// Covers addendum A2 part 2: Koh's own remote layout, served read-only from a public repo's mirror.
import { describe, expect, test } from "bun:test";
import { join } from "node:path";
import { inflateSync } from "node:zlib";
import { blake3 } from "@noble/hashes/blake3.js";
import { bytesToHex } from "@noble/hashes/utils.js";
import { openBucket } from "../src/bucket/reader.ts";
import { syncAll } from "../src/bucket/sync.ts";
import { instance } from "./browser.ts";
import { makeKohBucket } from "./fixture.ts";

const REPO = "mirror";
const NOT_FOUND = '{"error":"repo_not_found","message":"repo not found"}';
const fixture = await makeKohBucket(REPO);
const inst = await instance(fixture.bucketDir);
inst.kepr.run("UPDATE repos SET public = 1");

const head = fixture.saveIds[0] ?? "";
const checkpoint = fixture.saveIds[1] ?? "";
const oldest = fixture.saveIds[fixture.saveIds.length - 1] ?? "";
const get = (path: string) => inst.app.request(`/${REPO}/koh/${path}`);
const record = async (id: string) => JSON.parse(await (await get(`saves/${id}`)).text());

async function resync() {
	await syncAll({
		bucket: openBucket(inst.config.bucket),
		kepr: inst.kepr,
		mirrorDir: join(inst.dataDir, "mirror"),
	});
}

describe.serial("Koh's remote layout from the mirror", () => {
	test("the format, the head and the caches the addendum names", async () => {
		const format = await get("format");
		expect(format.status).toBe(200);
		expect(await format.text()).toBe("koh-remote 1");
		expect(format.headers.get("cache-control")).toBe("private, max-age=86400");
		const headResponse = await get("head");
		expect(headResponse.status).toBe(200);
		expect(await headResponse.text()).toBe(head);
		expect(headResponse.headers.get("cache-control")).toBe("no-cache");
	});

	test("a save record is Koh's, field for field, and checkpoints are part of the chain", async () => {
		const response = await get(`saves/${head}`);
		expect(response.status).toBe(200);
		expect(response.headers.get("cache-control")).toBe("private, max-age=60");
		const save = await record(head);
		expect(Object.keys(save)).toEqual([
			"id",
			"parent",
			"message",
			"created_at",
			"machine",
			"is_checkpoint",
			"size_bytes",
			"agent",
			"session",
			"restores",
			"replayed_from",
			"files",
		]);
		expect(save.id).toBe(head);
		expect(save.parent).toBe(checkpoint);
		// The mirror only keeps columns, so this is the proof that what it re-serves is what Koh
		// wrote, byte shape and all: empty optionals as "", booleans as booleans, no extra member.
		const written = await Bun.file(join(fixture.bucketDir, REPO, "saves", head)).json();
		expect(save).toEqual(written);
		expect(typeof save.size_bytes).toBe("number");
		expect(typeof save.is_checkpoint).toBe("boolean");
		expect(save.agent).toBe("");
		expect(Object.keys(save.files[0])).toEqual(["path", "hash", "executable"]);
		// The chain needs checkpoints, so these routes serve what the pages hide.
		const chain = await get(`saves/${checkpoint}`);
		expect(chain.status).toBe(200);
		expect((await record(checkpoint)).is_checkpoint).toBe(true);
		expect((await inst.app.request(`/${REPO}/saves/${checkpoint}`)).status).toBe(404);
	});

	test("the save and object prefixes list what a steal walks", async () => {
		const saves = await get("saves");
		expect(saves.status).toBe(200);
		expect(saves.headers.get("cache-control")).toBe("no-cache");
		expect((await saves.text()).trim().split("\n")).toContain(head);
		const save = await record(head);
		const objects = await get("objects");
		expect(objects.status).toBe(200);
		expect(objects.headers.get("cache-control")).toBe("no-cache");
		expect((await objects.text()).trim().split("\n")).toContain(save.files[0].hash);
	});

	test("an object is the stored zlib bytes and hashes back to its key", async () => {
		const save = await record(head);
		const file = save.files.find((entry: { path: string }) => entry.path === "src/main.ts");
		const object = await get(`objects/${file.hash}`);
		expect(object.status).toBe(200);
		expect(object.headers.get("cache-control")).toBe("private, max-age=31536000");
		expect(object.headers.get("cache-control")).not.toContain("immutable");
		const bytes = new Uint8Array(await object.arrayBuffer());
		expect(bytesToHex(blake3(inflateSync(bytes)))).toBe(file.hash);
		expect(new TextDecoder().decode(inflateSync(bytes))).toContain("hello");
	});

	test("the events are IDs, one per line, and one event is Koh's record", async () => {
		const events = await get("events");
		expect(events.status).toBe(200);
		expect(events.headers.get("cache-control")).toBe("no-cache");
		const ids = (await events.text()).trim().split("\n");
		expect(ids.length).toBeGreaterThan(0);
		const one = await get(`events/${ids[0]}`);
		expect(one.status).toBe(200);
		expect(one.headers.get("cache-control")).toBe("private, max-age=86400");
		const event = JSON.parse(await one.text());
		expect(Object.keys(event)).toEqual([
			"id",
			"kind",
			"save_id",
			"path",
			"reason",
			"created_at",
			"machine",
		]);
		const written = await Bun.file(join(fixture.bucketDir, REPO, "events", ids[0] ?? "")).json();
		expect(event).toEqual(written);
	});

	test("a private repo answers exactly as an unknown one", async () => {
		inst.kepr.run("UPDATE repos SET public = 0");
		try {
			for (const path of [
				"format",
				"head",
				"events",
				"saves",
				"objects",
				`saves/${head}`,
				`objects/${"a".repeat(64)}`,
				`events/${"b".repeat(12)}`,
			]) {
				const private_ = await get(path);
				const unknown = await inst.app.request(`/no-such-repo/koh/${path}`);
				const mine = `${private_.status} ${await private_.text()}`;
				expect(mine).toBe(`${unknown.status} ${await unknown.text()}`);
				expect(mine).toBe(`404 ${NOT_FOUND}`);
				expect(private_.headers.get("content-type")).toBe(unknown.headers.get("content-type"));
				expect(private_.headers.get("cache-control")).toBe(unknown.headers.get("cache-control"));
			}
		} finally {
			inst.kepr.run("UPDATE repos SET public = 1");
		}
	});

	test("an ID or hash the mirror does not hold answers the same 404", async () => {
		for (const path of [
			`saves/${"0".repeat(12)}`,
			"saves/not-an-id",
			`objects/${"f".repeat(64)}`,
		]) {
			const response = await get(path);
			expect(`${response.status} ${await response.text()}`).toBe(`404 ${NOT_FOUND}`);
		}
	});

	test("a stripped path leaves the record and the object the mirror serves", async () => {
		const before = await record(oldest);
		const secret = before.files.find((entry: { path: string }) => entry.path === "secret.txt");
		expect(secret).toBeDefined();
		await fixture.strip("secret.txt");
		await resync();
		const after = await record(oldest);
		expect(after.files.some((entry: { path: string }) => entry.path === "secret.txt")).toBe(false);
		expect((await get(`objects/${secret.hash}`)).status).toBe(404);
		const events = await (await get("events")).text();
		const strip = events
			.trim()
			.split("\n")
			.filter((id) => id.length > 0);
		expect(strip.length).toBeGreaterThan(0);
	});
});