import Foundation
import SwiftUI

// MARK: - Book

struct Book: Identifiable, Codable, Hashable {
    let id: String
    let slug: String
    let title: String
    let author: String
    let cover: String        // proxied via /api/cover/...
    let status: String
    let genres: [String]
    let summary: String
    let totalChapters: Int
    let sourceURL: String
    let ranking: Int
    let metaUpdated: String

    enum CodingKeys: String, CodingKey {
        case id, slug, title, author, cover, status, genres, summary, ranking
        case totalChapters = "total_chapters"
        case sourceURL     = "source_url"
        case metaUpdated   = "meta_updated"
    }

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        id           = try c.decode(String.self, forKey: .id)
        slug         = try c.decode(String.self, forKey: .slug)
        title        = try c.decode(String.self, forKey: .title)
        author       = try c.decodeIfPresent(String.self, forKey: .author) ?? ""
        cover        = try c.decodeIfPresent(String.self, forKey: .cover) ?? ""
        status       = try c.decodeIfPresent(String.self, forKey: .status) ?? ""
        totalChapters = try c.decodeIfPresent(Int.self, forKey: .totalChapters) ?? 0
        sourceURL    = try c.decodeIfPresent(String.self, forKey: .sourceURL) ?? ""
        ranking      = try c.decodeIfPresent(Int.self, forKey: .ranking) ?? 0
        metaUpdated  = try c.decodeIfPresent(String.self, forKey: .metaUpdated) ?? ""
        summary      = try c.decodeIfPresent(String.self, forKey: .summary) ?? ""

        // genres can arrive as a JSON-encoded string or a real array
        if let arr = try? c.decode([String].self, forKey: .genres) {
            genres = arr
        } else if let raw = try? c.decode(String.self, forKey: .genres),
                  let data = raw.data(using: .utf8),
                  let arr  = try? JSONDecoder().decode([String].self, from: data) {
            genres = arr
        } else {
            genres = []
        }
    }
}

// MARK: - Chapter index

struct ChapterIndex: Identifiable, Codable, Hashable {
    let id: String
    let slug: String
    let number: Int
    let title: String
    let dateLabel: String

    enum CodingKeys: String, CodingKey {
        case id, slug, number, title
        case dateLabel = "date_label"
    }
}

struct ChapterBrief: Identifiable, Codable, Hashable {
    var id: Int { number }
    let number: Int
    let title: String
}

// Full chapter response from /api/chapter-text/{slug}/{n}
struct ChapterResponse: Decodable {
    struct BookBrief: Decodable {
        let slug: String
        let title: String
        let cover: String
    }
    struct ChapterDetail: Decodable {
        let number: Int
        let title: String
        let dateLabel: String

        enum CodingKeys: String, CodingKey {
            case number, title
            case dateLabel = "date_label"
        }
    }

    let book: BookBrief
    let chapter: ChapterDetail
    let chapters: [ChapterBrief]
    let html: String
    let text: String
    let prev: Int?
    let next: Int?
}

// MARK: - Ranking

struct RankingItem: Codable, Identifiable {
    var id: String { slug }
    let rank: Int
    let slug: String
    let title: String
    let author: String
    let cover: String
    let status: String
    let genres: [String]
    let sourceURL: String

    enum CodingKeys: String, CodingKey {
        case rank, slug, title, author, cover, status, genres
        case sourceURL = "source_url"
    }
}

// MARK: - Browse listing

struct NovelListing: Codable, Identifiable {
    var id: String { slug }
    let slug: String
    let title: String
    let author: String?
    let cover: String?
    let status: String?
    let genres: [String]?
    let rank: Int?
    let rating: String?
    let chapters: String?   // e.g. "123 chapters"
    let url: String?
    let sourceURL: String?

    enum CodingKeys: String, CodingKey {
        case slug, title, author, cover, status, genres, rank, rating, chapters, url
        case sourceURL = "source_url"
    }
}

// MARK: - Home

struct HomeStats: Codable {
    let totalBooks: Int
    let totalChapters: Int
    let booksInProgress: Int

    enum CodingKeys: String, CodingKey {
        case totalBooks    = "total_books"
        case totalChapters = "total_chapters"
        case booksInProgress = "books_in_progress"
    }
}

struct ContinueReadingItem: Identifiable {
    var id: String { book.id }
    let book: Book
    let chapter: Int
}

struct SubscriptionFeedItem: Identifiable, Decodable {
    var id: String { book.id + readerUsername }
    let book: Book
    let readerUsername: String

    enum CodingKeys: String, CodingKey {
        case book
        case readerUsername = "readerUsername"
    }
}

// MARK: - User

struct AppUser: Codable, Identifiable {
    let id: String
    let username: String
    let role: String
    let created: String
    let avatarURL: String?

    var isAdmin: Bool { role == "admin" }

    enum CodingKeys: String, CodingKey {
        case id, username, role, created
        case avatarURL = "avatar_url"
    }

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        id        = try c.decode(String.self, forKey: .id)
        username  = try c.decode(String.self, forKey: .username)
        role      = try c.decodeIfPresent(String.self, forKey: .role) ?? "user"
        created   = try c.decodeIfPresent(String.self, forKey: .created) ?? ""
        avatarURL = try c.decodeIfPresent(String.self, forKey: .avatarURL)
    }

    init(id: String, username: String, role: String, created: String, avatarURL: String?) {
        self.id        = id
        self.username  = username
        self.role      = role
        self.created   = created
        self.avatarURL = avatarURL
    }
}

// MARK: - User settings

struct UserSettings: Codable {
    var autoNext: Bool
    var voice: String
    var speed: Double

    static let `default` = UserSettings(autoNext: false, voice: "af_bella", speed: 1.0)
}

// MARK: - Session

struct UserSession: Codable, Identifiable {
    let id: String
    let userAgent: String
    let ip: String
    let createdAt: String
    let lastSeen: String
    var isCurrent: Bool

    enum CodingKeys: String, CodingKey {
        case id, ip
        case userAgent = "user_agent"
        case createdAt = "created_at"
        case lastSeen  = "last_seen"
        case isCurrent = "is_current"
    }
}

// MARK: - Comments

struct BookComment: Identifiable, Codable, Hashable {
    let id: String
    let slug: String
    let userId: String
    let username: String
    let body: String
    var upvotes: Int
    var downvotes: Int
    let created: String
    let parentId: String
    var replies: [BookComment]?

    enum CodingKeys: String, CodingKey {
        case id, slug, username, body, upvotes, downvotes, created, replies
        case userId   = "user_id"
        case parentId = "parent_id"
    }

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        id        = try c.decode(String.self, forKey: .id)
        slug      = try c.decodeIfPresent(String.self, forKey: .slug) ?? ""
        userId    = try c.decodeIfPresent(String.self, forKey: .userId) ?? ""
        username  = try c.decodeIfPresent(String.self, forKey: .username) ?? ""
        body      = try c.decodeIfPresent(String.self, forKey: .body) ?? ""
        upvotes   = try c.decodeIfPresent(Int.self, forKey: .upvotes) ?? 0
        downvotes = try c.decodeIfPresent(Int.self, forKey: .downvotes) ?? 0
        created   = try c.decodeIfPresent(String.self, forKey: .created) ?? ""
        parentId  = try c.decodeIfPresent(String.self, forKey: .parentId) ?? ""
        replies   = try c.decodeIfPresent([BookComment].self, forKey: .replies)
    }
}

struct CommentsResponse: Decodable {
    let comments: [BookComment]
    let myVotes: [String: String]
    let avatarUrls: [String: String]

    enum CodingKeys: String, CodingKey {
        case comments, myVotes, avatarUrls
    }

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        comments   = try c.decode([BookComment].self, forKey: .comments)
        myVotes    = try c.decodeIfPresent([String: String].self, forKey: .myVotes) ?? [:]
        avatarUrls = try c.decodeIfPresent([String: String].self, forKey: .avatarUrls) ?? [:]
    }
}

// MARK: - Public user profile

struct PublicUserProfile: Decodable, Identifiable {
    let id: String
    let username: String
    let avatarUrl: String?
    let created: String
    let followerCount: Int
    let followingCount: Int
    let isSubscribed: Bool
    let isSelf: Bool

    enum CodingKeys: String, CodingKey {
        case id, username, created
        case avatarUrl      = "avatarUrl"
        case followerCount  = "followerCount"
        case followingCount = "followingCount"
        case isSubscribed   = "isSubscribed"
        case isSelf         = "isSelf"
    }

    init(from decoder: Decoder) throws {
        let c = try decoder.container(keyedBy: CodingKeys.self)
        id             = try c.decode(String.self, forKey: .id)
        username       = try c.decode(String.self, forKey: .username)
        avatarUrl      = try c.decodeIfPresent(String.self, forKey: .avatarUrl)
        created        = try c.decodeIfPresent(String.self, forKey: .created) ?? ""
        followerCount  = try c.decodeIfPresent(Int.self, forKey: .followerCount) ?? 0
        followingCount = try c.decodeIfPresent(Int.self, forKey: .followingCount) ?? 0
        isSubscribed   = try c.decodeIfPresent(Bool.self, forKey: .isSubscribed) ?? false
        isSelf         = try c.decodeIfPresent(Bool.self, forKey: .isSelf) ?? false
    }
}

struct PublicLibraryItem: Decodable, Identifiable {
    var id: String { book.id }
    let book: Book
    let lastChapter: Int?
    let saved: Bool

    enum CodingKeys: String, CodingKey {
        case book
        case lastChapter = "last_chapter"
        case saved
    }
}

struct PublicUserLibraryResponse: Decodable {
    let currentlyReading: [PublicLibraryItem]
    let library: [PublicLibraryItem]

    enum CodingKeys: String, CodingKey {
        case currentlyReading = "currently_reading"
        case library
    }
}

// MARK: - Reader Settings (local — UserDefaults)

enum ReaderTheme: String, CaseIterable, Codable {
    case white, sepia, night

    var backgroundColor: Color {
        switch self {
        case .white: return Color(.sRGB, white: 1.0, opacity: 1)
        case .sepia:  return Color(red: 0.97, green: 0.93, blue: 0.82)
        case .night:  return Color(red: 0.10, green: 0.10, blue: 0.12)
        }
    }

    var textColor: Color {
        switch self {
        case .white: return Color(.sRGB, white: 0.10, opacity: 1)
        case .sepia:  return Color(red: 0.25, green: 0.18, blue: 0.08)
        case .night:  return Color(red: 0.85, green: 0.85, blue: 0.87)
        }
    }

    var colorScheme: ColorScheme? {
        switch self {
        case .white: return nil
        case .sepia:  return .light
        case .night:  return .dark
        }
    }
}

enum ReaderFont: String, CaseIterable, Codable {
    case system  = "System"
    case georgia = "Georgia"
    case newYork = "New York"

    var fontName: String? {
        switch self {
        case .system:  return nil
        case .georgia: return "Georgia"
        case .newYork: return "NewYorkMedium-Regular"
        }
    }
}

struct ReaderSettings: Codable, Equatable {
    var fontSize: CGFloat    = 17
    var lineSpacing: CGFloat = 1.7
    var font: ReaderFont     = .system
    var theme: ReaderTheme   = .white
    var scrollMode: Bool     = false

    private static let key = "v2.readerSettings"

    static func load() -> ReaderSettings {
        guard let data = UserDefaults.standard.data(forKey: key),
              let decoded = try? JSONDecoder().decode(ReaderSettings.self, from: data)
        else { return ReaderSettings() }
        return decoded
    }

    func save() {
        if let data = try? JSONEncoder().encode(self) {
            UserDefaults.standard.set(data, forKey: ReaderSettings.key)
        }
    }
}

// MARK: - Audio prefetch status

enum NextPrefetchStatus {
    case none, prefetching, prefetched, failed
}