<?php

declare(strict_types=1);

namespace UseCases\Pipeline;

use Infrastructure\Persistence\PipelineRepository;

/**
 * PipelineRunStatusUseCase - Get detailed pipeline run status.
 *
 * Calculates progress, elapsed time, ETA, and detects stalled runs.
 */
class PipelineRunStatusUseCase
{
    private PipelineRepository $repository;

    public function __construct(?PipelineRepository $repository = null)
    {
        $this->repository = $repository ?? new PipelineRepository();
    }

    /**
     * Get detailed run status with progress calculations.
     *
     * @param int $pipelineId Pipeline ID
     * @param int $runId Run ID
     * @return array{success: bool, error?: string, data?: array}
     */
    public function execute(int $pipelineId, int $runId): array
    {
        $run = $this->repository->findRunById($runId);

        if ($run === null || (int) $run['pipeline_id'] !== $pipelineId) {
            return ['success' => false, 'error' => 'Run nicht gefunden'];
        }

        return [
            'success' => true,
            'data' => $this->buildStatusData($run),
        ];
    }

    /**
     * Build comprehensive status data from run record.
     */
    private function buildStatusData(array $run): array
    {
        $startedAt = strtotime($run['started_at'] ?? 'now');
        $elapsed = time() - $startedAt;

        $total = (int) ($run['documents_total'] ?? 0);
        $processed = (int) ($run['documents_processed'] ?? 0);
        $progress = $total > 0 ? min(100, round(($processed / $total) * 100)) : 0;

        // Cap processed display to not exceed total
        $processedDisplay = min($processed, $total);

        $estimatedRemaining = $this->calculateEta($elapsed, $processed, $total);

        $lastUpdate = strtotime($run['last_update_at'] ?? $run['started_at'] ?? 'now');
        $isStalled = (time() - $lastUpdate) > 60 && $run['status'] === 'running';

        $isTerminal = in_array($run['status'], ['completed', 'failed', 'cancelled'], true);

        return [
            'status' => $run['status'],
            'current_step' => $run['current_step'],
            'current_document' => $run['current_document'],
            'documents_total' => $total,
            'documents_processed' => $processed,
            'documents_failed' => (int) ($run['documents_failed'] ?? 0),
            'chunks_created' => (int) ($run['chunks_created'] ?? 0),
            'embeddings_created' => (int) ($run['embeddings_created'] ?? 0),
            'progress' => $progress,
            'elapsed' => $elapsed,
            'elapsed_formatted' => gmdate('i:s', $elapsed),
            'estimated_remaining' => $estimatedRemaining,
            'estimated_formatted' => $estimatedRemaining !== null ? gmdate('i:s', $estimatedRemaining) : null,
            'log_tail' => $run['log_tail'] ?? '',
            'is_stalled' => $isStalled,
            'is_terminal' => $isTerminal,
            'completed_at' => $run['completed_at'],
            'error_log' => $run['error_log'],
        ];
    }

    /**
     * Calculate estimated time remaining.
     */
    private function calculateEta(int $elapsed, int $processed, int $total): ?int
    {
        if ($processed <= 0 || $total <= $processed) {
            return null;
        }

        $avgTimePerDoc = $elapsed / $processed;
        $remaining = $total - $processed;

        return (int) ($avgTimePerDoc * $remaining);
    }
}