<?php
/**
 * Manage Categories - COMPLETE INTEGRATION
 * Add, edit, and manage expense categories and subcategories all in one place
 */

require_once __DIR__ . '/../config/database.php';
require_once __DIR__ . '/../config/settings.php';
require_once __DIR__ . '/../includes/functions.php';

startSession();
requireLogin();
requireRole(['admin', 'manager']);

$success = '';
$error = '';

// Handle Add Category
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['action']) && $_POST['action'] === 'add_category') {
    $category_name = trim($_POST['category_name']);
    $description = trim($_POST['description']);
    
    if (empty($category_name)) {
        $error = "Category name is required";
    } else {
        try {
            $conn = getDbConnection();
            
            // Check duplicate
            $check_sql = "SELECT category_id FROM expense_categories WHERE category_name = ?";
            $stmt = $conn->prepare($check_sql);
            $stmt->bind_param("s", $category_name);
            $stmt->execute();
            $result = $stmt->get_result();
            
            if ($result->num_rows > 0) {
                $error = "Category '$category_name' already exists";
            } else {
                // Insert
                $sql = "INSERT INTO expense_categories (category_name, description, status, created_at) 
                        VALUES (?, ?, 'active', NOW())";
                $stmt = $conn->prepare($sql);
                $stmt->bind_param("ss", $category_name, $description);
                
                if ($stmt->execute()) {
                    logActivity($_SESSION['user_id'], 'CREATE', 'expense_categories', "Created category: $category_name");
                    $success = "Category '$category_name' created successfully!";
                } else {
                    $error = "Failed to create category: " . $stmt->error;
                }
            }
        } catch (Exception $e) {
            $error = "Database error: " . $e->getMessage();
        }
    }
}

// Handle Add Subcategory
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_POST['action']) && $_POST['action'] === 'add_subcategory') {
    $category_id = intval($_POST['category_id']);
    $subcategory_name = trim($_POST['subcategory_name']);
    $description = trim($_POST['description']);
    
    if ($category_id <= 0) {
        $error = "Please select a category";
    } elseif (empty($subcategory_name)) {
        $error = "Subcategory name is required";
    } else {
        try {
            $conn = getDbConnection();
            
            // Check duplicate
            $check_sql = "SELECT subcategory_id FROM expense_subcategories 
                         WHERE category_id = ? AND subcategory_name = ?";
            $stmt = $conn->prepare($check_sql);
            $stmt->bind_param("is", $category_id, $subcategory_name);
            $stmt->execute();
            $result = $stmt->get_result();
            
            if ($result->num_rows > 0) {
                $error = "Subcategory '$subcategory_name' already exists in this category";
            } else {
                // Insert
                $sql = "INSERT INTO expense_subcategories (category_id, subcategory_name, description, status, created_at) 
                        VALUES (?, ?, ?, 'active', NOW())";
                $stmt = $conn->prepare($sql);
                $stmt->bind_param("iss", $category_id, $subcategory_name, $description);
                
                if ($stmt->execute()) {
                    logActivity($_SESSION['user_id'], 'CREATE', 'expense_subcategories', "Created subcategory: $subcategory_name");
                    $success = "Subcategory '$subcategory_name' created successfully!";
                } else {
                    $error = "Failed to create subcategory: " . $stmt->error;
                }
            }
        } catch (Exception $e) {
            $error = "Database error: " . $e->getMessage();
        }
    }
}

// Handle Toggle Status
if (isset($_GET['toggle_category'])) {
    $cat_id = intval($_GET['toggle_category']);
    $conn = getDbConnection();
    $sql = "UPDATE expense_categories SET status = IF(status = 'active', 'inactive', 'active') WHERE category_id = ?";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("i", $cat_id);
    $stmt->execute();
    $success = "Category status updated";
}

if (isset($_GET['toggle_subcategory'])) {
    $sub_id = intval($_GET['toggle_subcategory']);
    $conn = getDbConnection();
    $sql = "UPDATE expense_subcategories SET status = IF(status = 'active', 'inactive', 'active') WHERE subcategory_id = ?";
    $stmt = $conn->prepare($sql);
    $stmt->bind_param("i", $sub_id);
    $stmt->execute();
    $success = "Subcategory status updated";
}

// Get all categories
$categories = fetchAll("SELECT * FROM expense_categories ORDER BY category_name");

// Get all subcategories grouped by category
$subcategories_by_category = [];
$all_subcategories = fetchAll("
    SELECT s.*, c.category_name 
    FROM expense_subcategories s
    JOIN expense_categories c ON s.category_id = c.category_id
    ORDER BY c.category_name, s.subcategory_name
");

foreach ($all_subcategories as $sub) {
    $subcategories_by_category[$sub['category_id']][] = $sub;
}

$page_title = 'Manage Categories';
require_once __DIR__ . '/../includes/header.php';
?>

<h1 class="page-title">📂 Manage Expense Categories</h1>

<?php if ($success): ?>
<div class="alert alert-success"><?php echo htmlspecialchars($success); ?></div>
<?php endif; ?>

<?php if ($error): ?>
<div class="alert alert-error"><?php echo htmlspecialchars($error); ?></div>
<?php endif; ?>

<!-- Tab Navigation -->
<div class="tabs" style="margin-bottom: 2rem;">
    <button class="tab-btn active" onclick="showTab('categories')">
        📋 Categories (<?php echo count($categories); ?>)
    </button>
    <button class="tab-btn" onclick="showTab('add-category')">
        ➕ Add Category
    </button>
    <button class="tab-btn" onclick="showTab('add-subcategory')">
        ➕ Add Subcategory
    </button>
</div>

<!-- Tab: View Categories -->
<div id="tab-categories" class="tab-content active">
    <div class="card">
        <h2 class="card-title">All Categories & Subcategories</h2>
        
        <?php if (!empty($categories)): ?>
        <div class="accordion">
            <?php foreach ($categories as $cat): ?>
            <div class="accordion-item" style="margin-bottom: 1rem; border: 1px solid #dee2e6; border-radius: 5px;">
                <div class="accordion-header" style="
                    padding: 1rem;
                    background: <?php echo $cat['status'] === 'active' ? '#f8f9fa' : '#fff3cd'; ?>;
                    cursor: pointer;
                    display: flex;
                    justify-content: space-between;
                    align-items: center;
                " onclick="toggleAccordion(<?php echo $cat['category_id']; ?>)">
                    <div>
                        <strong style="font-size: 1.1rem;"><?php echo htmlspecialchars($cat['category_name']); ?></strong>
                        <?php if ($cat['description']): ?>
                            <br><small style="color: #666;"><?php echo htmlspecialchars($cat['description']); ?></small>
                        <?php endif; ?>
                    </div>
                    <div style="display: flex; gap: 0.5rem; align-items: center;">
                        <?php
                        $sub_count = isset($subcategories_by_category[$cat['category_id']]) ? 
                                    count($subcategories_by_category[$cat['category_id']]) : 0;
                        ?>
                        <span class="badge" style="background: #6c757d;">
                            <?php echo $sub_count; ?> subcategories
                        </span>
                        
                        <a href="?toggle_category=<?php echo $cat['category_id']; ?>" 
                           class="btn btn-sm" 
                           style="background: <?php echo $cat['status'] === 'active' ? '#ffc107' : '#28a745'; ?>; color: white;"
                           onclick="event.stopPropagation(); return confirm('Toggle category status?')">
                            <?php echo $cat['status'] === 'active' ? '⏸️ Deactivate' : '▶️ Activate'; ?>
                        </a>
                        
                        <span style="font-size: 1.5rem;">▼</span>
                    </div>
                </div>
                
                <div id="accordion-content-<?php echo $cat['category_id']; ?>" class="accordion-content" style="display: none; padding: 1rem; background: white;">
                    <?php if (isset($subcategories_by_category[$cat['category_id']])): ?>
                    <table style="width: 100%;">
                        <thead>
                            <tr>
                                <th>Subcategory Name</th>
                                <th>Description</th>
                                <th class="text-center">Status</th>
                                <th class="text-center">Actions</th>
                            </tr>
                        </thead>
                        <tbody>
                            <?php foreach ($subcategories_by_category[$cat['category_id']] as $sub): ?>
                            <tr>
                                <td><strong><?php echo htmlspecialchars($sub['subcategory_name']); ?></strong></td>
                                <td><?php echo htmlspecialchars($sub['description']); ?></td>
                                <td class="text-center">
                                    <?php if ($sub['status'] === 'active'): ?>
                                        <span style="color: #28a745;">✓ Active</span>
                                    <?php else: ?>
                                        <span style="color: #999;">Inactive</span>
                                    <?php endif; ?>
                                </td>
                                <td class="text-center">
                                    <a href="?toggle_subcategory=<?php echo $sub['subcategory_id']; ?>" 
                                       class="btn btn-sm btn-warning"
                                       onclick="return confirm('Toggle subcategory status?')">
                                        Toggle
                                    </a>
                                </td>
                            </tr>
                            <?php endforeach; ?>
                        </tbody>
                    </table>
                    <?php else: ?>
                    <p style="margin: 0; color: #666; text-align: center;">No subcategories yet</p>
                    <?php endif; ?>
                </div>
            </div>
            <?php endforeach; ?>
        </div>
        <?php else: ?>
        <div class="empty-state">
            <div class="empty-state-icon">📂</div>
            <h3>No categories yet</h3>
            <p>Create your first expense category to get started</p>
            <button onclick="showTab('add-category')" class="btn btn-success">➕ Add Category</button>
        </div>
        <?php endif; ?>
    </div>
</div>

<!-- Tab: Add Category -->
<div id="tab-add-category" class="tab-content">
    <div class="card" style="max-width: 600px; margin: 0 auto;">
        <h2 class="card-title">➕ Add New Category</h2>
        <form method="POST" action="">
            <input type="hidden" name="action" value="add_category">
            
            <div class="form-group">
                <label for="category_name">Category Name *</label>
                <input type="text" id="category_name" name="category_name" class="form-control" 
                       required placeholder="e.g., Fuel, Maintenance, Utilities">
            </div>
            
            <div class="form-group">
                <label for="description">Description (Optional)</label>
                <textarea id="description" name="description" class="form-control" rows="3" 
                          placeholder="Brief description of this category"></textarea>
            </div>
            
            <div class="form-actions">
                <button type="submit" class="btn btn-success">💾 Create Category</button>
                <button type="button" onclick="showTab('categories')" class="btn btn-secondary">Cancel</button>
            </div>
        </form>
    </div>
</div>

<!-- Tab: Add Subcategory -->
<div id="tab-add-subcategory" class="tab-content">
    <div class="card" style="max-width: 600px; margin: 0 auto;">
        <h2 class="card-title">➕ Add New Subcategory</h2>
        
        <?php if (empty($categories)): ?>
        <div class="alert alert-warning">
            No categories available. <button onclick="showTab('add-category')" class="btn btn-sm btn-primary">Create a category first</button>
        </div>
        <?php else: ?>
        
        <form method="POST" action="">
            <input type="hidden" name="action" value="add_subcategory">
            
            <div class="form-group">
                <label for="category_id">Category *</label>
                <select id="category_id" name="category_id" class="form-control" required>
                    <option value="">Select Category</option>
                    <?php foreach ($categories as $cat): ?>
                        <?php if ($cat['status'] === 'active'): ?>
                        <option value="<?php echo $cat['category_id']; ?>">
                            <?php echo htmlspecialchars($cat['category_name']); ?>
                        </option>
                        <?php endif; ?>
                    <?php endforeach; ?>
                </select>
            </div>
            
            <div class="form-group">
                <label for="subcategory_name">Subcategory Name *</label>
                <input type="text" id="subcategory_name" name="subcategory_name" class="form-control" 
                       required placeholder="e.g., Diesel, Petrol, Engine Oil">
            </div>
            
            <div class="form-group">
                <label for="description">Description (Optional)</label>
                <textarea id="description" name="description" class="form-control" rows="3" 
                          placeholder="Brief description of this subcategory"></textarea>
            </div>
            
            <div class="form-actions">
                <button type="submit" class="btn btn-success">💾 Create Subcategory</button>
                <button type="button" onclick="showTab('categories')" class="btn btn-secondary">Cancel</button>
            </div>
        </form>
        
        <?php endif; ?>
    </div>
</div>

<style>
.tabs {
    display: flex;
    gap: 0.5rem;
    border-bottom: 2px solid #dee2e6;
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    background: white;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-weight: 600;
    color: #666;
    transition: all 0.3s;
}

.tab-btn:hover {
    color: #17a2b8;
    background: #f8f9fa;
}

.tab-btn.active {
    color: #17a2b8;
    border-bottom-color: #17a2b8;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.6rem;
    font-size: 0.75rem;
    font-weight: 600;
    color: white;
    border-radius: 3px;
}
</style>

<script>
function showTab(tabName) {
    // Hide all tabs
    document.querySelectorAll('.tab-content').forEach(tab => {
        tab.classList.remove('active');
    });
    
    // Remove active from all buttons
    document.querySelectorAll('.tab-btn').forEach(btn => {
        btn.classList.remove('active');
    });
    
    // Show selected tab
    document.getElementById('tab-' + tabName).classList.add('active');
    
    // Activate button
    event.target.classList.add('active');
}

function toggleAccordion(categoryId) {
    const content = document.getElementById('accordion-content-' + categoryId);
    if (content.style.display === 'none' || content.style.display === '') {
        content.style.display = 'block';
    } else {
        content.style.display = 'none';
    }
}
</script>

<?php require_once __DIR__ . '/../includes/footer.php'; ?>