import { workerData, parentPort } from 'node:worker_threads';
import Database from 'better-sqlite3';
import { EmbeddingService } from '$lib/server/embeddings/embedding.service.js';
import { createProviderFromProfile } from '$lib/server/embeddings/registry.js';
import { EmbeddingProfileMapper } from '$lib/server/mappers/embedding-profile.mapper.js';
import { EmbeddingProfileEntity, type EmbeddingProfileEntityProps } from '$lib/server/models/embedding-profile.js';
import type { EmbedWorkerRequest, EmbedWorkerResponse, WorkerInitData } from './worker-types.js';

const { dbPath, embeddingProfileId } = workerData as WorkerInitData;

if (!embeddingProfileId) {
	parentPort!.postMessage({
		type: 'embed-failed',
		jobId: 'init',
		error: 'embeddingProfileId is required in workerData'
	} satisfies EmbedWorkerResponse);
	process.exit(1);
}

const db = new Database(dbPath);
db.pragma('journal_mode = WAL');
db.pragma('foreign_keys = ON');
db.pragma('busy_timeout = 5000');
db.pragma('synchronous = NORMAL');
db.pragma('cache_size = -65536');
db.pragma('temp_store = MEMORY');
db.pragma('mmap_size = 268435456');
db.pragma('wal_autocheckpoint = 1000');

// Load the embedding profile from DB
const rawProfile = db.prepare('SELECT * FROM embedding_profiles WHERE id = ?').get(embeddingProfileId);

if (!rawProfile) {
	db.close();
	parentPort!.postMessage({
		type: 'embed-failed',
		jobId: 'init',
		error: `Embedding profile ${embeddingProfileId} not found`
	} satisfies EmbedWorkerResponse);
	process.exit(1);
}

const profileEntity = new EmbeddingProfileEntity(rawProfile as EmbeddingProfileEntityProps);
const profile = EmbeddingProfileMapper.fromEntity(profileEntity);

// Create provider and embedding service
const provider = createProviderFromProfile(profile);
const embeddingService = new EmbeddingService(db, provider, embeddingProfileId);

// Signal ready after service initialization
parentPort!.postMessage({
	type: 'ready'
} satisfies EmbedWorkerResponse);

parentPort!.on('message', async (msg: EmbedWorkerRequest) => {
	if (msg.type === 'shutdown') {
		db.close();
		process.exit(0);
	}

	if (msg.type === 'embed') {
		try {
			const snippetIds = embeddingService.findSnippetIdsMissingEmbeddings(
				msg.repositoryId,
				msg.versionId
			);

			await embeddingService.embedSnippets(snippetIds, (done: number, total: number) => {
				parentPort!.postMessage({
					type: 'embed-progress',
					jobId: msg.jobId,
					done,
					total
				} satisfies EmbedWorkerResponse);
			});

			parentPort!.postMessage({
				type: 'embed-done',
				jobId: msg.jobId
			} satisfies EmbedWorkerResponse);
		} catch (err) {
			parentPort!.postMessage({
				type: 'embed-failed',
				jobId: msg.jobId,
				error: err instanceof Error ? err.message : String(err)
			} satisfies EmbedWorkerResponse);
		}
	}
});

process.on('uncaughtException', (err) => {
	parentPort!.postMessage({
		type: 'embed-failed',
		jobId: 'uncaught',
		error: err instanceof Error ? err.message : String(err)
	} satisfies EmbedWorkerResponse);
	process.exit(1);
});