import Commanding
import SwiftUI
import WidgetKit

/// The Lock Screen banner of the recording Live Activity: a centered stack of the timer of the elapsed recording time, the label
/// naming the current state, and the control buttons.
struct RecordingLiveActivityView: View {
    
    // MARK: Properties
    
    /// The dynamic content of the Live Activity to render.
    let state: RecordingActivityAttributes.ContentState
    
    // MARK: Body
    
    var body: some View {
        VStack(
            alignment: .center,
            spacing: Constant.Spacing.stack
        ) {
            RecordingTimerText(state: state)
                .font(.largeTitle)
                .fontWeight(.bold)
                .monospacedDigit()
            
            RecordingStateLabel(state: state)
            
            RecordingControls(state: state)
        }
    }
    
}

// MARK: - Constants

/// The constant values used across the recording Live Activity.
private enum Constant {
    /// The size constants.
    enum Size {
        /// The maximum width of the timer in the compact trailing presentation of the Dynamic Island.
        static let compactTimer: CGFloat = 44
    }
    
    /// The spacing constants.
    enum Spacing {
        /// The spacing between the elements of a stack.
        static let stack: CGFloat = 8
    }
    
    /// The system symbol constants.
    enum Symbol {
        /// The symbol of the discard button.
        static let discard = "trash"
        /// The symbol marking the recording flow.
        static let microphone = "mic.fill"
        /// The symbol of the main button while recording.
        static let pause = "pause.fill"
        /// The symbol of the main button while paused.
        static let record = "record.circle"
    }
    
    /// The time constants.
    enum Time {
        /// The span of the running timer, comfortably beyond the maximum lifetime of a Live Activity.
        static let span: TimeInterval = 24 * 60 * 60
    }
}

// MARK: - Previews

#Preview(
    "Recording Live Activity view",
    as: .content,
    using: RecordingActivityAttributes()
) {
    RecordingLiveActivity()
} contentStates: {
    RecordingActivityAttributes.ContentState(
        state: .recording,
        anchor: .now,
        elapsed: 0
    )
    RecordingActivityAttributes.ContentState(
        state: .paused,
        anchor: nil,
        elapsed: 42
    )
    RecordingActivityAttributes.ContentState(
        state: .processing,
        anchor: nil,
        elapsed: 42
    )
}