import { randomUUID } from "node:crypto";
import { promises as fs } from "node:fs";
import path from "node:path";
import type { ImportJob } from "@/lib/furni/import-job";
export const importRoot = () =>
	path.join(process.cwd(), "storage", "furniture-imports");
export const validJobId = (value: unknown): value is string =>
	typeof value === "string" &&
	/^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i.test(
		value,
	);
export class ImportJobStore {
	constructor(readonly root = importRoot()) {}
	async save(job: ImportJob) {
		await fs.mkdir(this.root, { recursive: true });
		const target = path.join(this.root, `${job.id}.json`),
			tmp = `${target}.${randomUUID()}.tmp`;
		job.updatedAt = new Date().toISOString();
		await fs.writeFile(tmp, JSON.stringify(job));
		await fs.rename(tmp, target);
	}
	async create(job: ImportJob) {
		if (!validJobId(job.id)) throw Error("Invalid import ID");
		await fs.mkdir(this.root, { recursive: true });
		const tmp = path.join(this.root, `${randomUUID()}.tmp`);
		await fs.writeFile(tmp, JSON.stringify(job));
		try {
			await fs.link(tmp, path.join(this.root, `${job.id}.json`));
			return job;
		} catch (error) {
			if ((error as NodeJS.ErrnoException).code !== "EEXIST") throw error;
			const existing = await this.read(job.id);
			if (existing.userId !== job.userId)
				throw Error("Request ID already used");
			return existing;
		} finally {
			await fs.unlink(tmp);
		}
	}
	async read(id: string): Promise<ImportJob> {
		if (!validJobId(id)) throw Error("Invalid import ID");
		return JSON.parse(
			await fs.readFile(path.join(this.root, `${id}.json`), "utf8"),
		);
	}
	async list(): Promise<ImportJob[]> {
		const files = await fs.readdir(this.root).catch((error) => {
			if (error.code === "ENOENT") return [];
			throw error;
		});
		const jobs = await Promise.all(
			files
				.filter((f) => f.endsWith(".json") && validJobId(f.slice(0, -5)))
				.map((f) => this.read(f.slice(0, -5))),
		);
		return jobs.sort((a, b) => a.createdAt.localeCompare(b.createdAt));
	}
}