SwiftUIExampleView.swift

import DSWaveformImage
import DSWaveformImageViews
import SwiftUI

@available(iOS 14.0, *)
struct SwiftUIExampleView: View {
    private static let colors = [UIColor.systemPink, UIColor.systemBlue, UIColor.systemGreen]
    private static var randomColor: UIColor { colors.randomElement()! }

    private static var audioURLs: [URL?] = [
        Bundle.main.url(forResource: "example_sound", withExtension: "m4a"),
        Bundle.main.url(forResource: "example_sound_2", withExtension: "m4a")
    ]
    private static var randomURL: URL? { audioURLs.randomElement()! }

    @StateObject private var audioRecorder: AudioRecorder = AudioRecorder()

    @State private var audioURL: URL? = Self.randomURL

    @State var configuration: Waveform.Configuration = Waveform.Configuration(
        style: .outlined(.blue, 3),
        verticalScalingFactor: 0.5
    )

    @State var liveConfiguration: Waveform.Configuration = Waveform.Configuration(
        style: .striped(.init(color: randomColor, width: 3, spacing: 3))
    )

    @State var silence: Bool = true
    @State var selection: Bool = true

    var body: some View {
        VStack {
            Text("SwiftUI examples")
                .font(.largeTitle.bold())

            if #available(iOS 15.0, *) {
                Picker("Hey", selection: $selection) {
                    Text("Recorder Example").tag(true)
                    Text("Overview").tag(false)
                }
                .pickerStyle(.segmented)
                .padding(.horizontal)

                if selection {
                    recordingExample
                } else {
                    overview
                }
            } else {
                Text("WaveformView & WaveformLiveCanvas require iOS 15.0")
            }
        }
        .padding(.vertical, 20)
    }

    @available(iOS 15.0, *)
    @ViewBuilder
    private var recordingExample: some View {
        HStack {
            Button {
                configuration = configuration.with(style: .filled(Self.randomColor))
                liveConfiguration = liveConfiguration.with(style: .striped(.init(color: Self.randomColor, width: 3, spacing: 3)))
            } label: {
                Label("color", systemImage: "arrow.triangle.2.circlepath")
                    .frame(maxWidth: .infinity)
            }
            .font(.body.bold())
            .padding()
            .background(Color(.systemGray6))
            .cornerRadius(10)

            Button {
                audioURL = Self.randomURL
                print("will draw \(audioURL!)")
            } label: {
                Label("waveform", systemImage: "arrow.triangle.2.circlepath")
                    .frame(maxWidth: .infinity)
            }
            .font(.body.bold())
            .padding()
            .background(Color(.systemGray6))
            .cornerRadius(10)
        }
        .padding()

        if let audioURL {
            WaveformView(
                audioURL: audioURL,
                configuration: configuration,
                renderer: CircularWaveformRenderer(kind: .ring(0.7))
            )
        }

        VStack {
            Toggle("draw silence", isOn: $silence).padding()

            WaveformLiveCanvas(
                samples: audioRecorder.samples,
                configuration: liveConfiguration,
                renderer: CircularWaveformRenderer(kind: .circle),
                shouldDrawSilencePadding: silence
            )
        }

        RecordingIndicatorView(
            samples: audioRecorder.samples,
            duration: audioRecorder.recordingTime,
            isRecording: $audioRecorder.isRecording
        )
            .padding()
    }

    @ViewBuilder
    private var overview: some View {
        if let audioURL {
            HStack {
                VStack {
                    WaveformView(audioURL: audioURL, configuration: .init(style: .filled(.red)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .outlined(.black, 0.5)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradient([.yellow, .orange])))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradientOutlined([.yellow, .orange], 1)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .striped(.init(color: .red, width: 2, spacing: 1))))
                }

                VStack {
                    WaveformView(audioURL: audioURL, configuration: .init(style: .filled(.red)), renderer: CircularWaveformRenderer())
                    WaveformView(audioURL: audioURL, configuration: .init(style: .outlined(.black, 0.5)), renderer: CircularWaveformRenderer())
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradient([.yellow, .orange])), renderer: CircularWaveformRenderer())
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradientOutlined([.yellow, .orange], 1)), renderer: CircularWaveformRenderer())
                    WaveformView(audioURL: audioURL, configuration: .init(style: .striped(.init(color: .red, width: 2, spacing: 2))), renderer: CircularWaveformRenderer())
                }

                VStack {
                    WaveformView(audioURL: audioURL, configuration: .init(style: .filled(.red)), renderer: CircularWaveformRenderer(kind: .ring(0.5)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .outlined(.black, 0.5)), renderer: CircularWaveformRenderer(kind: .ring(0.5)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradient([.yellow, .orange])), renderer: CircularWaveformRenderer(kind: .ring(0.5)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .gradientOutlined([.yellow, .orange], 1)), renderer: CircularWaveformRenderer(kind: .ring(0.5)))
                    WaveformView(audioURL: audioURL, configuration: .init(style: .striped(.init(color: .red, width: 2, spacing: 2))), renderer: CircularWaveformRenderer(kind: .ring(0.5)))
                }
            }
        }
    }
}

@available(iOS 15.0, *)
struct LiveRecordingView_Previews: PreviewProvider {
    static var previews: some View {
        SwiftUIExampleView()
    }
}

private class AudioRecorder: NSObject, ObservableObject, RecordingDelegate {
    @Published var samples: [Float] = []
    @Published var recordingTime: TimeInterval = 0
    @Published var isRecording: Bool = false {
        didSet {
            guard oldValue != isRecording else { return }
            isRecording ? startRecording() : stopRecording()
        }
    }

    private let audioManager: SCAudioManager

    override init() {
        audioManager = SCAudioManager()

        super.init()

        audioManager.prepareAudioRecording()
        audioManager.recordingDelegate = self
    }

    func startRecording() {
        samples = []
        audioManager.startRecording()
        isRecording = true
    }

    func stopRecording() {
        audioManager.stopRecording()
        isRecording = false
    }

    // MARK: - RecordingDelegate

    func audioManager(_ manager: SCAudioManager!, didAllowRecording flag: Bool) {}

    func audioManager(_ manager: SCAudioManager!, didFinishRecordingSuccessfully flag: Bool) {}

    func audioManager(_ manager: SCAudioManager!, didUpdateRecordProgress progress: CGFloat) {
        let linear = 1 - pow(10, manager.lastAveragePower() / 20)

        // Here we add the same sample 3 times to speed up the animation.
        // Usually you'd just add the sample once.
        recordingTime = audioManager.currentRecordingTime
        samples += [linear, linear, linear]
    }
}