//
//  WatchMainViewModel+WorkoutActions.swift
//  Werkout_watch Watch App
//
//  Created by Trey Tartt on 6/19/24.
//

import Foundation
import WatchConnectivity
import SwiftUI
import HealthKit

extension WatchMainViewModel {
    func initWorkout() -> Bool {
        let configuration = HKWorkoutConfiguration()
        configuration.activityType = .functionalStrengthTraining
        configuration.locationType = .indoor
        
        do {
            hkWorkoutSession = try HKWorkoutSession(healthStore: healthStore, configuration: configuration)
            hkBuilder = hkWorkoutSession?.associatedWorkoutBuilder()
        } catch {
            fatalError("Unable to create the workout session!")
        }
        guard let hkWorkoutSession = hkWorkoutSession, let hkBuilder = hkBuilder else {
            return false
        }
        // Setup session and builder.
        hkWorkoutSession.delegate = self
        hkBuilder.delegate = self
        
        /// Set the workout builder's data source.
        hkBuilder.dataSource = HKLiveWorkoutDataSource(healthStore: healthStore,
                                                       workoutConfiguration: configuration)
        return true
    }
    
    func startWorkout() {
        // Initialize our workout
        if initWorkout() {
            
            guard let hkWorkoutSession = hkWorkoutSession, let hkBuilder = hkBuilder else {
                return
            }
            
            // Start the workout session and begin data collection
            hkWorkoutSession.startActivity(with: Date())
            hkBuilder.beginCollection(withStart: Date()) { (succ, error) in
                if !succ {
                    fatalError("Error beginning collection from builder: \(String(describing: error)))")
                }
            }
            isInWorkout = true
        } else {
            print("did not init workout")
        }
    }
    
    func stopWorkout(sendDetails: Bool) {
        guard let hkWorkoutSession = hkWorkoutSession, let hkBuilder = hkBuilder else {
            return
        }
        
        hkWorkoutSession.end()
        hkBuilder.endCollection(withEnd: Date()) { (success, error) in
            hkBuilder.finishWorkout { (workout, error) in
                DispatchQueue.main.async() {
                    self.hkWorkoutSession = nil
                    self.hkBuilder = nil
                    self.heartRates.removeAll()
                    self.isInWorkout = false
                    
                    guard let id = workout?.uuid else {
                        return
                    }
                    let watchFinishWorkoutModel = WatchFinishWorkoutModel(healthKitUUID: id)
                    let data = try! JSONEncoder().encode(watchFinishWorkoutModel)
                    let watchAction = WatchActions.workoutComplete(data)
                    let watchActionData = try! JSONEncoder().encode(watchAction)
                    
                    if sendDetails {
                        self.send(watchActionData)
                    }
                }
            }
        }
    }
}

extension WatchMainViewModel: HKWorkoutSessionDelegate, HKLiveWorkoutBuilderDelegate {
    func workoutSession(_ workoutSession: HKWorkoutSession, didChangeTo toState: HKWorkoutSessionState, from fromState: HKWorkoutSessionState, date: Date) {
        print("[workoutSession] Changed State: \(toState.rawValue)")
    }
    
    func workoutSession(_ workoutSession: HKWorkoutSession, didFailWithError error: Error) {
        print("[workoutSession] Encountered an error: \(error)")
    }
    
    func workoutBuilder(_ workoutBuilder: HKLiveWorkoutBuilder, didCollectDataOf collectedTypes: Set<HKSampleType>) {
        for type in collectedTypes {
            guard let quantityType = type as? HKQuantityType else {
                return
            }
            switch quantityType {
            case HKQuantityType.quantityType(forIdentifier: .heartRate):
                DispatchQueue.main.async() {
                    let statistics = workoutBuilder.statistics(for: quantityType)
                    let heartRateUnit = HKUnit.count().unitDivided(by: HKUnit.minute())
                    let value = statistics!.mostRecentQuantity()?.doubleValue(for: heartRateUnit)
                    self.heartValue = Int(Double(round(1 * value!) / 1))
                    self.heartRates.append(Int(Double(round(1 * value!) / 1)))
                    print("[workoutBuilder] Heart Rate: \(String(describing: self.heartValue))")
                }
            default:
                return
            }
        }
    }
    
    func workoutBuilderDidCollectEvent(_ workoutBuilder: HKLiveWorkoutBuilder) {
        guard let workoutEventType = workoutBuilder.workoutEvents.last?.type else { return }
        print("[workoutBuilderDidCollectEvent] Workout Builder changed event: \(workoutEventType.rawValue)")
    }
}