import { afterEach, describe, expect, it } from "bun:test";
import { loadCredentials } from "../src/lib/credentials";

const realFetch = globalThis.fetch;
const envKeys = ["ATP_IDENTIFIER", "ATP_APP_PASSWORD", "PDS_URL"] as const;
const savedEnv = envKeys.map((key) => [key, process.env[key]] as const);

function mockFetch(handler: (url: string) => Response): void {
	globalThis.fetch = (async (input: RequestInfo | URL) =>
		handler(
			typeof input === "string" ? input : input.toString(),
		)) as typeof fetch;
}

afterEach(() => {
	globalThis.fetch = realFetch;
	for (const [key, value] of savedEnv) {
		if (value === undefined) {
			delete process.env[key];
		} else {
			process.env[key] = value;
		}
	}
});

describe("loadCredentials with app-password env vars", () => {
	it("resolves the PDS from the identifier when PDS_URL is unset", async () => {
		process.env.ATP_IDENTIFIER = "alice.example.com";
		process.env.ATP_APP_PASSWORD = "app-password";
		delete process.env.PDS_URL;

		mockFetch((url) =>
			url.includes("plc.directory")
				? Response.json({
						service: [
							{
								id: "#atproto_pds",
								type: "AtprotoPersonalDataServer",
								serviceEndpoint: "https://pds.example.com",
							},
						],
					})
				: Response.json({ did: "did:plc:abc123" }),
		);

		const credentials = await loadCredentials();

		expect(credentials).toEqual({
			type: "app-password",
			identifier: "alice.example.com",
			password: "app-password",
			pdsUrl: "https://pds.example.com",
		});
	});

	it("prefers an explicit PDS_URL without any lookup", async () => {
		process.env.ATP_IDENTIFIER = "alice.example.com";
		process.env.ATP_APP_PASSWORD = "app-password";
		process.env.PDS_URL = "https://custom.example.com";

		mockFetch(() => {
			throw new Error("should not fetch");
		});

		const credentials = await loadCredentials();

		expect(credentials).toMatchObject({
			pdsUrl: "https://custom.example.com",
		});
	});

	it("falls back to bsky.social when the identifier cannot be resolved", async () => {
		process.env.ATP_IDENTIFIER = "alice.example.com";
		process.env.ATP_APP_PASSWORD = "app-password";
		delete process.env.PDS_URL;

		mockFetch(() => new Response("nope", { status: 500 }));

		const credentials = await loadCredentials();

		expect(credentials).toMatchObject({ pdsUrl: "https://bsky.social" });
	});
});