 7)).length,
        'Rerank': allModels.filter(m => hasCategory(m, 8)).length,
      };

      return {
        code: 200,
        message: 'success',
        data: statistics
      };
    } catch (error) {
      console.error('Failed to fetch category statistics:', error);
      throw error;
    }
  }

  /**
   * 获取精选模型列表
   * API: GET /api/models/featured/list
   * @param limit 返回数量，范围1-10，默认3
   */
  async getFeaturedModels(limit: number = 3): Promise<ApiResponse<{ items: Model[] }>> {
    try {
      const queryParams = new URLSearchParams();
      queryParams.append('limit', limit.toString());

      const url = `${this.baseUrl}/featured/list?${queryParams.toString()}`;
      
      const response = await this.fetchApi(url, {
        method: 'GET',
      });

      const apiResponse: ApiResponse<FeaturedModelsResponse> = await response.json();

      if (apiResponse.code !== 200) {
        throw new Error(apiResponse.message || '获取精选模型列表失败');
      }

      // 转换后端数据格式为前端格式
      const convertedModels = apiResponse.data.items.map(convertBackendModelToModel);

      return {
        code: 200,
        message: 'success',
        data: {
          items: convertedModels
        }
      };
    } catch (error) {
      console.error('Failed to fetch featured models:', error);
      throw error;
    }
  }

  /**
   * 获取所有模型分组名称（去重排序）
   * API: GET /api/models/group-names/list
   */
  async getGroupNames(): Promise<ApiResponse<string[]>> {
    try {
      const url = `${this.baseUrl}/group-names/list`;
      
      const response = await this.fetchApi(url, {
        method: 'GET',
      });

      const apiResponse: ApiResponse<string[]> = await response.json();

      if (apiResponse.code !== 200) {
        throw new Error(apiResponse.message || '获取分组列表失败');
      }

      return apiResponse;
    } catch (error) {
      console.error('Failed to fetch group names:', error);
      throw error;
    }
  }

}

// 导出单例
export const modelApi = new ModelApiService();

let pricingMappingCache: Map<string, string> | null = null;
let pricingMappingPromise: Promise<Map<string, string>> | null = null;

export const getPricingMappingLookup = async (): Promise<Map<string, string>> => {
  if (pricingMappingCache) {
    return pricingMappingCache;
  }
  if (pricingMappingPromise) {
    return pricingMappingPromise;
  }

  pricingMappingPromise = modelApi.getParsedPricingMapping()
    .then((response) => {
      const mapping = new Map<string, string>();
      if (response?.data?.items) {
        response.data.items.forEach((item) => {
          if (item.normalized_key && item.model_code) {
            mapping.set(item.normalized_key, item.model_code);
          }
          if (item.source_key && item.model_code) {
            mapping.set(item.source_key, item.model_code);
          }
        });
      }
      pricingMappingCache = mapping;
      return mapping;
    })
    .catch((error) => {
      pricingMappingPromise = null;
      throw error;
    });

  return pricingMappingPromise;
};