<?php // phpcs:ignoreFile
header('Content-Type: application/json');
header('Cache-Control: no-cache, must-revalidate');

$payload = json_decode(file_get_contents('php://input'), true);

if (!is_array($payload)) {
    echo json_encode([
        'success' => false,
        'error'   => 'Invalid request payload.'
    ]);
    exit;
}

$tags = $payload['tags'] ?? [];

if (!is_array($tags) || count($tags) === 0) {
    echo json_encode([
        'success' => false,
        'error'   => 'At least one tag is required.'
    ]);
    exit;
}

$normalizedTags = [];
foreach ($tags as $tag) {
    $trimmed = trim((string) $tag);
    if ($trimmed === '') {
        continue;
    }
    $normalizedTags[$trimmed] = true;
}

if (count($normalizedTags) === 0) {
    echo json_encode([
        'success' => false,
        'error'   => 'No valid tag names provided.'
    ]);
    exit;
}

$servername = '192.168.0.13\\SQLEXPRESS';
$username   = 'opce';
$password   = 'opcelasuca';
$dbname     = 'history';

try {
    $pdo = new PDO(
        "sqlsrv:Server=$servername;Database=$dbname",
        $username,
        $password,
        [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC
        ]
    );

    $endTime   = new DateTimeImmutable('now');
    $startTime = $endTime->modify('-3 hours');

    $series = [];

    $query = $pdo->prepare(
        'WITH ordered_samples AS (
            SELECT TOP (7200)
                a.TimeStamp,
                a.Value
            FROM dbo.archive AS a
            INNER JOIN dbo.id_names AS n
                ON CAST(n.idnumber AS INT) = a.ID
            WHERE n.name = :tag_name
              AND a.TimeStamp BETWEEN :start_time AND :end_time
            ORDER BY a.TimeStamp DESC
        )
        SELECT TimeStamp, Value
        FROM ordered_samples
        ORDER BY TimeStamp ASC'
    );

    foreach (array_keys($normalizedTags) as $tagName) {
        $query->execute([
            ':tag_name'   => $tagName,
            ':start_time' => $startTime->format('Y-m-d H:i:s'),
            ':end_time'   => $endTime->format('Y-m-d H:i:s')
        ]);

        $rows = $query->fetchAll();
        $points = [];
        $values = [];

        foreach ($rows as $row) {
            $timestamp = $row['TimeStamp'] ?? null;
            $value     = isset($row['Value']) ? (float) $row['Value'] : null;

            if ($timestamp === null || $value === null) {
                continue;
            }

            $points[] = [
                'timestamp' => $timestamp,
                'value'     => $value
            ];
            $values[] = $value;
        }

        $series[] = [
            'tag'    => $tagName,
            'points' => $points,
            'stats'  => [
                'count'  => count($values),
                'min'    => count($values) > 0 ? min($values) : null,
                'max'    => count($values) > 0 ? max($values) : null,
                'latest' => count($values) > 0 ? end($values) : null
            ]
        ];
    }

    echo json_encode([
        'success' => true,
        'series'  => $series,
        'window'  => [
            'start' => $startTime->format(DateTimeInterface::ATOM),
            'end'   => $endTime->format(DateTimeInterface::ATOM)
        ]
    ]);
} catch (Throwable $exception) {
    echo json_encode([
        'success' => false,
        'error'   => $exception->getMessage()
    ]);
}