<?php

declare(strict_types=1);

namespace App\Services\TenantConfiguration;

use App\Models\ManagedEnvironment;
use App\Models\OperationRun;
use App\Models\ProviderConnection;
use App\Models\TenantConfigurationResourceType;
use App\Models\User;
use App\Services\Auth\ManagedEnvironmentAccessScopeResolver;
use App\Services\OperationRunService;
use App\Services\Providers\ProviderIdentityResolver;
use App\Services\Providers\ProviderOperationRegistry;
use App\Services\Providers\ProviderOperationTrustedStarter;
use App\Support\Auth\Capabilities;
use App\Support\OperationRunOutcome;
use App\Support\OperationRunStatus;
use App\Support\OperationRunType;
use App\Support\Operations\ExecutionAuthorityMode;
use App\Support\Operations\OperationRunCapabilityResolver;
use App\Support\Providers\Capabilities\ProviderCapabilityRegistry;
use App\Support\Providers\ProviderReasonCodes;
use Illuminate\Auth\Access\AuthorizationException;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Throwable;

final class ExchangePowerShellInvocationGate
{
    public const string OPERATION_TYPE = OperationRunType::TenantConfigurationExchangePowerShellInvocation->value;

    public const string FEATURE_CONFIG_PATH = 'tenantpilot.features.exchange_powershell_invocation';

    public const string RUNNER_MODE_FAKE = 'fake';

    public const string RUNNER_MODE_DISABLED = 'disabled';

    public const string REDACTION_POLICY = 'strict_no_raw_output';

    public function __construct(
        private readonly ManagedEnvironmentAccessScopeResolver $accessScopeResolver,
        private readonly ProviderOperationTrustedStarter $providerOperationStarter,
        private readonly OperationRunService $operationRuns,
        private readonly ProviderIdentityResolver $identityResolver,
        private readonly ProviderOperationRegistry $providerOperationRegistry,
        private readonly ProviderCapabilityRegistry $providerCapabilityRegistry,
        private readonly OperationRunCapabilityResolver $capabilityResolver,
        private readonly ResourceTypeRegistry $resourceTypeRegistry,
        private readonly CoverageSourceContractResolver $sourceContractResolver,
        private readonly ExchangePowerShellCommandContracts $commandContracts,
        private readonly ExchangePowerShellCommandRunner $runner,
    ) {}

    /**
     * @param  array<string, mixed>  $parameters
     */
    public function invoke(
        ManagedEnvironment $tenant,
        ProviderConnection $providerConnection,
        User $actor,
        string $canonicalType,
        ?string $commandName = null,
        array $parameters = [],
        string $runnerMode = self::RUNNER_MODE_DISABLED,
    ): OperationRun {
        $this->authorize($tenant, $actor);
        $this->assertProviderConnectionInScope($tenant, $providerConnection);

        $canonicalType = trim($canonicalType);
        $runnerMode = $this->normalizeRunnerMode($runnerMode);
        $startedRun = null;

        $result = $this->providerOperationStarter->start(
            tenant: $tenant,
            connection: $providerConnection,
            operationType: self::OPERATION_TYPE,
            dispatcher: function (OperationRun $run) use (&$startedRun): void {
                $startedRun = $run;
            },
            initiator: $actor,
            extraContext: $this->initialContext($tenant, $providerConnection, $canonicalType, $commandName, $parameters, $runnerMode),
        );

        if ($startedRun instanceof OperationRun && $result->status === 'started' && $result->dispatched) {
            return $this->executeStartedRun(
                run: $startedRun,
                tenant: $tenant,
                providerConnection: $providerConnection,
                canonicalType: $canonicalType,
                commandName: $commandName,
                parameters: $parameters,
                runnerMode: $runnerMode,
            );
        }

        return $result->run->fresh() ?? $result->run;
    }

    private function authorize(ManagedEnvironment $tenant, User $actor): void
    {
        $decision = $this->accessScopeResolver->decision($actor, $tenant, Capabilities::PROVIDER_RUN);

        if ($decision->allowed()) {
            return;
        }

        if ($decision->shouldDenyAsNotFound()) {
            throw new NotFoundHttpException('Managed environment not found.');
        }

        throw (new AuthorizationException('This action is unauthorized.'))->withStatus(403);
    }

    private function assertProviderConnectionInScope(ManagedEnvironment $tenant, ProviderConnection $providerConnection): void
    {
        if ((int) $providerConnection->managed_environment_id !== (int) $tenant->getKey()
            || (int) $providerConnection->workspace_id !== (int) $tenant->workspace_id
        ) {
            throw new NotFoundHttpException('Provider connection not found.');
        }
    }

    /**
     * @param  array<string, mixed>  $parameters
     * @return array<string, mixed>
     */
    private function initialContext(
        ManagedEnvironment $tenant,
        ProviderConnection $providerConnection,
        string $canonicalType,
        ?string $commandName,
        array $parameters,
        string $runnerMode,
    ): array {
        $context = [
            'operation' => [
                'type' => self::OPERATION_TYPE,
            ],
            'source' => 'spec431_exchange_powershell_invocation_gate',
            'target_resource_type' => $this->safeTargetResourceType($canonicalType),
            'parameter_count' => count($parameters),
            'runner_mode' => $this->knownRunnerMode($runnerMode) ? $runnerMode : 'invalid',
            'redaction_policy' => self::REDACTION_POLICY,
            'required_capability' => Capabilities::PROVIDER_RUN,
            'execution_authority_mode' => ExecutionAuthorityMode::ActorBound->value,
            'feature_gate' => [
                'operation_type' => self::OPERATION_TYPE,
                'config_path' => self::FEATURE_CONFIG_PATH,
                'enabled' => (bool) config(self::FEATURE_CONFIG_PATH, false),
            ],
            'provider_identity_resolution_mode' => $runnerMode === self::RUNNER_MODE_FAKE
                ? 'fake_runner_bypass'
                : 'provider_identity_required',
            'target_scope' => [
                'workspace_id' => (int) $tenant->workspace_id,
                'managed_environment_id' => (int) $tenant->getKey(),
                'provider_connection_id' => (int) $providerConnection->getKey(),
            ],
        ];

        $safeCommandName = $this->safeCommandName($canonicalType, $commandName);

        if ($safeCommandName !== null) {
            $context['command_name'] = $safeCommandName;
        }

        return $context;
    }

    /**
     * @param  array<string, mixed>  $parameters
     */
    private function executeStartedRun(
        OperationRun $run,
        ManagedEnvironment $tenant,
        ProviderConnection $providerConnection,
        string $canonicalType,
        ?string $commandName,
        array $parameters,
        string $runnerMode,
    ): OperationRun {
        try {
            $registryFailure = $this->registryFailure();

            if ($registryFailure !== null) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'operation_registration_invalid',
                    message: $registryFailure,
                );
            }

            $contract = $this->commandContracts->contractForCanonicalType($canonicalType);

            if ($contract === null) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'source_contract_missing',
                    message: 'Exchange PowerShell source contract is not registered for this resource type.',
                    context: ['target_resource_type' => $this->safeTargetResourceType($canonicalType)],
                );
            }

            $sourceDecision = $this->sourceContractDecision($canonicalType);

            if (! $this->sourceContractAllowsInvocation($sourceDecision)) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'source_contract_not_verified',
                    message: 'Exchange PowerShell source contract is not verified for invocation.',
                    context: $this->sourceContractContext($sourceDecision),
                );
            }

            $run = $this->mergeContext($run, [
                'source_contract' => $this->sourceContractContext($sourceDecision),
            ]);

            $resolvedCommandName = $commandName === null
                ? (string) $contract['command_name']
                : trim($commandName);

            if ($resolvedCommandName !== (string) $contract['command_name']) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'command_contract_rejected',
                    message: 'Exchange PowerShell command is not allowed for the requested resource type.',
                    context: ['command_validation' => ['reason_code' => 'command_contract_mismatch']],
                );
            }

            $validation = $this->commandContracts->validateInvocation($contract, $parameters);

            if (! $validation['accepted']) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'command_contract_rejected',
                    message: 'Exchange PowerShell invocation contract rejected the request.',
                    context: ['command_validation' => $this->safeCommandValidationContext($validation)],
                );
            }

            if (! $this->knownRunnerMode($runnerMode)) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'execution_blocked_runner_mode_invalid',
                    message: 'Exchange PowerShell runner mode is not supported.',
                    context: ['runner_mode' => 'invalid'],
                );
            }

            if (! (bool) config(self::FEATURE_CONFIG_PATH, false)) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: ProviderReasonCodes::ProviderBindingUnsupported,
                    failureCode: 'execution_blocked_feature_disabled',
                    message: 'Exchange PowerShell invocation feature gate is disabled.',
                    context: [
                        'feature_gate' => [
                            'operation_type' => self::OPERATION_TYPE,
                            'config_path' => self::FEATURE_CONFIG_PATH,
                            'enabled' => false,
                        ],
                    ],
                );
            }

            $credentialSource = null;

            if ($runnerMode === self::RUNNER_MODE_FAKE) {
                $run = $this->mergeContext($run, [
                    'credential_policy' => [
                        'mode' => 'fake_runner_bypass',
                        'live_credentials_required' => false,
                    ],
                ]);
            } else {
                $identity = $this->identityResolver->resolve($providerConnection);

                if (! $identity->resolved) {
                    return $this->blockRun(
                        run: $run,
                        reasonCode: $identity->effectiveReasonCode(),
                        failureCode: 'execution_blocked_missing_credential_reference',
                        message: $identity->message ?? 'Provider identity could not be resolved.',
                        context: [
                            'credential_policy' => [
                                'mode' => 'provider_identity_required',
                                'credential_source' => $identity->credentialSource,
                            ],
                        ],
                    );
                }

                $credentialSource = $identity->credentialSource;
                $run = $this->mergeContext($run, [
                    'credential_policy' => [
                        'mode' => 'provider_identity_required',
                        'credential_source' => $credentialSource,
                    ],
                ]);
            }

            $run = $this->operationRuns->updateRun(
                run: $run,
                status: OperationRunStatus::Running->value,
                summaryCounts: $this->emptySummaryCounts(),
            );

            $invocationContext = new ExchangePowerShellInvocationContext(
                operationRunId: (int) $run->getKey(),
                workspaceId: (int) $tenant->workspace_id,
                managedEnvironmentId: (int) $tenant->getKey(),
                providerConnectionId: (int) $providerConnection->getKey(),
                canonicalType: $canonicalType,
                commandName: $resolvedCommandName,
                runnerMode: $runnerMode,
                redactionPolicy: self::REDACTION_POLICY,
                sourceContractState: CoverageSourceContractDecision::CONTRACT_VERIFIED_PENDING_CAPTURE,
                credentialSource: $credentialSource,
            );

            $verifiedContract = ExchangePowerShellCommandContract::fromVerifiedArray($contract, $this->commandContracts, $parameters);
            $result = $this->runner->run($verifiedContract, $invocationContext);

            return $this->finishRunWithResult($run, $verifiedContract, $result);
        } catch (Throwable $exception) {
            $run = $this->mergeContext($run, [
                'runner_exception' => [
                    'class' => class_basename($exception),
                    'raw_message_persisted' => false,
                ],
            ]);

            return $this->failRun(
                run: $run,
                reasonCode: ProviderReasonCodes::UnknownError,
                failureCode: 'execution_failed_unexpected_exception',
                message: 'Exchange PowerShell invocation failed safely before output promotion.',
            );
        }
    }

    private function registryFailure(): ?string
    {
        $definition = $this->providerOperationRegistry->get(self::OPERATION_TYPE);
        $providerCapabilityKeys = $definition['provider_capability_keys'] ?? [];

        if (($definition['required_capability'] ?? null) !== Capabilities::PROVIDER_RUN) {
            return 'Exchange PowerShell provider operation is not registered with provider-run capability.';
        }

        if ($this->capabilityResolver->requiredExecutionCapabilityForType(self::OPERATION_TYPE) !== Capabilities::PROVIDER_RUN) {
            return 'Exchange PowerShell operation run execution capability is not provider-run.';
        }

        if (! is_array($providerCapabilityKeys) || ! in_array('exchange_powershell_invoke', $providerCapabilityKeys, true)) {
            return 'Exchange PowerShell provider capability is not registered for the operation.';
        }

        foreach ($providerCapabilityKeys as $providerCapabilityKey) {
            $this->providerCapabilityRegistry->get((string) $providerCapabilityKey);
        }

        return null;
    }

    private function sourceContractDecision(string $canonicalType): ?CoverageSourceContractDecision
    {
        $resourceType = $this->resourceTypeRegistry->findActive($canonicalType);

        if (! $resourceType instanceof TenantConfigurationResourceType) {
            return null;
        }

        return $this->sourceContractResolver->resolve($resourceType);
    }

    private function sourceContractAllowsInvocation(?CoverageSourceContractDecision $decision): bool
    {
        if (! $decision instanceof CoverageSourceContractDecision) {
            return false;
        }

        $metadata = $decision->sourceMetadata;

        return ($decision->sourceContractState ?? data_get($metadata, 'source_contract_state')) === CoverageSourceContractDecision::CONTRACT_VERIFIED_PENDING_CAPTURE
            && data_get($metadata, 'provider_adapter_state') === 'adapter_contract_available'
            && data_get($metadata, 'provider_calls_allowed') === false
            && data_get($metadata, 'execution_enabled') === false;
    }

    /**
     * @return array<string, mixed>
     */
    private function sourceContractContext(?CoverageSourceContractDecision $decision): array
    {
        if (! $decision instanceof CoverageSourceContractDecision) {
            return [
                'source_contract_state' => 'missing',
            ];
        }

        return array_filter([
            'canonical_type' => $decision->canonicalType,
            'source_contract_key' => $decision->contractKey,
            'source_contract_state' => $decision->sourceContractState ?? data_get($decision->sourceMetadata, 'source_contract_state'),
            'provider_adapter_state' => data_get($decision->sourceMetadata, 'provider_adapter_state'),
            'provider_calls_allowed' => data_get($decision->sourceMetadata, 'provider_calls_allowed'),
            'execution_enabled' => data_get($decision->sourceMetadata, 'execution_enabled'),
            'fake_runner_testable' => data_get($decision->sourceMetadata, 'fake_runner_testable'),
            'source_version' => $decision->sourceVersion,
        ], static fn (mixed $value): bool => $value !== null && $value !== '');
    }

    private function finishRunWithResult(
        OperationRun $run,
        ExchangePowerShellCommandContract $contract,
        ExchangePowerShellInvocationResult $result,
    ): OperationRun {
        $safeRunnerResultContext = $this->safeRunnerResultContext($result);

        if ($safeRunnerResultContext !== []) {
            $run = $this->mergeContext($run, ['runner_result' => $safeRunnerResultContext]);
        }

        if (! $result->successful) {
            if ($result->blocked) {
                return $this->blockRun(
                    run: $run,
                    reasonCode: $result->reasonCode ?? ProviderReasonCodes::UnknownError,
                    failureCode: $result->failureCode ?? 'execution_blocked',
                    message: $result->message ?? 'Exchange PowerShell invocation was blocked.',
                );
            }

            return $this->failRun(
                run: $run,
                reasonCode: $result->reasonCode ?? ProviderReasonCodes::UnknownError,
                failureCode: $result->failureCode ?? 'execution_failed',
                message: $result->message ?? 'Exchange PowerShell invocation failed.',
                summaryCounts: $result->summaryCounts,
            );
        }

        if (! $this->collectionShapeIsSafe($result->collection, $contract->toArray())) {
            return $this->failRun(
                run: $run,
                reasonCode: ProviderReasonCodes::ProviderConnectionInvalid,
                failureCode: 'execution_failed_shape_unsafe',
                message: 'Exchange PowerShell runner returned an unsafe response shape.',
                context: ['response_shape' => ['safe' => false]],
            );
        }

        return $this->operationRuns->updateRun(
            run: $run,
            status: OperationRunStatus::Completed->value,
            outcome: OperationRunOutcome::Succeeded->value,
            summaryCounts: $this->summaryCountsForCollection($result->collection),
        );
    }

    /**
     * @param  array<string, mixed>  $contract
     */
    private function collectionShapeIsSafe(mixed $collection, array $contract): bool
    {
        if (! is_array($collection) || ! array_is_list($collection)) {
            return false;
        }

        foreach ($collection as $item) {
            if (! is_array($item) || ! $this->itemHasIdentityCandidate($item, $contract)) {
                return false;
            }
        }

        return true;
    }

    /**
     * @param  array<string, mixed>  $item
     * @param  array<string, mixed>  $contract
     */
    private function itemHasIdentityCandidate(array $item, array $contract): bool
    {
        $fields = [
            ...$this->stringList(data_get($contract, 'response_shape.required_identity_candidate_fields')),
            ...$this->stringList(data_get($contract, 'response_shape.derived_identity_candidate_fields')),
        ];

        foreach ($fields as $field) {
            if (! array_key_exists($field, $item)) {
                continue;
            }

            $value = $item[$field];

            if (is_scalar($value) && trim((string) $value) !== '') {
                return true;
            }
        }

        return false;
    }

    /**
     * @return list<string>
     */
    private function stringList(mixed $values): array
    {
        if (! is_array($values)) {
            return [];
        }

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

    /**
     * @param  array<string, mixed>  $context
     */
    private function blockRun(
        OperationRun $run,
        string $reasonCode,
        string $failureCode,
        string $message,
        array $context = [],
    ): OperationRun {
        $run = $this->mergeContext($run, [
            'failure_code' => $failureCode,
            ...$context,
        ]);

        return $this->operationRuns->finalizeBlockedRun(
            run: $run,
            reasonCode: $reasonCode,
            message: $message,
        );
    }

    /**
     * @param  array<string, mixed>  $summaryCounts
     * @param  array<string, mixed>  $context
     */
    private function failRun(
        OperationRun $run,
        string $reasonCode,
        string $failureCode,
        string $message,
        array $summaryCounts = [],
        array $context = [],
    ): OperationRun {
        $run = $this->mergeContext($run, [
            'failure_code' => $failureCode,
            ...$context,
        ]);

        return $this->operationRuns->updateRun(
            run: $run,
            status: OperationRunStatus::Completed->value,
            outcome: OperationRunOutcome::Failed->value,
            summaryCounts: $summaryCounts !== [] ? $summaryCounts : $this->failureSummaryCounts(),
            failures: [
                [
                    'code' => $failureCode,
                    'reason_code' => $reasonCode,
                    'message' => $message,
                ],
            ],
        );
    }

    /**
     * @param  array<string, mixed>  $context
     */
    private function mergeContext(OperationRun $run, array $context): OperationRun
    {
        if ($context === []) {
            return $run;
        }

        $existing = is_array($run->context) ? $run->context : [];
        $run->forceFill([
            'context' => array_replace_recursive($existing, $context),
        ])->save();
        $run->refresh();

        return $run;
    }

    /**
     * @return array<string, int>
     */
    private function emptySummaryCounts(): array
    {
        return [
            'total' => 0,
            'processed' => 0,
            'succeeded' => 0,
            'failed' => 0,
            'skipped' => 0,
            'items' => 0,
        ];
    }

    /**
     * @param  list<array<string, mixed>>  $collection
     * @return array<string, int>
     */
    private function summaryCountsForCollection(array $collection): array
    {
        $count = count($collection);

        return [
            'total' => $count,
            'processed' => $count,
            'succeeded' => $count,
            'failed' => 0,
            'skipped' => 0,
            'items' => $count,
        ];
    }

    /**
     * @return array<string, int>
     */
    private function failureSummaryCounts(): array
    {
        return [
            'total' => 1,
            'processed' => 1,
            'succeeded' => 0,
            'failed' => 1,
            'skipped' => 0,
            'items' => 0,
        ];
    }

    private function normalizeRunnerMode(string $runnerMode): string
    {
        $runnerMode = trim($runnerMode);

        return $runnerMode !== '' ? $runnerMode : self::RUNNER_MODE_DISABLED;
    }

    private function knownRunnerMode(string $runnerMode): bool
    {
        return in_array($runnerMode, [self::RUNNER_MODE_FAKE, self::RUNNER_MODE_DISABLED], true);
    }

    private function safeCommandName(string $canonicalType, ?string $commandName): ?string
    {
        $contract = $this->commandContracts->contractForCanonicalType($canonicalType);

        if (! is_array($contract)) {
            return null;
        }

        if ($commandName === null) {
            return (string) $contract['command_name'];
        }

        $commandName = trim($commandName);
        $validation = $this->commandContracts->validateCommandName($commandName);

        return $validation['accepted'] ? $commandName : null;
    }

    private function safeTargetResourceType(string $canonicalType): string
    {
        $canonicalType = trim($canonicalType);

        if (preg_match('/(secret|token|password|credential)/i', $canonicalType) === 1) {
            return 'invalid';
        }

        if (preg_match('/\A[A-Za-z][A-Za-z0-9_.-]{0,79}\z/', $canonicalType) === 1) {
            return $canonicalType;
        }

        return 'invalid';
    }

    /**
     * @param  array<string, mixed>  $validation
     * @return array<string, mixed>
     */
    private function safeCommandValidationContext(array $validation): array
    {
        return array_filter([
            'accepted' => (bool) ($validation['accepted'] ?? false),
            'reason_code' => is_string($validation['reason_code'] ?? null) ? $validation['reason_code'] : null,
            'rejected_parameter_present' => (bool) ($validation['rejected_parameter_present'] ?? false) ?: null,
        ], static fn (mixed $value): bool => $value !== null && $value !== '');
    }

    /**
     * @return array<string, mixed>
     */
    private function safeRunnerResultContext(ExchangePowerShellInvocationResult $result): array
    {
        $context = [];

        foreach (['runner_mode', 'execution_enabled', 'failure_mode', 'retryable'] as $key) {
            $value = $result->context[$key] ?? null;

            if (is_scalar($value) || $value === null) {
                $context[$key] = $value;
            }
        }

        return array_filter([
            'blocked' => $result->blocked,
            'reason_code' => $result->reasonCode,
            'failure_code' => $result->failureCode,
            'message_persisted' => $result->message !== null,
            ...$context,
        ], static fn (mixed $value): bool => $value !== null && $value !== '');
    }
}