import Alamofire
import Foundation
import SwiftyJSON

final class Video: Identifiable, ObservableObject {
    let id: String
    var title: String
    var thumbnailURL: URL?
    var author: String
    var length: TimeInterval
    var published: String
    var views: Int

    var channelID: String

    @Published var url: URL?
    @Published var error: Bool = false

    init(
        id: String,
        title: String,
        thumbnailURL: URL?,
        author: String,
        length: TimeInterval,
        published: String,
        channelID: String,
        views: Int = 0
    ) {
        self.id = id
        self.title = title
        self.thumbnailURL = thumbnailURL
        self.author = author
        self.length = length
        self.published = published
        self.channelID = channelID
        self.views = views
    }

    init(_ json: JSON) {
        func extractThumbnailURL(from details: JSON) -> URL? {
            if details["videoThumbnails"].arrayValue.isEmpty {
                return nil
            }

            let thumbnail = details["videoThumbnails"].arrayValue.first(where: { $0["quality"].stringValue == "medium" })!
            return thumbnail["url"].url!
        }

        func extractFormatStreamURL(from streams: [JSON]) -> URL? {
            if streams.isEmpty {
                error = true
                return nil
            }

            let stream = streams.last!

            return stream["url"].url
        }

        id = json["videoId"].stringValue
        title = json["title"].stringValue
        thumbnailURL = extractThumbnailURL(from: json)
        author = json["author"].stringValue
        length = json["lengthSeconds"].doubleValue
        published = json["publishedText"].stringValue
        views = json["viewCount"].intValue
        channelID = json["authorId"].stringValue

        url = extractFormatStreamURL(from: json["formatStreams"].arrayValue)
    }

    var playTime: String? {
        let formatter = DateComponentsFormatter()

        formatter.unitsStyle = .positional
        formatter.allowedUnits = length >= (60 * 60) ? [.hour, .minute, .second] : [.minute, .second]
        formatter.zeroFormattingBehavior = [.pad]

        return formatter.string(from: length)
    }

    var viewsCount: String {
        let formatter = NumberFormatter()
        formatter.numberStyle = .decimal
        formatter.maximumFractionDigits = 1

        var number: NSNumber
        var unit: String

        if views < 1_000_000 {
            number = NSNumber(value: Double(views) / 1000.0)
            unit = "K"
        } else {
            number = NSNumber(value: Double(views) / 1_000_000.0)
            unit = "M"
        }

        return "\(formatter.string(from: number)!)\(unit)"
    }
}