<?php
session_start();
require_once 'db.php';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    // Check if it's an update or insert
    if (isset($_POST['update'])) {
        // **Update Existing Record**
        $id = $_POST['id'];  // Ensure ID is provided
        $name = trim($_POST['value']);
        $measurement = trim($_POST['measurment']);

        // Check if the name already exists (excluding the current ID)
        $check_query = "SELECT COUNT(*) as count FROM forms_value WHERE name = ? AND fid != ?";
        $stmt = $con->prepare($check_query);
        $stmt->bind_param("si", $name, $id);
        $stmt->execute();
        $result = $stmt->get_result();
        $exists = $result->fetch_assoc()['count'];

        if ($exists) {
            echo "exists";
            exit;
        }

        // Update query
        $update_query = "UPDATE forms_value SET name = ?, measurement = ? WHERE fid = ?";
        $stmt = $con->prepare($update_query);
        $stmt->bind_param("ssi", $name, $measurement, $id);

        if ($stmt->execute()) {
            echo "updated";
        } else {
            echo "error";
        }
    } 
    elseif (isset($_POST['insert'])) {
        // **Insert New Record**
        $values = $_POST['value'];
        $measurements = $_POST['measurment'];

        // Start transaction
        mysqli_autocommit($con, FALSE);
        try {
            $success = true;

            foreach ($values as $index => $value) {
                $name = trim($value);
                $measurement = trim($measurements[$index]);

                // Check for duplicate name
                $check_query = "SELECT COUNT(*) as count FROM forms_value WHERE name = ?";
                $stmt = $con->prepare($check_query);
                $stmt->bind_param("s", $name);
                $stmt->execute();
                $result = $stmt->get_result();
                $exists = $result->fetch_assoc()['count'];

                if ($exists) {
                    throw new Exception("exists");
                }

                // Insert record
                $insert_query = "INSERT INTO forms_value (name, measurement) VALUES (?, ?)";
                $stmt = $con->prepare($insert_query);
                $stmt->bind_param("ss", $name, $measurement);

                if (!$stmt->execute()) {
                    $success = false;
                    break;
                }
            }

            if ($success) {
                mysqli_commit($con);
                echo "successfully";
            } else {
                throw new Exception("error");
            }

        } catch (Exception $e) {
            mysqli_rollback($con);
            echo $e->getMessage();
        }

        // Restore autocommit
        mysqli_autocommit($con, TRUE);
    }  else {
        $id = intval($_POST['id']);
        
        $con->begin_transaction();
        $stmt = $con->prepare("DELETE FROM forms_value WHERE fid = ?");
        $stmt->bind_param("i", $id);
        
        if ($stmt->execute()) {
            echo "success|Value deleted successfully.";
            $con->commit();
        } else {
            $con->rollback();
            throw new Exception("Error deleting attribute: " . $stmt->error);
        }
        $stmt->close();
    } 
} else {
    echo "invalid_request";
}
?>