/**
 * agents.test.ts — markdown agent-definition loader.
 */
import { describe, expect, it } from "bun:test";
import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { extensionRoot, loadAgents } from "../src/agents.js";

/** Build an agent markdown file with frontmatter + body. */
async function writeAgent(
	dir: string,
	file: string,
	name: string,
	body: string,
	tools?: string[],
): Promise<string> {
	const lines = ["---", `name: ${name}`];
	if (tools) {
		lines.push("allowedTools:");
		for (const t of tools) lines.push(`  - ${t}`);
	}
	lines.push("---", body, "");
	await writeFile(join(dir, file), lines.join("\n"), "utf8");
	return join(dir, file);
}

describe("loadAgents", () => {
	it("loads scanner.md and fixer.md shipped with the extension", async () => {
		const agents = await loadAgents();
		expect(agents.has("scanner")).toBe(true);
		expect(agents.has("fixer")).toBe(true);
		const scanner = agents.get("scanner");
		expect(scanner).toBeDefined();
		expect(scanner?.systemPrompt).toContain("scanner");
		expect(scanner?.allowedTools).toContain("read");
		expect(scanner?.allowedTools).not.toContain("edit"); // scanner is read-only
		expect(scanner?.sourcePath).toContain("agents/scanner.md");
		const fixer = agents.get("fixer");
		expect(fixer?.allowedTools).toContain("edit");
	});

	it("extensionRoot resolves to the package directory", () => {
		expect(extensionRoot()).toMatch(/(pygenium|pygienium)$/);
	});

	it("project-local agents override the extension's by name", async () => {
		const cwd = await mkdtemp(join(tmpdir(), "pygium-agents-"));
		try {
			await mkdir(join(cwd, "agents"));
			const path = await writeAgent(
				join(cwd, "agents"),
				"scanner.md",
				"scanner",
				"Project-tuned scanner prompt.",
				["read", "grep", "find", "edit"],
			);
			const agents = await loadAgents({ cwd });
			const scanner = agents.get("scanner");
			expect(scanner?.systemPrompt).toContain("Project-tuned");
			expect(scanner?.allowedTools).toContain("edit"); // repo override widens tools
			expect(scanner?.sourcePath).toBe(path);
			// Extension baseline is retained for agents the repo doesn't override.
			expect(agents.get("fixer")).toBeDefined();
		} finally {
			await rm(cwd, { recursive: true, force: true });
		}
	});

	it("project-local agents can add brand-new agents", async () => {
		const cwd = await mkdtemp(join(tmpdir(), "pygium-agents-"));
		try {
			await mkdir(join(cwd, "agents"));
			await writeAgent(
				join(cwd, "agents"),
				"judge.md",
				"judge",
				"Scoring judge.",
			);
			const agents = await loadAgents({ cwd });
			expect(agents.has("judge")).toBe(true);
			expect(agents.get("judge")?.systemPrompt).toContain("Scoring judge");
		} finally {
			await rm(cwd, { recursive: true, force: true });
		}
	});

	it("a project without agents/ falls back to the extension agents", async () => {
		const cwd = await mkdtemp(join(tmpdir(), "pygium-agents-"));
		try {
			const agents = await loadAgents({ cwd });
			expect(agents.has("scanner")).toBe(true);
			expect(agents.has("fixer")).toBe(true);
		} finally {
			await rm(cwd, { recursive: true, force: true });
		}
	});
});