<?php

declare(strict_types=1);

final class UserRepository
{
    private string $path;

    public function __construct()
    {
        $this->path = storage_path('system/users.json');
    }

    public function hasAnyUsers(): bool
    {
        return count($this->all()) > 0;
    }

    public function all(): array
    {
        $data = decode_json_file($this->path, ['users' => []]);

        return array_values(array_filter($data['users'] ?? [], 'is_array'));
    }

    public function find(string $username): ?array
    {
        $needle = normalize_username($username);

        foreach ($this->all() as $user) {
            if (($user['username'] ?? '') === $needle) {
                return $user;
            }
        }

        return null;
    }

    public function verify(string $username, string $password): ?array
    {
        $user = $this->find($username) ?? [];

        if ($user === null) {
            return null;
        }

        if (!password_verify($password, (string) ($user['password_hash'] ?? ''))) {
            return null;
        }

        return $user;
    }

    public function findByRememberToken(string $selector, string $validator): ?array
    {
        $validatorHash = hash('sha256', $validator);
        $now = time();

        foreach ($this->all() as $user) {
            $token = $user['remember_token'] ?? null;

            if (!is_array($token) || !hash_equals((string) ($token['selector'] ?? ''), $selector)) {
                continue;
            }

            $expiresAt = strtotime((string) ($token['expires_at'] ?? '')) ?: 0;

            if ($expiresAt < $now) {
                return null;
            }

            if (!hash_equals((string) ($token['validator_hash'] ?? ''), $validatorHash)) {
                return null;
            }

            return $user;
        }

        return null;
    }

    public function storeRememberToken(string $username, string $selector, string $validatorHash, int $expiresAt): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized) {
                continue;
            }

            $user['remember_token'] = [
                'selector' => $selector,
                'validator_hash' => $validatorHash,
                'expires_at' => date(DATE_ATOM, $expiresAt),
                'created_at' => date(DATE_ATOM),
            ];
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if (!$updated) {
            throw new RuntimeException('Der Remember-Me-Token konnte keinem Benutzer zugeordnet werden.');
        }

        $this->write(['users' => $users]);
    }

    public function clearRememberToken(string $username): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized || !array_key_exists('remember_token', $user)) {
                continue;
            }

            unset($user['remember_token']);
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if ($updated) {
            $this->write(['users' => $users]);
        }
    }

    public function findByHealthImportToken(string $token): ?array
    {
        $tokenHash = hash('sha256', $token);

        foreach ($this->all() as $user) {
            $config = $user['health_import'] ?? null;

            if (!is_array($config) || empty($config['enabled'])) {
                continue;
            }

            if (hash_equals((string) ($config['token_hash'] ?? ''), $tokenHash)) {
                return $user;
            }
        }

        return null;
    }

    public function healthImportConfig(string $username): array
    {
        $user = $this->find($username);
        $config = is_array($user['health_import'] ?? null) ? $user['health_import'] : [];

        return [
            'enabled' => !empty($config['enabled']),
            'token_prefix' => (string) ($config['token_prefix'] ?? ''),
            'created_at' => (string) ($config['created_at'] ?? ''),
            'last_import_at' => (string) ($config['last_import_at'] ?? ''),
            'last_status' => (string) ($config['last_status'] ?? ''),
            'last_message' => (string) ($config['last_message'] ?? ''),
            'progress_done' => max(0, (int) ($config['progress_done'] ?? 0)),
            'progress_total' => max(0, (int) ($config['progress_total'] ?? 0)),
            'started_at' => (string) ($config['started_at'] ?? ''),
            'updated_at' => (string) ($config['updated_at'] ?? ''),
            'finished_at' => (string) ($config['finished_at'] ?? ''),
        ];
    }

    public function issueHealthImportToken(string $username): string
    {
        $token = 'mood_health_' . bin2hex(random_bytes(24));
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized) {
                continue;
            }

            $currentConfig = is_array($user['health_import'] ?? null) ? $user['health_import'] : [];
            $user['health_import'] = [
                'enabled' => true,
                'token_hash' => hash('sha256', $token),
                'token_prefix' => substr($token, 0, 18),
                'created_at' => date(DATE_ATOM),
                'last_import_at' => (string) ($currentConfig['last_import_at'] ?? ''),
                'last_status' => (string) ($currentConfig['last_status'] ?? ''),
                'last_message' => (string) ($currentConfig['last_message'] ?? ''),
                'progress_done' => max(0, (int) ($currentConfig['progress_done'] ?? 0)),
                'progress_total' => max(0, (int) ($currentConfig['progress_total'] ?? 0)),
                'started_at' => (string) ($currentConfig['started_at'] ?? ''),
                'updated_at' => (string) ($currentConfig['updated_at'] ?? ''),
                'finished_at' => (string) ($currentConfig['finished_at'] ?? ''),
            ];
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if (!$updated) {
            throw new RuntimeException('Der Health-Import-Token konnte keinem Benutzer zugeordnet werden.');
        }

        $this->write(['users' => $users]);

        return $token;
    }

    public function revokeHealthImportToken(string $username): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized || !array_key_exists('health_import', $user)) {
                continue;
            }

            unset($user['health_import']);
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if ($updated) {
            $this->write(['users' => $users]);
        }
    }

    public function recordHealthImport(string $username, string $status, string $message): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized) {
                continue;
            }

            $config = is_array($user['health_import'] ?? null) ? $user['health_import'] : [];
            $config['last_import_at'] = date(DATE_ATOM);
            $config['last_status'] = $status;
            $config['last_message'] = substr($message, 0, 240);
            $config['updated_at'] = date(DATE_ATOM);
            if ($status !== 'running') {
                $config['finished_at'] = date(DATE_ATOM);
                if ($status === 'ok') {
                    $total = max(0, (int) ($config['progress_total'] ?? 0));
                    $config['progress_done'] = $total > 0 ? $total : max(0, (int) ($config['progress_done'] ?? 0));
                }
            }
            $user['health_import'] = $config;
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if ($updated) {
            $this->write(['users' => $users]);
        }
    }

    public function recordHealthImportProgress(string $username, string $message, int $done, int $total, ?string $startedAt = null): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();
        $updated = false;

        foreach ($users as &$user) {
            if (($user['username'] ?? '') !== $normalized) {
                continue;
            }

            $config = is_array($user['health_import'] ?? null) ? $user['health_import'] : [];
            $config['last_status'] = 'running';
            $config['last_message'] = substr($message, 0, 240);
            $config['progress_done'] = max(0, min($done, max($total, 0)));
            $config['progress_total'] = max(0, $total);
            $config['started_at'] = $startedAt ?? (string) ($config['started_at'] ?? date(DATE_ATOM));
            $config['updated_at'] = date(DATE_ATOM);
            $config['finished_at'] = '';
            $user['health_import'] = $config;
            $user['updated_at'] = date(DATE_ATOM);
            $updated = true;
            break;
        }
        unset($user);

        if ($updated) {
            $this->write(['users' => $users]);
        }
    }

    public function create(string $username, string $password, bool $isAdmin = false): array
    {
        $normalized = normalize_username($username);

        if ($normalized === '' || $this->find($normalized) !== null) {
            throw new RuntimeException('Benutzername existiert bereits oder ist ungültig.');
        }

        $users = $this->all();
        $users[] = [
            'username' => $normalized,
            'password_hash' => password_hash($password, PASSWORD_DEFAULT),
            'is_admin' => $isAdmin,
            'created_at' => date(DATE_ATOM),
        ];

        $this->write(['users' => $users]);

        $createdUser = $this->find($normalized);

        if ($createdUser === null) {
            throw new RuntimeException('Der Account konnte nicht gespeichert werden.');
        }

        return $createdUser;
    }

    public function changePassword(string $username, string $password): void
    {
        $normalized = normalize_username($username);
        $users = $this->all();

        foreach ($users as &$user) {
            if (($user['username'] ?? '') === $normalized) {
                $user['password_hash'] = password_hash($password, PASSWORD_DEFAULT);
                $user['updated_at'] = date(DATE_ATOM);
            }
        }
        unset($user);

        $this->write(['users' => $users]);
    }

    private function write(array $payload): void
    {
        if (!is_dir(dirname($this->path))) {
            mkdir(dirname($this->path), 0775, true);
        }

        $bytes = file_put_contents(
            $this->path,
            json_encode($payload, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES),
            LOCK_EX
        );

        if ($bytes === false) {
            throw new RuntimeException('Die Benutzerdatei konnte nicht geschrieben werden. Bitte prüfe die Schreibrechte von storage/system.');
        }
    }
}