import CoreTransferable
import Foundation
import UniformTypeIdentifiers

// MARK: - Custom UTTypes for drag-and-drop

extension UTType {
    static let chadTrack = UTType(exportedAs: "com.mixboard.chad-track")
    static let chadAlbum = UTType(exportedAs: "com.mixboard.chad-album")
}

// MARK: - Chad Music API Response Models

/// Navigation value for drilling into a category (e.g., artist "Pink Floyd" → show their albums).
struct CategoryFilter: Hashable {
    let category: ChadCategoryType
    let value: String
}

/// A category entry from GET /api/cat/:category (e.g., album, artist, genre).
/// Server returns: {"item": "Rock", "count": 42}
struct ChadCategory: Codable, Identifiable, Hashable {
    let item: String
    let count: Int?

    // No server-side ID — use item name as identity
    var id: String { item }
    var name: String { item }
}

/// An album from the Chad Music API.
/// Server keys: id, artist, year, album (title), publisher, country, genre, type, status, mb_id, track_count, total_duration, cover
struct ChadAlbum: Codable, Identifiable, Hashable {
    let id: String
    let album: String?         // server can return null for some releases
    let artist: String?
    let year: Int?
    let genre: String?
    let trackCount: Int?
    let cover: String?
    let publisher: String?
    let country: String?
    let type: String?
    let status: String?
    let totalDuration: Double?
    let originalDate: String?
    let mbId: String?

    /// Display-friendly title.
    var title: String { album ?? "Untitled" }

    enum CodingKeys: String, CodingKey {
        case id, album, artist, year, genre, cover, publisher, country
        case trackCount = "track_count"
        case totalDuration = "total_duration"
        case originalDate = "original_date"
        case mbId = "mb_id"
        case type, status
    }
}

/// A track from GET /api/album/:id/tracks.
/// Server keys: id, artist, album_artist, album, year, no (track#), title, bit_rate, duration, url, cover
struct ChadTrack: Codable, Identifiable, Hashable {
    let id: String
    let title: String
    let artist: String?
    let albumArtist: String?
    let album: String?
    let duration: Double?
    let no: Int?              // server calls track number "no"
    let url: String           // relative path for streaming
    let bitRate: Int?
    let year: Int?
    let cover: String?

    /// Track number for display.
    var trackNumber: Int? { no }

    enum CodingKeys: String, CodingKey {
        case id, title, artist, album, duration, no, url, year, cover
        case albumArtist = "album_artist"
        case bitRate = "bit_rate"
    }

    /// Human-readable duration string.
    var formattedDuration: String {
        guard let duration else { return "—" }
        let total = Int(duration)
        let minutes = total / 60
        let seconds = total % 60
        return String(format: "%d:%02d", minutes, seconds)
    }
}

extension ChadTrack: Transferable {
    static var transferRepresentation: some TransferRepresentation {
        CodableRepresentation(contentType: .chadTrack)
    }
}

extension ChadAlbum: Transferable {
    static var transferRepresentation: some TransferRepresentation {
        CodableRepresentation(contentType: .chadAlbum)
    }
}

/// The album-tracks endpoint returns a plain array of tracks (not a wrapper object).
/// We decode as [ChadTrack] directly in the API client.

/// Library statistics from GET /api/stats.
/// Server keys: tracks, albums, artists, duration (formatted string), rescans
struct ChadStats: Codable {
    let tracks: Int?
    let albums: Int?
    let artists: Int?
    let duration: String?     // server returns pre-formatted string like "3d 14h 22m"
}

/// The browsable category types exposed by the API.
enum ChadCategoryType: String, CaseIterable, Identifiable {
    case album
    case artist
    case genre
    case year
    case publisher
    case country
    case type
    case status

    var id: String { rawValue }

    var displayName: String {
        switch self {
        case .album: "Albums"
        case .artist: "Artists"
        case .genre: "Genres"
        case .year: "Years"
        case .publisher: "Publishers"
        case .country: "Countries"
        case .type: "Types"
        case .status: "Status"
        }
    }

    var icon: String {
        switch self {
        case .album: "square.stack"
        case .artist: "person.2"
        case .genre: "guitars"
        case .year: "calendar"
        case .publisher: "building.2"
        case .country: "globe"
        case .type: "tag"
        case .status: "checkmark.circle"
        }
    }
}