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

require_once 'db/config.php';

$messages = [];
$conn = db();

function create_lifecycle_table($conn) {
    $messages = [];
    try {
        $sql_lifecycle = "
        CREATE TABLE IF NOT EXISTS lifecycle (
            id INT AUTO_INCREMENT PRIMARY KEY,
            product_id VARCHAR(255),
            custcode VARCHAR(255),
            first_ship_month VARCHAR(255),
            last_ship_month VARCHAR(255),
            total_ship INT,
            avg_ship FLOAT,
            maxstores INT,
            mock_pct FLOAT,
            store_count INT,
            runrate FLOAT
        );";
        $conn->exec($sql_lifecycle);
        $messages['success'][] = "Table 'lifecycle' created or already exists.";

    } catch (PDOException $e) {
        $messages['danger'][] = "Table creation failed: " . $e->getMessage();
    }
    return $messages;
}

function create_customers_table($conn) {
    $messages = [];
    try {
        $sql_customers = "
        CREATE TABLE IF NOT EXISTS customers (
            id INT AUTO_INCREMENT PRIMARY KEY,
            custcode VARCHAR(255),
            custname VARCHAR(255),
            channel VARCHAR(255),
            country VARCHAR(255),
            maxstores INT
        );";
        $conn->exec($sql_customers);
        $messages['success'][] = "Table 'customers' created or already exists.";

    } catch (PDOException $e) {
        $messages['danger'][] = "Table creation failed: " . $e->getMessage();
    }
    return $messages;
}

function create_products_table($conn) {
    $messages = [];
    try {
        $sql_products = "
        CREATE TABLE IF NOT EXISTS products (
            product_id VARCHAR(255) PRIMARY KEY,
            prodname VARCHAR(255),
            brand VARCHAR(255),
            subbrand VARCHAR(255),
            sub_brand_abbreviation VARCHAR(255),
            listprice FLOAT
        );";
        $conn->exec($sql_products);
        $messages['success'][] = "Table 'products' created or already exists.";

    } catch (PDOException $e) {
        $messages['danger'][] = "Table creation failed: " . $e->getMessage();
    }
    return $messages;
}

function create_shipments_table($conn) {
    $messages = [];
    try {
        $sql_shipments = "
        CREATE TABLE IF NOT EXISTS shipments (
            id INT AUTO_INCREMENT PRIMARY KEY,
            product_id VARCHAR(255),
            month VARCHAR(255),
            custcode VARCHAR(255),
            ship INT
        );";
        $conn->exec($sql_shipments);
        $messages['success'][] = "Table 'shipments' created or already exists.";

    } catch (PDOException $e) {
        $messages['danger'][] = "Table creation failed: " . $e->getMessage();
    }
    return $messages;
}

function import_csv($conn, $filePath, $tableName, $fieldMap, &$messages) {
    try {
        $conn->exec("TRUNCATE TABLE `$tableName`");
    } catch (PDOException $e) {
        $messages['danger'][] = "Error truncating table $tableName: " . $e->getMessage();
        return ['count' => 0, 'error' => "Error truncating table: " . $e->getMessage()];
    }

    if (!file_exists($filePath) || !is_readable($filePath)) {
        return ['count' => 0, 'error' => "File not found or not readable: $filePath"];
    }

    $file = fopen($filePath, 'r');
    if (!$file) {
        return ['count' => 0, 'error' => "Failed to open file: $filePath"];
    }

    $header = fgetcsv($file);
    if (!$header) {
        return ['count' => 0, 'error' => "Failed to read header from file: $filePath"];
    }
    
    $indices = [];
    foreach ($fieldMap as $dbField => $csvField) {
        $index = array_search($csvField, $header);
        if ($index === false) {
            // Allow for flexibility with headers that have dots
            $csvFieldWithDot = str_replace('_', '.', $csvField);
             if (in_array($csvFieldWithDot, $header)) {
                $index = array_search($csvFieldWithDot, $header);
            } else {
                return ['count' => 0, 'error' => "Column '$csvField' (or '$csvFieldWithDot') not found in $tableName CSV."];
            }
        }
        $indices[$dbField] = $index;
    }
    
    $placeholders = implode(', ', array_fill(0, count($fieldMap), '?'));
    $columns = implode(', ', array_keys($fieldMap));

    if ($tableName === 'products') {
        $sql = "INSERT IGNORE INTO $tableName ($columns) VALUES ($placeholders)";
    } else {
        $sql = "INSERT INTO $tableName ($columns) VALUES ($placeholders)";
    }
    $stmt = $conn->prepare($sql);

    $count = 0;
    $conn->beginTransaction();
    while (($row = fgetcsv($file)) !== false) {
        $params = [];

        foreach ($fieldMap as $dbField => $csvField) {
            $value = $row[$indices[$dbField]];
            if ($tableName === 'lifecycle') {
                if (in_array($dbField, ['total_ship', 'maxstores', 'store_count'])) {
                    $params[] = (int)filter_var($value, FILTER_SANITIZE_NUMBER_INT);
                } elseif (in_array($dbField, ['avg_ship', 'mock_pct', 'runrate'])) {
                    $params[] = (float)filter_var($value, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION);
                } else {
                    $params[] = trim($value);
                }
            } elseif ($tableName === 'customers') {
                if (in_array($dbField, ['maxstores'])) {
                    $params[] = (int)filter_var($value, FILTER_SANITIZE_NUMBER_INT);
                } else {
                    $params[] = trim($value);
                }
            } elseif ($tableName === 'products') {
                if (in_array($dbField, ['listprice'])) {
                    $params[] = (float)filter_var($value, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION);
                } else {
                    $params[] = trim($value);
                }
            } elseif ($tableName === 'shipments') {
                if (in_array($dbField, ['ship'])) {
                    $params[] = (int)filter_var($value, FILTER_SANITIZE_NUMBER_INT);
                } else {
                    $params[] = trim($value);
                }
            } else {
                $params[] = trim($value);
            }
        }
        $stmt->execute($params);
        $count++;
    }
    $conn->commit();
    fclose($file);

    return ['count' => $count, 'error' => null];
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $messages = array_merge_recursive($messages, create_lifecycle_table($conn));
    $messages = array_merge_recursive($messages, create_customers_table($conn));
    $messages = array_merge_recursive($messages, create_products_table($conn));
    $messages = array_merge_recursive($messages, create_shipments_table($conn));
    
    $uploadDir = 'uploads/';
    if (!is_dir($uploadDir)) {
        mkdir($uploadDir, 0777, true);
    }

    $files = [
        'lifecycle' => ['lifecycle', [
            'product_id' => 'product_id',
            'custcode' => 'custcode',
            'first_ship_month' => 'first_ship_month',
            'last_ship_month' => 'last_ship_month',
            'total_ship' => 'total_ship',
            'avg_ship' => 'avg_ship',
            'maxstores' => 'maxstores',
            'mock_pct' => 'mock_pct',
            'store_count' => 'store_count',
            'runrate' => 'runrate'
        ]],
        'customers' => ['customers', [
            'custcode' => 'custcode',
            'custname' => 'custname',
            'channel' => 'channel',
            'country' => 'country',
            'maxstores' => 'maxstores'
        ]],
        'products' => ['products', [
            'product_id' => 'product_id',
            'prodname' => 'prodname',
            'brand' => 'brand',
            'subbrand' => 'subbrand',
            'sub_brand_abbreviation' => 'sub_brand.abbreviation',
            'listprice' => 'listprice'
        ]],
        'shipments' => ['shipments', [
            'product_id' => 'product_id',
            'month' => 'month',
            'custcode' => 'custcode',
            'ship' => 'ship'
        ]]
    ];

    foreach ($files as $fileKey => $fileInfo) {
        if (isset($_FILES[$fileKey]) && $_FILES[$fileKey]['error'] == UPLOAD_ERR_OK) {
            $tableName = $fileInfo[0];
            $fieldMap = $fileInfo[1];
            $tmpName = $_FILES[$fileKey]['tmp_name'];
            $filePath = $uploadDir . basename($_FILES[$fileKey]['name']);
            
            if (move_uploaded_file($tmpName, $filePath)) {
                $result = import_csv($conn, $filePath, $tableName, $fieldMap, $messages);
                if ($result['error']) {
                    $messages['danger'][] = "Error importing $tableName: " . $result['error'];
                } else {
                    $messages['success'][] = "Successfully imported " . $result['count'] . " records into '$tableName'.";
                }
            } else {
                $messages['danger'][] = "Failed to move uploaded file for $fileKey.";
            }
        } elseif (isset($_FILES[$fileKey]) && !empty($_FILES[$fileKey]['name'])) {
             $errorCode = $_FILES[$fileKey]['error'];
             $errorMessage = "An unknown error occurred.";
             if ($errorCode === UPLOAD_ERR_INI_SIZE) {
                $maxSize = ini_get('upload_max_filesize');
                $errorMessage = "The file is too large. The server's maximum upload size is {$maxSize}.";
             }
             $messages['warning'][] = "An error occurred with the '$fileKey' upload: " . $errorMessage;
        }
    }
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Data Importer</title>
    <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet">
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/font/bootstrap-icons.min.css">
</head>
<body>
    <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
        <div class="container-fluid">
            <a class="navbar-brand" href="/">CRUD App</a>
            <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
                <span class="navbar-toggler-icon"></span>
            </button>
            <div class="collapse navbar-collapse" id="navbarNav">
                <ul class="navbar-nav">
                    <li class="nav-item">
                        <a class="nav-link" href="/">Home</a>
                    </li>
                    <li class="nav-item">
                        <a class="nav-link active" aria-current="page" href="/import.php">Import Data</a>
                    </li>
                </ul>
            </div>
        </div>
    </nav>

    <div class="container mt-5">
        <div class="row">
            <div class="col-md-8 offset-md-2">
                <div class="card">
                    <div class="card-header">
                        <h1 class="card-title text-center">Data Importer</h1>
                    </div>
                    <div class="card-body">
                        <p class="card-text">Upload your CSV files to populate the database. The system will create the necessary tables and import the data.</p>
                        
                        <?php if (!empty($messages)): ?>
                            <div class="mb-4">
                                <?php foreach ($messages as $type => $msgs): ?>
                                    <?php foreach ($msgs as $msg): ?>
                                        <div class="alert alert-<?php echo htmlspecialchars($type); ?>" role="alert">
                                            <?php echo htmlspecialchars($msg); ?>
                                        </div>
                                    <?php endforeach; ?>
                                <?php endforeach; ?>
                            </div>
                        <?php endif; ?>

                        <form action="import.php" method="post" enctype="multipart/form-data">
                            <div class="mb-3">
                                <label for="lifecycle" class="form-label">Lifecycle CSV File</label>
                                <input class="form-control" type="file" id="lifecycle" name="lifecycle">
                                <div class="form-text">Fields: product_id, custcode, first_ship_month, last_ship_month, total_ship, avg_ship, maxstores, mock_pct, store_count, runrate</div>
                            </div>
                            <div class="mb-3">
                                <label for="customers" class="form-label">Customers CSV File</label>
                                <input class="form-control" type="file" id="customers" name="customers">
                                <div class="form-text">Fields: custcode, custname, channel, country, maxstores</div>
                            </div>
                            <div class="mb-3">
                                <label for="products" class="form-label">Products CSV File</label>
                                <input class="form-control" type="file" id="products" name="products">
                                <div class="form-text">Fields: product_id, prodname, brand, subbrand, sub_brand.abbreviation, listprice</div>
                            </div>
                             <div class="mb-3">
                                <label for="shipments" class="form-label">Shipments CSV File</label>
                                <input class="form-control" type="file" id="shipments" name="shipments">
                                <div class="form-text">Fields: product_id, month, custcode, ship</div>
                            </div>
                            <div class="d-grid">
                                <button type="submit" class="btn btn-primary btn-lg"><i class="bi bi-cloud-upload-fill"></i> Preview & Import</button>
                            </div>
                        </form>
                    </div>
                    <div class="card-footer text-muted">
                        Ensure your CSV files have a header row that matches the specified fields.
                    </div>
                </div>
            </div>
        </div>
    </div>

    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"></script>
</body>
</html>