//
//  KMTTSManager.swift
//  PDF Reader Pro
//
//  Created by liujiajie on 2023/12/12.
//

@objc(KMTTSManagerDelegate)
protocol KMTTSManagerDelegate: AnyObject {
    @objc optional func ttsMananger(_ tts: KMTTSManager, willSpeak selection: CPDFSelection)
    @objc optional func ttsManangerDidFinishSpeech(_ tts: KMTTSManager) -> Bool
    @objc optional func ttsManangerdidErrorSpeech(_ tts: KMTTSManager, message: String)
}

let KMTTS_SETTING_SPEECHSPEED_KEY = "TTS_Setting_SpeechSpeed_Key"
let KMTTS_SETTING_ISCONTINUE_KEY = "TTS_Setting_IsContinue_Key"
let KMTTS_SETTING_LANGUAGE_KEY = "TTS_Setting_Language_Key"


import Foundation

class KMTTSManager: NSObject, NSSpeechSynthesizerDelegate{
    var delegate: KMTTSManagerDelegate?

    var rate: Float {
        get{
            return self.speechSynthesizer.rate
        }
        set{
            self.speechSynthesizer.rate = newValue
            UserDefaults.standard.setValue(newValue, forKey: KMTTS_SETTING_SPEECHSPEED_KEY)
            UserDefaults.standard.synchronize()
        }
    }
    var isContinue = false {
        willSet {
           
        }
        didSet {
            UserDefaults.standard.setValue(isContinue, forKey: KMTTS_SETTING_ISCONTINUE_KEY)
            UserDefaults.standard.synchronize()
        }
    }
    func isSpeaking() -> Bool {
        return self.speechSynthesizer.isSpeaking
    }
    var isPaused = false
    var speechSynthesizer: NSSpeechSynthesizer!

    var speechPDFPage: CPDFPage?
    var speechPDFSelection: CPDFSelection?
    
    static let defalutManager = KMTTSManager()
    
    override init() {
        super.init()
        let array = NSSpeechSynthesizer.availableVoices

        var voice: NSSpeechSynthesizer.VoiceName = array.first ?? NSSpeechSynthesizer.VoiceName(rawValue: "")
        
        if (UserDefaults.standard.object(forKey: KMTTS_SETTING_LANGUAGE_KEY) != nil){
            voice = UserDefaults.standard.object(forKey: KMTTS_SETTING_LANGUAGE_KEY) as! NSSpeechSynthesizer.VoiceName
        }
        
        self.speechSynthesizer = NSSpeechSynthesizer(voice: voice)
        self.speechSynthesizer.delegate = self
        self.speechSynthesizer.usesFeedbackWindow = true
        var rate: Float = 175
        if let savedRate = UserDefaults.standard.object(forKey: KMTTS_SETTING_SPEECHSPEED_KEY) as? Float {
            rate = savedRate
        }
        self.speechSynthesizer.rate = rate
        
        var isContinue = false
        if let savedContinue = UserDefaults.standard.object(forKey: KMTTS_SETTING_ISCONTINUE_KEY) as? Bool {
            isContinue = savedContinue
        }
        self.isContinue = isContinue
    }
    
    func voice() -> NSSpeechSynthesizer.VoiceName {
        return self.speechSynthesizer.voice() ?? NSSpeechSynthesizer.VoiceName(rawValue: "")
    }
    func setVoice(voice: NSSpeechSynthesizer.VoiceName) {
        self.speechSynthesizer.setVoice(voice)
        UserDefaults.standard.setValue(voice, forKey: KMTTS_SETTING_LANGUAGE_KEY)
        UserDefaults.standard.synchronize()
    }
    
    //MARK: Public
    func startSpeakingPDFPage(_ page: CPDFPage) -> Bool {
        guard let string = page.string else { return false }
        guard string.count > 0 else { return false }
        isPaused = false
        if speechSynthesizer.isSpeaking {
            speechSynthesizer.stopSpeaking(at: .immediateBoundary)
        }
        speechPDFPage = page 
        speechPDFSelection = nil
        return speechSynthesizer.startSpeaking(string)
    }
    func startSpeakingPDFSelection(_ selection: CPDFSelection) -> Bool {
        guard let string = selection.string() else { return false }
        guard string.count > 0 else { return false }
        isPaused = false
        if speechSynthesizer.isSpeaking {
            speechSynthesizer.stopSpeaking(at: .immediateBoundary)
        }
        speechPDFPage = nil
        speechPDFSelection = selection
        return speechSynthesizer.startSpeaking(string)
    }
    func stopSpeaking() { 
        if speechSynthesizer.isSpeaking || isPaused {
            isPaused = false
            speechSynthesizer.stopSpeaking(at: .immediateBoundary)
        }
    }
    func pauseSpeaking() {
        if speechSynthesizer.isSpeaking {
            isPaused = true
            speechSynthesizer.pauseSpeaking(at: .immediateBoundary)
        }
    }
    func continueSpeaking() {
        isPaused = false
        speechSynthesizer.continueSpeaking()
    }
    func availableVoices() -> [NSSpeechSynthesizer.VoiceName] {
        return NSSpeechSynthesizer.availableVoices
    }
    func attributesForVoice(_ voice: NSSpeechSynthesizer.VoiceName) -> [NSSpeechSynthesizer.VoiceAttributeKey : Any] {
        return NSSpeechSynthesizer.attributes(forVoice: voice)
    }
    func speechSynthesizer(_ sender: NSSpeechSynthesizer, didFinishSpeaking finishedSpeaking: Bool) {
        isPaused = false
        let _ = delegate?.ttsManangerDidFinishSpeech?(self)
    }
    func speechSynthesizer(_ sender: NSSpeechSynthesizer, willSpeakWord characterRange: NSRange, of string: String) {
        var selection: CPDFSelection?
        if let page = speechPDFPage {
            if characterRange.length > 0 {
                selection = page.selection(for: characterRange)
            }
        } else if let pdfSelection = speechPDFSelection {
            selection = pdfSelection
        }
        if let data = selection {
            delegate?.ttsMananger?(self, willSpeak: data)
        }
    }
    func speechSynthesizer(_ sender: NSSpeechSynthesizer, didEncounterErrorAt characterIndex: Int, of string: String, message: String) {
        delegate?.ttsManangerdidErrorSpeech?(self, message: message)
    }
    func speechSynthesizer(_ sender: NSSpeechSynthesizer, didEncounterSyncMessage message: String) {
        delegate?.ttsManangerdidErrorSpeech?(self, message: message)
    }
}