/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    An object that implements the `IntentHandler` and `INStartWorkoutIntentHandling` protocols to handle requests to start a new workout.

*/

import Intents

import AscentFramework

class StartWorkoutIntentHandler: NSObject, IntentHandler, INStartWorkoutIntentHandling {

    // MARK: IntentHandler

    func canHandle(_ intent: INIntent) -> Bool {

        return intent is INStartWorkoutIntent

    }

    // MARK: Parameter resolution

    func resolveWorkoutName(forStartWorkout intent: INStartWorkoutIntent, with completion: @escaping (INSpeakableStringResolutionResult) -> Void) {

        let result: INSpeakableStringResolutionResult

        let workoutHistory = WorkoutHistory.load()

        if let name = intent.workoutName {

            // Try to determine the obstacle (wall or boulder) from the supplied workout name.

            if Workout.Obstacle(intentWorkoutName: name) != nil {

                result = INSpeakableStringResolutionResult.success(with: name)

            }

            else {

                result = INSpeakableStringResolutionResult.needsValue()

            }

        }

        else if let lastWorkout = workoutHistory.last {

            // A name hasn't been supplied so suggest the last obstacle.

            result = INSpeakableStringResolutionResult.confirmationRequired(with: lastWorkout.obstacle.intentWorkoutName)

        }

        else {

            result = INSpeakableStringResolutionResult.needsValue()

        }

        completion(result)

    }

    func resolveWorkoutGoalUnitType(forStartWorkout intent: INStartWorkoutIntent, with completion: @escaping (INWorkoutGoalUnitTypeResolutionResult) -> Void) {

        let result: INWorkoutGoalUnitTypeResolutionResult

        // Allow time based or open goals.

        switch intent.workoutGoalUnitType {

            case .hour, .minute, .second, .unknown:

                result = INWorkoutGoalUnitTypeResolutionResult.success(with: intent.workoutGoalUnitType)

            default:

                result = INWorkoutGoalUnitTypeResolutionResult.unsupported()

        }

        completion(result)

    }

    // MARK: Intent confirmation

    func confirm(startWorkout intent: INStartWorkoutIntent, completion: @escaping (INStartWorkoutIntentResponse) -> Void) {

        let response: INStartWorkoutIntentResponse

        // Validate the intent by attempting create a `Workout` with it.

        if Workout(startWorkoutIntent: intent) != nil {

            response = INStartWorkoutIntentResponse(code: .continueInApp, userActivity: nil)

        }

        else {

            response = INStartWorkoutIntentResponse(code: .failure, userActivity: nil)

        }

        completion(response)

    }

    // MARK: Intent handling

    func handle(startWorkout intent: INStartWorkoutIntent, completion: @escaping (INStartWorkoutIntentResponse) -> Void) {

        let response: INStartWorkoutIntentResponse

        if let workout = Workout(startWorkoutIntent: intent) {

            // Create a response with a `NSUserActivity` that contains the information needed to start a workout.

            let userActivity = NSUserActivity(ascentActivityType: .start(workout))

            response = INStartWorkoutIntentResponse(code: .continueInApp, userActivity: userActivity)

        }

        else {

            response = INStartWorkoutIntentResponse(code: .failure, userActivity: nil)

        }

        completion(response)

    }

}