import { afterEach, describe, expect, it } from "bun:test";
import * as fs from "node:fs/promises";
import * as os from "node:os";
import * as path from "node:path";
import type { FetchImpl } from "@oh-my-pi/pi-ai/types";
import { resetSettingsForTest, Settings } from "@oh-my-pi/pi-coding-agent/config/settings";
import { searchSearXNG } from "@oh-my-pi/pi-coding-agent/web/search/providers/searxng";
import { SearchProviderError } from "@oh-my-pi/pi-coding-agent/web/search/types";

describe("SearXNG web search provider", () => {
	afterEach(() => {
		resetSettingsForTest();
		delete process.env.SEARXNG_ENDPOINT;
		delete process.env.SEARXNG_TOKEN;
		delete process.env.SEARXNG_BASIC_USERNAME;
		delete process.env.SEARXNG_BASIC_PASSWORD;
	});

	it("sends RFC 7617 Basic auth when username and password are configured", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org/";
		process.env.SEARXNG_BASIC_USERNAME = "alice";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		const captured: { url?: URL; headers?: Headers } = {};
		const fetchMock: FetchImpl = (input, init) => {
			captured.url = new URL(input.toString());
			captured.headers = new Headers(init?.headers);
			return Promise.resolve(
				new Response(
					JSON.stringify({
						results: [{ title: "SearXNG", url: "https://example.com/result", content: "Metasearch result" }],
						suggestions: ["related search"],
					}),
					{ status: 200, headers: { "Content-Type": "application/json" } },
				),
			);
		};

		const response = await searchSearXNG({
			query: "private search",
			num_results: 1,
			recency: "week",
			fetch: fetchMock,
		});

		expect(captured.url?.origin).toBe("https://searx.example.org");
		expect(captured.url?.pathname).toBe("/search");
		expect(captured.url?.searchParams.get("q")).toBe("private search");
		expect(captured.url?.searchParams.get("format")).toBe("json");
		expect(captured.url?.searchParams.get("time_range")).toBe("month");
		expect(captured.headers?.get("Authorization")).toBe(
			`Basic ${Buffer.from("alice:s3cret", "utf-8").toString("base64")}`,
		);
		expect(response).toMatchObject({
			provider: "searxng",
			relatedQuestions: ["related search"],
			sources: [{ title: "SearXNG", url: "https://example.com/result", snippet: "Metasearch result" }],
		});
	});

	it("reads Basic auth credentials from nested config.yml settings", async () => {
		const agentDir = await fs.mkdtemp(path.join(os.tmpdir(), "searxng-settings-"));
		try {
			await Bun.write(
				path.join(agentDir, "config.yml"),
				[
					"searxng:",
					"  endpoint: https://searx.example.org",
					"  basicUsername: alice",
					"  basicPassword: s3cret",
					"",
				].join("\n"),
			);
			await Settings.init({ agentDir });

			const captured: { headers?: Headers } = {};
			const fetchMock: FetchImpl = (_input, init) => {
				captured.headers = new Headers(init?.headers);
				return Promise.resolve(
					new Response(JSON.stringify({ results: [] }), {
						status: 200,
						headers: { "Content-Type": "application/json" },
					}),
				);
			};

			await searchSearXNG({ query: "settings basic auth", fetch: fetchMock });

			expect(captured.headers?.get("Authorization")).toBe(
				`Basic ${Buffer.from("alice:s3cret", "utf-8").toString("base64")}`,
			);
		} finally {
			await fs.rm(agentDir, { recursive: true, force: true });
		}
	});

	it("prefers Basic auth over bearer token when both are configured", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_TOKEN = "bearer-token";
		process.env.SEARXNG_BASIC_USERNAME = "alice";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		const captured: { headers?: Headers } = {};
		const fetchMock: FetchImpl = (_input, init) => {
			captured.headers = new Headers(init?.headers);
			return Promise.resolve(
				new Response(JSON.stringify({ results: [] }), {
					status: 200,
					headers: { "Content-Type": "application/json" },
				}),
			);
		};

		await searchSearXNG({ query: "auth precedence", fetch: fetchMock });

		expect(captured.headers?.get("Authorization")).toBe(
			`Basic ${Buffer.from("alice:s3cret", "utf-8").toString("base64")}`,
		);
	});

	it("sends Basic auth when the password is intentionally empty", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "alice";
		process.env.SEARXNG_BASIC_PASSWORD = "";

		const captured: { headers?: Headers } = {};
		const fetchMock: FetchImpl = (_input, init) => {
			captured.headers = new Headers(init?.headers);
			return Promise.resolve(
				new Response(JSON.stringify({ results: [] }), {
					status: 200,
					headers: { "Content-Type": "application/json" },
				}),
			);
		};

		await searchSearXNG({ query: "empty password", fetch: fetchMock });

		expect(captured.headers?.get("Authorization")).toBe(`Basic ${Buffer.from("alice:", "utf-8").toString("base64")}`);
	});

	it("sends Basic auth when the username is intentionally empty", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		const captured: { headers?: Headers } = {};
		const fetchMock: FetchImpl = (_input, init) => {
			captured.headers = new Headers(init?.headers);
			return Promise.resolve(
				new Response(JSON.stringify({ results: [] }), {
					status: 200,
					headers: { "Content-Type": "application/json" },
				}),
			);
		};

		await searchSearXNG({ query: "empty username", fetch: fetchMock });

		expect(captured.headers?.get("Authorization")).toBe(
			`Basic ${Buffer.from(":s3cret", "utf-8").toString("base64")}`,
		);
	});

	it("requires both Basic auth username and password", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "alice";

		await expect(searchSearXNG({ query: "missing password" })).rejects.toThrow(
			"SearXNG Basic auth requires both searxng.basicUsername and searxng.basicPassword",
		);
	});

	it("requires a Basic auth username when only password is configured", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		await expect(searchSearXNG({ query: "missing username" })).rejects.toThrow(
			"SearXNG Basic auth requires both searxng.basicUsername and searxng.basicPassword",
		);
	});

	it("rejects Basic auth usernames containing a colon", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "alice:admin";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		await expect(searchSearXNG({ query: "invalid username" })).rejects.toThrow(
			"SearXNG Basic auth username cannot contain ':'",
		);
	});

	it("rejects Basic auth usernames containing control characters", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "alice\u0007";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret";

		await expect(searchSearXNG({ query: "invalid username control character" })).rejects.toThrow(
			"SearXNG Basic auth credentials must not contain RFC 7617 control characters",
		);
	});

	it("rejects Basic auth passwords containing control characters", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_BASIC_USERNAME = "alice";
		process.env.SEARXNG_BASIC_PASSWORD = "s3cret\u0001";

		await expect(searchSearXNG({ query: "invalid password control character" })).rejects.toThrow(
			"SearXNG Basic auth credentials must not contain RFC 7617 control characters",
		);
	});

	it("keeps bearer token authentication when Basic auth is not configured", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";
		process.env.SEARXNG_TOKEN = "bearer-token";

		const captured: { headers?: Headers } = {};
		const fetchMock: FetchImpl = (_input, init) => {
			captured.headers = new Headers(init?.headers);
			return Promise.resolve(
				new Response(JSON.stringify({ results: [] }), {
					status: 200,
					headers: { "Content-Type": "application/json" },
				}),
			);
		};

		await searchSearXNG({ query: "bearer search", fetch: fetchMock });

		expect(captured.headers?.get("Authorization")).toBe("Bearer bearer-token");
	});

	it("treats empty SearXNG results with upstream failures as a provider error", async () => {
		process.env.SEARXNG_ENDPOINT = "https://searx.example.org";

		const fetchMock: FetchImpl = () =>
			Promise.resolve(
				new Response(
					JSON.stringify({
						results: [],
						unresponsive_engines: [
							["brave", "Suspended: too many requests"],
							["duckduckgo", "CAPTCHA"],
						],
					}),
					{ status: 200, headers: { "Content-Type": "application/json" } },
				),
			);

		await expect(searchSearXNG({ query: "throttled search", fetch: fetchMock })).rejects.toThrow(SearchProviderError);
		await expect(searchSearXNG({ query: "throttled search", fetch: fetchMock })).rejects.toThrow(
			"SearXNG returned no usable results; upstream engines failed: brave: Suspended: too many requests; duckduckgo: CAPTCHA",
		);
	});
});