import { Database } from "bun:sqlite";
import { beforeAll, describe, expect, test } from "bun:test";
import { cp, mkdir, mkdtemp, readFile, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { deflateSync } from "node:zlib";
import { openBucket } from "../src/bucket/reader.ts";
import { syncAll } from "../src/bucket/sync.ts";
import {
	fileAt,
	filesAt,
	flagReason,
	headId,
	history,
	objectBytes,
	repoStats,
	saveByPrefix,
	timeline,
} from "../src/mirror/queries.ts";
import { mirrorState, openMirror } from "../src/mirror/store.ts";
import { openKeprDb } from "../src/server/db.ts";
import { Browser, instance } from "./browser.ts";
import { type Fixture, makeKohBucket } from "./fixture.ts";

const text = (bytes: Uint8Array | null) => new TextDecoder().decode(bytes ?? new Uint8Array());

async function syncTarget(fx: Fixture) {
	const dataDir = await mkdtemp(join(tmpdir(), "kepr-data-"));
	const target = {
		bucket: openBucket({ kind: "folder", path: fx.bucketDir }),
		kepr: openKeprDb(dataDir),
		mirrorDir: join(dataDir, "mirror"),
		tarballDir: join(dataDir, "tarballs"),
	};
	return { ...target, mirror: () => openMirror(target.mirrorDir, fx.repo) };
}

describe("a first sync of a koh3 bucket", () => {
	let fx: Fixture;
	let t: Awaited<ReturnType<typeof syncTarget>>;
	beforeAll(async () => {
		fx = await makeKohBucket();
		t = await syncTarget(fx);
		await syncAll(t);
	});
	const [head, checkpoint, second, first] = [0, 1, 2, 3].map((i) => () => fx.saveIds[i] as string);

	test("registers the repo private, with a clean last sync", () => {
		const row = t.kepr.query("SELECT public, last_sync_at, last_sync_error FROM repos").get() as {
			public: number;
			last_sync_at: number;
			last_sync_error: string | null;
		};
		expect(row.public).toBe(0);
		expect(row.last_sync_error).toBeNull();
		expect(row.last_sync_at).toBeGreaterThan(0);
	});

	test("history is newest first and leaves out the checkpoint", () => {
		expect(headId(t.mirror())).toBe(head());
		expect(history(t.mirror(), 10, 0).map((s) => s.id)).toEqual([head(), second(), first()]);
		expect(history(t.mirror(), 1, 1).map((s) => s.message)).toEqual(["add readme and entry point"]);
		expect(timeline(t.mirror()).map((s) => s.id)).toEqual([first(), second(), head()]);
		expect(saveByPrefix(t.mirror(), checkpoint())?.is_checkpoint).toBe(true);
	});

	test("finds a save by a unique prefix of six or more characters", () => {
		const save = saveByPrefix(t.mirror(), second().slice(0, 6));
		expect([save?.id, save?.agent, save?.session]).toEqual([second(), "test-agent", "fixture"]);
		expect(saveByPrefix(t.mirror(), second().slice(0, 5))).toBeNull();
		expect(saveByPrefix(t.mirror(), "zzzzzz")).toBeNull();
	});

	test("reads files and their bytes at any save", () => {
		const paths = filesAt(t.mirror(), head()).map((f) => f.path);
		expect(paths).toContain("src/lib/deep/util.ts");
		const now = fileAt(t.mirror(), head(), "src/main.ts");
		const then = fileAt(t.mirror(), second(), "src/main.ts");
		expect(text(objectBytes(t.mirror(), now?.hash as string))).toContain("hello");
		expect(text(objectBytes(t.mirror(), then?.hash as string))).toContain("'hi'");
		expect(fileAt(t.mirror(), first(), "src/main.ts")).toBeNull();
		expect(fileAt(t.mirror(), head(), "docs/logo.png")?.size).toBe(70);
	});

	test("counts saves without checkpoints, and lines and language at head", () => {
		const stats = repoStats(t.mirror());
		expect(stats.saves).toBe(3);
		expect(stats.language).toBe("TypeScript");
		// README 9 + guide 3 + secret 1 + util 1 + main 2 + .kohignore
		expect(stats.lines).toBeGreaterThan(16);
		// vendor/big.c's 100 lines of C count toward neither.
		expect(stats.lines).toBeLessThan(100);
		expect(stats.updated).toBe(saveByPrefix(t.mirror(), head())?.created_at ?? -1);
	});

	test("stores the flag event", () => {
		const flag = t.mirror().query("SELECT kind, save_id, reason FROM events").get();
		expect(flag).toEqual({ kind: "flag", save_id: first(), reason: "holds a secret" });
	});

	test("a save's flag state is its newest flag or clear event, by time and then ID", async () => {
		expect(flagReason(t.mirror(), first())).toBe("holds a secret");
		expect(flagReason(t.mirror(), head())).toBeNull();
		const mirror = openMirror(await mkdtemp(join(tmpdir(), "kepr-flags-")), "flags");
		const event = mirror.query(
			"INSERT INTO events (id, kind, save_id, reason, created_at, machine) VALUES (?, ?, 'aaaaaaaaaaaa', ?, ?, 'm')",
		);
		event.run("000000000001", "flag", "first", 10);
		expect(flagReason(mirror, "aaaaaaaaaaaa")).toBe("first");
		event.run("000000000002", "clear", null, 20);
		expect(flagReason(mirror, "aaaaaaaaaaaa")).toBeNull();
		// Same second: the larger ID is the newer.
		event.run("000000000003", "flag", "again", 20);
		expect(flagReason(mirror, "aaaaaaaaaaaa")).toBe("again");
		event.run("000000000000", "clear", null, 20);
		expect(flagReason(mirror, "aaaaaaaaaaaa")).toBe("again");
	});

	test("a strip reaches the mirror and drops the object", async () => {
		const secret = fileAt(t.mirror(), head(), "secret.txt")?.hash as string;
		expect(objectBytes(t.mirror(), secret)).not.toBeNull();
		await fx.strip("secret.txt");
		await syncAll(t);
		for (const id of fx.saveIds) expect(fileAt(t.mirror(), id, "secret.txt")).toBeNull();
		expect(objectBytes(t.mirror(), secret)).toBeNull();
		expect(fileAt(t.mirror(), head(), "src/main.ts")).not.toBeNull();
	});
});

test("a new save syncs incrementally and a bad format is recorded as the last sync error", async () => {
	const fx = await makeKohBucket("growing");
	const t = await syncTarget(fx);
	await syncAll(t);
	await writeFile(join(fx.repoDir, "new.txt"), "new\n");
	Bun.spawnSync(["koh3", "save", "add new"], {
		cwd: fx.repoDir,
		env: { PATH: process.env.PATH, HOME: join(fx.repoDir, "../../home"), NO_COLOR: "1" },
	});
	await syncAll(t);
	expect(history(t.mirror(), 1, 0)[0]?.message).toBe("add new");

	await writeFile(join(fx.bucketDir, fx.repo, "format"), "koh-remote 2");
	await syncAll(t);
	const row = t.kepr.query("SELECT last_sync_error FROM repos").get() as {
		last_sync_error: string;
	};
	expect(row.last_sync_error).toContain('remote format "koh-remote 2"');
});

test("a whole-history strip reaches every save, those arriving after it too, whatever their time (§10.2)", async () => {
	const fx = await makeKohBucket("late");
	const view = await mkdtemp(join(tmpdir(), "kepr-view-"));
	const viewRepo = join(view, fx.repo);
	await cp(join(fx.bucketDir, fx.repo), viewRepo, { recursive: true });
	// A strip older than every save here: a strip bans its path from all of history, so no save
	// keeps it, however much later it was made or arrives.
	await mkdir(join(viewRepo, "events"), { recursive: true });
	await writeFile(
		join(viewRepo, "events", "0000000000bb"),
		JSON.stringify({
			id: "0000000000bb",
			kind: "strip",
			save_id: "",
			path: "secret.txt",
			reason: "a secret got saved",
			created_at: 1,
			machine: "elsewhere",
		}),
	);
	const oldest = fx.saveIds.at(-1) as string;
	const newest = fx.saveIds[0] as string;
	// First sync: the strip and the oldest save only.
	await writeFile(join(viewRepo, "head"), oldest);
	const t = await syncTarget({ ...fx, bucketDir: view });
	await syncAll(t);
	expect(fileAt(t.mirror(), oldest, "secret.txt")).toBeNull();
	// Then the rest arrive, each made long after the strip.
	await writeFile(join(viewRepo, "head"), newest);
	await syncAll(t);
	expect(headId(t.mirror())).toBe(newest);
	for (const id of fx.saveIds) expect(fileAt(t.mirror(), id, "secret.txt")).toBeNull();
	expect(fileAt(t.mirror(), newest, "src/main.ts")).not.toBeNull();
});

describe("the mirror's schema version", () => {
	test("a version 2 mirror reopens and any other version is refused as disposable", async () => {
		const dir = await mkdtemp(join(tmpdir(), "kepr-mirror-"));
		const created = openMirror(dir, "one");
		created.run("PRAGMA wal_checkpoint(TRUNCATE)");
		await Bun.write(join(dir, "copy.db"), Bun.file(join(dir, "one.db")));
		expect(openMirror(dir, "copy").query("PRAGMA user_version").get()).toEqual({
			user_version: 2,
		});

		for (const version of [1, 3]) {
			const other = new Database(join(dir, `v${version}.db`));
			other.run(`PRAGMA user_version = ${version}`);
			other.close();
			expect(() => openMirror(dir, `v${version}`)).toThrow("disposable");
		}
	});
});

test("a strip that arrives older than the saves already mirrored still strips them (§10.2, R6)", async () => {
	const fx = await makeKohBucket("older-strip");
	const t = await syncTarget(fx);
	await syncAll(t);
	// Every save in the mirror holds secret.txt …
	for (const id of fx.saveIds) expect(fileAt(t.mirror(), id, "secret.txt")).not.toBeNull();

	// … and now a strip arrives whose own time is older than all of them, which is what a
	// strip made on another machine and offered late looks like. Every save is reached, whatever
	// its time.
	const events = join(fx.bucketDir, fx.repo, "events");
	await mkdir(events, { recursive: true });
	await writeFile(
		join(events, "0000000000aa"),
		JSON.stringify({
			id: "0000000000aa",
			kind: "strip",
			save_id: "",
			path: "secret.txt",
			reason: "a secret got saved",
			created_at: 1,
			machine: "elsewhere",
		}),
	);
	await syncAll(t);

	for (const id of fx.saveIds) expect(fileAt(t.mirror(), id, "secret.txt")).toBeNull();
	expect(fileAt(t.mirror(), fx.saveIds[0] as string, "src/main.ts")).not.toBeNull();
});

test("a save with an unsafe path lands without it, keeps syncing, and the admin status names it (A3)", async () => {
	const fx = await makeKohBucket("quarantine");
	const head = fx.saveIds[0] as string;
	const key = join(fx.bucketDir, fx.repo, "saves", head);
	const record = JSON.parse(await readFile(key, "utf8"));
	record.files.push({ ...record.files[0], path: "Icon\r" });
	await writeFile(key, JSON.stringify(record));
	const inst = await instance(fx.bucketDir);
	const mirror = openMirror(join(inst.dataDir, "mirror"), fx.repo);
	expect(inst.kepr.query("SELECT last_sync_error FROM repos").get()).toEqual({
		last_sync_error: null,
	});
	expect(filesAt(mirror, head).map((file) => file.path)).toContain("README.md");
	expect(filesAt(mirror, head).map((file) => file.path)).not.toContain("Icon\r");

	await writeFile(join(fx.repoDir, "later.txt"), "later\n");
	const env = { PATH: process.env.PATH, HOME: join(fx.repoDir, "../../home"), NO_COLOR: "1" };
	Bun.spawnSync(["koh3", "save", "a later save"], { cwd: fx.repoDir, env });
	Bun.spawnSync(["koh3", "offer"], { cwd: fx.repoDir, env });
	await syncAll({
		bucket: openBucket({ kind: "folder", path: fx.bucketDir }),
		kepr: inst.kepr,
		mirrorDir: join(inst.dataDir, "mirror"),
		tarballDir: join(inst.dataDir, "tarballs"),
	});
	expect(history(mirror, 1, 0)[0]?.message).toBe("a later save");

	const browser = new Browser(inst.app);
	await browser.signIn();
	const page = await (await browser.get("/admin/repos")).text();
	expect(page).toContain("1 path quarantined: Icon\\x0d");
});

test("a strip event with an illegal path is ignored, as Koh ignores it (§5.5)", async () => {
	const fx = await makeKohBucket("illegal-strip");
	for (const [id, path] of [
		["aaaaaaaaaaaa", "src//"],
		["bbbbbbbbbbbb", ""],
		["cccccccccccc", "src\ud800"],
	]) {
		const event = { id, kind: "strip", save_id: "", path, reason: "", created_at: 1, machine: "x" };
		await writeFile(join(fx.bucketDir, fx.repo, "events", id as string), JSON.stringify(event));
	}
	const t = await syncTarget(fx);
	await syncAll(t);
	expect(t.kepr.query("SELECT last_sync_error FROM repos").get()).toEqual({
		last_sync_error: null,
	});
	expect(filesAt(t.mirror(), fx.saveIds[0] as string).map((file) => file.path)).toContain(
		"src/main.ts",
	);
});

test("an object that inflates past 512 MiB is quarantined without stopping the sync (A3)", async () => {
	const fx = await makeKohBucket("oversized");
	const head = fx.saveIds[0] as string;
	const key = join(fx.bucketDir, fx.repo, "saves", head);
	const record = JSON.parse(await readFile(key, "utf8"));
	const hash = "ab".repeat(32);
	record.files.push({ path: "huge.bin", hash, executable: false });
	await writeFile(key, JSON.stringify(record));
	await writeFile(
		join(fx.bucketDir, fx.repo, "objects", hash),
		deflateSync(new Uint8Array(512 * 1024 * 1024 + 1)),
	);
	const t = await syncTarget(fx);
	await syncAll(t);
	expect(t.kepr.query("SELECT last_sync_error FROM repos").get()).toEqual({
		last_sync_error: null,
	});
	expect(filesAt(t.mirror(), head).map((file) => file.path)).not.toContain("huge.bin");
	expect(JSON.parse(mirrorState(t.mirror(), "quarantined") ?? "[]")).toEqual(["huge.bin"]);
});

test("the line count skips a file over 8 MiB (A3)", async () => {
	const fx = await makeKohBucket("large-text");
	const t = await syncTarget(fx);
	await syncAll(t);
	const before = repoStats(t.mirror()).lines;
	await writeFile(join(fx.repoDir, "big.txt"), "x\n".repeat(4.5 * 1024 * 1024));
	const env = { PATH: process.env.PATH, HOME: join(fx.repoDir, "../../home"), NO_COLOR: "1" };
	Bun.spawnSync(["koh3", "save", "add a big text file"], { cwd: fx.repoDir, env });
	Bun.spawnSync(["koh3", "offer"], { cwd: fx.repoDir, env });
	await syncAll(t);
	expect(history(t.mirror(), 1, 0)[0]?.message).toBe("add a big text file");
	expect(repoStats(t.mirror()).lines).toBe(before);
});