<?php

require_once __DIR__ . '/../UserProviderInterface.php';
require_once __DIR__ . '/../User.php';

/**
 * JsonUserProvider stores users in a JSON file
 */
class JsonUserProvider implements UserProviderInterface
{
    private string $filePath;
    private array $users = [];

    public function __construct(string $filePath)
    {
        $this->filePath = $filePath;
        $this->loadUsers();
    }

    /**
     * Load users from JSON file
     */
    private function loadUsers(): void
    {
        if (!file_exists($this->filePath)) {
            $this->users = [];
            $this->saveUsers();
            return;
        }

        $content = file_get_contents($this->filePath);
        $data = json_decode($content, true) ?? [];
        
        $this->users = [];
        foreach ($data as $userData) {
            $this->users[$userData['id']] = new User($userData);
        }
    }

    /**
     * Save users to JSON file
     */
    private function saveUsers(): void
    {
        $data = [];
        foreach ($this->users as $user) {
            $userData = [
                'id' => $user->id,
                'username' => $user->username,
                'email' => $user->email,
                'password' => $user->password,
                'remember_token' => $user->rememberToken,
                'created_at' => $user->createdAt,
                'updated_at' => $user->updatedAt,
            ] + $user->attributes;
            $data[] = $userData;
        }

        file_put_contents($this->filePath, json_encode($data, JSON_PRETTY_PRINT));
    }

    /**
     * Generate next user ID
     */
    private function generateId(): int
    {
        if (empty($this->users)) {
            return 1;
        }
        return max(array_keys($this->users)) + 1;
    }

    public function findById(int|string $id): ?User
    {
        return $this->users[$id] ?? null;
    }

    public function findByEmail(string $email): ?User
    {
        foreach ($this->users as $user) {
            if ($user->email === $email) {
                return $user;
            }
        }
        return null;
    }

    public function findByUsername(string $username): ?User
    {
        foreach ($this->users as $user) {
            if ($user->username === $username) {
                return $user;
            }
        }
        return null;
    }

    public function findByCredentials(string $identifier): ?User
    {
        // Check if identifier is email
        if (filter_var($identifier, FILTER_VALIDATE_EMAIL)) {
            return $this->findByEmail($identifier);
        }
        
        // Otherwise treat as username
        return $this->findByUsername($identifier);
    }

    public function findByRememberToken(string $token): ?User
    {
        foreach ($this->users as $user) {
            if ($user->rememberToken === $token) {
                return $user;
            }
        }
        return null;
    }

    public function create(array $data): User
    {
        $data['id'] = $data['id'] ?? $this->generateId();
        $data['created_at'] = $data['created_at'] ?? date('Y-m-d H:i:s');
        $data['updated_at'] = $data['updated_at'] ?? date('Y-m-d H:i:s');

        $user = new User($data);
        $this->users[$user->id] = $user;
        $this->saveUsers();

        return $user;
    }

    public function update(User $user, array $data): bool
    {
        if (!isset($this->users[$user->id])) {
            return false;
        }

        foreach ($data as $key => $value) {
            if (property_exists($user, $key)) {
                $user->$key = $value;
            } else {
                $user->attributes[$key] = $value;
            }
        }

        $user->updatedAt = date('Y-m-d H:i:s');
        $this->users[$user->id] = $user;
        $this->saveUsers();

        return true;
    }

    public function updateRememberToken(User $user, ?string $token): bool
    {
        if (!isset($this->users[$user->id])) {
            return false;
        }

        $user->rememberToken = $token;
        $this->users[$user->id] = $user;
        $this->saveUsers();

        return true;
    }

    public function verifyPassword(User $user, string $password): bool
    {
        return password_verify($password, $user->password);
    }
}