<?php

namespace App\Jobs;

use App\Models\DocumentChunk;
use App\Models\ProcessingLog;
use App\Services\Ollama\OllamaService;
use App\Services\Qdrant\QdrantService;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Queue\Queueable;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;
use RuntimeException;

/**
 * ReindexChunkJob
 *
 * Reindex satu chunk sahaja:
 *   1. Embed semula getEmbeddableText() (final_text > cleaned_text > content)
 *   2. Upsert point ke Qdrant (guna semula qdrant_point_id lama jika ada)
 *   3. Kemaskini chunk: markAsEmbedded(), needs_reindex=false
 *
 * Berbeza dari ReindexDocumentJob yang reindex SELURUH dokumen.
 * Job ini digunakan untuk:
 *   - Edit final_text oleh admin
 *   - Include semula chunk yang excluded
 *   - Manual trigger reindex
 *   - Child chunks hasil split (perlu embed buat pertama kali)
 */
class ReindexChunkJob implements ShouldQueue
{
    use Queueable;

    public int $tries   = 3;
    public int $backoff = 30;   // Tunggu 30s sebelum retry
    public int $timeout = 120;  // 2 minit maksimum per chunk

    public function __construct(
        public readonly int $chunkId,
    ) {
        $this->onQueue(config('knowledgebase.queue.ingestion', 'default'));
    }

    public function handle(OllamaService $ollama, QdrantService $qdrant): void
    {
        // Load chunk dengan semua relasi yang diperlukan untuk toQdrantPayload()
        $chunk = DocumentChunk::with(['document.category', 'documentVersion'])
            ->find($this->chunkId);

        if (! $chunk) {
            Log::warning("ReindexChunkJob: Chunk #{$this->chunkId} tidak dijumpai. Job dilangkau.");
            return;
        }

        // ── Guard: Jangan reindex chunk yang tidak sepatutnya ──────────────

        if ($chunk->isSuperseded()) {
            Log::info("ReindexChunkJob: Chunk #{$this->chunkId} adalah superseded. Job dilangkau.", [
                'chunk_index' => $chunk->chunk_index,
            ]);
            return;
        }

        if ($chunk->exclude_from_index) {
            Log::info("ReindexChunkJob: Chunk #{$this->chunkId} dikecualikan dari index. Job dilangkau.", [
                'chunk_index'  => $chunk->chunk_index,
                'chunk_status' => $chunk->chunk_status,
            ]);
            return;
        }

        // ── Ambil teks untuk embedding ─────────────────────────────────────

        $textToEmbed = $chunk->getEmbeddableText();

        if (empty(trim($textToEmbed))) {
            $chunk->update(['chunk_status' => DocumentChunk::STATUS_FAILED_EMBEDDING]);

            Log::error("ReindexChunkJob: Chunk #{$this->chunkId} mempunyai teks kosong.", [
                'has_final_text'   => ! is_null($chunk->final_text),
                'has_cleaned_text' => ! is_null($chunk->cleaned_text),
                'content_length'   => mb_strlen($chunk->content),
            ]);
            return;
        }

        // ── Log: mula proses ───────────────────────────────────────────────

        ProcessingLog::record(
            DocumentChunk::class,
            $chunk->id,
            ProcessingLog::STAGE_EMBED,
            ProcessingLog::STATUS_STARTED,
            null,
            [
                'chunk_index'  => $chunk->chunk_index,
                'text_source'  => $chunk->final_text ? 'final_text'
                    : ($chunk->cleaned_text ? 'cleaned_text' : 'content'),
                'text_length'  => mb_strlen($textToEmbed),
                'is_reindex'   => true,
            ]
        );

        try {
            // ── Embed teks ─────────────────────────────────────────────────
            $vector = $ollama->embed($textToEmbed);

            // ── Tentukan point ID ──────────────────────────────────────────
            // Guna semula qdrant_point_id lama jika ada → upsert akan overwrite
            // Ini mengelakkan "ghost points" yang tidak dirujuk oleh mana-mana chunk
            $pointId = $chunk->qdrant_point_id ?? (string) Str::uuid();

            // ── Upsert ke Qdrant ───────────────────────────────────────────
            $qdrant->ensureCollectionExists();
            $qdrant->upsertPoint($pointId, $vector, $chunk->toQdrantPayload());

            // ── Kemaskini chunk ────────────────────────────────────────────
            $chunk->markAsEmbedded($pointId);

            ProcessingLog::record(
                DocumentChunk::class,
                $chunk->id,
                ProcessingLog::STAGE_QDRANT,
                ProcessingLog::STATUS_COMPLETED,
                null,
                [
                    'point_id'   => $pointId,
                    'is_reindex' => true,
                ]
            );

            Log::info("ReindexChunkJob: Chunk #{$this->chunkId} berjaya direindex.", [
                'chunk_index' => $chunk->chunk_index,
                'point_id'    => $pointId,
            ]);

        } catch (RuntimeException $e) {
            // Tandakan failed — job akan cuba semula (mengikut $tries)
            $chunk->update(['chunk_status' => DocumentChunk::STATUS_FAILED_EMBEDDING]);

            ProcessingLog::record(
                DocumentChunk::class,
                $chunk->id,
                ProcessingLog::STAGE_EMBED,
                ProcessingLog::STATUS_FAILED,
                $e->getMessage(),
                ['attempt' => $this->attempts()]
            );

            Log::error("ReindexChunkJob: Gagal reindex chunk #{$this->chunkId}.", [
                'error'   => $e->getMessage(),
                'attempt' => $this->attempts(),
            ]);

            throw $e; // Allow retry
        }
    }

    /**
     * Dipanggil selepas semua retry habis.
     */
    public function failed(\Throwable $e): void
    {
        DocumentChunk::where('id', $this->chunkId)
            ->update(['chunk_status' => DocumentChunk::STATUS_FAILED_EMBEDDING]);

        Log::error("ReindexChunkJob: Chunk #{$this->chunkId} gagal selepas semua cubaan semula.", [
            'error' => $e->getMessage(),
        ]);
    }
}