<?php

declare(strict_types=1);

namespace App\Services\TenantConfiguration;

use App\Models\ProviderConnection;
use App\Models\ProviderCredential;
use App\Support\Providers\ProviderCredentialKind;
use App\Support\Providers\ProviderReasonCodes;
use Illuminate\Support\Carbon;

final class ExchangePowerShellCredentialReferenceResolver
{
    public function resolve(ProviderConnection $connection): ExchangePowerShellGateResult
    {
        $credential = ProviderCredential::query()
            ->where('provider_connection_id', (int) $connection->getKey())
            ->first();

        if (! $credential instanceof ProviderCredential) {
            return $this->blocked(
                reasonCode: ProviderReasonCodes::ProviderCredentialMissing,
                failureCode: 'credential_blocked_missing_reference',
                message: 'Exchange PowerShell requires a provider credential reference.',
                context: ['credential_state' => 'missing'],
            );
        }

        $kind = $this->credentialKind($credential);
        $baseContext = [
            'credential_state' => 'blocked',
            'credential_kind' => $this->safeCredentialKindLabel($kind),
            'credential_reference_id' => (int) $credential->getKey(),
            'credential_material_persisted' => false,
        ];

        if ($kind === ProviderCredentialKind::ClientSecret->value) {
            return $this->blocked(
                reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
                failureCode: 'credential_blocked_secret_based_app',
                message: 'Secret-based app credentials are not supported for Exchange PowerShell production invocation.',
                context: $this->credentialContext($baseContext, 'secret_based_app_unsupported'),
            );
        }

        if ($kind === ProviderCredentialKind::Certificate->value) {
            if (! $credential->last_rotated_at instanceof Carbon || ! $credential->expires_at instanceof Carbon) {
                return $this->blocked(
                    reasonCode: ProviderReasonCodes::ProviderCredentialMissing,
                    failureCode: 'credential_blocked_certificate_missing',
                    message: 'Certificate credential metadata is incomplete.',
                    context: $this->credentialContext($baseContext, 'certificate_missing'),
                );
            }

            if ($credential->expires_at instanceof Carbon && $credential->expires_at->isPast()) {
                return $this->blocked(
                    reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
                    failureCode: 'credential_blocked_certificate_expired',
                    message: 'Certificate credential reference is expired.',
                    context: $this->credentialContext($baseContext, 'certificate_expired'),
                );
            }

            if ($this->credentialKindSupported($kind)) {
                return ExchangePowerShellGateResult::allowed($this->credentialContext($baseContext, 'certificate_supported'));
            }

            return $this->blocked(
                reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
                failureCode: 'credential_blocked_certificate_unsupported',
                message: 'Certificate credentials are not enabled for Exchange PowerShell production invocation.',
                context: $this->credentialContext($baseContext, 'certificate_unsupported'),
            );
        }

        if ($kind === ProviderCredentialKind::Federated->value) {
            if (! $credential->last_rotated_at instanceof Carbon) {
                return $this->blocked(
                    reasonCode: ProviderReasonCodes::ProviderCredentialMissing,
                    failureCode: 'credential_blocked_federated_missing',
                    message: 'Federated credential metadata is incomplete.',
                    context: $this->credentialContext($baseContext, 'federated_missing'),
                );
            }

            if ($this->credentialKindSupported($kind)) {
                return ExchangePowerShellGateResult::allowed($this->credentialContext($baseContext, 'federated_supported'));
            }

            return $this->blocked(
                reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
                failureCode: 'credential_blocked_federated_unsupported',
                message: 'Federated credentials are not enabled for Exchange PowerShell production invocation.',
                context: $this->credentialContext($baseContext, 'federated_unsupported'),
            );
        }

        if ($kind === 'managed_identity') {
            if ($this->credentialKindSupported($kind)) {
                return ExchangePowerShellGateResult::allowed($this->credentialContext($baseContext, 'managed_identity_supported'));
            }

            return $this->blocked(
                reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
                failureCode: 'credential_blocked_managed_identity_unsupported',
                message: 'Managed identity credentials are not enabled for Exchange PowerShell production invocation.',
                context: $this->credentialContext($baseContext, 'managed_identity_unsupported'),
            );
        }

        return $this->blocked(
            reasonCode: ProviderReasonCodes::ProviderCredentialInvalid,
            failureCode: 'credential_blocked_unknown_kind',
            message: 'Provider credential kind is not supported for Exchange PowerShell production invocation.',
            context: $this->credentialContext($baseContext, 'unknown_kind'),
        );
    }

    private function credentialKind(ProviderCredential $credential): string
    {
        $kind = $credential->getRawOriginal('credential_kind');

        if (! is_string($kind) || trim($kind) === '') {
            $kind = $credential->getRawOriginal('type');
        }

        return is_string($kind) ? strtolower(trim($kind)) : '';
    }

    private function credentialKindSupported(string $kind): bool
    {
        $supportedKinds = config('tenantpilot.exchange_powershell.credentials.supported_reference_kinds', []);

        if (is_string($supportedKinds)) {
            $supportedKinds = explode(',', $supportedKinds);
        }

        if (! is_array($supportedKinds)) {
            return false;
        }

        $supportedKinds = array_map(
            static fn (mixed $supportedKind): string => strtolower(trim((string) $supportedKind)),
            $supportedKinds,
        );

        return in_array($kind, $supportedKinds, true);
    }

    private function safeCredentialKindLabel(string $kind): string
    {
        return match ($kind) {
            ProviderCredentialKind::ClientSecret->value => 'secret_based_app',
            ProviderCredentialKind::Certificate->value => 'certificate',
            ProviderCredentialKind::Federated->value => 'federated',
            'managed_identity' => 'managed_identity',
            default => 'unknown',
        };
    }

    /**
     * @param  array<string, mixed>  $baseContext
     * @return array<string, mixed>
     */
    private function credentialContext(array $baseContext, string $state): array
    {
        return array_replace($baseContext, ['credential_state' => $state]);
    }

    /**
     * @param  array<string, mixed>  $context
     */
    private function blocked(string $reasonCode, string $failureCode, string $message, array $context): ExchangePowerShellGateResult
    {
        return ExchangePowerShellGateResult::blocked(
            reasonCode: $reasonCode,
            failureCode: $failureCode,
            message: $message,
            context: $context,
        );
    }
}