//
//  TimerManager.swift
//  DynamicIsland
//
//  Timer management for the Dynamic Island
//

import Foundation
import Combine
import SwiftUI
import AVFoundation
import AppKit

class TimerManager: ObservableObject {
    // MARK: - Properties
    static let shared = TimerManager()
    
    @Published var isTimerActive: Bool = false
    @Published var timerName: String = "Timer"
    @Published var totalDuration: TimeInterval = 0
    @Published var remainingTime: TimeInterval = 0
    @Published var elapsedTime: TimeInterval = 0
    @Published var isPaused: Bool = false
    @Published var isFinished: Bool = false
    @Published var isOvertime: Bool = false // Timer has gone past 0 and is counting negative
    @Published var lastUpdated: Date = .distantPast
    
    // Timer progress (0.0 to 1.0, or >1.0 for overtime)
    var progress: Double {
        guard totalDuration > 0 else { return 0.0 }
        if isOvertime {
            // For overtime, progress goes beyond 1.0
            return 1.0 + min(1.0, abs(remainingTime) / totalDuration)
        } else {
            return min(1.0, max(0.0, elapsedTime / totalDuration))
        }
    }
    
    // Color based on progress: green -> yellow -> red -> flashing red for overtime
    var timerColor: Color {
        if isOvertime {
            // Flashing red for overtime
            return .red
        }
        
        let p = progress
        if p < 0.6 {
            // Green phase (0-60%)
            return .green
        } else if p < 0.9 {
            // Yellow phase (60-90%)
            let yellowProgress = (p - 0.6) / 0.3
            return Color(
                red: 1.0 - (1.0 - yellowProgress) * 0.5, // Gradually more red
                green: 1.0,
                blue: 0.0
            )
        } else {
            // Red phase (90-100%)
            return .red
        }
    }
    
    // Computed properties for UI
    var isRunning: Bool {
        return isTimerActive && !isPaused
    }
    
    var currentColor: Color {
        return timerColor
    }
    
    var formattedTimeRemaining: String {
        return formattedRemainingTime()
    }
    
    var statusText: String {
        if isOvertime {
            return "Overtime"
        } else if isPaused {
            return "Paused"
        } else if isTimerActive {
            return "Running"
        } else {
            return "Ready"
        }
    }
    
    // NSColor version for compatibility
    var timerNSColor: NSColor {
        if isOvertime {
            return NSColor.systemRed
        }
        
        let p = progress
        if p < 0.6 {
            return NSColor.systemGreen
        } else if p < 0.9 {
            let yellowProgress = (p - 0.6) / 0.3
            return NSColor(
                red: 1.0 - (1.0 - yellowProgress) * 0.5,
                green: 1.0,
                blue: 0.0,
                alpha: 1.0
            )
        } else {
            return NSColor.systemRed
        }
    }
    
    private var timerInstance: Timer?
    private var cancellables = Set<AnyCancellable>()
    private var soundPlayer: AVAudioPlayer?
    
    // MARK: - Initialization
    private init() {
        // Simple initialization
    }
    
    deinit {
        timerInstance?.invalidate()
        soundPlayer?.stop()
        cancellables.removeAll()
    }
    
    // MARK: - Timer Methods
    func startTimer(duration: TimeInterval, name: String = "Timer") {
        // Stop any existing timer
        timerInstance?.invalidate()
        
        // Start new timer
        isTimerActive = true
        isFinished = false
        isOvertime = false
        timerName = name
        totalDuration = duration
        remainingTime = duration
        elapsedTime = 0
        isPaused = false
        lastUpdated = Date()
        
        triggerTimerSneakPeek()
        
        // Start countdown timer
        timerInstance = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            guard let self = self else { return }
            
            Task { @MainActor in
                if !self.isPaused {
                    if self.remainingTime > 0 {
                        // Normal countdown
                        self.remainingTime -= 1
                        self.elapsedTime = self.totalDuration - self.remainingTime
                        self.lastUpdated = Date()
                    } else if self.remainingTime == 0 {
                        // Timer just finished - play sound and start overtime
                        self.isFinished = true
                        self.isOvertime = true
                        self.playTimerSound()
                        self.remainingTime = -1
                        self.lastUpdated = Date()
                    } else {
                        // Overtime - count negative
                        self.remainingTime -= 1
                        self.lastUpdated = Date()
                    }
                }
            }
        }
    }
    
    func startDemoTimer(duration: TimeInterval) {
        startTimer(duration: duration, name: "Demo Timer")
    }
    
    func stopTimer() {
        timerInstance?.invalidate()
        timerInstance = nil
        soundPlayer?.stop()
        
        // Smooth close animation for live activity
        if isTimerActive {
            scheduleSmoothClose()
        }
        
        resetTimer()
    }
    
    func forceStopTimer() {
        // Immediate stop for user action (stop button)
        timerInstance?.invalidate()
        timerInstance = nil
        soundPlayer?.stop()
        isTimerActive = false
        resetTimer()
    }
    
    func pauseTimer() {
        guard isTimerActive && !isPaused else { return }
        isPaused = true
        timerInstance?.invalidate()
        timerInstance = nil
    }
    
    func resumeTimer() {
        guard isTimerActive && isPaused else { return }
        isPaused = false
        lastUpdated = Date()
        
        // Resume countdown timer with same logic as start timer
        timerInstance = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            guard let self = self else { return }
            
            Task { @MainActor in
                if !self.isPaused {
                    if self.remainingTime > 0 {
                        // Normal countdown
                        self.remainingTime -= 1
                        self.elapsedTime = self.totalDuration - self.remainingTime
                        self.lastUpdated = Date()
                    } else if self.remainingTime == 0 {
                        // Timer just finished - play sound and start overtime
                        self.isFinished = true
                        self.isOvertime = true
                        self.playTimerSound()
                        self.remainingTime = -1
                        self.lastUpdated = Date()
                    } else {
                        // Overtime - count negative
                        self.remainingTime -= 1
                        self.lastUpdated = Date()
                    }
                }
            }
        }
    }
    
    private func resetTimer() {
        isTimerActive = false
        timerName = "Timer"
        totalDuration = 0
        remainingTime = 0
        elapsedTime = 0
        isPaused = false
        isFinished = false
        isOvertime = false
    }
    
    private func scheduleSmoothClose() {
        // Wait 3 seconds then smoothly close the live activity
        DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
            withAnimation(.easeInOut(duration: 1.0)) {
                self.isTimerActive = false
            }
        }
    }
    
    private func playTimerSound() {
        // Play default macOS timer sound
        guard let soundURL = Bundle.main.url(forResource: "dynamic", withExtension: "m4a") else {
            // Fallback to system sound
            NSSound.beep()
            return
        }
        
        do {
            soundPlayer = try AVAudioPlayer(contentsOf: soundURL)
            soundPlayer?.numberOfLoops = -1 // Loop indefinitely
            soundPlayer?.play()
        } catch {
            // Fallback to system sound
            NSSound.beep()
        }
    }
    
    private func triggerTimerSneakPeek() {
        let coordinator = DynamicIslandViewCoordinator.shared
        
        DispatchQueue.main.async {
            coordinator.sneakPeek.show = true
            coordinator.sneakPeek.type = .timer
            coordinator.sneakPeek.value = CGFloat(self.progress) // Use timer progress (0.0 to 1.0)
            
            // Hide sneak peek after delay
            DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
                coordinator.sneakPeek.show = false
            }
        }
    }
    
    // MARK: - Formatted Time Strings
    func formattedRemainingTime() -> String {
        if isOvertime && remainingTime < 0 {
            return "-" + timeString(from: abs(remainingTime))
        } else {
            return timeString(from: remainingTime)
        }
    }
    
    func formattedElapsedTime() -> String {
        return timeString(from: elapsedTime)
    }
    
    func formattedTotalDuration() -> String {
        return timeString(from: totalDuration)
    }
    
    private func timeString(from seconds: TimeInterval) -> String {
        let totalMinutes = Int(seconds) / 60
        let remainingSeconds = Int(seconds) % 60
        let hours = totalMinutes / 60
        let minutes = totalMinutes % 60
        
        if hours > 0 {
            return String(format: "%d:%02d:%02d", hours, minutes, remainingSeconds)
        } else {
            return String(format: "%d:%02d", minutes, remainingSeconds)
        }
    }
}