<?php

namespace MintyPHP\Service\Audit;

use MintyPHP\Http\ApiAuth;
use MintyPHP\Repository\Audit\ApiAuditLogRepository;
use MintyPHP\Repository\Support\RepoQuery;

class ApiAuditService
{
    private const RETENTION_DAYS = 90;
    private const MAX_USER_AGENT_LENGTH = 255;
    private const MAX_STRING_LENGTH = 500;
    private const MAX_ARRAY_ITEMS = 30;

    private static ?array $context = null;

    public static function startRequestContext(): void
    {
        if (self::$context !== null) {
            return;
        }

        $method = strtoupper(trim((string) ($_SERVER['REQUEST_METHOD'] ?? 'GET')));
        if ($method === 'OPTIONS') {
            self::$context = ['active' => false, 'finished' => true];
            return;
        }

        $path = parse_url((string) ($_SERVER['REQUEST_URI'] ?? ''), PHP_URL_PATH);
        $path = is_string($path) ? trim($path) : '';
        if ($path === '') {
            self::$context = ['active' => false, 'finished' => true];
            return;
        }

        self::$context = [
            'active' => true,
            'finished' => false,
            'started_at' => microtime(true),
            'request_id' => RepoQuery::uuidV4(),
            'method' => substr($method !== '' ? $method : 'GET', 0, 8),
            'path' => substr($path, 0, 255),
            'query_json' => self::buildRedactedQueryJson($_GET),
        ];
    }

    public static function finish(int $statusCode, ?string $errorCode = null): void
    {
        if (!is_array(self::$context)) {
            return;
        }
        if (!empty(self::$context['finished'])) {
            return;
        }
        self::$context['finished'] = true;

        if (empty(self::$context['active'])) {
            return;
        }

        $durationMs = null;
        if (isset(self::$context['started_at'])) {
            $durationMs = (int) round((microtime(true) - (float) self::$context['started_at']) * 1000);
            if ($durationMs < 0) {
                $durationMs = 0;
            }
        }

        $statusCode = ($statusCode >= 100 && $statusCode <= 999) ? $statusCode : 500;
        $normalizedErrorCode = trim((string) ($errorCode ?? ''));
        if ($normalizedErrorCode === '') {
            $normalizedErrorCode = null;
        } elseif (strlen($normalizedErrorCode) > 100) {
            $normalizedErrorCode = substr($normalizedErrorCode, 0, 100);
        }

        $ip = trim((string) ($_SERVER['REMOTE_ADDR'] ?? ''));
        if ($ip === '') {
            $ip = null;
        } elseif (strlen($ip) > 45) {
            $ip = substr($ip, 0, 45);
        }

        $userAgent = trim((string) ($_SERVER['HTTP_USER_AGENT'] ?? ''));
        if ($userAgent === '') {
            $userAgent = null;
        } elseif (strlen($userAgent) > self::MAX_USER_AGENT_LENGTH) {
            $userAgent = substr($userAgent, 0, self::MAX_USER_AGENT_LENGTH);
        }

        $userId = ApiAuth::isAuthenticated() ? ApiAuth::userId() : 0;
        $tenantId = ApiAuth::isAuthenticated() ? (int) (ApiAuth::tenantId() ?? 0) : 0;
        $apiTokenId = ApiAuth::isAuthenticated() ? (int) (ApiAuth::tokenId() ?? 0) : 0;
        $tokenTenantId = ApiAuth::isAuthenticated() ? (int) (ApiAuth::scopedTenantId() ?? 0) : 0;

        $payload = [
            'request_id' => (string) (self::$context['request_id'] ?? RepoQuery::uuidV4()),
            'method' => (string) (self::$context['method'] ?? ''),
            'path' => (string) (self::$context['path'] ?? ''),
            'query_json' => self::$context['query_json'] ?? null,
            'status_code' => $statusCode,
            'duration_ms' => $durationMs,
            'error_code' => $normalizedErrorCode,
            'user_id' => $userId > 0 ? $userId : null,
            'tenant_id' => $tenantId > 0 ? $tenantId : null,
            'api_token_id' => $apiTokenId > 0 ? $apiTokenId : null,
            'token_tenant_id' => $tokenTenantId > 0 ? $tokenTenantId : null,
            'ip' => $ip,
            'user_agent' => $userAgent,
        ];

        try {
            ApiAuditLogRepository::create($payload);
        } catch (\Throwable $exception) {
            // Never break API responses because of audit logging failures.
        }
    }

    public static function listPaged(array $filters): array
    {
        return ApiAuditLogRepository::listPaged($filters);
    }

    public static function find(int $id): ?array
    {
        return ApiAuditLogRepository::find($id);
    }

    public static function purgeExpired(): int
    {
        return ApiAuditLogRepository::purgeOlderThanDays(self::RETENTION_DAYS);
    }

    private static function buildRedactedQueryJson(array $query): ?string
    {
        if (!$query) {
            return null;
        }
        $redacted = self::redactArray($query);
        if ($redacted === []) {
            return null;
        }
        $encoded = json_encode($redacted, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
        return is_string($encoded) ? $encoded : null;
    }

    private static function redactArray(array $data): array
    {
        $result = [];
        $i = 0;
        foreach ($data as $rawKey => $value) {
            if ($i >= self::MAX_ARRAY_ITEMS) {
                break;
            }
            $key = trim((string) $rawKey);
            if ($key === '') {
                continue;
            }

            if (self::isSensitiveKey($key)) {
                $result[$key] = '[REDACTED]';
            } else {
                $result[$key] = self::normalizeValue($value);
            }
            $i++;
        }
        return $result;
    }

    private static function normalizeValue(mixed $value): mixed
    {
        if (is_array($value)) {
            return self::redactArray($value);
        }

        if (is_bool($value) || is_int($value) || is_float($value) || $value === null) {
            return $value;
        }

        $string = trim((string) $value);
        if ($string === '') {
            return '';
        }
        if (strlen($string) > self::MAX_STRING_LENGTH) {
            return substr($string, 0, self::MAX_STRING_LENGTH);
        }
        return $string;
    }

    private static function isSensitiveKey(string $key): bool
    {
        $key = strtolower(trim($key));
        if ($key === '') {
            return false;
        }

        if (in_array($key, [
            'token',
            'access_token',
            'refresh_token',
            'id_token',
            'secret',
            'password',
            'authorization',
            'api_key',
            'client_secret',
            'key',
        ], true)) {
            return true;
        }

        return str_contains($key, 'token')
            || str_contains($key, 'secret')
            || str_contains($key, 'password')
            || str_contains($key, 'authorization')
            || str_ends_with($key, '_key');
    }

}