import fs from "node:fs/promises";
import os from "node:os";
import path from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import { agentInstructionsService } from "../services/agent-instructions.js";

type TestAgent = {
  id: string;
  companyId: string;
  name: string;
  adapterConfig: Record<string, unknown>;
};

async function makeTempDir(prefix: string) {
  return fs.mkdtemp(path.join(os.tmpdir(), prefix));
}

function makeAgent(adapterConfig: Record<string, unknown>): TestAgent {
  return {
    id: "agent-1",
    companyId: "company-1",
    name: "Agent 1",
    adapterConfig,
  };
}

describe("agent instructions service", () => {
  const originalPaperclipHome = process.env.PAPERCLIP_HOME;
  const originalPaperclipInstanceId = process.env.PAPERCLIP_INSTANCE_ID;
  const cleanupDirs = new Set<string>();

  afterEach(async () => {
    if (originalPaperclipHome === undefined) delete process.env.PAPERCLIP_HOME;
    else process.env.PAPERCLIP_HOME = originalPaperclipHome;
    if (originalPaperclipInstanceId === undefined) delete process.env.PAPERCLIP_INSTANCE_ID;
    else process.env.PAPERCLIP_INSTANCE_ID = originalPaperclipInstanceId;

    await Promise.all([...cleanupDirs].map(async (dir) => {
      await fs.rm(dir, { recursive: true, force: true });
      cleanupDirs.delete(dir);
    }));
  });

  it("copies the existing bundle into the managed root when switching to managed mode", async () => {
    const paperclipHome = await makeTempDir("paperclip-agent-instructions-home-");
    const externalRoot = await makeTempDir("paperclip-agent-instructions-external-");
    cleanupDirs.add(paperclipHome);
    cleanupDirs.add(externalRoot);
    process.env.PAPERCLIP_HOME = paperclipHome;
    process.env.PAPERCLIP_INSTANCE_ID = "test-instance";

    await fs.writeFile(path.join(externalRoot, "AGENTS.md"), "# External Agent\n", "utf8");
    await fs.mkdir(path.join(externalRoot, "docs"), { recursive: true });
    await fs.writeFile(path.join(externalRoot, "docs", "TOOLS.md"), "## Tools\n", "utf8");

    const svc = agentInstructionsService();
    const agent = makeAgent({
      instructionsBundleMode: "external",
      instructionsRootPath: externalRoot,
      instructionsEntryFile: "AGENTS.md",
      instructionsFilePath: path.join(externalRoot, "AGENTS.md"),
    });

    const result = await svc.updateBundle(agent, { mode: "managed" });

    expect(result.bundle.mode).toBe("managed");
    expect(result.bundle.managedRootPath).toBe(
      path.join(
        paperclipHome,
        "instances",
        "test-instance",
        "companies",
        "company-1",
        "agents",
        "agent-1",
        "instructions",
      ),
    );
    expect(result.bundle.files.map((file) => file.path)).toEqual(["AGENTS.md", "docs/TOOLS.md"]);
    await expect(fs.readFile(path.join(result.bundle.managedRootPath, "AGENTS.md"), "utf8")).resolves.toBe("# External Agent\n");
    await expect(fs.readFile(path.join(result.bundle.managedRootPath, "docs", "TOOLS.md"), "utf8")).resolves.toBe("## Tools\n");
  });

  it("creates the target entry file when switching to a new external root", async () => {
    const paperclipHome = await makeTempDir("paperclip-agent-instructions-home-");
    const managedRoot = path.join(
      paperclipHome,
      "instances",
      "test-instance",
      "companies",
      "company-1",
      "agents",
      "agent-1",
      "instructions",
    );
    const externalRoot = await makeTempDir("paperclip-agent-instructions-new-external-");
    cleanupDirs.add(paperclipHome);
    cleanupDirs.add(externalRoot);
    process.env.PAPERCLIP_HOME = paperclipHome;
    process.env.PAPERCLIP_INSTANCE_ID = "test-instance";

    await fs.mkdir(managedRoot, { recursive: true });
    await fs.writeFile(path.join(managedRoot, "AGENTS.md"), "# Managed Agent\n", "utf8");

    const svc = agentInstructionsService();
    const agent = makeAgent({
      instructionsBundleMode: "managed",
      instructionsRootPath: managedRoot,
      instructionsEntryFile: "AGENTS.md",
      instructionsFilePath: path.join(managedRoot, "AGENTS.md"),
    });

    const result = await svc.updateBundle(agent, {
      mode: "external",
      rootPath: externalRoot,
      entryFile: "docs/AGENTS.md",
    });

    expect(result.bundle.mode).toBe("external");
    expect(result.bundle.rootPath).toBe(externalRoot);
    await expect(fs.readFile(path.join(externalRoot, "docs", "AGENTS.md"), "utf8")).resolves.toBe("# Managed Agent\n");
  });
});