<?php

declare(strict_types=1);

namespace App\Services\TenantConfiguration;

final readonly class ExchangePowerShellRuntimePolicy
{
    /**
     * @param  list<string>  $allowedEnvironments
     */
    public function __construct(
        public bool $invocationEnabled,
        public bool $productionRunnerEnabled,
        public array $allowedEnvironments,
        public string $currentEnvironment,
        public string $powershellBinary,
        public bool $moduleCheckEnabled,
        public int $checkTimeoutSeconds,
        public int $invocationTimeoutSeconds,
        public int $stdoutMaxBytes,
        public int $stderrMaxBytes,
        public int $itemLimit,
        public int $lockTtlSeconds,
        public bool $tempFilesEnabled,
        public ?string $tempDirectory,
    ) {}

    public static function fromConfig(): self
    {
        $runtime = config('tenantpilot.exchange_powershell.runtime', []);
        $runtime = is_array($runtime) ? $runtime : [];

        return new self(
            invocationEnabled: (bool) config(ExchangePowerShellInvocationGate::FEATURE_CONFIG_PATH, false),
            productionRunnerEnabled: (bool) config(ExchangePowerShellInvocationGate::PRODUCTION_RUNNER_CONFIG_PATH, false),
            allowedEnvironments: self::stringList($runtime['allowed_environments'] ?? ['local', 'testing']),
            currentEnvironment: app()->environment(),
            powershellBinary: self::nonEmptyString($runtime['powershell_binary'] ?? null, 'pwsh'),
            moduleCheckEnabled: (bool) ($runtime['module_check_enabled'] ?? true),
            checkTimeoutSeconds: max(0, (int) ($runtime['check_timeout_seconds'] ?? 5)),
            invocationTimeoutSeconds: max(0, (int) ($runtime['invocation_timeout_seconds'] ?? 60)),
            stdoutMaxBytes: max(0, (int) ($runtime['stdout_max_bytes'] ?? 524288)),
            stderrMaxBytes: max(0, (int) ($runtime['stderr_max_bytes'] ?? 65536)),
            itemLimit: max(0, (int) ($runtime['item_limit'] ?? 1000)),
            lockTtlSeconds: max(0, (int) ($runtime['lock_ttl_seconds'] ?? 300)),
            tempFilesEnabled: (bool) ($runtime['temp_files_enabled'] ?? false),
            tempDirectory: self::nullableString($runtime['temp_directory'] ?? null),
        );
    }

    public function environmentAllowed(): bool
    {
        return in_array($this->currentEnvironment, $this->allowedEnvironments, true);
    }

    public function timeoutPolicyValid(): bool
    {
        return $this->checkTimeoutSeconds > 0
            && $this->invocationTimeoutSeconds > 0
            && $this->stdoutMaxBytes > 0
            && $this->stderrMaxBytes > 0
            && $this->itemLimit > 0
            && $this->lockTtlSeconds > 0;
    }

    public function tempPolicySafe(): bool
    {
        if (! $this->tempFilesEnabled) {
            return true;
        }

        if ($this->tempDirectory === null || $this->tempDirectory === '') {
            return false;
        }

        $allowedPrefix = rtrim(storage_path('app/tmp'), DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR;
        $directory = rtrim($this->tempDirectory, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR;

        return str_starts_with($directory, $allowedPrefix);
    }

    /**
     * @return list<string>
     */
    private static function stringList(mixed $values): array
    {
        if (is_string($values)) {
            $values = explode(',', $values);
        }

        if (! is_array($values)) {
            return [];
        }

        return array_values(array_filter(
            array_map(static fn (mixed $value): string => trim((string) $value), $values),
            static fn (string $value): bool => $value !== '',
        ));
    }

    private static function nonEmptyString(mixed $value, string $fallback): string
    {
        $value = is_string($value) ? trim($value) : '';

        return $value !== '' ? $value : $fallback;
    }

    private static function nullableString(mixed $value): ?string
    {
        $value = is_string($value) ? trim($value) : '';

        return $value !== '' ? $value : null;
    }
}