import { Task } from "@/model/task";
import { ITaskRepository } from "@/ports";
import { TASK_FILE_EXTENSION } from "@/model/taskFile";
import { beforeEach, describe, expect, it } from "vitest";
import { InMemoryFileSystem } from "../../tests/helpers/InMemoryFileSystem";
import { FsTaskRepository } from "./FsTaskRepository";

const UUID_RE =
	/^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;

describe("FsTaskRepository", () => {
	let fs: InMemoryFileSystem;
	let repo: ITaskRepository;
	let clockStep: number;

	const folder = "/tasks";
	const t0 = "2026-01-01T00:00:00.000Z";
	const t1 = "2026-01-01T00:00:01.000Z";
	const t2 = "2026-01-01T00:00:02.000Z";

	const sampleTask = {
		title: "Fix login bug",
		description: "Token validation error",
		status: "todo" as const,
		priority: "high" as const,
		tags: ["bug", "frontend"],
		assignee: "ivanov",
	};

	beforeEach(() => {
		fs = new InMemoryFileSystem();
		clockStep = 0;
		const timestamps = [t0, t1, t2];
		repo = new FsTaskRepository(fs, TASK_FILE_EXTENSION, () => {
			const value = timestamps[clockStep] ?? t2;
			clockStep += 1;
			return value;
		});
	});

	it("creates a task and writes it as a task file", async () => {
		const task = await repo.create(folder, sampleTask);

		expect(task.id).toMatch(UUID_RE);
		expect(task.title).toBe("Fix login bug");
		expect(task.created).toBe(t0);
		expect(task.updated).toBe(t0);

		const files = await fs.readdir(folder);
		expect(files).toEqual([`fix-login-bug${TASK_FILE_EXTENSION}`]);

		const content = await fs.readFile(
			`${folder}/fix-login-bug${TASK_FILE_EXTENSION}`,
		);
		expect(content).toContain("Fix login bug");
		expect(content).toContain("status: todo");
	});

	it("list returns created tasks sorted by updated desc", async () => {
		await repo.create(folder, { ...sampleTask, title: "A" });
		await repo.create(folder, { ...sampleTask, title: "B" });

		const tasks = await repo.list(folder);
		expect(tasks).toHaveLength(2);
		expect(tasks[0].title).toBe("B");
		expect(tasks[0].updated).toBe(t1);
		expect(tasks[1].title).toBe("A");
		expect(tasks[1].updated).toBe(t0);
	});

	it("getById returns the correct task", async () => {
		const created = await repo.create(folder, sampleTask);
		const found = await repo.getById(folder, created.id);
		expect(found).toEqual(created);
	});

	it("getById returns undefined for unknown id", async () => {
		const found = await repo.getById(folder, "nonexistent");
		expect(found).toBeUndefined();
	});

	it("update modifies fields and bumps updated timestamp", async () => {
		const task = await repo.create(folder, sampleTask);
		const updated: Task = { ...task, status: "done" };

		await repo.update(folder, updated);
		const found = await repo.getById(folder, task.id);

		expect(found!.status).toBe("done");
		expect(found!.title).toBe(task.title);
		expect(found!.updated).toBe(t1);
		expect(found!.created).toBe(t0);
	});

	it("update renames file when title changes", async () => {
		const task = await repo.create(folder, sampleTask);
		expect(await fs.readdir(folder)).toEqual([
			`fix-login-bug${TASK_FILE_EXTENSION}`,
		]);

		await repo.update(folder, { ...task, title: "Fixed!" });

		const files = await fs.readdir(folder);
		expect(files).toEqual([`fixed${TASK_FILE_EXTENSION}`]);
		const found = await repo.getById(folder, task.id);
		expect(found!.title).toBe("Fixed!");
		expect(found!.updated).toBe(t1);
	});

	it("update of unknown id writes a new file", async () => {
		const orphan: Task = {
			...sampleTask,
			id: "orphan-id",
			title: "Orphan",
			created: t0,
			updated: t0,
		};

		await repo.update(folder, orphan);

		const found = await repo.getById(folder, "orphan-id");
		expect(found).toMatchObject({
			id: "orphan-id",
			title: "Orphan",
			updated: t0,
		});
		expect(await fs.readdir(folder)).toEqual([`orphan${TASK_FILE_EXTENSION}`]);
	});

	it("delete removes the task file", async () => {
		const task = await repo.create(folder, sampleTask);
		await repo.delete(folder, task.id);

		const tasks = await repo.list(folder);
		expect(tasks).toHaveLength(0);
		expect(await fs.readdir(folder)).toEqual([]);
	});

	it("delete is a no-op for unknown id", async () => {
		await expect(repo.delete(folder, "nope")).resolves.toBeUndefined();
	});

	it("list returns empty array for non-existent folder", async () => {
		const tasks = await repo.list("/nonexistent");
		expect(tasks).toEqual([]);
	});

	it("filters files by extension", async () => {
		await fs.writeFile(`${folder}/notes.txt`, "hello");
		await fs.writeFile(`${folder}/chore.md`, "---\nid: x\n---\n");

		await repo.create(folder, sampleTask);

		const tasks = await repo.list(folder);
		expect(tasks).toHaveLength(1);
	});

	it("list returns empty when only non-matching extensions exist", async () => {
		await fs.writeFile(`${folder}/notes.txt`, "hello");
		await fs.writeFile(`${folder}/chore.md`, "---\nid: x\n---\n");

		const tasks = await repo.list(folder);
		expect(tasks).toEqual([]);
	});

	it("skips files without id", async () => {
		await fs.writeFile(
			`${folder}/no-id${TASK_FILE_EXTENSION}`,
			"not valid frontmatter",
		);
		await fs.writeFile(
			`${folder}/empty-id${TASK_FILE_EXTENSION}`,
			"---\ntitle: No Id\n---\n",
		);

		await repo.create(folder, sampleTask);
		const tasks = await repo.list(folder);
		expect(tasks).toHaveLength(1);
		expect(tasks[0].title).toBe("Fix login bug");
	});

	it("create with same title overwrites the previous file", async () => {
		const first = await repo.create(folder, sampleTask);
		const second = await repo.create(folder, {
			...sampleTask,
			description: "second",
		});

		const files = await fs.readdir(folder);
		expect(files).toEqual([`fix-login-bug${TASK_FILE_EXTENSION}`]);

		const tasks = await repo.list(folder);
		expect(tasks).toHaveLength(1);
		expect(tasks[0].id).toBe(second.id);
		expect(tasks[0].id).not.toBe(first.id);
		expect(tasks[0].description).toBe("second");
	});

	it("creates task with Cyrillic title and slug", async () => {
		const task = await repo.create(folder, {
			...sampleTask,
			title: "Тестовая задача",
		});
		expect(task.title).toBe("Тестовая задача");

		const files = await fs.readdir(folder);
		expect(files).toEqual([`тестовая-задача${TASK_FILE_EXTENSION}`]);
	});

	it("creates task with title exactly at MAX_TASK_TITLE_LENGTH", async () => {
		const title = "a".repeat(80);
		const task = await repo.create(folder, { ...sampleTask, title });
		expect(task.title).toBe(title);

		const files = await fs.readdir(folder);
		expect(files).toEqual([`${title}${TASK_FILE_EXTENSION}`]);

		const found = await repo.getById(folder, task.id);
		expect(found?.title).toBe(title);
	});

	it("creates task with tags containing special characters", async () => {
		const task = await repo.create(folder, {
			...sampleTask,
			tags: ["c#", "c++", "tag name", "tag:value"],
		});

		const files = await fs.readdir(folder);
		expect(files).toHaveLength(1);

		const content = await fs.readFile(
			`${folder}/fix-login-bug${TASK_FILE_EXTENSION}`,
		);
		expect(content).toContain("c#");
		expect(content).toContain("tag:value");
	});

	it("getFilePath produces consistent slug regardless of special characters", async () => {
		const task = await repo.create(folder, {
			...sampleTask,
			title: "Fix___bug...",
		});
		const files = await fs.readdir(folder);
		expect(files).toEqual([`fix-bug${TASK_FILE_EXTENSION}`]);
	});
});