<?php
require_once 'client-session.php';
requireClientLogin();  // Client login

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

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

try {
    $pdo = getDBConnection();
    
    $data = json_decode(file_get_contents('php://input'), true);
    $action = $data['action'] ?? '';
    $selection_id = (int)($data['selection_id'] ?? 0);
    
    if (!$selection_id) {
        throw new Exception('Invalid selection ID');
    }
    
    // Get selection and project details
    $stmt = $pdo->prepare("
        SELECT ps.*, p.status as project_status
        FROM project_selections ps
        INNER JOIN projects p ON ps.project_id = p.id
        WHERE ps.id = ?
    ");
    $stmt->execute([$selection_id]);
    $selection = $stmt->fetch();
    
    if (!$selection) {
        throw new Exception('Selection not found');
    }
    
    // Handle different actions
    switch ($action) {
        case 'update_status':
            $new_status = $data['status'] ?? '';
            
            // Validate status transitions
            $allowed_transitions = [
                'draft' => ['launched'],
                'launched' => ['paused', 'closed'],
                'paused' => ['launched', 'closed'],
                'closed' => [] // Cannot change from closed
            ];
            
            $current_status = $selection['status'];
            
            // Check if project is closed
            if ($selection['project_status'] === 'closed') {
                throw new Exception('Cannot change selection status when project is closed');
            }
            
            // Check if transition is allowed
            if (!in_array($new_status, $allowed_transitions[$current_status])) {
                throw new Exception('Invalid status transition');
            }
            
            // Update status
            $stmt = $pdo->prepare("
                UPDATE project_selections 
                SET status = ?,
                    launched_at = CASE WHEN ? = 'launched' AND launched_at IS NULL THEN NOW() ELSE launched_at END,
                    updated_at = NOW()
                WHERE id = ?
            ");
            $stmt->execute([$new_status, $new_status, $selection_id]);
            
            // Log activity
            $stmt = $pdo->prepare("
                INSERT INTO selection_activity_log (selection_id, action, description, performed_by)
                VALUES (?, ?, ?, ?)
            ");
            $stmt->execute([
                $selection_id,
                'status_changed',
                "Status changed from {$current_status} to {$new_status}",
                $_SESSION['admin_id']
            ]);
            
            echo json_encode([
                'success' => true,
                'message' => 'Status updated successfully'
            ]);
            break;
            
        case 'delete':
            // Can only delete if draft
            if ($selection['status'] !== 'draft') {
                throw new Exception('Can only delete draft selections');
            }
            
            // Delete selection (cascade will delete criteria and members)
            $stmt = $pdo->prepare("DELETE FROM project_selections WHERE id = ?");
            $stmt->execute([$selection_id]);
            
            echo json_encode([
                'success' => true,
                'message' => 'Selection deleted successfully'
            ]);
            break;
            
        default:
            throw new Exception('Unknown action');
    }
    
} catch (Exception $e) {
    error_log("Selection action error: " . $e->getMessage());
    echo json_encode([
        'success' => false,
        'message' => $e->getMessage()
    ]);
}