<?php
// WEVAL — ERP Gap Scans API
// GET /api/erp-gap-scans.php[?erp=<id>&min_conf=0.5&limit=20&source=llm|rss|playwright]
// Returns aggregated scan data for pain-points-atlas integration

header('Content-Type: application/json');
header('Cache-Control: public, max-age=60');
header('Access-Control-Allow-Origin: *');

$erp = $_GET['erp'] ?? null;
$min_conf = isset($_GET['min_conf']) ? (float)$_GET['min_conf'] : 0.3;
$limit = isset($_GET['limit']) ? min(100, (int)$_GET['limit']) : 50;
$source = $_GET['source'] ?? null; // llm|rss|playwright

try {
    $pdo = new PDO('pgsql:host=10.1.0.3;port=5432;dbname=adx_system', 'admin', 'admin123', [
        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_TIMEOUT => 3,
    ]);
    
    // Source filter
    $source_clause = "";
    $params_stats = [];
    if ($source) {
        $source_clause = " WHERE query LIKE :source_pattern";
        $params_stats[':source_pattern'] = $source . '_%';
    }
    
    // Global stats
    $stmt = $pdo->prepare("SELECT 
        COUNT(*) as total_gaps,
        COUNT(DISTINCT erp_id) as erps_covered,
        ROUND(AVG(confidence_score)::NUMERIC, 3) as avg_confidence,
        MAX(scanned_at) as last_scan_at,
        COUNT(*) FILTER (WHERE query LIKE 'llm_%') as gaps_llm,
        COUNT(*) FILTER (WHERE query LIKE 'rss_%') as gaps_rss,
        COUNT(*) FILTER (WHERE query LIKE 'playwright%') as gaps_playwright
      FROM erp_gap_scans" . $source_clause);
    $stmt->execute($params_stats);
    $stats = $stmt->fetch(PDO::FETCH_ASSOC);
    
    // Per-ERP breakdown
    $stmt = $pdo->prepare("-- V96.4: GROUP BY erp_id only (not erp_name) to avoid duplicates (Oracle Fusion vs Oracle Fusion Cloud ERP)
      SELECT 
        erp_id, 
        MAX(erp_name) as erp_name,  -- canonical display name
        COUNT(*) as gaps_count,
        ROUND(AVG(confidence_score)::NUMERIC, 3) as avg_conf,
        MAX(scanned_at) as last_scan,
        array_agg(DISTINCT CASE 
          WHEN query LIKE 'llm_%' THEN 'LLM'
          WHEN query LIKE 'rss_%' THEN 'RSS'
          WHEN query LIKE 'playwright%' THEN 'Playwright'
          ELSE 'Other'
        END) as sources
      FROM erp_gap_scans" . $source_clause . "
      GROUP BY erp_id
      ORDER BY gaps_count DESC");
    $stmt->execute($params_stats);
    $per_erp = $stmt->fetchAll(PDO::FETCH_ASSOC);
    
    // Detail gaps (filtered)
    $detail_sql = "SELECT id, erp_id, erp_name, title, snippet, source_url, confidence_score, keywords, 
                     CASE 
                       WHEN query LIKE 'llm_%' THEN 'LLM'
                       WHEN query LIKE 'rss_%' THEN 'RSS'
                       WHEN query LIKE 'playwright%' THEN 'Playwright'
                       ELSE 'Other'
                     END as source,
                     scanned_at
                   FROM erp_gap_scans
                   WHERE confidence_score >= :min_conf";
    $params = [':min_conf' => $min_conf];
    if ($erp) { $detail_sql .= " AND erp_id = :erp"; $params[':erp'] = $erp; }
    if ($source) { $detail_sql .= " AND query LIKE :src"; $params[':src'] = $source . '_%'; }
    $detail_sql .= " ORDER BY confidence_score DESC, scanned_at DESC LIMIT " . (int)$limit;
    $stmt = $pdo->prepare($detail_sql);
    $stmt->execute($params);
    $details = $stmt->fetchAll(PDO::FETCH_ASSOC);
    
    // Latest scans per source
    $stmt = $pdo->query("SELECT 
        CASE 
          WHEN query LIKE 'llm_%' THEN 'LLM'
          WHEN query LIKE 'rss_%' THEN 'RSS'
          WHEN query LIKE 'playwright%' THEN 'Playwright'
          ELSE 'Other'
        END as source,
        MAX(scanned_at) as last_scan,
        COUNT(*) as gaps,
        COUNT(DISTINCT erp_id) as erps
      FROM erp_gap_scans GROUP BY source ORDER BY last_scan DESC");
    $sources = $stmt->fetchAll(PDO::FETCH_ASSOC);
    
    echo json_encode([
        'generated_at' => date('c'),
        'version' => 'V96',
        'module' => 'ERP Gap Scans — consolidated D+C+B',
        'stats' => $stats,
        'sources' => $sources,
        'per_erp' => $per_erp,
        'gaps' => $details,
        'filters_applied' => [
            'erp' => $erp,
            'min_confidence' => $min_conf,
            'limit' => $limit,
            'source' => $source,
        ],
    ], JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
    
} catch (Exception $e) {
    http_response_code(500);
    echo json_encode(['error' => 'db_error', 'message' => $e->getMessage()]);
}