//
//  SeriesMainHomeBannerView.swift
//  SodaLive
//
//  Created by klaus on 11/15/25.
//

import SwiftUI

struct SeriesMainHomeBannerView: View {
    let bannerList: [SeriesBannerResponse]
    
    @State var currentIndex = 0
    @State var timer = Timer.publish(every: 4, on: .main, in: .common).autoconnect()
    
    @State var width: CGFloat = 0
    @State var height: CGFloat = 0
    
    var body: some View {
        VStack(spacing: 0) {
            TabView(selection: $currentIndex) {
                ForEach(0..<bannerList.count, id: \.self) { index in
                    let item = bannerList[index]
                    
                    NavigationLink {
                        SeriesDetailView(seriesId: item.seriesId)
                    } label: {
                        SeriesMainHomeBannerImageView(url: item.imagePath, width: width, height: height)
                    }
                }
            }
            .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
            .frame(
                width: width,
                height: height
            )
            
            HStack(spacing: 4) {
                ForEach(0..<bannerList.count, id: \.self) { index in
                    Capsule()
                        .foregroundColor(
                            index == currentIndex
                            ? .button
                            : .gray90
                        )
                        .frame(
                            width: index == currentIndex ? 18 : 6,
                            height: 6
                        )
                        .tag(index)
                }
            }
            .padding(.top, 13.3)
        }
        .frame(maxWidth: .infinity)
        .onAppear {
            width = screenSize().width
            // 352x198
            height = width * 198 / 352
            timer = Timer.publish(every: 4, on: .main, in: .common).autoconnect()
        }
        .onDisappear {
            timer.upstream.connect().cancel()
        }
        .onReceive(timer) { _ in
            DispatchQueue.main.async {
                withAnimation {
                    if currentIndex == bannerList.count - 1 {
                        currentIndex = 0
                    } else {
                        currentIndex += 1
                    }
                }
            }
        }
    }
}

struct SeriesMainHomeBannerImageView: View {
    let url: String
    let width: CGFloat
    let height: CGFloat
    
    var body: some View {
        Group {
            if let boundURL = URL(string: url.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? url) {
                DownsampledKFImage(
                    url: boundURL,
                    size: CGSize(width: width, height: height)
                )
                .cornerRadius(4.7)
            } else {
                Color.clear
                    .frame(width: width, height: height)
                    .cornerRadius(4.7)
            }
        }
        .contentShape(Rectangle())
    }
}

#Preview {
    SeriesMainHomeBannerView(
        bannerList: [
            SeriesBannerResponse(seriesId: 1, imagePath: "https://picsum.photos/352/198"),
            SeriesBannerResponse(seriesId: 2, imagePath: "https://picsum.photos/352/198"),
            SeriesBannerResponse(seriesId: 3, imagePath: "https://picsum.photos/352/198"),
        ]
    )
}