<?php
// opus-arch-graphrag.php - Cap 17 GraphRAG
header('Content-Type: application/json');
$action = $_GET['action'] ?? 'query';
if ($action === 'build') {
    $srcs = ['/var/www/html/wiki', '/opt/obsidian-vault/doctrines', '/opt/wevads/vault'];
    $ents = []; $rels = [];
    foreach ($srcs as $dir) {
        if (!is_dir($dir)) continue;
        foreach (array_slice(glob($dir.'/*.md'), 0, 50) as $f) {
            $c = file_get_contents($f);
            preg_match_all('/\b([A-Z][A-Z_]{3,})\b/', $c, $m);
            foreach ($m[1] as $e) $ents[$e] = ($ents[$e] ?? 0) + 1;
            preg_match_all('/\b(V\d+|WEVIA|OPUS|YACINE|CLAUDE)\b/', $c, $m2);
            $u = array_unique($m2[1]);
            foreach ($u as $i=>$a) foreach (array_slice($u,$i+1) as $b) $rels[$a.':'.$b] = ($rels[$a.':'.$b] ?? 0) + 1;
        }
    }
    arsort($ents); arsort($rels);
    $g = ['entities_top20'=>array_slice($ents,0,20,true), 'relations_top20'=>array_slice($rels,0,20,true), 'total_e'=>count($ents), 'total_r'=>count($rels)];
    @file_put_contents('/opt/weval-ops/graphrag-index.json', json_encode($g));
    echo json_encode(['ok'=>true,'graph'=>$g]); exit;
}
if ($action === 'query') {
    $q = strtoupper($_GET['q'] ?? '');
    $f = '/opt/weval-ops/graphrag-index.json';
    if (!file_exists($f)) { echo json_encode(['ok'=>false,'error'=>'build first']); exit; }
    $g = json_decode(file_get_contents($f), true);
    $em = []; $rm = [];
    foreach (($g['entities_top20'] ?? []) as $k=>$v) if (strpos($k,$q) !== false) $em[$k] = $v;
    foreach (($g['relations_top20'] ?? []) as $k=>$v) if (strpos($k,$q) !== false) $rm[$k] = $v;
    echo json_encode(['ok'=>true,'q'=>$q,'entities'=>$em,'relations'=>$rm]); exit;
}
echo json_encode(['ok'=>false,'actions'=>['build','query']]);