<?php
/**
 * User Controller
 */

namespace Modules\User;

use Core\Database;
use Core\Request;
use Core\Response;
use Utils\Helpers;

class UserController
{
    private Database $db;

    public function __construct(Database $db)
    {
        $this->db = $db;
    }

    /**
     * GET /users/:id
     */
    public function show(Request $request, array $params): void
    {
        $userId = $params['id'] ?? $request->userId ?? null;
        
        if (!$userId) {
            Response::unauthorized();
            return;
        }

        $pdo = $this->db->getInstance();
        
        $stmt = $pdo->prepare('
            SELECT id, username, email, display_name, bio, avatar_url, photos,
                   gender, interested_in, age, location, interests, is_online,
                   last_seen, settings, created_at
            FROM users WHERE id = ?
        ');
        $stmt->execute([$userId]);
        $user = $stmt->fetch();

        if (!$user) {
            Response::notFound('User not found');
            return;
        }

        // Parse JSON fields
        $user['photos'] = Helpers::parseJson($user['photos'], []);
        $user['interested_in'] = Helpers::parseJson($user['interested_in'], []);
        $user['location'] = Helpers::parseJson($user['location'], null);
        $user['interests'] = Helpers::parseJson($user['interests'], []);
        $user['settings'] = Helpers::parseJson($user['settings'], []);
        $user['is_online'] = (bool) $user['is_online'];

        // Check if own profile to show full data
        $isOwnProfile = isset($request->userId) && $request->userId === $userId;
        
        if (!$isOwnProfile) {
            // Hide sensitive data for other users
            unset($user['email']);
            unset($user['settings']);
        }

        Response::success(['user' => $user]);
    }

    /**
     * PATCH /users/:id
     */
    public function update(Request $request, array $params): void
    {
        $userId = $params['id'] ?? $request->userId ?? null;
        
        if (!$userId) {
            Response::unauthorized();
            return;
        }

        // Can only update own profile
        if (!isset($request->userId) || $request->userId !== $userId) {
            Response::forbidden('You can only update your own profile');
            return;
        }

        $body = $request->getBody();
        $pdo = $this->db->getInstance();

        // Build update query dynamically
        $allowedFields = [
            'display_name', 'bio', 'avatar_url', 'photos', 'gender',
            'interested_in', 'age', 'location', 'interests', 'settings'
        ];

        $updates = [];
        $values = [];

        foreach ($allowedFields as $field) {
            if (isset($body[$field])) {
                $value = $body[$field];
                
                // Encode arrays to JSON
                if (in_array($field, ['photos', 'interested_in', 'interests'])) {
                    $value = Helpers::jsonEncode($value);
                } elseif ($field === 'location') {
                    $value = Helpers::jsonEncode($value);
                } elseif ($field === 'settings') {
                    $value = Helpers::jsonEncode($value);
                } elseif ($field === 'bio') {
                    $value = substr($value, 0, 500); // Max 500 chars
                } elseif ($field === 'age') {
                    $value = (int) $value;
                    if ($value < 18 || $value > 120) {
                        Response::validationError(['age' => 'Age must be between 18 and 120']);
                        return;
                    }
                }
                
                $updates[] = "{$field} = ?";
                $values[] = $value;
            }
        }

        if (empty($updates)) {
            Response::validationError(['general' => 'No valid fields to update']);
            return;
        }

        $updates[] = 'updated_at = ?';
        $values[] = Helpers::timestamp();
        $values[] = $userId;

        $sql = 'UPDATE users SET ' . implode(', ', $updates) . ' WHERE id = ?';
        $stmt = $pdo->prepare($sql);
        $stmt->execute($values);

        // Fetch updated user
        $stmt = $pdo->prepare('SELECT * FROM users WHERE id = ?');
        $stmt->execute([$userId]);
        $user = $stmt->fetch();

        // Parse JSON fields
        $user['photos'] = Helpers::parseJson($user['photos'], []);
        $user['interested_in'] = Helpers::parseJson($user['interested_in'], []);
        $user['location'] = Helpers::parseJson($user['location'], null);
        $user['interests'] = Helpers::parseJson($user['interests'], []);
        $user['settings'] = Helpers::parseJson($user['settings'], []);

        Response::success(['user' => $user], 'Profile updated successfully');
    }

    /**
     * DELETE /users/:id
     */
    public function destroy(Request $request, array $params): void
    {
        $userId = $params['id'] ?? $request->userId ?? null;
        
        if (!$userId) {
            Response::unauthorized();
            return;
        }

        // Can only delete own account
        if (!isset($request->userId) || $request->userId !== $userId) {
            Response::forbidden('You can only delete your own account');
            return;
        }

        $pdo = $this->db->getInstance();

        // Delete user (cascade will handle related records)
        $stmt = $pdo->prepare('DELETE FROM users WHERE id = ?');
        $stmt->execute([$userId]);

        Response::success(null, 'Account deleted successfully');
    }

    /**
     * GET /users/search
     */
    public function search(Request $request): void
    {
        $query = $request->getQuery('q', '');
        $limit = min((int) $request->getQuery('limit', 20), 100);
        $offset = (int) $request->getQuery('offset', 0);

        if (strlen($query) < 2) {
            Response::validationError(['q' => 'Search query must be at least 2 characters']);
            return;
        }

        $pdo = $this->db->getInstance();
        $searchTerm = "%{$query}%";

        $stmt = $pdo->prepare('
            SELECT id, username, display_name, bio, avatar_url, age, location, interests, is_online
            FROM users
            WHERE (username LIKE ? OR display_name LIKE ?)
            LIMIT ? OFFSET ?
        ');
        $stmt->execute([$searchTerm, $searchTerm, $limit, $offset]);
        $users = $stmt->fetchAll();

        // Parse JSON fields for each user
        foreach ($users as &$user) {
            $user['location'] = Helpers::parseJson($user['location'], null);
            $user['interests'] = Helpers::parseJson($user['interests'], []);
            $user['is_online'] = (bool) $user['is_online'];
        }

        Response::success([
            'users' => $users,
            'limit' => $limit,
            'offset' => $offset
        ]);
    }

    /**
     * GET /users/:id/posts
     */
    public function posts(Request $request, array $params): void
    {
        $userId = $params['id'] ?? null;
        
        if (!$userId) {
            Response::notFound('User ID required');
            return;
        }

        $limit = min((int) $request->getQuery('limit', 20), 100);
        $offset = (int) $request->getQuery('offset', 0);

        $pdo = $this->db->getInstance();

        $stmt = $pdo->prepare('
            SELECT * FROM posts
            WHERE user_id = ?
            ORDER BY created_at DESC
            LIMIT ? OFFSET ?
        ');
        $stmt->execute([$userId, $limit, $offset]);
        $posts = $stmt->fetchAll();

        // Parse JSON fields
        foreach ($posts as &$post) {
            $post['media_urls'] = Helpers::parseJson($post['media_urls'], []);
            $post['location'] = Helpers::parseJson($post['location'], null);
        }

        Response::success([
            'posts' => $posts,
            'limit' => $limit,
            'offset' => $offset
        ]);
    }

    /**
     * GET /users/:id/friends
     */
    public function friends(Request $request, array $params): void
    {
        $userId = $params['id'] ?? null;
        
        if (!$userId) {
            Response::notFound('User ID required');
            return;
        }

        $pdo = $this->db->getInstance();

        // Get mutual friends (where both users follow each other)
        $stmt = $pdo->prepare('
            SELECT u.id, u.username, u.display_name, u.avatar_url, u.bio, u.is_online
            FROM users u
            INNER JOIN relationships r1 ON u.id = r1.following_id
            INNER JOIN relationships r2 ON u.id = r2.follower_id
            WHERE r1.follower_id = ? AND r2.following_id = ?
            AND r1.type = "friend" AND r2.type = "friend"
            AND r1.status = "active" AND r2.status = "active"
        ');
        $stmt->execute([$userId, $userId]);
        $friends = $stmt->fetchAll();

        foreach ($friends as &$friend) {
            $friend['is_online'] = (bool) $friend['is_online'];
        }

        Response::success(['friends' => $friends]);
    }

    /**
     * GET /users/:id/followers
     */
    public function followers(Request $request, array $params): void
    {
        $userId = $params['id'] ?? null;
        
        if (!$userId) {
            Response::notFound('User ID required');
            return;
        }

        $pdo = $this->db->getInstance();

        $stmt = $pdo->prepare('
            SELECT u.id, u.username, u.display_name, u.avatar_url, u.bio, u.is_online
            FROM users u
            INNER JOIN relationships r ON u.id = r.follower_id
            WHERE r.following_id = ? AND r.status = "active"
        ');
        $stmt->execute([$userId]);
        $followers = $stmt->fetchAll();

        foreach ($followers as &$follower) {
            $follower['is_online'] = (bool) $follower['is_online'];
        }

        Response::success(['followers' => $followers]);
    }

    /**
     * GET /users/:id/following
     */
    public function following(Request $request, array $params): void
    {
        $userId = $params['id'] ?? null;
        
        if (!$userId) {
            Response::notFound('User ID required');
            return;
        }

        $pdo = $this->db->getInstance();

        $stmt = $pdo->prepare('
            SELECT u.id, u.username, u.display_name, u.avatar_url, u.bio, u.is_online
            FROM users u
            INNER JOIN relationships r ON u.id = r.following_id
            WHERE r.follower_id = ? AND r.status = "active"
        ');
        $stmt->execute([$userId]);
        $following = $stmt->fetchAll();

        foreach ($following as &$user) {
            $user['is_online'] = (bool) $user['is_online'];
        }

        Response::success(['following' => $following]);
    }
}