<?php

declare(strict_types=1);

namespace App\Services;

use App\Models\OperationRun;
use App\Support\OperationCatalog;
use App\Support\OperationRunStatus;
use App\Support\Operations\Reconciliation\OperationRunReconciliationAdapter;
use App\Support\Operations\Reconciliation\OperationRunReconciliationRegistry;
use App\Support\Operations\Reconciliation\ReconciliationResult;
use Carbon\CarbonImmutable;
use Illuminate\Database\Eloquent\Builder;
use Throwable;

final class AdapterRunReconciler
{
    public function __construct(
        private readonly OperationRunReconciliationRegistry $registry,
        private readonly OperationRunService $operationRuns,
    ) {}

    /**
     * @return array<int, string>
     */
    public function supportedTypes(): array
    {
        return $this->registry->supportedTypes();
    }

    /**
     * @param  array{type?: string|null, managed_environment_id?: int|null, older_than_minutes?: int, limit?: int, dry_run?: bool}  $options
     * @return array{candidates:int,reconciled:int,skipped:int,changes:array<int,array<string,mixed>>}
     */
    public function reconcile(array $options = []): array
    {
        $type = $this->normalizeRequestedType($options['type'] ?? null);
        $tenantId = $options['managed_environment_id'] ?? null;
        $olderThanMinutes = max(1, (int) ($options['older_than_minutes'] ?? 10));
        $limit = max(1, (int) ($options['limit'] ?? 50));
        $dryRun = (bool) ($options['dry_run'] ?? true);

        $cutoff = CarbonImmutable::now()->subMinutes($olderThanMinutes);
        $candidateTypes = $this->candidateRawTypes($type);

        $query = OperationRun::query()
            ->whereIn('type', $candidateTypes)
            ->whereIn('status', [OperationRunStatus::Queued->value, OperationRunStatus::Running->value])
            ->where(function (Builder $q) use ($cutoff): void {
                $q
                    ->where(function (Builder $q2) use ($cutoff): void {
                        $q2->whereNull('started_at')->where('created_at', '<', $cutoff);
                    })
                    ->orWhere(function (Builder $q2) use ($cutoff): void {
                        $q2->whereNotNull('started_at')->where('started_at', '<', $cutoff);
                    });
            })
            ->orderBy('id')
            ->limit($limit);

        if (is_int($tenantId) && $tenantId > 0) {
            $query->where('managed_environment_id', $tenantId);
        }

        $candidates = $query->get();

        $changes = [];
        $reconciled = 0;
        $skipped = 0;

        foreach ($candidates as $run) {
            $change = $this->reconcileOperationRun($run, $dryRun);

            if ($change === null) {
                $skipped++;

                continue;
            }

            $changes[] = $change;

            if (($change['applied'] ?? false) === true) {
                $reconciled++;
            }
        }

        return [
            'candidates' => $candidates->count(),
            'reconciled' => $reconciled,
            'skipped' => $skipped,
            'changes' => $changes,
        ];
    }

    /**
     * @return array<string, mixed>|null
     */
    public function reconcileOperationRun(OperationRun $run, bool $dryRun = false): ?array
    {
        $adapter = $this->resolveAdapter($run);

        return $this->reconcileUsingAdapter(
            run: $run,
            result: $adapter?->reconcile($run),
            adapter: $adapter,
            dryRun: $dryRun,
        );
    }

    /**
     * @return array<string, mixed>|null
     */
    public function reconcileOperationRunFailure(OperationRun $run, Throwable $throwable, bool $dryRun = false): ?array
    {
        $adapter = $this->resolveAdapter($run);

        return $this->reconcileUsingAdapter(
            run: $run,
            result: $adapter?->reconcileException($run, $throwable),
            adapter: $adapter,
            dryRun: $dryRun,
        );
    }

    /**
     * @return array<string, mixed>|null
     */
    private function reconcileUsingAdapter(
        OperationRun $run,
        ?ReconciliationResult $result,
        ?OperationRunReconciliationAdapter $adapter,
        bool $dryRun,
    ): ?array {
        if (! $adapter instanceof OperationRunReconciliationAdapter || ! $result instanceof ReconciliationResult) {
            return null;
        }

        $before = [
            'status' => (string) $run->status,
            'outcome' => (string) $run->outcome,
        ];

        $after = $result->shouldFinalizeRun()
            ? [
                'status' => (string) $result->status,
                'outcome' => (string) $result->outcome,
            ]
            : null;

        if ($dryRun) {
            return array_merge([
                'applied' => false,
                'operation_run_id' => (int) $run->getKey(),
                'type' => (string) $run->type,
                'adapter' => $adapter->key(),
                'before' => $before,
            ], $result->toArray(), $after !== null ? ['after' => $after] : []);
        }

        if (! $result->shouldFinalizeRun()) {
            return null;
        }

        $this->operationRuns->applyReconciliationResult(
            run: $run,
            result: $result,
            source: 'adapter_reconciler',
            adapter: $adapter->key(),
        );

        $run->refresh();
        $this->syncRestoreLifecycleTimestamps($run, $result);

        return array_merge([
            'applied' => true,
            'operation_run_id' => (int) $run->getKey(),
            'type' => (string) $run->type,
            'adapter' => $adapter->key(),
            'before' => $before,
            'after' => $after ?? [],
        ], $result->toArray());
    }

    private function resolveAdapter(OperationRun $run): ?OperationRunReconciliationAdapter
    {
        return $this->registry->forType($run->canonicalOperationType());
    }

    /**
     * @return array<int, string>
     */
    private function candidateRawTypes(?string $type = null): array
    {
        $canonicalTypes = $type !== null ? [$type] : $this->supportedTypes();

        return array_values(array_unique(array_merge(
            ...array_map(
                static fn (string $canonicalType): array => OperationCatalog::rawValuesForCanonical($canonicalType),
                $canonicalTypes,
            ),
        )));
    }

    private function normalizeRequestedType(mixed $type): ?string
    {
        if (! is_string($type) || trim($type) === '') {
            return null;
        }

        $canonicalType = OperationCatalog::canonicalCode($type);

        if (! in_array($canonicalType, $this->supportedTypes(), true)) {
            throw new \InvalidArgumentException('Unsupported adapter run type: '.$type);
        }

        return $canonicalType;
    }

    private function syncRestoreLifecycleTimestamps(OperationRun $run, ReconciliationResult $result): void
    {
        if (! array_key_exists('restore_run_id', $result->evidence)) {
            return;
        }

        if ($run->started_at === null && is_string($result->evidence['restore_started_at'] ?? null)) {
            $run->started_at = $result->evidence['restore_started_at'];
        }

        if ($run->completed_at === null && is_string($result->evidence['restore_completed_at'] ?? null)) {
            $run->completed_at = $result->evidence['restore_completed_at'];
        }

        $run->save();
    }
}