import { describe, expect, it } from "vitest";
import { rankDocuments, type SearchDocument, tokenize } from "../src/search.ts";

function doc(name: string, text: string, namespaceText?: string): SearchDocument {
	return namespaceText === undefined ? { name, text } : { name, text, namespaceText };
}

describe("tokenize", () => {
	it("splits camelCase and snake_case, drops stop words, and folds plurals", () => {
		expect(tokenize("listIssues for the GitHub_repo")).toEqual(["list", "issue", "git", "hub", "repo"]);
		expect(tokenize("searches queries HTTPServer")).toEqual(["search", "query", "http", "server"]);
		expect(tokenize("repo.issues/search:queries")).toEqual(["repo", "issue", "search", "query"]);
	});

	it.each([
		["搜索仓库问题", ["搜索", "仓库", "问题"]],
		["文書を検索", ["文書", "を", "検索"]],
		["문서 검색", ["문서", "검색"]],
		["ค้นหาเอกสาร", ["ค้นหา", "เอกสาร"]],
		["Поиск документов", ["поиск", "документов"]],
		["البحث عن الملفات", ["البحث", "عن", "الملفات"]],
		["फ़ाइल खोजें", ["फ़ाइल", "खोजें"]],
		["Éléments cafés", ["éléments", "cafés"]],
	])("segments Unicode words in %s", (text, expected) => {
		expect(tokenize(text)).toEqual(expected);
	});

	it("preserves non-ASCII words and splits mixed-language identifiers", () => {
		expect(tokenize("搜索GitHub_repoIssues résumé cafés")).toEqual([
			"搜索",
			"git",
			"hub",
			"repo",
			"issue",
			"résumé",
			"cafés",
		]);
	});

	it("normalizes canonically equivalent Unicode text", () => {
		expect(tokenize("CAFÉ cafe\u0301")).toEqual(["café", "café"]);
	});

	it("ignores whitespace, punctuation, and emoji", () => {
		expect(tokenize(" \t，。!? 😀 ")).toEqual([]);
	});
});

describe("rankDocuments", () => {
	const documents = [
		doc("mcp__github__list_issues", "List issues in a repository. state open or closed"),
		doc("mcp__github__create_pull_request", "Open a pull request."),
		doc("mcp__linear__search_issues", "Search Linear issues by text."),
		doc("mcp__docs__search", "Search the documentation."),
	];

	it("ranks by term relevance and respects the limit", () => {
		expect(rankDocuments("issue", documents, 8)).toEqual(["mcp__linear__search_issues", "mcp__github__list_issues"]);
		expect(rankDocuments("pull requests", documents, 8)[0]).toBe("mcp__github__create_pull_request");
		expect(rankDocuments("search", documents, 1)).toHaveLength(1);
		expect(rankDocuments("closed", documents, 8)).toEqual(["mcp__github__list_issues"]);
	});

	it.each([
		["搜索仓库问题", "问题"],
		["文書を検索", "検索"],
		["문서 검색", "검색"],
		["ค้นหาเอกสาร", "เอกสาร"],
		["Поиск документов", "документов"],
		["البحث عن الملفات", "الملفات"],
		["फ़ाइल खोजें", "खोजें"],
		["Rechercher un café", "cafe\u0301"],
	])("matches Unicode queries against %s", (text, query) => {
		expect(rankDocuments(query, [...documents, doc("localized", text)], 8)).toEqual(["localized"]);
	});

	it("returns nothing for unknown or empty queries", () => {
		expect(rankDocuments("kubernetes", documents, 8)).toEqual([]);
		expect(rankDocuments("the", documents, 8)).toEqual([]);
		expect(rankDocuments("未知", documents, 8)).toEqual([]);
	});

	it("searches the namespace text", () => {
		const namespaced = [doc("mcp__x__run", "Run it.", "mcp__x Kubernetes cluster tools")];
		expect(rankDocuments("kubernetes", namespaced, 8)).toEqual(["mcp__x__run"]);
	});

	// https://github.com/earendil-works/pi/issues/11331
	it("ranks a tool first when the query is its name", () => {
		const named = [
			doc("mcp__app__queue_read", "Read a queued message of this thread."),
			doc(
				"mcp__dev-app__thread_read",
				"Read durable state and a paginated timeline from any thread. The default view returns user messages, assistant messages and plans. Continue with afterPosition until hasMore is false.",
			),
		];
		for (const query of ["thread_read", "dev_app__thread_read", "mcp__dev-app__thread_read", "Thread_Read"]) {
			expect(rankDocuments(query, named, 1)).toEqual(["mcp__dev-app__thread_read"]);
		}
		// Partial names still rank by BM25.
		expect(rankDocuments("read", named, 1)).toEqual(["mcp__app__queue_read"]);
	});

	// https://github.com/earendil-works/pi/issues/11331
	it("ranks a name match above mentions in descriptions", () => {
		const ci = [
			doc("mcp__ci__status", "Deploy status: last deploy, deploy log, deploy errors."),
			doc(
				"mcp__ci__deploy_release",
				"Start a release of the current branch to an environment, run the migrations, switch traffic over, and wait until the new version is live and healthy.",
			),
		];
		expect(rankDocuments("deploy", ci, 1)).toEqual(["mcp__ci__deploy_release"]);
	});

	// https://github.com/earendil-works/pi/issues/11331
	it("ranks a tool first when the query contains its whole name", () => {
		const peekaboo = "mcp__peekaboo Peekaboo controls macOS apps by app name.";
		const named = [
			doc("mcp__peekaboo__see", "Capture the app window of the peekaboo app and describe the app.", peekaboo),
			doc("mcp__peekaboo__menu", "Click a menu item of an app.", peekaboo),
			doc(
				"mcp__peekaboo__app",
				"Launch, quit, relaunch, focus, hide, or switch applications. Targets an application by name, bundle identifier, or process ID, and can wait until it is ready.",
				peekaboo,
			),
			doc("mcp__app__queue_read", "Read a queued message of this thread."),
			doc(
				"mcp__dev-app__thread_read",
				"Read durable state and a paginated timeline from any thread. The default view returns user messages, assistant messages and plans.",
			),
		];
		expect(rankDocuments("peekaboo app", named, 1)).toEqual(["mcp__peekaboo__app"]);
		expect(rankDocuments("open the peekaboo app tool", named, 1)).toEqual(["mcp__peekaboo__app"]);
		expect(rankDocuments("read thread_read state", named, 1)).toEqual(["mcp__dev-app__thread_read"]);
		// Without the whole name, mentions in descriptions decide.
		expect(rankDocuments("describe window", named, 1)).toEqual(["mcp__peekaboo__see"]);
	});

	// https://github.com/earendil-works/pi/issues/11331
	it("ranks a tool matching more query terms first, whatever the scores", () => {
		const peekaboo = [
			doc("mcp__peekaboo__app", "Launch, quit, focus, or switch applications by name or bundle identifier."),
			doc("mcp__peekaboo__see", "Capture the app window and describe the UI elements of the app."),
			doc("mcp__peekaboo__window", "Move, resize, or close a window of an app."),
			doc("mcp__peekaboo__image", "Take a screenshot of the screen, an app, or a window."),
		];
		// `window` and `app` are whole names, but each covers one of the two terms.
		expect(rankDocuments("screenshot window", peekaboo, 1)).toEqual(["mcp__peekaboo__image"]);
		expect(rankDocuments("describe app", peekaboo, 1)).toEqual(["mcp__peekaboo__see"]);
		// An exact name still ranks first.
		expect(rankDocuments("window", peekaboo, 1)).toEqual(["mcp__peekaboo__window"]);
	});
});