//
//  AutoScrollView.swift
//  OnCue
//
//  Created by Pradyun Setti on 23/06/2024.
//

import SwiftUI
import SwiftData

//struct AutoScrollView<Content: View>: View {
//    let content: Content
//    var scrollSpeed: Double = 15.0
//
//    @State private var offset: Double = 0.0
//
//    init(scrollSpeed: Double = 0, @ViewBuilder _ content: () -> Content) {
//        self.content = content()
//        self.scrollSpeed = scrollSpeed
//    }
//
//    var body: some View {
//        ScrollView {
//            content
//                .offset(y: offset)
//        }
//    }
//
//    func startScrolling() {
//
//    }
//
//    func stopScrolling() {
//
//    }
//
//    mutating func setScrollSpeed(_ speed: Double) {
//        self.scrollSpeed = speed
//    }
//}

struct AutoScrollView<Content: View>: View {
    @State private var scrollOffset: CGFloat = 0
    @State private var timer: Timer? = nil

    let content: Content
    var scrollSpeed: CGFloat // Adjust this value to control the scroll speed
    
    init(scrollSpeed: Double = 1.0, @ViewBuilder _ content: () -> Content) {
        self.content = content()
        self.scrollSpeed = scrollSpeed
    }
    
    var body: some View {
        ScrollViewReader { proxy in
            ScrollView {
                content
                    .id(0) // Assign an ID to the content
                    .background(GeometryReader { geo in
                        Color.clear.onAppear {
                            let contentHeight = geo.size.height
                            startTimer(proxy: proxy, contentHeight: contentHeight)
                        }
                    })
            }
        }
        .onDisappear {
            stopTimer()
        }
    }
    
    private func startTimer(proxy: ScrollViewProxy, contentHeight: CGFloat) {
        timer?.invalidate() // Invalidate any existing timer
        timer = Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true) { _ in
            withAnimation {
                scrollOffset += scrollSpeed
                proxy.scrollTo(0, anchor: .bottom)
                proxy.scrollTo(scrollOffset, anchor: .bottom)
            }
            
            // Reset scroll offset when it reaches the end
            if scrollOffset >= contentHeight {
                stopTimer()
            }
        }
    }
    
    private func stopTimer() {
        timer?.invalidate()
        timer = nil
    }
}

#Preview {
    let config = ModelConfiguration(isStoredInMemoryOnly: true)
    let container = try! ModelContainer(for: OCProject.self, configurations: config)
    
    container.mainContext.insert(PreviewData.project)
    
    return AutoScrollView {
        Text(PreviewData.project.script)
            .font(.system(size: 45))
            .padding(.horizontal)
    }
}