import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
import { writeFileSync, readFileSync, mkdtempSync, rmSync } from 'node:fs';
import { join } from 'node:path';
import { tmpdir } from 'node:os';
import { createConfigCommand } from '../../src/commands/config.js';
import type { ApiClient } from '../../src/api-client.js';
import { DEFAULT_MCPCTL_GATEWAY_URL } from '../../src/config/prime-agent.js';

function mockClient(): ApiClient {
  return {
    get: vi.fn(async () => ({})),
    post: vi.fn(async () => ({ token: 'impersonated-tok', user: { email: 'other@test.com' } })),
    put: vi.fn(async () => ({})),
    delete: vi.fn(async () => {}),
  } as unknown as ApiClient;
}

describe('config prime-agent', () => {
  let client: ReturnType<typeof mockClient>;
  let output: string[];
  let tmpDir: string;
  const log = (...args: string[]) => output.push(args.join(' '));

  let prevCwd: string;

  beforeEach(() => {
    client = mockClient();
    output = [];
    tmpDir = mkdtempSync(join(tmpdir(), 'mcpctl-config-prime-agent-'));
    // config prime-agent writes the .mcpctl-project marker into cwd, so run
    // every test from an isolated temp dir to avoid polluting the repo.
    prevCwd = process.cwd();
    process.chdir(tmpDir);
  });

  afterEach(() => {
    process.chdir(prevCwd);
    process.exitCode = 0;
    rmSync(tmpDir, { recursive: true, force: true });
  });

  it('requires --project', async () => {
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--skip-skills'], { from: 'user' });
    expect(output.join('\n')).toContain('--project is required');
    expect(process.exitCode).toBe(1);
  });

  it('writes proxy MCP entry into prime-agent settings.json', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--project', 'homeautomation', '-o', settingsPath, '--skip-skills'], { from: 'user' });

    const written = JSON.parse(readFileSync(settingsPath, 'utf-8'));
    expect(written.mcpServers['homeautomation']).toEqual({
      type: 'http',
      url: `${DEFAULT_MCPCTL_GATEWAY_URL}/projects/homeautomation/mcp`,
    });
    expect(output.join('\n')).toContain('homeautomation');
  });

  it('merges with existing servers and preserves other settings', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    writeFileSync(settingsPath, JSON.stringify({
      defaultProvider: 'itaz',
      mcpServers: {
        sre: { type: 'http', url: `${DEFAULT_MCPCTL_GATEWAY_URL}/projects/sre/mcp` },
      },
    }));

    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--project', 'proj-1', '-o', settingsPath, '--skip-skills'], { from: 'user' });

    const written = JSON.parse(readFileSync(settingsPath, 'utf-8'));
    expect(written.defaultProvider).toBe('itaz'); // untouched
    expect(written.mcpServers['sre']).toBeDefined(); // preserved
    expect(written.mcpServers['proj-1']).toEqual({
      type: 'http',
      url: `${DEFAULT_MCPCTL_GATEWAY_URL}/projects/proj-1/mcp`,
    });
  });

  it('writes a project marker for later skills sync', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--project', 'sre', '-o', settingsPath, '--skip-skills'], { from: 'user' });

    const markerPath = join(tmpDir, '.mcpctl-project');
    expect(readFileSync(markerPath, 'utf-8').trim()).toBe('sre');
  });

  it('--dry-run prints the change without writing', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--project', 'proj-2', '-o', settingsPath, '--dry-run'], { from: 'user' });

    expect(output.join('\n')).toContain('proj-2');
    // No file should have been created.
    expect(exceptionSafeRead(settingsPath)).toBeNull();
  });

  it('does not call the API when --skip-skills is set', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent', '--project', 'proj-3', '-o', settingsPath, '--skip-skills'], { from: 'user' });

    expect(client.get).not.toHaveBeenCalled();
  });

  it('backward compat: prime-agent-generate still works', async () => {
    const settingsPath = join(tmpDir, 'settings.json');
    const cmd = createConfigCommand(
      { configDeps: { configDir: tmpDir }, log },
      { client, credentialsDeps: { configDir: tmpDir }, log },
    );
    await cmd.parseAsync(['prime-agent-generate', '--project', 'proj-1', '-o', settingsPath, '--skip-skills'], { from: 'user' });

    const written = JSON.parse(readFileSync(settingsPath, 'utf-8'));
    expect(written.mcpServers['proj-1']).toBeDefined();
  });
});

function exceptionSafeRead(path: string): string | null {
  try {
    return readFileSync(path, 'utf-8');
  } catch {
    return null;
  }
}