//
//  RootView.swift
//  Mobile Music Assistant
//
//  Created by Sven Hanold on 26.03.26.
//

import SwiftUI
import UIKit

struct RootView: View {
    @Environment(MAService.self) private var service

    @State private var isInitializing = true
    @State private var loadingProgress: Double = 0.0
    @State private var loadingPhase: String = "Starting…"

    var body: some View {
        Group {
            if isInitializing {
                SplashView(progress: loadingProgress, phase: loadingPhase)
                    .transition(.opacity)
            } else if service.isConnected {
                MainTabView()
                    .transition(.opacity)
            } else {
                LoginView()
                    .transition(.opacity)
            }
        }
        .animation(.easeInOut(duration: 0.4), value: isInitializing)
        .animation(.easeInOut(duration: 0.4), value: service.isConnected)
        .applyTheme()
        .applyLocale()
        .task {
            await initializeConnection()
        }
    }

    // MARK: - Initialization

    private func initializeConnection() async {
        guard service.authManager.isAuthenticated else {
            // No saved credentials — skip straight to login
            withAnimation { loadingProgress = 1.0 }
            try? await Task.sleep(for: .milliseconds(300))
            isInitializing = false
            return
        }

        // Phase 1: Connect to server
        withAnimation { loadingPhase = "Connecting to server…"; loadingProgress = 0.1 }
        do {
            try await service.connectWithSavedCredentials()
        } catch {
            print("Auto-connect failed: \(error.localizedDescription)")
            withAnimation { loadingProgress = 1.0 }
            try? await Task.sleep(for: .milliseconds(300))
            isInitializing = false
            return
        }

        // Phase 2: Load players
        withAnimation { loadingPhase = "Loading players…"; loadingProgress = 0.55 }
        try? await service.playerManager.loadPlayers()

        // Done
        withAnimation { loadingPhase = "Ready"; loadingProgress = 1.0 }
        try? await Task.sleep(for: .milliseconds(400))
        isInitializing = false
    }
}

// MARK: - Splash Screen

private let splashBackground = Color(red: 0.07, green: 0.09, blue: 0.12)
private let splashTeal = Color(red: 0.0, green: 0.82, blue: 0.75)

private struct SplashView: View {
    let progress: Double
    let phase: String

    var body: some View {
        ZStack {
            splashBackground.ignoresSafeArea()

            VStack(spacing: 0) {
                Spacer()

                // App icon
                if let icon = UIImage(named: "AppIcon") {
                    Image(uiImage: icon)
                        .resizable()
                        .frame(width: 120, height: 120)
                        .clipShape(RoundedRectangle(cornerRadius: 27))
                        .shadow(color: splashTeal.opacity(0.25), radius: 24, y: 8)
                } else {
                    // Fallback: recreate the waveform icon in SwiftUI
                    WaveformIcon()
                        .frame(width: 120, height: 120)
                }

                Spacer().frame(height: 24)

                // App name
                Text("Mobile MA")
                    .font(.title2)
                    .fontWeight(.semibold)
                    .foregroundStyle(.white)

                Text("A client for Music Assistant")
                    .font(.subheadline)
                    .foregroundStyle(.white.opacity(0.45))

                Spacer()

                // Progress section
                VStack(spacing: 10) {
                    GeometryReader { geo in
                        ZStack(alignment: .leading) {
                            Capsule()
                                .fill(.white.opacity(0.1))
                                .frame(height: 3)
                            Capsule()
                                .fill(splashTeal)
                                .frame(width: geo.size.width * progress, height: 3)
                                .animation(.easeInOut(duration: 0.4), value: progress)
                        }
                    }
                    .frame(height: 3)
                    .padding(.horizontal, 48)

                    Text(phase)
                        .font(.caption)
                        .foregroundStyle(.white.opacity(0.4))
                        .animation(.easeInOut, value: phase)
                }
                .padding(.bottom, 60)
            }
        }
    }
}

/// Fallback waveform graphic matching the app icon style.
private struct WaveformIcon: View {
    private let barHeights: [CGFloat] = [0.32, 0.55, 0.75, 1.0, 0.78, 0.52, 0.28]

    var body: some View {
        ZStack {
            RoundedRectangle(cornerRadius: 27)
                .fill(splashBackground)
            HStack(alignment: .center, spacing: 5) {
                ForEach(Array(barHeights.enumerated()), id: \.offset) { _, h in
                    Capsule()
                        .fill(splashTeal.opacity(0.5 + 0.5 * h))
                        .frame(width: 10, height: 70 * h)
                }
            }
        }
    }
}

#Preview {
    RootView()
        .environment(MAService())
}