import { describe, test, expect } from 'vitest';
import { fileURLToPath } from 'node:url';
import { dirname, join } from 'node:path';
import { makeWikiGraphTools } from '../src/tools.js';
import { GraphCache } from '../src/cache.js';

const here = dirname(fileURLToPath(import.meta.url));
const FIXTURE = join(here, 'fixtures', 'wiki');

function toolMap() {
  const tools = makeWikiGraphTools(new GraphCache());
  return new Map(tools.map((t) => [t.name, t]));
}

function textOf(res: { content: Array<{ type: string; text: string }>; isError?: boolean }) {
  return res.content.map((c) => c.text).join('\n');
}

describe('wiki-graph MCP tools', () => {
  const tools = toolMap();

  test('exposes exactly the five v1 tools', () => {
    expect([...tools.keys()].sort()).toEqual([
      'backlinks',
      'neighbors',
      'orphans',
      'path',
      'stats',
    ]);
  });

  test('every tool requires a corpus argument', () => {
    for (const t of tools.values()) {
      expect(t.inputSchema.required).toContain('corpus');
    }
  });

  test('path: returns the chain', () => {
    const res = tools.get('path')!.handler({ corpus: FIXTURE, from: 'a', to: 'c' });
    expect(textOf(res)).toContain('a → b → c');
  });

  test('path: reports absence', () => {
    const res = tools.get('path')!.handler({ corpus: FIXTURE, from: 'a', to: 'e' });
    expect(textOf(res).toLowerCase()).toContain('no path');
  });

  test('neighbors: honors depth', () => {
    const res = tools.get('neighbors')!.handler({ corpus: FIXTURE, node: 'a', depth: 2 });
    const txt = textOf(res);
    expect(txt).toContain('b');
    expect(txt).toContain('c');
  });

  test('backlinks: lists incoming', () => {
    const res = tools.get('backlinks')!.handler({ corpus: FIXTURE, node: 'c' });
    const txt = textOf(res);
    expect(txt).toContain('b');
    expect(txt).toContain('d');
  });

  test('orphans: lists unlinked pages and dangling targets', () => {
    const res = tools.get('orphans')!.handler({ corpus: FIXTURE });
    const txt = textOf(res);
    expect(txt).toContain('e');
    expect(txt).toContain('<todo-module>');
  });

  test('stats: reports counts', () => {
    const res = tools.get('stats')!.handler({ corpus: FIXTURE });
    const txt = textOf(res);
    expect(txt).toContain('5');
    expect(txt).toContain('nodes');
  });

  test('missing corpus is a clean error, not a throw', () => {
    const res = tools.get('stats')!.handler({});
    expect(res.isError).toBe(true);
    expect(textOf(res).toLowerCase()).toContain('corpus');
  });
});