<?php
/**
 * getDashboardStats.php - Liefert Statistiken für das Dashboard
 */

header('Content-Type: application/json; charset=utf-8');

include "db_connection.php";

$conn = mysqli_connect(HOST, USER, PASSWORD, DATABASE);
if (mysqli_connect_errno()) {
    echo json_encode(['error' => 'Datenbankverbindung fehlgeschlagen']);
    exit();
}

mysqli_set_charset($conn, "utf8");

$stats = [];

// 1. Anzahl Datensätze pro Typ
$types = ['Subject', 'Person', 'Corporate', 'Publisher', 'Classification'];
$counts = [];

foreach ($types as $type) {
    $sql = "SELECT COUNT(*) as cnt FROM Anchor WHERE Type = '$type'";
    $res = mysqli_query($conn, $sql);
    if ($res) {
        $row = mysqli_fetch_assoc($res);
        $counts[$type] = intval($row['cnt']);
    } else {
        $counts[$type] = 0;
    }
}

$stats['counts'] = $counts;
$stats['total'] = array_sum($counts);

// 2. Anzahl Relationen
$sql = "SELECT COUNT(*) as cnt FROM Linking";
$res = mysqli_query($conn, $sql);
if ($res) {
    $row = mysqli_fetch_assoc($res);
    $stats['relationsTotal'] = intval($row['cnt']);
} else {
    $stats['relationsTotal'] = 0;
}

// 3. Zuletzt geänderte Einträge (Top 10)
$sql = "SELECT a.ID, a.Text, a.Type, e.DateModified 
        FROM Anchor a
        JOIN Entry e ON a.Text = e.Text
        WHERE e.DateModified > '2000-01-01'
        ORDER BY e.DateModified DESC
        LIMIT 10";
$res = mysqli_query($conn, $sql);
$recentlyModified = [];
if ($res) {
    while ($row = mysqli_fetch_assoc($res)) {
        $recentlyModified[] = [
            'id' => $row['ID'],
            'text' => $row['Text'],
            'type' => $row['Type'],
            'date' => $row['DateModified']
        ];
    }
}
$stats['recentlyModified'] = $recentlyModified;

// 4. Zuletzt hinzugefügte Einträge (Top 10)
$sql = "SELECT a.ID, a.Text, a.Type, e.DateCreated 
        FROM Anchor a
        JOIN Entry e ON a.Text = e.Text
        WHERE e.DateCreated > '2000-01-01'
        ORDER BY e.DateCreated DESC
        LIMIT 10";
$res = mysqli_query($conn, $sql);
$recentlyCreated = [];
if ($res) {
    while ($row = mysqli_fetch_assoc($res)) {
        $recentlyCreated[] = [
            'id' => $row['ID'],
            'text' => $row['Text'],
            'type' => $row['Type'],
            'date' => $row['DateCreated']
        ];
    }
}
$stats['recentlyCreated'] = $recentlyCreated;

// 5. Qualitäts-Check: Einträge ohne Relationen (Waisen)
$orphanCounts = [];
foreach ($types as $type) {
    $sql = "SELECT COUNT(*) as cnt FROM Anchor a 
            WHERE a.Type = '$type' 
            AND a.ID NOT IN (SELECT DISTINCT IDAnchor FROM Linking)";
    $res = mysqli_query($conn, $sql);
    if ($res) {
        $row = mysqli_fetch_assoc($res);
        $orphanCounts[$type] = intval($row['cnt']);
    } else {
        $orphanCounts[$type] = 0;
    }
}
$stats['orphans'] = $orphanCounts;
$stats['orphansTotal'] = array_sum($orphanCounts);

// 6. Deskriptoren vs. Non-Deskriptoren (für Schlagworte)
$sql = "SELECT 
        SUM(CASE WHEN DetailType = 'Deskriptor' OR DetailType = 'deskriptor' THEN 1 ELSE 0 END) as descriptors,
        SUM(CASE WHEN DetailType != 'Deskriptor' AND DetailType != 'deskriptor' THEN 1 ELSE 0 END) as nonDescriptors
        FROM Anchor WHERE Type = 'Subject'";
$res = mysqli_query($conn, $sql);
if ($res) {
    $row = mysqli_fetch_assoc($res);
    $stats['descriptors'] = intval($row['descriptors']);
    $stats['nonDescriptors'] = intval($row['nonDescriptors']);
} else {
    $stats['descriptors'] = 0;
    $stats['nonDescriptors'] = 0;
}

mysqli_close($conn);

echo json_encode($stats, JSON_UNESCAPED_UNICODE);
?>