<?php
ini_set('display_errors', 1);
error_reporting(E_ALL);

header('Content-Type: application/json');

include('include/headscript.php');

try {
    if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
        echo json_encode(['success' => false, 'message' => 'Invalid request method.']);
        exit;
    }

    $db = DBHandlerSelect::getInstance();
    $pdo = $db->getConnection();

    $paramId     = isset($_POST['param_id']) ? (int)$_POST['param_id'] : 0;
    $lineId      = isset($_POST['line_id']) ? (int)$_POST['line_id'] : 0;
    $position    = isset($_POST['position']) ? (int)$_POST['position'] : 0;
    $shortLabel  = isset($_POST['short_label']) ? trim($_POST['short_label']) : '';
    $label       = isset($_POST['label']) ? trim($_POST['label']) : '';
    $icon        = isset($_POST['icon']) ? trim($_POST['icon']) : '';

    if ($lineId <= 0) {
        echo json_encode(['success' => false, 'message' => 'Invalid line ID.']);
        exit;
    }

    if ($position <= 0) {
        echo json_encode(['success' => false, 'message' => 'Position must be greater than zero.']);
        exit;
    }

    if ($shortLabel === '' || $label === '') {
        echo json_encode(['success' => false, 'message' => 'Short label and label are required.']);
        exit;
    }

    // Check that line exists
    $stmtLine = $pdo->prepare("SELECT id FROM production_lines WHERE id = :id");
    $stmtLine->execute([':id' => $lineId]);
    if (!$stmtLine->fetchColumn()) {
        echo json_encode(['success' => false, 'message' => 'Production line not found.']);
        exit;
    }

    if ($paramId > 0) {
        // Update
        $sql = "
            UPDATE production_line_params
            SET line_id = :line_id,
                position = :position,
                short_label = :short_label,
                label = :label,
                icon = :icon
            WHERE id = :id
        ";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([
            ':line_id'     => $lineId,
            ':position'    => $position,
            ':short_label' => $shortLabel,
            ':label'       => $label,
            ':icon'        => ($icon !== '' ? $icon : null),
            ':id'          => $paramId,
        ]);

        echo json_encode([
            'success' => true,
            'message' => 'Parameter updated successfully.',
            'id'      => $paramId
        ]);
    } else {
        // Insert
        $sql = "
            INSERT INTO production_line_params (line_id, position, short_label, label, icon)
            VALUES (:line_id, :position, :short_label, :label, :icon)
        ";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([
            ':line_id'     => $lineId,
            ':position'    => $position,
            ':short_label' => $shortLabel,
            ':label'       => $label,
            ':icon'        => ($icon !== '' ? $icon : null),
        ]);

        $newId = (int)$pdo->lastInsertId();

        echo json_encode([
            'success' => true,
            'message' => 'Parameter created successfully.',
            'id'      => $newId
        ]);
    }
} catch (Exception $e) {
    echo json_encode([
        'success' => false,
        'message' => 'Server error: ' . $e->getMessage()
    ]);
}