import { describe, expect, it } from "vitest";
import { Task } from "@/model/task";
import {
	TASK_STATUS_META,
	TASK_STATUS_ORDER,
	TaskStatus,
} from "@/model/taskStatus";
import { buildKanbanBoard } from "./buildKanbanBoard";

function task(partial: Partial<Task> & Pick<Task, "id" | "title">): Task {
	return {
		description: "",
		status: TaskStatus.TODO,
		priority: "medium",
		tags: [],
		assignee: "",
		created: "2026-01-01T00:00:00.000Z",
		updated: "2026-01-01T00:00:00.000Z",
		...partial,
	};
}

const visibleStatuses = TASK_STATUS_ORDER.filter(
	(status) => !TASK_STATUS_META[status].defaultHidden,
);

describe("buildKanbanBoard", () => {
	const tasks: Task[] = [
		task({
			id: "a",
			title: "Done one",
			status: TaskStatus.DONE,
			updated: "2026-01-01T00:00:02.000Z",
		}),
		task({
			id: "b",
			title: "Todo older",
			status: TaskStatus.TODO,
			updated: "2026-01-01T00:00:01.000Z",
		}),
		task({
			id: "c",
			title: "Todo newer",
			status: TaskStatus.TODO,
			updated: "2026-01-01T00:00:03.000Z",
		}),
		task({
			id: "d",
			title: "In progress",
			status: TaskStatus.IN_PROGRESS,
			updated: "2026-01-01T00:00:04.000Z",
		}),
		task({
			id: "e",
			title: "Backlog item",
			status: TaskStatus.BACKLOG,
			updated: "2026-01-01T00:00:00.000Z",
		}),
		task({
			id: "f",
			title: "Cancelled",
			status: TaskStatus.CANCELLED,
			updated: "2026-01-01T00:00:05.000Z",
		}),
	];

	it("hides defaultHidden statuses by default", () => {
		const board = buildKanbanBoard(tasks);
		const statuses = board.columns.map((col) => col.status);

		expect(statuses).toEqual(visibleStatuses);
		for (const col of board.columns) {
			expect(TASK_STATUS_META[col.status].defaultHidden).toBe(false);
			expect(col.label).toBe(TASK_STATUS_META[col.status].label);
		}
	});

	it("includes all statuses when showHiddenStatuses is true", () => {
		const board = buildKanbanBoard(tasks, { showHiddenStatuses: true });

		expect(board.columns.map((col) => col.status)).toEqual(TASK_STATUS_ORDER);
		for (const col of board.columns) {
			expect(col.label).toBe(TASK_STATUS_META[col.status].label);
		}
	});

	it("places each task into the column matching its status", () => {
		const board = buildKanbanBoard(tasks, { showHiddenStatuses: true });

		for (const col of board.columns) {
			for (const t of col.tasks) {
				expect(t.status).toBe(col.status);
			}
		}

		const byStatus = Object.fromEntries(
			board.columns.map((col) => [col.status, col.tasks.map((t) => t.id)]),
		);
		expect(byStatus[TaskStatus.TODO]).toEqual(["c", "b"]);
		expect(byStatus[TaskStatus.IN_PROGRESS]).toEqual(["d"]);
		expect(byStatus[TaskStatus.DONE]).toEqual(["a"]);
		expect(byStatus[TaskStatus.BACKLOG]).toEqual(["e"]);
		expect(byStatus[TaskStatus.CANCELLED]).toEqual(["f"]);
	});

	it("sorts tasks within a column by updated desc", () => {
		const board = buildKanbanBoard(tasks);
		const todo = board.columns.find((col) => col.status === TaskStatus.TODO);
		expect(todo?.tasks.map((t) => t.id)).toEqual(["c", "b"]);
	});

	it("returns empty visible columns when there are no tasks", () => {
		const board = buildKanbanBoard([]);

		expect(board.columns.map((col) => col.status)).toEqual(visibleStatuses);
		for (const col of board.columns) {
			expect(col.tasks).toEqual([]);
		}
	});

	it("preserves input order for tasks with same updated timestamp (stable sort)", () => {
		const sameUpdated = "2026-01-01T00:00:00.000Z";
		const tasks: Task[] = [
			task({
				id: "a",
				title: "A",
				status: TaskStatus.TODO,
				updated: sameUpdated,
			}),
			task({
				id: "b",
				title: "B",
				status: TaskStatus.TODO,
				updated: sameUpdated,
			}),
			task({
				id: "c",
				title: "C",
				status: TaskStatus.TODO,
				updated: sameUpdated,
			}),
		];
		const board = buildKanbanBoard(tasks);
		const todo = board.columns.find((col) => col.status === TaskStatus.TODO);
		expect(todo?.tasks.map((t) => t.id)).toEqual(["a", "b", "c"]);
	});
});