import { describe, expect, test } from "bun:test";
import {
	type DirEnt,
	makeExcluder,
	type ScanFs,
	scanRoot,
} from "../src/domain/scanner.js";
import { platformById } from "../src/domain/platforms.js";

/** A synthetic filesystem from a flat `{ absPath: contents }` map (dirs inferred). */
const synthFs = (files: Record<string, string>): ScanFs => {
	const norm = (p: string) => p.replace(/\/+$/, "");
	return {
		readDir(dir): DirEnt[] {
			const base = norm(dir);
			const children = new Map<string, boolean>(); // name → isDir
			for (const f of Object.keys(files)) {
				if (!f.startsWith(`${base}/`)) continue;
				const rest = f.slice(base.length + 1);
				const slash = rest.indexOf("/");
				if (slash === -1) children.set(rest, false);
				else children.set(rest.slice(0, slash), true);
			}
			return [...children].map(([name, isDir]) => ({
				name,
				isDir,
				isFile: !isDir,
			}));
		},
		readText(file) {
			const c = files[norm(file)];
			if (c === undefined) throw new Error(`no such file: ${file}`);
			return c;
		},
	};
};

const snes = platformById("snes")!;
const ps1 = platformById("ps1")!;

const rels = (
	root: string,
	files: Record<string, string>,
	platform = snes,
	excludes?: string[],
) =>
	scanRoot(synthFs(files), root, platform, excludes)
		.map((c) => c.relPath)
		.sort();

describe("scanRoot — cartridge platform", () => {
	test("matches platform extensions, recurses, ignores others", () => {
		const got = rels("/roms/snes", {
			"/roms/snes/Chrono Trigger (USA).sfc": "",
			"/roms/snes/Super Metroid.smc": "",
			"/roms/snes/readme.txt": "",
			"/roms/snes/sub/Zelda.sfc": "",
		});
		expect(got).toEqual([
			"Chrono Trigger (USA).sfc",
			"Super Metroid.smc",
			"sub/Zelda.sfc",
		]);
	});

	test("accepts archives regardless of extension list", () => {
		const got = rels("/roms/snes", {
			"/roms/snes/Game.zip": "",
			"/roms/snes/x.foo": "",
		});
		expect(got).toEqual(["Game.zip"]);
	});

	test("excludes apply (glob + directory)", () => {
		const got = rels(
			"/roms/snes",
			{
				"/roms/snes/A.sfc": "",
				"/roms/snes/A.sav": "",
				"/roms/snes/bios/x.sfc": "",
			},
			snes,
			["*.sav", "bios/**"],
		);
		expect(got).toEqual(["A.sfc"]);
	});
});

describe("scanRoot — disc folding", () => {
	test("m3u playlist folds its cues and their bins into one entry", () => {
		const got = rels(
			"/roms/ps1",
			{
				"/roms/ps1/FF7.m3u": "FF7 (Disc 1).cue\nFF7 (Disc 2).cue\n",
				"/roms/ps1/FF7 (Disc 1).cue":
					'FILE "FF7 (Disc 1).bin" BINARY\n  TRACK 01 MODE2/2352',
				"/roms/ps1/FF7 (Disc 1).bin": "",
				"/roms/ps1/FF7 (Disc 2).cue": 'FILE "FF7 (Disc 2).bin" BINARY',
				"/roms/ps1/FF7 (Disc 2).bin": "",
			},
			ps1,
		);
		expect(got).toEqual(["FF7.m3u"]);
	});

	test("a standalone cue hides its bin", () => {
		const got = rels(
			"/roms/ps1",
			{
				"/roms/ps1/Tekken.cue": 'FILE "Tekken.bin" BINARY',
				"/roms/ps1/Tekken.bin": "",
			},
			ps1,
		);
		expect(got).toEqual(["Tekken.cue"]);
	});

	test("chd stands alone", () => {
		const got = rels("/roms/ps1", { "/roms/ps1/Crash.chd": "" }, ps1);
		expect(got).toEqual(["Crash.chd"]);
	});
});

describe("makeExcluder", () => {
	test("bare pattern matches at any depth; negation re-includes", () => {
		const ex = makeExcluder(["*.sav", "!keep/**"]);
		expect(ex("a/b/x.sav")).toBe(true);
		expect(ex("keep/x.sav")).toBe(false);
		expect(ex("a/b/x.sfc")).toBe(false);
	});
});