import {
    ref,
    onUnmounted,
    readonly
} from 'vue';

const defaultExtractSpeechText = (text) => text;


export function useTTSPlayer() {
    const synth = window.speechSynthesis;
    const isSpeaking = ref(false);
    const isPaused = ref(false);
    const utteranceRef = ref(null);

    const cleanup = () => {
        isSpeaking.value = false;
        isPaused.value = false;
        utteranceRef.value = null;
    };

    /**
     * @param {string} text - The text to be spoken.
     * @param {object} [options] - Optional settings for the speech.
     * @param {string} [options.lang] - Language (e.g., 'en-US', 'es-ES').
     * @param {number} [options.rate] - Speed (0.1 to 10, default 1).
     * @param {number} [options.pitch] - Pitch (0 to 2, default 1).
     * @param {SpeechSynthesisVoice} [options.voice] - A specific voice object.
     * @param {function(string): string} [options.extractSpeechText] - A function to filter/clean the text before speaking.
     */
    const speak = (text, options = {}) => {
        if (!synth) {
            console.error('SpeechSynthesis API is not supported in this browser.');
            return;
        }

        if (isSpeaking.value) {
            synth.cancel();
        }

        const filteredText = extractSpeechText(text);

        if (!filteredText || typeof filteredText !== 'string' || filteredText.trim() === '') {
            console.warn('Text to speak is empty after filtering.');
            cleanup(); // Ensure state is clean
            return;
        }

        const newUtterance = new SpeechSynthesisUtterance(filteredText); // Use filtered text
        utteranceRef.value = newUtterance;

        newUtterance.rate = options.rate || 1;
        newUtterance.pitch = options.pitch || 1;
        if (options.voice) {
            newUtterance.voice = options.voice;
        }

        newUtterance.onstart = () => {
            isSpeaking.value = true;
            isPaused.value = false;
        };

        newUtterance.onpause = () => {
            isPaused.value = true;
        };
        newUtterance.onresume = () => {
            isPaused.value = false;
        };
        newUtterance.onend = () => {
            cleanup();
        };
        newUtterance.onerror = (event) => {
            console.error('SpeechSynthesis Error:', event.error);
            cleanup();
        };

        synth.speak(newUtterance);
    };

    const pause = () => {
        if (synth && isSpeaking.value && !isPaused.value) {
            synth.pause();
        }
    };

    const resume = () => {
        if (synth && isPaused.value) {
            synth.resume();
        }
    };

    const cancelAudio = () => {
        if (synth) {
            synth.cancel();
        }
        cleanup();
    };

    onUnmounted(() => {
        cancelAudio();
    });

    return {
        speak,
        pause,
        resume,
        cancelAudio,
        isSpeaking: readonly(isSpeaking),
        isPaused: readonly(isPaused),
    };
}

function extractSpeechText(markdown) {
    const jobRegex = /``` job-json\s*({[\s\S]*?})\s*```/g;
    const jobs = [];
    let match;
    let lastJobEndIndex = 0;
    let firstJobStartIndex = -1;

    // 提取岗位 json 数据及前后位置
    while ((match = jobRegex.exec(markdown)) !== null) {
        const jobStr = match[1];
        try {
            const job = JSON.parse(jobStr);
            jobs.push(job);
            if (firstJobStartIndex === -1) {
                firstJobStartIndex = match.index;
            }
            lastJobEndIndex = jobRegex.lastIndex;
        } catch (e) {
            console.warn('JSON 解析失败', e);
        }
    }

    // 提取引导语（第一个 job-json 之前的文字）
    const guideText = firstJobStartIndex > 0 ?
        markdown.slice(0, firstJobStartIndex).trim() :
        '';

    // 提取结束语（最后一个 job-json 之后的文字）
    const endingText = lastJobEndIndex < markdown.length ?
        markdown.slice(lastJobEndIndex).trim() :
        '';

    // 岗位信息格式化为语音文本
    const jobTexts = jobs.map((job, index) => {
        return `第 ${index + 1} 个岗位，岗位名称是：${job.jobTitle}，公司是：${job.companyName}，薪资：${job.salary}，地点：${job.location}，学历要求：${job.education}，经验要求：${job.experience}。`;
    });

    // 拼接总语音内容
    const finalTextParts = [];
    if (guideText) finalTextParts.push(guideText);
    finalTextParts.push(...jobTexts);
    if (endingText) finalTextParts.push(endingText);

    return finalTextParts.join('\n');
}