<?php
require_once 'db/config.php';
$pageTitle = 'Import Labour Activities';

$message = '';
$error = '';
$results = [];

if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['csv_file'])) {
    $file = $_FILES['csv_file'];
    
    if ($file['error'] !== UPLOAD_ERR_OK) {
        $error = 'File upload failed.';
    } else {
        $handle = fopen($file['tmp_name'], 'r');
        $header = fgetcsv($handle);
        
        $expected = ['project_code', 'employee_email', 'date', 'hours', 'labour_type', 'evidence_type', 'notes'];
        
        if (!$header || count(array_intersect($expected, $header)) < 1) {
            $error = 'Invalid CSV format. Please use the provided template.';
        } else {
            $columnMap = array_flip($header);
            
            // Pre-fetch lookups
            $projects = [];
            $stmt = db()->query("SELECT id, code FROM projects WHERE tenant_id = 1");
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) $projects[$row['code']] = $row['id'];
            
            $employees = [];
            $stmt = db()->query("SELECT id, email FROM employees WHERE tenant_id = 1");
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) $employees[$row['email']] = $row['id'];
            
            $labourTypes = [];
            $stmt = db()->query("SELECT id, name FROM labour_types");
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) $labourTypes[strtolower($row['name'])] = $row['id'];
            
            $evidenceTypes = [];
            $stmt = db()->query("SELECT id, name FROM evidence_types");
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) $evidenceTypes[strtolower($row['name'])] = $row['id'];

            $rowCount = 0;
            $importCount = 0;
            $skippedCount = 0;
            
            db()->beginTransaction();
            try {
                $stmt = db()->prepare("INSERT INTO labour_entries (tenant_id, project_id, employee_id, entry_date, hours, labour_type_id, evidence_type_id, notes) VALUES (?, ?, ?, ?, ?, ?, ?, ?)");
                
                while (($row = fgetcsv($handle)) !== false) {
                    $rowCount++;
                    $data = [];
                    foreach ($expected as $col) {
                        $data[$col] = isset($columnMap[$col]) && isset($row[$columnMap[$col]]) ? trim($row[$columnMap[$col]]) : '';
                    }
                    
                    $rowErrors = [];
                    
                    $projectId = $projects[$data['project_code']] ?? null;
                    $employeeId = $employees[$data['employee_email']] ?? null;
                    $labourTypeId = $labourTypes[strtolower($data['labour_type'])] ?? null;
                    $evidenceTypeId = $evidenceTypes[strtolower($data['evidence_type'])] ?? 5; // Default to 'None'
                    
                    if (!$projectId) $rowErrors[] = "Invalid Project Code: " . $data['project_code'];
                    if (!$employeeId) $rowErrors[] = "Invalid Employee Email: " . $data['employee_email'];
                    if (!$labourTypeId) $rowErrors[] = "Invalid Labour Type: " . $data['labour_type'];
                    if (empty($data['date']) || !strtotime($data['date'])) $rowErrors[] = "Invalid Date: " . $data['date'];
                    if (!is_numeric($data['hours'])) $rowErrors[] = "Invalid Hours: " . $data['hours'];

                    if (!empty($rowErrors)) {
                        $skippedCount++;
                        $results[] = "Row $rowCount: Skipped (" . implode(', ', $rowErrors) . ")";
                        continue;
                    }
                    
                    $stmt->execute([
                        1,
                        $projectId,
                        $employeeId,
                        date('Y-m-d', strtotime($data['date'])),
                        $data['hours'],
                        $labourTypeId,
                        $evidenceTypeId,
                        $data['notes']
                    ]);
                    $importCount++;
                }
                db()->commit();
                $message = "Import completed successfully. $importCount activities imported, $skippedCount skipped.";
            } catch (Exception $e) {
                db()->rollBack();
                $error = 'Database error: ' . $e->getMessage();
            }
        }
        fclose($handle);
    }
}

include 'includes/header.php';
?>

<div class="container mt-4">
    <div class="d-flex justify-content-between align-items-center mb-4">
        <h2><i class="bi bi-clock-history me-2"></i>Import Labour Activities</h2>
        <a href="samples/labour_template.csv" class="btn btn-outline-primary btn-sm">
            <i class="bi bi-download me-1"></i>Download Template
        </a>
    </div>

    <?php if ($message): ?>
        <div class="alert alert-success alert-dismissible fade show" role="alert">
            <?= $message ?>
            <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
        </div>
    <?php endif; ?>

    <?php if ($error): ?>
        <div class="alert alert-danger alert-dismissible fade show" role="alert">
            <?= $error ?>
            <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
        </div>
    <?php endif; ?>

    <div class="row">
        <div class="col-md-6">
            <div class="card shadow-sm border-0">
                <div class="card-body p-4">
                    <form action="import_labour.php" method="POST" enctype="multipart/form-data">
                        <div class="mb-4">
                            <label for="csv_file" class="form-label fw-bold">Select CSV File</label>
                            <input type="file" class="form-control" id="csv_file" name="csv_file" accept=".csv" required>
                            <div class="form-text mt-2">
                                Max file size: 5MB. Only .csv files are allowed.
                            </div>
                        </div>
                        <button type="submit" class="btn btn-primary w-100 py-2">
                            <i class="bi bi-upload me-2"></i>Upload and Import
                        </button>
                    </form>
                </div>
            </div>
        </div>
        <div class="col-md-6">
            <div class="card shadow-sm border-0 h-100">
                <div class="card-header bg-white py-3">
                    <h5 class="mb-0">Import Instructions</h5>
                </div>
                <div class="card-body">
                    <ol class="small text-muted">
                        <li>Download the CSV template using the button above.</li>
                        <li>Ensure <strong>Project Code</strong> and <strong>Employee Email</strong> match existing records.</li>
                        <li><strong>Date</strong> should be in YYYY-MM-DD format.</li>
                        <li><strong>Labour Type</strong> must match one of: 
                            <ul class="mb-0">
                                <li>Experimental Development</li>
                                <li>Technical Support</li>
                                <li>Technical Planning</li>
                            </ul>
                        </li>
                        <li>Upload and review the logs for any skipped rows.</li>
                    </ol>
                </div>
            </div>
        </div>
    </div>

    <?php if (!empty($results)): ?>
        <div class="card shadow-sm border-0 mt-4">
            <div class="card-header bg-white py-3">
                <h5 class="mb-0">Import Logs</h5>
            </div>
            <div class="card-body">
                <div class="list-group list-group-flush small">
                    <?php foreach ($results as $res): ?>
                        <div class="list-group-item px-0 border-0 py-1">
                            <i class="bi bi-exclamation-triangle-fill text-warning me-1"></i><?= $res ?>
                        </div>
                    <?php endforeach; ?>
                </div>
            </div>
        </div>
    <?php endif; ?>
</div>

<?php include 'includes/footer.php'; ?>