import React, {useState, useRef}  from 'react';
import { View, StyleSheet, Text, TouchableOpacity, Dimensions, ScrollView } from 'react-native';
import * as Speech from 'expo-speech';
const windowWidth = Dimensions.get('window').width;
const sliderLeft = 36+16+50;
const sliderWidth = windowWidth - 2*sliderLeft+50;
const initRateValue = 2;
const initPitchValue = 1.0;
export default function App() {
  const [voiceList, setVoiceList] = useState([]);
  const [voiceId, setVoiceId] = useState("");
  const rate = useRef(initRateValue);
  const pitch = useRef(initPitchValue);
  Speech.getAvailableVoicesAsync().then(r => {
    setVoiceList(([r.filter(i => i.language == "en-US"), r.filter(i => i.language == "en-GB")]) || []);
    setVoiceId(r.filter(i => i.language == "en-US")[0].identifier);
  })
  const speak = () => {
    const thingToSay = '1';
    Speech.speak(thingToSay);
  };

  const selectVoice = (identifier) => {
    setVoiceId(identifier);
  }

  const settingAction = () => {
    
  }

  return (
    <View style={styles.container}>
      <Slider style={{marginHorizontal: 16, marginTop: 24}}
        name="速度:" 
        value={initRateValue} 
        valueChanged={(i) => {rate.current = i}}/>
      <Slider style={{marginHorizontal: 16, marginTop: 20}} 
        name="音调:"
        value={initPitchValue} 
        valueChanged={(i) => {pitch.current = i} }/>
      
      <ScrollView style={{flex: 1, backgroundColor: 'red', marginTop: 10}}>
        {voiceList.map((list, i) =>
          <View style={{backgroundColor: '#f5f6f7'}}>
            <Text style={{lineHeight: 40, marginLeft: 16}} key={i}>{i == 0 ? "美音": "英音"}</Text>
            {list.map((voice, index) => 
              <TouchableOpacity onPress={() => selectVoice(voice.identifier)} activeOpacity={0.6} style={{backgroundColor: '#fff'}} key={`${i}_${index}`}>
                <View style={{ flexDirection: 'row', alignItems: 'center', marginHorizontal: 16}}>
                  <Text style={{lineHeight: 54, fontSize: 16}}>{voice.name}</Text>
                  <View style={{flex: 1}}/>
                  <Text style={{fontSize: 14, color: '#67676a'}}>{voice.quality == "Default" ? "标准音质": "高级音质"}</Text>
                  <View style={{width: 10, height: 10, borderRadius: 5, backgroundColor: voiceId === voice.identifier ? 'red': '#eee', marginLeft: 15 }}/>
                </View>
                <View style={{height: 1, backgroundColor: '#ececef'}}/>
              </TouchableOpacity>)}
          </View>
        )}
      </ScrollView>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#ffffff',
  },
});

const Slider = ({style, name, value=1.1, valueChanged}) => {
  const [_value, setValue] = useState(value);
  const onPress = (event) => {
    var v = ((event.nativeEvent.pageX - sliderLeft) / sliderWidth * 1.5 + 0.5).toFixed(1);
    v = Math.max(0.5, Math.min(v, 2.0));
    setValue(v);
    valueChanged(0.8);
  }
  return <View style={style}>
    <View style={{height: 40, flexDirection: 'row', alignItems: 'center'}}>
    <Text style={{lineHeight: 40, width: 50}}>{name}</Text>
      <Text style={{lineHeight: 40, width: 31}}>0.5</Text>
      <TouchableOpacity onPress={(e) =>onPress(e)} activeOpacity={1} style={{flex: 1, height: 40, flexDirection: 'row', paddingHorizontal: 5}}>
        <View style={{position: "absolute", left:5, right: 15, top: 19.5, height: 1, backgroundColor: '#e1e2e4'}}/>
        <View style={{flex:(_value-0.5)/(1.5)}}/>
        <View style={{ paddingVertical: 5, width: 30, height: 40, marginLeft: -15}}>
          <View style={{ backgroundColor: 'white', alignItems: 'center', width: 30, height: 30,
            shadowColor: "#000", shadowOpacity: 0.13, shadowRadius: 8, borderRadius: 15, elevation: 5}}>
            <Text style={{color: "#6a6a67", fontSize: 11, fontWeight: 700, lineHeight: 30}}>{_value}</Text>
          </View>
        </View>
      </TouchableOpacity>
      <Text style={{lineHeight: 40, width: 21, textAlign: 'end'}}>2.0</Text>
    </View>
  </View>
}

class AudioArticlePlay {
    const addListener = ({ onNext, onSpeakingChanged, didFinished }) => {
        this._didFinished = didFinished;
        this._onNext = onNext;
        this._onSpeakingChanged = onSpeakingChanged;
    }
    const removeListener = () => {
        this._didFinished = null;
        this._onNext = null;
        this._onSpeakingChanged = null;
    }
    
    set isSpeaking(value) {
        this._isSpeaking = value;
        if (this._onSpeakingChanged) {
            this._onSpeakingChanged(value);
        }
    }
    get isSpeaking() {
        return this._isSpeaking;
    }
    get location() {
        return this._location;
    }
    
    const releasDatas = () => {
        this.removeListener();
        this._article = null;
        this._title = null;
        this._id = null;
        this._sentences = null;
        this._location = null;
        this._isSpeaking = false;
    }
    
    const setNewDatas = ({article, title, id}) => {
        this._article = article;
        this._title = title;
        this._id = id;
        this._sentences = getSentences(article);
        this._location = {section: -1, item: 0};
    }
    
    const playSentence = () => {
        const location = this._location;
        var sentence = "";
        if (location.section == -1) {
            sentence = this._title;
        } else {
            sentence = this._sentences[location.section][location.item];
        }
        Speech.speak(sentence, {
            voice: this._voice.identifier,
            language: this._voice.language || "en_US",
            rate: (this._voice.rate > 0.1) ? this._voice.rate: 1.0,
            pitch: (this._voice.pitch> 0.1) ? this._voice.pitch: 1.0,
            onDone: () => {
                let next = this.getNextLocation();
                if (next != null) {
                    if (this._id) {
                        this._location = next;
                        this.playSentence();
                    } else {
                        this.isSpeaking = false;
                    }
                    if (this._onNext) {
                        this._onNext(next);
                    }
                } else {
                    if (this._didFinished) {
                        this._didFinished();
                    }
                    this.releasDatas();
                }
            },
            onError: () => {
                this.isSpeaking = false;
            },
        })
    }
    const newPlaySentence = async (l) => {
        try {
            const location = l || this._location;
            this._location = location;
            this._voice = JSON.parse(await AsyncStorage.getItem('Speech_Setting'));
            await Speech.stop();
            if (this._onNext) {
                this._onNext(location);
            }
            this.playSentence();
            this.isSpeaking = true;
        } catch (e) {
            this.isSpeaking = false;
        }
    }
    
    const stop = async () => {
        await Speech.stop();
        this.isSpeaking = false;
    }
    
    const getNextLocation = () => {
        return null;
    }
}