<?php
// OPUS5 — Knowledge Graph souverain (doctrine 75)
// Stack : Ollama embeddings (nomic-embed-text ou mxbai-embed-large) + Qdrant + PG relations
// Pas de Zep (service externe). Qdrant = vector store, PG = graph edges.
header('Content-Type: application/json');
$R = ['ts'=>date('c'), 'source'=>'opus5-knowledge-graph'];

$OLLAMA = 'http://127.0.0.1:11434';
$QDRANT = 'http://127.0.0.1:6333';
$COLLECTION = 'wevia_graph';
$PG_DSN = 'pgsql:host=10.1.0.3;port=5432;dbname=adx_system;user=admin;password=admin123';

$action = $_GET['action'] ?? 'health';
$raw = file_get_contents('php://input');
$d = json_decode($raw, true) ?: [];

function ollama_embed($text, $OLLAMA) {
    $ch = curl_init("$OLLAMA/api/embeddings");
    curl_setopt_array($ch, [
        CURLOPT_POST => true,
        CURLOPT_POSTFIELDS => json_encode(['model'=>'nomic-embed-text', 'prompt'=>substr($text, 0, 2000)]),
        CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 15
    ]);
    $resp = curl_exec($ch);
    curl_close($ch);
    $d = @json_decode($resp, true);
    return $d['embedding'] ?? null;
}

function qdrant_req($method, $path, $body, $QDRANT) {
    $ch = curl_init("$QDRANT$path");
    $opts = [
        CURLOPT_CUSTOMREQUEST => $method,
        CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 10
    ];
    if ($body !== null) $opts[CURLOPT_POSTFIELDS] = json_encode($body);
    curl_setopt_array($ch, $opts);
    $resp = curl_exec($ch);
    $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    return ['code'=>$code, 'body'=>@json_decode($resp, true)];
}

if ($action === 'health') {
    $o_ch = curl_init("$OLLAMA/api/tags");
    curl_setopt_array($o_ch, [CURLOPT_RETURNTRANSFER=>true, CURLOPT_TIMEOUT=>3]);
    $o_resp = curl_exec($o_ch);
    $o_code = curl_getinfo($o_ch, CURLINFO_HTTP_CODE);
    curl_close($o_ch);
    
    $q = qdrant_req('GET', '/collections', null, $QDRANT);
    
    $R['ollama_up'] = ($o_code === 200);
    $R['ollama_models'] = array_column(@json_decode($o_resp, true)['models'] ?? [], 'name');
    $R['qdrant_up'] = ($q['code'] === 200);
    $R['qdrant_collections_count'] = count($q['body']['result']['collections'] ?? []);
    $R['wevia_graph_exists'] = in_array($COLLECTION, array_column($q['body']['result']['collections'] ?? [], 'name'));
    
    // Check PG connectivity
    try {
        $db = new PDO($PG_DSN, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, PDO::ATTR_TIMEOUT => 3]);
        $R['pg_up'] = true;
    } catch (Throwable $e) { $R['pg_up'] = false; $R['pg_err'] = substr($e->getMessage(), 0, 100); }
    echo json_encode($R, JSON_PRETTY_PRINT);
    exit;
}

if ($action === 'init') {
    // Create wevia_graph collection if missing
    $q = qdrant_req('GET', "/collections/$COLLECTION", null, $QDRANT);
    if ($q['code'] !== 200) {
        // Nomic embed = 768 dimensions
        $create = qdrant_req('PUT', "/collections/$COLLECTION", [
            'vectors' => ['size' => 768, 'distance' => 'Cosine']
        ], $QDRANT);
        $R['collection_created'] = $create['code'] === 200;
        $R['create_response'] = $create['body'];
    } else {
        $R['collection_exists'] = true;
    }
    
    // Create PG edges table
    try {
        $db = new PDO($PG_DSN, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
        $db->exec("CREATE TABLE IF NOT EXISTS admin.wevia_graph_edges (
            id SERIAL PRIMARY KEY,
            src_node VARCHAR(128),
            rel_type VARCHAR(64),
            dst_node VARCHAR(128),
            weight FLOAT DEFAULT 1.0,
            metadata JSONB,
            created_at TIMESTAMP DEFAULT NOW()
        )");
        $db->exec("CREATE INDEX IF NOT EXISTS idx_graph_src ON admin.wevia_graph_edges(src_node)");
        $db->exec("CREATE INDEX IF NOT EXISTS idx_graph_dst ON admin.wevia_graph_edges(dst_node)");
        $R['pg_table_ready'] = true;
    } catch (Throwable $e) { $R['pg_err'] = substr($e->getMessage(), 0, 200); }
    
    $R['doctrine'] = '75 — knowledge graph souverain (Ollama embed + Qdrant vectors + PG edges)';
    echo json_encode($R, JSON_PRETTY_PRINT);
    exit;
}

if ($action === 'add_node') {
    $node_id = (string)($d['node_id'] ?? '');
    $text = (string)($d['text'] ?? '');
    $metadata = $d['metadata'] ?? [];
    if (!$node_id || !$text) { http_response_code(400); echo json_encode(['err'=>'missing node_id or text']); exit; }
    
    $vec = ollama_embed($text, $OLLAMA);
    if (!$vec) { http_response_code(503); echo json_encode(['err'=>'ollama_embed_failed']); exit; }
    
    $point_id = abs(crc32($node_id));
    $upsert = qdrant_req('PUT', "/collections/$COLLECTION/points", [
        'points' => [[
            'id' => $point_id,
            'vector' => $vec,
            'payload' => array_merge($metadata, ['node_id'=>$node_id, 'text'=>substr($text,0,500)])
        ]]
    ], $QDRANT);
    $R['upsert_code'] = $upsert['code'];
    $R['node_id'] = $node_id;
    $R['point_id'] = $point_id;
    $R['vec_dim'] = count($vec);
    echo json_encode($R, JSON_PRETTY_PRINT);
    exit;
}

if ($action === 'add_edge') {
    $src = (string)($d['src'] ?? '');
    $rel = (string)($d['rel'] ?? 'related_to');
    $dst = (string)($d['dst'] ?? '');
    if (!$src || !$dst) { http_response_code(400); echo json_encode(['err'=>'missing src or dst']); exit; }
    try {
        $db = new PDO($PG_DSN, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
        $stmt = $db->prepare("INSERT INTO admin.wevia_graph_edges (src_node, rel_type, dst_node, weight, metadata) VALUES (?,?,?,?,?)");
        $stmt->execute([$src, $rel, $dst, (float)($d['weight'] ?? 1.0), json_encode($d['metadata'] ?? [])]);
        $R['edge_id'] = $db->lastInsertId();
    } catch (Throwable $e) { http_response_code(500); echo json_encode(['err'=>'pg_err', 'msg'=>$e->getMessage()]); exit; }
    echo json_encode($R, JSON_PRETTY_PRINT);
    exit;
}

if ($action === 'query') {
    $query_text = (string)($d['query'] ?? '');
    $limit = (int)($d['limit'] ?? 5);
    if (!$query_text) { http_response_code(400); echo json_encode(['err'=>'no_query']); exit; }
    
    $qvec = ollama_embed($query_text, $OLLAMA);
    if (!$qvec) { http_response_code(503); echo json_encode(['err'=>'ollama_embed_failed']); exit; }
    
    $search = qdrant_req('POST', "/collections/$COLLECTION/points/search", [
        'vector' => $qvec,
        'limit' => $limit,
        'with_payload' => true
    ], $QDRANT);
    
    $results = [];
    foreach (($search['body']['result'] ?? []) as $h) {
        $results[] = [
            'score' => round((float)$h['score'], 4),
            'node_id' => $h['payload']['node_id'] ?? '?',
            'text' => substr($h['payload']['text'] ?? '', 0, 200)
        ];
    }
    $R['query'] = $query_text;
    $R['results'] = $results;
    
    // Also fetch edges for top result
    if (!empty($results)) {
        try {
            $db = new PDO($PG_DSN, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
            $stmt = $db->prepare("SELECT src_node, rel_type, dst_node, weight FROM admin.wevia_graph_edges WHERE src_node=? OR dst_node=? LIMIT 10");
            $stmt->execute([$results[0]['node_id'], $results[0]['node_id']]);
            $R['related_edges'] = $stmt->fetchAll(PDO::FETCH_ASSOC);
        } catch (Throwable $e) { $R['edges_err'] = $e->getMessage(); }
    }
    echo json_encode($R, JSON_PRETTY_PRINT|JSON_UNESCAPED_UNICODE);
    exit;
}

if ($action === 'stats') {
    $q = qdrant_req('GET', "/collections/$COLLECTION", null, $QDRANT);
    $R['qdrant'] = $q['body']['result'] ?? null;
    try {
        $db = new PDO($PG_DSN, null, null, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
        $R['edges_count'] = (int)$db->query("SELECT COUNT(*) FROM admin.wevia_graph_edges")->fetchColumn();
        $R['distinct_nodes'] = (int)$db->query("SELECT COUNT(DISTINCT src_node) + COUNT(DISTINCT dst_node) FROM admin.wevia_graph_edges")->fetchColumn();
    } catch (Throwable $e) { $R['pg_err'] = $e->getMessage(); }
    echo json_encode($R, JSON_PRETTY_PRINT);
    exit;
}

http_response_code(400);
echo json_encode(['err'=>'unknown_action', 'available'=>['health', 'init', 'add_node', 'add_edge', 'query', 'stats']]);