content.js

(function () {
    'use strict';

    const SELECTOR_DATA = 'script[data-target*="embeddedData"], script[type="application/json"]';
    const INJECT_CLASS = 'gh-repo-creation-date';

    // In-memory cache for repository creation dates keyed by "owner/repo"
    const dateCache = new Map();
    const pendingFetches = new Map();

    function getRepoKey() {
        const parts = window.location.pathname.split('/').filter(Boolean);
        if (parts.length >= 2) {
            const nonRepoRoots = [
                'settings', 'marketplace', 'explore', 'topics', 'trending',
                'collections', 'events', 'sponsors', 'organizations',
                'account', 'notifications', 'login', 'signup', 'orgs'
            ];
            if (!nonRepoRoots.includes(parts[0].toLowerCase())) {
                return `${parts[0]}/${parts[1]}`.toLowerCase();
            }
        }
        return null;
    }

    function findRepoCreatedAt(obj) {
        if (typeof obj !== 'object' || obj === null) return null;
        if (obj.repo && obj.repo.createdAt) return obj.repo.createdAt;
        if (obj.repository && obj.repository.createdAt) return obj.repository.createdAt;
        if (obj.createdAt && typeof obj.createdAt === 'string' && obj.createdAt.includes('T')) {
            if (obj.name || obj.id || obj.owner) return obj.createdAt;
        }
        for (const key in obj) {
            try {
                const res = findRepoCreatedAt(obj[key]);
                if (res) return res;
            } catch (e) { }
        }
        return null;
    }

    async function getCreatedAtDate() {
        const repoKey = getRepoKey();
        if (repoKey && dateCache.has(repoKey)) {
            return dateCache.get(repoKey);
        }

        // 1. Try finding in embedded JSON script tags
        const scriptTags = Array.from(document.querySelectorAll(SELECTOR_DATA));
        for (const tag of scriptTags) {
            try {
                const data = JSON.parse(tag.textContent);
                const createdAt = findRepoCreatedAt(data);
                if (createdAt) {
                    if (repoKey) dateCache.set(repoKey, createdAt);
                    return createdAt;
                }
            } catch (e) { }
        }

        // 2. Fallback: Fetch directly from GitHub API
        if (repoKey) {
            if (pendingFetches.has(repoKey)) {
                return pendingFetches.get(repoKey);
            }

            const fetchPromise = (async () => {
                try {
                    const response = await fetch(`https://api.github.com/repos/${repoKey}`);
                    if (response.ok) {
                        const data = await response.json();
                        if (data && data.created_at) {
                            dateCache.set(repoKey, data.created_at);
                            return data.created_at;
                        }
                    }
                } catch (err) {
                    console.warn('[GitHub Repo Creation Date] API fallback failed:', err);
                } finally {
                    pendingFetches.delete(repoKey);
                }
                return null;
            })();

            pendingFetches.set(repoKey, fetchPromise);
            return fetchPromise;
        }

        return null;
    }

    function getInjectionPoints() {
        // GitHub can render multiple "About" headings (e.g. desktop sidebar vs responsive mobile section)
        const aboutHeadings = Array.from(document.querySelectorAll('h2, [data-component="Heading"]'))
            .filter(h => {
                const text = h.textContent.trim();
                return /^(about|repository details)/i.test(text);
            });

        if (aboutHeadings.length === 0) return [];

        const injectionPoints = [];
        const selectors = [
            'p.f4',
            'p[class*="description"]',
            'div.tmp-my-3',
            'div[class*="websiteRow"]',
            '.list-topics-container',
            'div[class*="TopicTagGroup"]',
            'div[class*="tagGroup"]'
        ];

        for (const aboutHeading of aboutHeadings) {
            const aboutSection = aboutHeading.closest('[class*="sidebarSection"], [class*="BorderGrid-cell"], [class*="borderGrid"] > div') || aboutHeading.parentElement;
            if (!aboutSection) continue;

            // Skip if this section already has our creation date element
            if (aboutSection.querySelector(`.${INJECT_CLASS}`)) continue;

            const containers = Array.from(aboutSection.querySelectorAll(selectors.join(', ')));
            if (containers.length > 0) {
                const lastContainer = containers[containers.length - 1];
                injectionPoints.push({ section: aboutSection, element: lastContainer, position: 'afterend' });
            } else {
                injectionPoints.push({ section: aboutSection, element: aboutHeading, position: 'afterend' });
            }
        }

        return injectionPoints;
    }

    function createCreationBlock(formattedDate) {
        const creationBlock = document.createElement('div');
        creationBlock.className = `${INJECT_CLASS} mt-2 color-fg-muted`;

        creationBlock.innerHTML = `<h3 class="sr-only">Creation Date</h3><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" class="octicon octicon-calendar mr-2" style="vertical-align: text-bottom; margin-right: 8px !important;"><path d="M4.75 0a.75.75 0 0 1 .75.75V2h5V.75a.75.75 0 0 1 1.5 0V2h1.25c.966 0 1.75.784 1.75 1.75v10.5A1.75 1.75 0 0 1 13.25 16H2.75A1.75 1.75 0 0 1 1 14.25V3.75C1 2.784 1.784 2 2.75 2H4V.75A.75.75 0 0 1 4.75 0ZM2.5 7.5v6.75c0 .138.112.25.25.25h10.5a.25.25 0 0 0 .25-.25V7.5Zm10.75-4H2.75a.25.25 0 0 0-.25.25V6h11V3.75a.25.25 0 0 0-.25-.25Z"></path></svg><span>${formattedDate}</span>`;

        return creationBlock;
    }

    async function injectCreationDate(forceClear) {
        if (forceClear) {
            document.querySelectorAll(`.${INJECT_CLASS}`).forEach(el => el.remove());
        }

        const injectionPoints = getInjectionPoints();
        if (injectionPoints.length === 0) return;

        try {
            const createdAt = await getCreatedAtDate();
            if (!createdAt) return;

            const date = new Date(createdAt);
            const formattedDate = date.toLocaleDateString(undefined, {
                year: 'numeric',
                month: 'short',
                day: 'numeric'
            });

            // Re-fetch points in case DOM shifted while awaiting
            const currentPoints = getInjectionPoints();
            for (const injection of currentPoints) {
                if (!injection.section.querySelector(`.${INJECT_CLASS}`)) {
                    const block = createCreationBlock(formattedDate);
                    injection.element.insertAdjacentElement(injection.position, block);
                }
            }
        } catch (e) {
            console.warn('[GitHub Repo Creation Date] Injection error:', e);
        }
    }

    console.log('[GitHub Repo Creation Date Extension] Active');
    injectCreationDate(false);

    // Support GitHub Turbo / soft-navigation events
    let currentRepo = getRepoKey();
    function handleNavigation() {
        const newRepo = getRepoKey();
        const repoChanged = newRepo !== currentRepo;
        if (repoChanged) {
            currentRepo = newRepo;
            injectCreationDate(true);
        } else {
            injectCreationDate(false);
        }
    }

    document.addEventListener('turbo:load', () => handleNavigation());
    document.addEventListener('turbo:render', () => handleNavigation());
    document.addEventListener('soft-nav:end', () => handleNavigation());

    let lastUrl = location.href;
    const observer = new MutationObserver(() => {
        const url = location.href;
        if (url !== lastUrl) {
            lastUrl = url;
            handleNavigation();
        } else if (getInjectionPoints().length > 0) {
            injectCreationDate(false);
        }
    });

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

})();