import Foundation

/// Completion state of a workout or an individual exercise log. Persisted as its
/// raw string in both the JSON documents and the SwiftData cache.
enum WorkoutStatus: String, CaseIterable, Codable, Sendable {
    case notStarted
    case inProgress
    case completed
    case skipped

    var displayName: String {
        switch self {
        case .notStarted: "Not Started"
        case .inProgress: "In Progress"
        case .completed: "Completed"
        case .skipped: "Skipped"
        }
    }

    var name: String { displayName }
}

/// How an exercise's effort is measured. Persisted as its raw `Int` value.
enum LoadType: Int, CaseIterable, Codable, Sendable {
    case none = 0
    case weight = 1
    case duration = 2

    var name: String {
        switch self {
        case .none: "None"
        case .weight: "Weight"
        case .duration: "Duration"
        }
    }
}

/// The kind of training a split represents — used to tag the Apple Health workout
/// so it lands in the right category (and credits the rings correctly), and to pick
/// a MET value when the phone has to estimate calories without watch sensor data.
/// Persisted as its raw `Int` on `SplitDocument`; the `HKWorkoutActivityType`
/// mapping lives in `Shared/HealthKit/HealthKitMapping.swift` to keep this enum
/// HealthKit-free.
enum WorkoutActivityType: Int, CaseIterable, Codable, Sendable {
    case traditionalStrength = 0    // default
    case functionalStrength = 1
    case hiit = 2
    case coreTraining = 3
    case cardio = 4
    case cycling = 5

    var displayName: String {
        switch self {
        case .traditionalStrength: "Strength Training"
        case .functionalStrength: "Functional Strength"
        case .hiit: "HIIT"
        case .coreTraining: "Core Training"
        case .cardio: "Cardio"
        case .cycling: "Cycling"
        }
    }

    var systemImage: String {
        switch self {
        case .traditionalStrength: "dumbbell.fill"
        case .functionalStrength: "figure.strengthtraining.functional"
        case .hiit: "figure.highintensity.intervaltraining"
        case .coreTraining: "figure.core.training"
        case .cardio: "figure.run"
        case .cycling: "figure.outdoor.cycle"
        }
    }

    /// Metabolic-equivalent value used only for the phone-side calorie estimate
    /// (`kcal ≈ MET × bodyweightKg × hours`) when no watch metrics are available.
    var met: Double {
        switch self {
        case .traditionalStrength: 5.0
        case .functionalStrength: 4.0
        case .hiit: 8.0
        case .coreTraining: 4.0
        case .cardio: 7.0
        case .cycling: 7.5
        }
    }
}

/// Where a workout's health metrics came from: real watch sensors, or a phone-side
/// estimate written when no watch session ran. Persisted in `WorkoutMetrics`.
enum MetricSource: String, Codable, Sendable {
    case watch
    case phoneEstimate
}

/// Display unit for weights. The stored weight values are plain integers and are
/// never rewritten when this changes — switching only relabels what's shown.
enum WeightUnit: String, CaseIterable, Codable, Sendable {
    case lb
    case kg

    var displayName: String {
        switch self {
        case .lb: "Pounds (lb)"
        case .kg: "Kilograms (kg)"
        }
    }

    var abbreviation: String {
        switch self {
        case .lb: "lb"
        case .kg: "kg"
        }
    }

    /// Render a stored weight value with the current unit's label, e.g. "135 lb".
    func format(_ value: Int) -> String { "\(value) \(abbreviation)" }
}