import {beforeEach, describe, expect, it} from "bun:test";
import type {RolloverFile, RolloverIO} from "../src/rollover";
import {isTodayNote, rollOverPastTasks} from "../src/rollover";
import type {MarkdownTasksSettings} from "../src/settings";

class InMemoryRolloverIO implements RolloverIO {
	files: Map<string, string> = new Map();
	frontmatters: Map<string, Record<string, unknown>> = new Map();
	writes: string[] = [];

	add(path: string, content = "", frontmatter: Record<string, unknown> = {}) {
		this.files.set(path, content);
		this.frontmatters.set(path, {...frontmatter});
	}

	private describe(path: string): RolloverFile {
		const segments = path.split("/");
		const name = segments.pop() ?? path;
		return {
			path,
			basename: name.replace(/\.md$/, ""),
			parentPath: segments.join("/"),
		};
	}

	listMarkdownFiles(): RolloverFile[] {
		return [...this.files.keys()].filter((p) => p.endsWith(".md")).map((p) => this.describe(p));
	}

	readFile(path: string): Promise<string> {
		const content = this.files.get(path);
		if (content === undefined) return Promise.reject(new Error(`Not found: ${path}`));
		return Promise.resolve(content);
	}

	writeFile(path: string, content: string): Promise<void> {
		this.files.set(path, content);
		this.writes.push(path);
		return Promise.resolve();
	}

	getOrCreateFile(path: string): Promise<RolloverFile> {
		if (!this.files.has(path)) {
			this.files.set(path, "");
			this.frontmatters.set(path, {});
		}
		return Promise.resolve(this.describe(path));
	}

	processFrontMatter(
		path: string,
		fn: (frontmatter: Record<string, unknown>) => void,
	): Promise<void> {
		const fm = this.frontmatters.get(path) ?? {};
		fn(fm);
		this.frontmatters.set(path, fm);
		return Promise.resolve();
	}
}

const settings = (overrides: Partial<MarkdownTasksSettings> = {}): MarkdownTasksSettings =>
	({
		completedSymbol: "x",
		inProgressSymbol: "/",
		movedSymbol: ">",
		rolloverSourceAction: "mark-moved",
		rolloverContext: "none",
		rolloverHeader: "## Past tasks",
		rolloverOnTodayCreate: true,
		dailyNoteFormat: "YYYY-MM-DD",
		dailyNotesFolder: "",
		enableAutoProcessing: true,
		pendingTasksProperty: "Pending tasks",
		pendingTasksCountProperty: "Pending tasks count",
		totalTasksCountProperty: "Total tasks count",
		enableTaskCounts: false,
		countRootTasksOnly: false,
		excludeFolders: [],
		includeFolders: [],
		...overrides,
	}) as MarkdownTasksSettings;

const today = new Date(2026, 4, 6); // 2026-05-06

describe("isTodayNote", () => {
	it("matches when basename equals today's formatted date and folder matches", () => {
		const file = {basename: "2026-05-06", parentPath: "Daily"};
		expect(isTodayNote(file, settings({dailyNotesFolder: "Daily"}), today)).toBe(true);
	});

	it("rejects when folder does not match", () => {
		const file = {basename: "2026-05-06", parentPath: "Other"};
		expect(isTodayNote(file, settings({dailyNotesFolder: "Daily"}), today)).toBe(false);
	});

	it("rejects when basename is not today", () => {
		const file = {basename: "2026-05-05", parentPath: ""};
		expect(isTodayNote(file, settings(), today)).toBe(false);
	});
});

describe("rollOverPastTasks – orchestration", () => {
	let io: InMemoryRolloverIO;

	beforeEach(() => {
		io = new InMemoryRolloverIO();
	});

	it("returns no-op result when there are no past notes", async () => {
		io.add("notes/random.md", "- [ ] not a daily note");
		const result = await rollOverPastTasks(io, settings(), today);
		expect(result).toEqual({rolledOverFiles: 0, migratedBlocks: 0, destinationPath: null});
		expect(io.writes).toEqual([]);
	});

	it("skips past notes without pending tasks", async () => {
		io.add("2026-05-04.md", "- [x] done\n");
		const result = await rollOverPastTasks(io, settings(), today);
		expect(result.migratedBlocks).toBe(0);
		expect(result.rolledOverFiles).toBe(0);
		expect(io.writes).toEqual([]);
	});

	it("rolls over pending tasks from past notes to today's note", async () => {
		io.add("2026-05-04.md", "- [ ] yesterday-yesterday\n");
		io.add("2026-05-05.md", "- [ ] yesterday\n");
		const result = await rollOverPastTasks(io, settings(), today);
		expect(result.migratedBlocks).toBe(2);
		expect(result.rolledOverFiles).toBe(2);
		expect(result.destinationPath).toBe("2026-05-06.md");

		expect(io.files.get("2026-05-04.md")).toContain("- [>] yesterday-yesterday");
		expect(io.files.get("2026-05-05.md")).toContain("- [>] yesterday");

		const todayContent = io.files.get("2026-05-06.md");
		expect(todayContent).toContain("## Past tasks");
		expect(todayContent).toContain("- [ ] yesterday-yesterday");
		expect(todayContent).toContain("- [ ] yesterday");
	});

	it("respects the daily notes folder filter", async () => {
		io.add("Daily/2026-05-05.md", "- [ ] in-folder\n");
		io.add("Other/2026-05-05.md", "- [ ] outside-folder\n");
		const result = await rollOverPastTasks(io, settings({dailyNotesFolder: "Daily"}), today);
		expect(result.rolledOverFiles).toBe(1);
		expect(io.files.get("Other/2026-05-05.md")).toBe("- [ ] outside-folder\n");
		expect(io.files.get("Daily/2026-05-05.md")).toContain("- [>] in-folder");
		expect(result.destinationPath).toBe("Daily/2026-05-06.md");
	});

	it("ignores future-dated notes", async () => {
		io.add("2027-01-01.md", "- [ ] future\n");
		const result = await rollOverPastTasks(io, settings(), today);
		expect(result.migratedBlocks).toBe(0);
		expect(io.files.get("2027-01-01.md")).toBe("- [ ] future\n");
	});
});

describe("rollOverPastTasks – pending-tasks frontmatter refresh", () => {
	let io: InMemoryRolloverIO;

	beforeEach(() => {
		io = new InMemoryRolloverIO();
	});

	it("clears the pending property on the source after pending tasks are migrated", async () => {
		io.add("2026-05-05.md", "- [ ] yesterday\n", {"Pending tasks": true});
		await rollOverPastTasks(io, settings(), today);
		const fm = io.frontmatters.get("2026-05-05.md");
		expect(fm).toBeDefined();
		expect(fm).not.toHaveProperty("Pending tasks");
	});

	it("sets the pending property on today's note after it receives migrated tasks", async () => {
		io.add("2026-05-05.md", "- [ ] yesterday\n");
		await rollOverPastTasks(io, settings(), today);
		expect(io.frontmatters.get("2026-05-06.md")).toEqual({"Pending tasks": true});
	});

	it("writes count properties when enableTaskCounts is on", async () => {
		io.add("2026-05-05.md", "- [ ] one\n- [ ] two\n");
		await rollOverPastTasks(io, settings({enableTaskCounts: true}), today);
		expect(io.frontmatters.get("2026-05-06.md")).toEqual({
			"Pending tasks": true,
			"Pending tasks count": 2,
			"Total tasks count": 2,
		});
	});

	it("skips frontmatter refresh entirely when enableAutoProcessing is off", async () => {
		io.add("2026-05-05.md", "- [ ] yesterday\n", {"Pending tasks": true});
		await rollOverPastTasks(io, settings({enableAutoProcessing: false}), today);
		expect(io.frontmatters.get("2026-05-05.md")).toEqual({"Pending tasks": true});
		expect(io.frontmatters.get("2026-05-06.md")).toEqual({});
	});

	it("skips frontmatter refresh on excluded folders", async () => {
		io.add("Templates/2026-05-05.md", "- [ ] task\n", {"Pending tasks": true});
		await rollOverPastTasks(io, settings({excludeFolders: ["Templates"]}), today);
		expect(io.frontmatters.get("Templates/2026-05-05.md")).toEqual({"Pending tasks": true});
	});

	it("respects include-folder restrictions on the source", async () => {
		io.add("Daily/2026-05-05.md", "- [ ] yesterday\n", {"Pending tasks": true});
		await rollOverPastTasks(
			io,
			settings({dailyNotesFolder: "Daily", includeFolders: ["Other"]}),
			today,
		);
		// Source is in "Daily" but include filter restricts to "Other" → no refresh
		expect(io.frontmatters.get("Daily/2026-05-05.md")).toEqual({"Pending tasks": true});
	});
});