import Foundation

enum APIError: LocalizedError {
    case invalidURL
    case networkError(Error)
    case invalidResponse(Int)
    case decodingError(Error)
    case noData

    var errorDescription: String? {
        switch self {
        case .invalidURL: return "无效的 URL"
        case .networkError(let error): return "网络错误: \(error.localizedDescription)"
        case .invalidResponse(let code): return "服务器错误: \(code)"
        case .decodingError(let error): return "解析错误: \(error.localizedDescription)"
        case .noData: return "无数据"
        }
    }
}

actor APIClient {
    static let shared = APIClient()

    private let baseURL = "https://ddys.io"
    private let session: URLSession

    private init() {
        let config = URLSessionConfiguration.default
        config.httpAdditionalHeaders = [
            "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36",
            "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
            "Accept-Language": "zh-CN,zh;q=0.9,en;q=0.8",
            "Referer": "https://ddys.io/",
        ]
        config.httpCookieStorage = .shared
        self.session = URLSession(configuration: config)
    }

    // MARK: - HTML 页面请求

    func fetchHTML(path: String) async throws -> String {
        guard let url = URL(string: baseURL + path) else {
            throw APIError.invalidURL
        }
        let (data, response) = try await session.data(from: url)
        guard let httpResponse = response as? HTTPURLResponse else {
            throw APIError.noData
        }
        guard (200...299).contains(httpResponse.statusCode) else {
            throw APIError.invalidResponse(httpResponse.statusCode)
        }
        guard let html = String(data: data, encoding: .utf8) else {
            throw APIError.noData
        }
        return html
    }

    // MARK: - 首页

    func fetchHomePage() async throws -> String {
        try await fetchHTML(path: "/")
    }

    // MARK: - 分类列表

    func fetchCategoryPage(category: ContentCategory, page: Int = 1, filter: FilterState = FilterState()) async throws -> String {
        var path = filter.buildPath(base: category.pathPrefix)
        if page > 1 {
            path += "/page/\(page)"
        }
        return try await fetchHTML(path: path)
    }

    // MARK: - 详情页

    func fetchDetailPage(path: String) async throws -> String {
        try await fetchHTML(path: path)
    }

    // MARK: - 搜索

    func fetchSearchPage(query: String, page: Int = 1) async throws -> String {
        let encoded = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? query
        var path = "/search?q=\(encoded)&type=all"
        if page > 1 {
            path += "&page=\(page)"
        }
        return try await fetchHTML(path: path)
    }

    // MARK: - JSON API

    func fetchHotMovies() async throws -> [HotMovieItem] {
        guard let url = URL(string: baseURL + "/api/hot-movies") else {
            throw APIError.invalidURL
        }
        let (data, response) = try await session.data(from: url)
        guard let httpResponse = response as? HTTPURLResponse,
              (200...299).contains(httpResponse.statusCode) else {
            throw APIError.invalidResponse((response as? HTTPURLResponse)?.statusCode ?? 0)
        }
        let result = try JSONDecoder().decode(HotMoviesResponse.self, from: data)
        return result.data
    }
}

// MARK: - API Response Models

struct HotMoviesResponse: Codable {
    let success: Bool
    let data: [HotMovieItem]
}

struct HotMovieItem: Codable, Identifiable {
    let id: Int?
    let title: String
    let slug: String
    let poster: String?

    var itemId: String { slug }
}