/**
 * InsightReply Content Script
 * 负责解析 X (Twitter) 页面 DOM，提取推文内容并注入交互按钮
 */

console.log('InsightReply Content Script Loaded');

// 1. 定义推文数据结构
interface TweetData {
    id: string;
    author: string;
    content: string;
    stats: {
        replies: string;
        retweets: string;
        likes: string;
    };
}

let relevanceKeywords: string[] = [];

chrome.storage.local.get(['relevance_keywords'], (res) => {
    if (res.relevance_keywords) {
        relevanceKeywords = String(res.relevance_keywords).split(',').map((k: string) => k.trim().toLowerCase()).filter(Boolean);
    }
});

chrome.storage.onChanged.addListener((changes, namespace) => {
    if (namespace === 'local' && changes.relevance_keywords) {
        const val = String(changes.relevance_keywords.newValue || '');
        relevanceKeywords = val.split(',').map((k: string) => k.trim().toLowerCase()).filter(Boolean);
    }
});

// 2. 提取推文内容的逻辑
const parseStat = (statString: string): number => {
    if (!statString) return 0;
    const match = statString.match(/([\d,\.]+)\s*([KkMmB])?/i);
    if (!match) return 0;
    const baseStr = match[1] || '0';
    let num = parseFloat(baseStr.replace(/,/g, ''));
    const multiplier = match[2] ? match[2].toUpperCase() : '';
    if (multiplier === 'K') num *= 1000;
    if (multiplier === 'M') num *= 1000000;
    if (multiplier === 'B') num *= 1000000000;
    return num;
};

const extractTweetData = (tweetElement: HTMLElement): TweetData | null => {
    try {
        const textElement = tweetElement.querySelector('[data-testid="tweetText"]');
        const authorElement = tweetElement.querySelector('[data-testid="User-Name"]');
        const linkElement = tweetElement.querySelector('time')?.parentElement as HTMLAnchorElement;

        if (!textElement || !authorElement || !linkElement) {
            console.debug('[InsightReply] Missing elements for tweet extraction:', {
                hasText: !!textElement,
                hasAuthor: !!authorElement,
                hasLink: !!linkElement
            });
            return null;
        }

        const getStat = (testid: string) => {
            const el = tweetElement.querySelector(`[data-testid="${testid}"]`);
            return el?.getAttribute('aria-label') || '0';
        };

        const tweetId = linkElement.href.split('/').pop() || '';

        return {
            id: tweetId,
            author: authorElement.textContent || 'Unknown',
            content: textElement.textContent || '',
            stats: {
                replies: getStat('reply'),
                retweets: getStat('retweet'),
                likes: getStat('like'),
            }
        };
    } catch (e) {
        console.error('Failed to extract tweet data:', e);
        return null;
    }
};

const injectBadges = (tweetElement: HTMLElement, data: TweetData) => {
    if (tweetElement.dataset.insightBadged === 'true') return;
    tweetElement.dataset.insightBadged = 'true';

    const likes = parseStat(data.stats.likes);
    const retweets = parseStat(data.stats.retweets);
    const replies = parseStat(data.stats.replies);
    const heatScore = likes * 1 + retweets * 2 + replies * 3;

    let badgeText = '';
    let badgeStyle = '';

    if (heatScore > 50000) {
        badgeText = '🔥 Trending';
        badgeStyle = 'color: #f97316; background: rgba(249, 115, 22, 0.1); border: 1px solid rgba(249, 115, 22, 0.2);';
    } else if (heatScore > 5000) {
        badgeText = '⚡ Rising';
        badgeStyle = 'color: #3b82f6; background: rgba(59, 130, 246, 0.1); border: 1px solid rgba(59, 130, 246, 0.2);';
    }

    let isRelevant = false;
    if (relevanceKeywords.length > 0 && data.content) {
        const contentLower = data.content.toLowerCase();
        isRelevant = relevanceKeywords.some(kw => contentLower.includes(kw));
    }

    if (!badgeText && !isRelevant) return;

    const authorSection = tweetElement.querySelector('[data-testid="User-Name"]');
    if (!authorSection) return;

    const container = document.createElement('div');
    container.className = 'insight-badges-container';
    container.style.cssText = `display: inline-flex; align-items: center; gap: 4px; margin-left: 8px;`;

    if (badgeText) {
        const heatBadge = document.createElement('span');
        heatBadge.style.cssText = `padding: 2px 6px; border-radius: 4px; font-size: 10px; font-weight: bold; ${badgeStyle}`;
        heatBadge.innerText = badgeText;
        container.appendChild(heatBadge);
    }

    if (isRelevant) {
        const relBadge = document.createElement('span');
        relBadge.style.cssText = `padding: 2px 6px; border-radius: 4px; font-size: 10px; font-weight: bold; color: #10b981; background: rgba(16, 185, 129, 0.1); border: 1px solid rgba(16, 185, 129, 0.2);`;
        relBadge.innerText = '🎯 Relevant';
        container.appendChild(relBadge);
    }

    const firstLine = authorSection.firstElementChild;
    if (firstLine) {
        firstLine.appendChild(container);
    } else {
        authorSection.appendChild(container);
    }
};

// 3. 注入“Insight”按钮
const injectInsightButton = (tweetElement: HTMLElement) => {
    const actionBar = tweetElement.querySelector('[role="group"]');
    if (!actionBar || actionBar.querySelector('.insight-reply-btn')) return;

    const btnContainer = document.createElement('div');
    btnContainer.className = 'insight-reply-btn';
    btnContainer.style.display = 'flex';
    btnContainer.style.alignItems = 'center';
    btnContainer.style.marginLeft = '12px';
    btnContainer.style.cursor = 'pointer';

    const innerDiv = document.createElement('div');
    innerDiv.style.cssText = 'padding: 4px; border-radius: 9999px; transition: background 0.2s;';

    // Use event listeners instead of inline handlers to comply with Content Security Policy
    innerDiv.addEventListener('mouseover', () => {
        innerDiv.style.background = 'rgba(139, 92, 246, 0.1)';
    });
    innerDiv.addEventListener('mouseout', () => {
        innerDiv.style.background = 'transparent';
    });

    innerDiv.innerHTML = `
      <svg viewBox="0 0 24 24" width="20" height="20" fill="currentColor" style="color: #8B5CF6;">
        <path d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm1 15h-2v-2h2v2zm0-4h-2V7h2v6z"></path>
      </svg>
    `;
    btnContainer.appendChild(innerDiv);

    btnContainer.onclick = (e) => {
        e.stopPropagation();
        e.preventDefault();
        console.log('[InsightReply] Insight button clicked');

        const data = extractTweetData(tweetElement);
        if (data) {
            console.log('[InsightReply] Extracted Tweet Data:', data);
            chrome.runtime.sendMessage({ type: 'SHOW_INSIGHT', payload: data }, (response) => {
                console.log('[InsightReply] Background script responsed SHOW_INSIGHT with:', response);
                if (chrome.runtime.lastError) {
                    console.error('[InsightReply] Error sending SHOW_INSIGHT message:', chrome.runtime.lastError);
                }
            });
        } else {
            console.warn('[InsightReply] Failed to extract tweet data on click');
        }
    };

    actionBar.appendChild(btnContainer);
};

// 4. 定时或监听 DOM 变化进行扫描
const scanTweets = () => {
    const tweets = document.querySelectorAll('article[data-testid="tweet"]');
    tweets.forEach((tweet) => {
        const el = tweet as HTMLElement;
        injectInsightButton(el);
        const data = extractTweetData(el);
        if (data) injectBadges(el, data);
    });
};

// 使用 MutationObserver 监听动态加载
const observer = new MutationObserver(() => {
    scanTweets();
});

observer.observe(document.body, { childList: true, subtree: true });

// 初始扫描
scanTweets();