/** 正文引用标记，如 [1]、[1-7]、<blue>[4,6,8]</blue> */
const CITATION_BRACKET_RE = /(?:<blue>\s*)?\[([^\]]+)\](?:\s*<\/blue>)?/gi;

function decodeHtmlEntities(text) {
    return String(text || '')
        .replace(/&nbsp;/g, ' ')
        .replace(/&amp;/g, '&')
        .replace(/&lt;/g, '<')
        .replace(/&gt;/g, '>')
        .replace(/&quot;/g, '"');
}

function escapeHtml(text) {
    return String(text || '')
        .replace(/&/g, '&amp;')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;');
}

export function htmlToPlainText(html) {
    const raw = String(html || '');
    if (typeof document !== 'undefined') {
        const node = document.createElement('div');
        node.innerHTML = raw;
        return (node.textContent || node.innerText || '').replace(/\u00a0/g, ' ').trim();
    }
    return decodeHtmlEntities(raw.replace(/<br\s*\/?>/gi, '\n').replace(/<[^>]*>/g, '')).trim();
}

export function expandCitationBracket(inner) {
    const result = [];
    const text = String(inner || '')
        .replace(/<[^>]+>/g, '')
        .trim();
    if (!text) {
        return result;
    }

    text.split(/\s*,\s*/).forEach(function (part) {
        const token = part.trim();
        const range = token.match(/^(\d+)\s*[\-–−]\s*(\d+)$/);
        if (range) {
            const a = Number(range[1]);
            const b = Number(range[2]);
            const lo = Math.min(a, b);
            const hi = Math.max(a, b);
            let i = 0;
            for (i = lo; i <= hi; i += 1) {
                result.push(i);
            }
            return;
        }
        if (/^\d+$/.test(token)) {
            result.push(Number(token));
        }
    });

    return result;
}

/** 从段落 HTML 提取引用编号（按出现顺序，段内去重） */
export function parseCitationNumbersFromHtml(html) {
    const nums = [];
    const seen = {};
    const re = new RegExp(CITATION_BRACKET_RE.source, 'gi');
    let match = null;

    while ((match = re.exec(String(html || ''))) !== null) {
        expandCitationBracket(match[1]).forEach(function (num) {
            if (!seen[num]) {
                seen[num] = true;
                nums.push(num);
            }
        });
    }

    return nums;
}

export function stripHtmlTags(html) {
    return htmlToPlainText(html);
}

export function formatReferencePlainText(ref) {
    if (!ref) {
        return '';
    }

    if (ref.refer_frag) {
        const frag = stripHtmlTags(ref.refer_frag);
        if (frag) {
            return frag;
        }
    }

    const parts = [];
    if (ref.author) {
        parts.push(stripHtmlTags(ref.author));
    }
    if (ref.title) {
        parts.push(stripHtmlTags(ref.title));
    }
    if (ref.joura) {
        parts.push(stripHtmlTags(ref.joura));
    }
    if (ref.dateno) {
        parts.push(stripHtmlTags(ref.dateno));
    }
    if (ref.doilink) {
        parts.push(String(ref.doilink).trim());
    }
    if (ref.isbn) {
        parts.push('ISBN: ' + String(ref.isbn).trim());
    }

    return parts.filter(Boolean).join('. ').replace(/\.\s*\./g, '.').trim();
}

function isTextParagraphItem(item) {
    if (!item) {
        return false;
    }
    if (item.type == 1 || item.type == 2) {
        return false;
    }
    const html = String(item.content || item.text || '').trim();
    return !!html;
}

function buildCitationEntry(citeNum, refList) {
    const ref = refList[citeNum - 1] || null;
    return {
        citeNum: citeNum,
        reference: ref,
        referenceText: formatReferencePlainText(ref),
        referenceMissing: !ref
    };
}

export function formatCitationNumsLabel(citeNums) {
    return (citeNums || []).map(function (n) {
        return '[' + n + ']';
    }).join(' ');
}

export function getCitationReviewGroupMeta(item, index, labels) {
    const l = labels || {};
    const groupNo = index + 1;
    const paragraphNo = item.paragraphIndex + 1;
    const citeNumsLabel = formatCitationNumsLabel(item.citeNums);
    const citeNumsPlain = (item.citeNums || []).join('、');

    let title = '正文段落 ' + paragraphNo + ' · ' + citeNumsLabel;
    if (l.groupLabel) {
        title = l.groupLabel
            .replace('{group}', groupNo)
            .replace('{paragraph}', paragraphNo)
            .replace('{refs}', citeNumsLabel);
    }

    return {
        id: 'cite-group-' + groupNo,
        groupNo: groupNo,
        paragraphNo: paragraphNo,
        citeNumsLabel: citeNumsLabel,
        citeNumsPlain: citeNumsPlain,
        title: title
    };
}

/**
 * 构建核查队列：每个含引文的正文段落一组，该段全部参考文献一并询问；
 * 同一条文献出现在不同段落时，会在各段落中分别询问。
 */
export function buildCitationReviewQueue(wordList, references) {
    const items = [];
    const refList = references || [];

    (wordList || []).forEach(function (item, paragraphIndex) {
        if (!isTextParagraphItem(item)) {
            return;
        }

        const html = item.content || item.text || '';
        const citeNums = parseCitationNumbersFromHtml(html);
        if (!citeNums.length) {
            return;
        }

        const paragraphText = htmlToPlainText(html);
        const citations = citeNums.map(function (citeNum) {
            return buildCitationEntry(citeNum, refList);
        });

        items.push({
            paragraphIndex: paragraphIndex,
            amId: item.am_id,
            paragraphHtml: html,
            paragraphText: paragraphText,
            citeNums: citeNums.slice(),
            citations: citations,
            hasMissingReference: citations.some(function (c) {
                return c.referenceMissing;
            })
        });
    });

    return items;
}

export function buildWenaiRelevancePrompt(item) {
    if (!item) {
        return '';
    }

    const paragraphText = item.paragraphText || '';
    const citations = item.citations || [];
    const citeLabels = citations.map(function (c) {
        return '[' + c.citeNum + ']';
    });

    let refBlock = '';
    citations.forEach(function (c) {
        const text = c.referenceText || '（未找到该条参考文献）';
        refBlock += '[' + c.citeNum + ']\n' + text + '\n\n';
    });

    const labelList = citeLabels.join('、') || '';

    return (
        '请审读以下正文段落及其引用文献，结合该段落的论述内容，判断各文献与正文的相关程度。\n\n' +
        '【正文段落】\n' +
        paragraphText +
        '\n\n' +
        '【参考文献】\n' +
        refBlock.trim() +
        '\n\n' +
        '【输出要求】\n' +
        '请以期刊编辑审稿批注的语气，为作者撰写一段文件批注（不要用邮件格式，不要称呼、落款、主题行或分条邮件体）。\n' +
        '请按文献序号 ' +
        labelList +
        ' 依次说明，保留原文序号且顺序连续，不要重新编号或跳号。\n' +
        '对每条文献分别给出关联判断：直接相关 / 强相关 / 弱相关 / 不相关，并用一句话简要说明理由。\n' +
        '将全部内容合并写成一段连贯的批注文字，语气客观、专业、克制，可直接作为稿件文件批注使用。'
    );
}

/** 合并全部批次提示词 */
export function buildAllWenaiRelevancePrompts(reviewItems, labels) {
    return (reviewItems || [])
        .map(function (item, index) {
            const meta = getCitationReviewGroupMeta(item, index, labels);
            const header = '========== ' + meta.title + ' ==========';
            return header + '\n\n' + buildWenaiRelevancePrompt(item);
        })
        .filter(Boolean)
        .join('\n\n\n');
}

/** 生成可独立打开的 HTML 文档（含锚点导航与复制） */
export function buildCitationReviewStandaloneHtml(reviewItems, labels) {
    const l = labels || {};
    const items = reviewItems || [];
    const total = items.length;
    const pageTitle = l.pageTitle || '引文相关性核查';
    const groupTotalText = (l.groupTotal || '共 {n} 组').replace('{n}', total);
    const jumpTitle = l.jumpTitle || '快速跳转';
    const copyGroupText = l.copyGroup || '复制本组';
    const copyAllText = l.copyAll || '复制全部';
    const copySuccessText = l.copySuccess || '已复制';
    const copyFailText = l.copyFail || '复制失败';

    let navHtml = '';
    let bodyHtml = '';
    let i = 0;

    for (i = 0; i < items.length; i += 1) {
        const item = items[i];
        const meta = getCitationReviewGroupMeta(item, i, labels);
        const prompt = buildWenaiRelevancePrompt(item);
        const promptId = 'cite-prompt-' + meta.groupNo;

        navHtml +=
            '<a class="nav-link" href="#' +
            meta.id +
            '">' +
            escapeHtml(meta.title) +
            '</a>';

        bodyHtml +=
            '<section class="group-card" id="' +
            meta.id +
            '">' +
            '<div class="group-head">' +
            '<h3>' +
            escapeHtml(meta.title) +
            '</h3>' +
            '<button type="button" class="copy-btn" data-target="' +
            promptId +
            '">' +
            escapeHtml(copyGroupText) +
            '</button>' +
            '</div>' +
            '<pre class="group-prompt" id="' +
            promptId +
            '">' +
            escapeHtml(prompt) +
            '</pre>' +
            '</section>';
    }

    const allPrompt = escapeHtml(buildAllWenaiRelevancePrompts(items, labels));

    return (
        '<!DOCTYPE html><html lang="zh-CN"><head><meta charset="UTF-8">' +
        '<meta name="viewport" content="width=device-width,initial-scale=1">' +
        '<title>' +
        escapeHtml(pageTitle) +
        '</title>' +
        '<style>' +
        '*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;background:#f5f7fa;color:#303133;line-height:1.5}' +
        '.page{max-width:960px;margin:0 auto;padding:20px}' +
        '.header{background:#fff;border-radius:8px;padding:16px 20px;margin-bottom:12px;box-shadow:0 1px 4px rgba(0,0,0,.08)}' +
        '.header h1{margin:0 0 8px;font-size:20px}' +
        '.summary{color:#606266;font-size:14px;margin-bottom:12px}' +
        '.actions{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:12px}' +
        '.btn{border:1px solid #409eff;background:#409eff;color:#fff;border-radius:4px;padding:6px 14px;font-size:13px;cursor:pointer}' +
        '.btn.plain{background:#ecf5ff;color:#409eff}' +
        '.nav{background:#fff;border-radius:8px;padding:12px 16px;margin-bottom:12px;box-shadow:0 1px 4px rgba(0,0,0,.08)}' +
        '.nav-title{font-weight:600;margin-bottom:8px;font-size:14px}' +
        '.nav-links{display:flex;flex-wrap:wrap;gap:8px}' +
        '.nav-link{display:inline-block;padding:4px 10px;background:#f4f4f5;border-radius:4px;color:#409eff;text-decoration:none;font-size:12px}' +
        '.nav-link:hover{background:#ecf5ff}' +
        '.group-card{background:#fff;border-radius:8px;padding:16px 20px;margin-bottom:12px;box-shadow:0 1px 4px rgba(0,0,0,.08);scroll-margin-top:16px}' +
        '.group-head{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:10px}' +
        '.group-head h3{margin:0;font-size:15px;color:#303133}' +
        '.copy-btn{border:1px solid #409eff;background:#ecf5ff;color:#409eff;border-radius:4px;padding:4px 12px;font-size:12px;cursor:pointer;white-space:nowrap}' +
        '.copy-btn:hover{background:#409eff;color:#fff}' +
        '.group-prompt{margin:0;padding:12px;background:#fafafa;border:1px solid #ebeef5;border-radius:4px;white-space:pre-wrap;word-break:break-word;font-size:13px;font-family:Consolas,"Courier New",monospace}' +
        '#all-prompt{display:none}' +
        '</style></head><body><div class="page">' +
        '<div class="header"><h1>' +
        escapeHtml(pageTitle) +
        '</h1>' +
        '<div class="summary">' +
        escapeHtml(groupTotalText) +
        '</div>' +
        '<div class="actions">' +
        '<button type="button" class="btn plain" id="copy-all-btn">' +
        escapeHtml(copyAllText) +
        '</button></div></div>' +
        '<div class="nav"><div class="nav-title">' +
        escapeHtml(jumpTitle) +
        '</div><div class="nav-links">' +
        navHtml +
        '</div></div>' +
        bodyHtml +
        '<pre id="all-prompt">' +
        allPrompt +
        '</pre></div>' +
        '<script>(function(){' +
        'var okMsg=' +
        JSON.stringify(copySuccessText) +
        ';var failMsg=' +
        JSON.stringify(copyFailText) +
        ';function copyFromEl(el,btn){var text=el?(el.innerText||el.textContent||""):"";if(!text){alert(failMsg);return;}' +
        'function done(){if(btn){var old=btn.innerText;btn.innerText=okMsg;setTimeout(function(){btn.innerText=old;},1200);}else{alert(okMsg);}}' +
        'if(navigator.clipboard&&navigator.clipboard.writeText){navigator.clipboard.writeText(text).then(done).catch(function(){fallback(text,done);});return;}' +
        'fallback(text,done);}' +
        'function fallback(text,done){var ta=document.createElement("textarea");ta.value=text;ta.style.position="fixed";ta.style.opacity="0";document.body.appendChild(ta);ta.select();try{document.execCommand("copy");done();}catch(e){alert(failMsg);}document.body.removeChild(ta);}' +
        'document.querySelectorAll(".copy-btn").forEach(function(btn){btn.addEventListener("click",function(){var id=btn.getAttribute("data-target");copyFromEl(document.getElementById(id),btn);});});' +
        'var allBtn=document.getElementById("copy-all-btn");if(allBtn){allBtn.addEventListener("click",function(){copyFromEl(document.getElementById("all-prompt"),allBtn);});}' +
        '})();<' +
        '/script></body></html>'
    );
}

export function downloadCitationReviewHtml(reviewItems, labels, fileName) {
    const html = buildCitationReviewStandaloneHtml(reviewItems, labels);
    const blob = new Blob([html], { type: 'text/html;charset=utf-8' });
    const url = URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = url;
    link.download = fileName || 'citation-relevance.html';
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
    URL.revokeObjectURL(url);
}

export function buildCitationReviewHtmlLabels(translate) {
    const t = translate || function (key) {
        return key;
    };
    return {
        pageTitle: t('commonTable.citeRelevanceTitle'),
        groupTotal: t('commonTable.citeRelevanceGroupTotal', { n: '{n}' }),
        jumpTitle: t('commonTable.citeRelevanceJumpTo'),
        copyGroup: t('commonTable.citeRelevanceCopyGroup'),
        copyAll: t('commonTable.citeRelevanceCopyAllWenai'),
        copySuccess: t('commonTable.citeRelevanceCopySuccess'),
        copyFail: t('commonTable.citeRelevanceCopyFail'),
        groupLabel: t('commonTable.citeRelevanceGroupNavLabel')
    };
}