//
//  ListView.swift
//  dimensionhub
//
//  Created by 安礼成 on 2025/2/21.
//
import SwiftUI
import Observation

@Observable
final class DetailModel {
    
    struct Episode: Codable, Identifiable {
        let id = UUID().uuidString
        let name: String
        let num_name: String
        let thumb: String
        let play: String
        
        enum CodingKeys: String, CodingKey {
            case name, num_name, thumb, play
        }
    }
    
    // 渠道
    struct Channel: Codable {
        let name: String
        let episodes: [Episode]
    }
    
    struct DramaDetailResponse: Codable {
        let name: String
        let summary: String
        let thumb: String
        let status: [String]
        let channels: [Channel]
    }
    
    // 状态信息
    struct DramaStatus {
        struct DisplayConfig {
            let name: String
            let bgColor: Color
            let fontColor: Color
        }
        
        let status: String
        let config: DisplayConfig
        
        init?(_ rawValue: String) {
            switch rawValue {
            case "first_row":
                self.status = rawValue
                self.config = DisplayConfig(name: "前排占位", bgColor: .black, fontColor: .white)
            case "following":
                self.status = rawValue
                self.config = DisplayConfig(name: "♡ 追番", bgColor: .black, fontColor: .white)
            case "catching_up":
                self.status = rawValue
                self.config = DisplayConfig(name: "补番", bgColor: .black, fontColor: .white)
            case "dropping":
                self.status = rawValue
                self.config = DisplayConfig(name: "弃番", bgColor: .white, fontColor: Color(hex: "#333333"))
            case "finished":
                self.status = rawValue
                self.config = DisplayConfig(name: "补完", bgColor: .black, fontColor: .white)
            default:
                return nil
            }
        }
        
    }
    
    enum FollowResult {
        case success
        case error(String, String)
    }
    
    var name: String = ""
    var summary: String = ""
    var thumb: String = ""
    var statuses: [DramaStatus] = []
    var channels: [Channel] = []
    
    // 当前选中的channel
    var selectedChannelIdx: Int = 0
    var selectedEpisodes: [Episode] = []
    
    func loadData(userId: String, id: Int) async {
        let response = await API.getDramaDetail(userId: userId, id: id, as: DramaDetailResponse.self)
        switch response {
        case .error(let code, let message):
            print(code)
            print(message)
        case .result(let detail):
            await MainActor.run {
                self.name = detail.name
                self.summary = Utils.converHtmlToString(html: detail.summary) ?? ""
                self.thumb = detail.thumb
                self.statuses = detail.status.flatMap({ s in
                    if let status = DramaStatus(s) {
                        return [status]
                    } else {
                        return []
                    }
                })
                self.channels = detail.channels
                
                self.selectedChannelIdx = 0
                self.selectedEpisodes = detail.channels[0].episodes
            }
        }
    }
    
    func toggleChannel(channelIdx: Int) {
        self.selectedChannelIdx = channelIdx
        self.selectedEpisodes = self.channels[channelIdx].episodes
    }
    
    func onTapFollowButton(userId: String, id: Int, status: String) async -> FollowResult {
        let response = await API.followDrama(userId: userId, id: id, status: status, as: [String].self)
        switch response {
        case .error(_, let message):
            return .error("错误", message)
        case .result(let newStatuses):
            self.statuses = newStatuses.flatMap({ s in
                if let status = DramaStatus(s) {
                    return [status]
                } else {
                    return []
                }
            })
            return .success
        }
    }
    
}

struct DetailView: View {
    @AppStorage("userId") private var userId: String = Utils.defaultUserId()
    
    @State var detailModel = DetailModel()
    @State var showAllSummary: Bool = false
    
    // 错误提示信息
    @State var showAlert: Bool = false
    @State var errorInfo: (String, String) = ("", "")
    
    let id: Int
    
    var body: some View {
        VStack(alignment: .center) {
            
            VStack(alignment: .leading, spacing: 10) {
                HStack {
                    Text(detailModel.name)
                        .font(.system(size: 28))
                        .fontWeight(.bold)
                        .foregroundColor(Color(hex: "#333333"))
                    Spacer()
                }
                
                if showAllSummary {
                    Text(detailModel.summary)
                        .lineLimit(nil)
                        .multilineTextAlignment(.leading)
                        .frame(maxWidth: .infinity, alignment: .leading)
                        .onTapGesture {
                            withAnimation {
                                self.showAllSummary = false
                            }
                        }
                    
                } else {
                    Text(detailModel.summary)
                        .lineLimit(3)
                        .multilineTextAlignment(.leading)
                        .frame(maxWidth: .infinity, alignment: .leading)
                        .onTapGesture {
                            withAnimation {
                                self.showAllSummary = true
                            }
                        }
                }
            }
            .padding(10)
            .background(Color(hex: "#F2F2F2"), ignoresSafeAreaEdges: [.top])
            
            VStack(alignment: .center) {
                HStack(alignment: .center, spacing: 10) {
                    Spacer()
                    ForEach(detailModel.statuses, id: \.status) { status in
                        FollowButtonView(dramaStatus: status) { followStatus in
                            Task {
                                let result = await detailModel.onTapFollowButton(userId: self.userId, id: id, status: followStatus)
                                switch result {
                                case .success:
                                    ()
                                case .error(let title, let message):
                                    DispatchQueue.main.async {
                                        self.errorInfo = (title, message)
                                        self.showAlert = true
                                    }
                                }
                            }
                        }
                    }
                }
                
                // 渠道列表
                HStack(alignment: .center, spacing: 15) {
                    ForEach(Array(detailModel.channels.enumerated()), id: \.offset) { idx, channel in
                        Text(channel.name)
                            .font(.system(size: 13))
                            .foregroundColor(idx == detailModel.selectedChannelIdx ? Color(hex: "#169BD5") : Color(hex: "#666666"))
                            .onTapGesture {
                                DispatchQueue.main.async {
                                    detailModel.toggleChannel(channelIdx: idx)
                                }
                            }
                    }
                    Spacer()
                }
                .padding(.leading, 10)
                
                // 渠道相关的数据列表
                ScrollView(.horizontal, showsIndicators: false) {
                    LazyHStack(alignment: .center) {
                        ForEach(detailModel.selectedEpisodes) { episode in
                            EpisodeView(episode: episode)
                        }
                    }
                    .frame(height: 100)
                }
                
                if detailModel.selectedEpisodes.count >= 5 {
                    HStack(alignment: .center) {
                        NavigationLink(destination: ListView(id: self.id)) {
                            Rectangle()
                                .frame(width: 200, height: 25)
                                .foregroundColor(Color(hex: "#F2F2F2"))
                                .overlay {
                                    Text("展开全部剧集")
                                        .font(.system(size: 13))
                                        .foregroundColor(Color(hex: "#999999"))
                                        .fontWeight(.regular)
                                }
                        }
                    }
                }
                
                Spacer()
            }
            .frame(width: 370, alignment: .center)
        }
        .alert(isPresented: $showAlert) {
            Alert(title: Text(self.errorInfo.0), message: Text(self.errorInfo.1), dismissButton: .default(Text("OK")))
        }
        .task {
            await detailModel.loadData(userId: self.userId, id: self.id)
            print(detailModel.summary)
        }
    }
}

extension DetailView {
    
    struct FollowButtonView: View {
        let dramaStatus: DetailModel.DramaStatus
        let onTap: (String) -> Void
        
        var body: some View {
            Rectangle()
                .frame(width: 140, height: 40)
                .foregroundColor(dramaStatus.config.bgColor)
                .cornerRadius(5)
                .overlay {
                    RoundedRectangle(cornerRadius: 5)
                        .stroke(Color.black, lineWidth: 1)
                    
                    Text(dramaStatus.config.name)
                        .font(.system(size: 13))
                        .foregroundColor(dramaStatus.config.fontColor)
                        .fontWeight(.regular)
                }
                .onTapGesture {
                    onTap(dramaStatus.status)
                }
        }
    }
    
    struct EpisodeView: View {
        let episode: DetailModel.Episode
        
        var body: some View {
            VStack(alignment: .center) {
                
                AsyncImage(url: URL(string: episode.thumb)) { phase in
                    switch phase {
                    case .empty:
                        ProgressView()
                    case .success(let image):
                        image
                            .resizable()
                            .aspectRatio(contentMode: .fill)
                            .frame(width: 90, height: 70)
                            .clipped()
                    default:
                        Image("ph_img_small")
                            .resizable()
                            .aspectRatio(contentMode: .fill)
                            .clipped()
                    }
                    
                }
                .frame(width: 90, height: 70)
                .overlay(alignment: .topLeading) {
                    if !episode.num_name.isEmpty {
                        Text(episode.num_name)
                            .font(.system(size: 12))
                            .foregroundColor(.white)
                            .padding(3)
                            .background(Color.black.opacity(0.5))
                            .cornerRadius(3)
                            .padding(3)
                    } else {
                        EmptyView()
                    }
                }
                
                Text(episode.name)
                    .font(.system(size: 12))
                    .foregroundColor(Color(hex: "#333333"))
                    .lineLimit(1)
            }
            .frame(width: 90)
            .onTapGesture {
                if let playUrl = URL(string: episode.play) {
                    UIApplication.shared.open(playUrl)
                }
            }
        }
    }
    
}

#Preview {
    DetailView(id: 19625)
}