voicediary/VoiceDiary/Services/AudioRecorderService.swift

import AVFoundation
import Foundation

@Observable
final class AudioRecorderService: NSObject {
	var isRecording = false
	var recordingDuration: TimeInterval = 0

	private var audioRecorder: AVAudioRecorder?
	private var timer: Timer?
	private var startTime: Date?

	func startRecording() throws -> URL {
		let session = AVAudioSession.sharedInstance()
		try session.setCategory(.record, mode: .default)
		try session.setActive(true)

		let fileName = "memo-\(Date.now.ISO8601Format()).m4a"
			.replacingOccurrences(of: ":", with: "-")
		let url = VoiceMemo.audioDirectory.appendingPathComponent(fileName)

		let settings: [String: Any] = [
			AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
			AVSampleRateKey: 44100.0,
			AVNumberOfChannelsKey: 1,
			AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue,
		]

		audioRecorder = try AVAudioRecorder(url: url, settings: settings)
		audioRecorder?.delegate = self
		audioRecorder?.record()

		isRecording = true
		recordingDuration = 0
		startTime = .now

		timer = Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { [weak self] _ in
			guard let self, let startTime = self.startTime else { return }
			self.recordingDuration = Date.now.timeIntervalSince(startTime)
		}

		return url
	}

	func stopRecording() -> (url: URL, duration: TimeInterval)? {
		guard let recorder = audioRecorder else { return nil }

		let url = recorder.url
		let duration = recorder.currentTime

		recorder.stop()
		timer?.invalidate()
		timer = nil
		audioRecorder = nil
		isRecording = false
		startTime = nil

		try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)

		return (url, duration)
	}
}

extension AudioRecorderService: AVAudioRecorderDelegate {
	func audioRecorderDidFinishRecording(_ recorder: AVAudioRecorder, successfully flag: Bool) {
		if !flag {
			isRecording = false
			timer?.invalidate()
			timer = nil
		}
	}
}