import { HF_DATASET_BASE_URL, MAX_DOCS_TO_SCAN, getCorpora, getLinksRepoPath, getDocRepoPath } from '../../../utils/config.js';

export const dynamic = 'force-dynamic';

/**
 * GET /api/leaderboard
 * Scans ALL corpora and returns annotator rankings.
 */
export async function GET() {
    try {
        const corpora = getCorpora();
        const stats = {}; // annotator -> { verified, correct, incorrect, docs, humanAdded }

        for (const corpus of corpora) {
            const linksPath = getLinksRepoPath(corpus);
            const linksUrl = `${HF_DATASET_BASE_URL}/raw/main/${linksPath}`;
            const linksRes = await fetch(linksUrl, {
                headers: { 'Authorization': `Bearer ${process.env.HF_TOKEN}` },
                cache: 'no-store'
            });

            if (!linksRes.ok) continue;

            const links = await linksRes.json();
            const activeLinks = links
                .filter(l => l.status === 'success' && l.has_revalidation === true)
                .slice(0, MAX_DOCS_TO_SCAN);

            await Promise.allSettled(
                activeLinks.map(async (link) => {
                    const docRepoPath = getDocRepoPath(corpus, link.index);
                    const docUrl = `${HF_DATASET_BASE_URL}/raw/main/${docRepoPath}`;
                    const docRes = await fetch(docUrl, {
                        headers: { 'Authorization': `Bearer ${process.env.HF_TOKEN}` },
                        cache: 'no-store'
                    });
                    if (!docRes.ok) return;

                    const pagesData = await docRes.json();

                    for (const page of pagesData) {
                        for (const ds of (page.datasets || [])) {
                            if (ds.source === 'human' && ds.annotator) {
                                if (!stats[ds.annotator]) {
                                    stats[ds.annotator] = { verified: 0, correct: 0, incorrect: 0, docs: new Set(), humanAdded: 0 };
                                }
                                stats[ds.annotator].humanAdded++;
                                stats[ds.annotator].docs.add(`${corpus.id}:${link.index}`);
                            }

                            for (const v of (ds.validations || [])) {
                                if (!v.annotator || !v.human_validated) continue;
                                if (!stats[v.annotator]) {
                                    stats[v.annotator] = { verified: 0, correct: 0, incorrect: 0, docs: new Set(), humanAdded: 0 };
                                }
                                stats[v.annotator].verified++;
                                if (v.human_verdict === true) stats[v.annotator].correct++;
                                else stats[v.annotator].incorrect++;
                                stats[v.annotator].docs.add(`${corpus.id}:${link.index}`);
                            }
                        }
                    }
                })
            );
        }

        const leaderboard = Object.entries(stats)
            .map(([annotator, s]) => ({
                annotator,
                verified: s.verified,
                correct: s.correct,
                incorrect: s.incorrect,
                humanAdded: s.humanAdded,
                docsWorked: s.docs.size,
                score: s.verified + s.humanAdded,
            }))
            .sort((a, b) => b.score - a.score);

        return new Response(JSON.stringify({ leaderboard }), {
            status: 200,
            headers: {
                'Content-Type': 'application/json',
                'Cache-Control': 'no-cache, no-store, must-revalidate'
            }
        });
    } catch (error) {
        console.error('Leaderboard API error:', error);
        return new Response(
            JSON.stringify({ error: 'Failed to compute leaderboard' }),
            { status: 500, headers: { 'Content-Type': 'application/json' } }
        );
    }
}