import { describe, it, expect, beforeEach } from 'vitest';
import { mkdtemp, mkdir } from 'node:fs/promises';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { makeKnowledgeTools } from '../../src/tools/knowledge.js';
import { writeCache, type CacheFile } from '../../src/lib/cache.js';
import type { Backend, CommitFileArgs, FileWithSha } from '../../src/lib/backend.js';

let wikiRoot: string;
let projectCwd: string;
let cacheFile: string;

beforeEach(async () => {
  wikiRoot = await mkdtemp(join(tmpdir(), 'kw-shared-'));
  await mkdir(wikiRoot, { recursive: true });
  projectCwd = await mkdtemp(join(tmpdir(), 'kw-cwd-'));
  cacheFile = join(await mkdtemp(join(tmpdir(), 'kw-cache-')), 'cache.json');
});

interface FetchedPage {
  body: string;
}

/**
 * Pages are keyed by qualified `<owner>/<repo>` so the mock backend can verify
 * that handlers route fetches to the correct owner — the whole point of the
 * cross-owner regression in [multi-owner-ask-projects-owner-fix].
 */
function makeBackend(pages: Record<string, Record<string, FetchedPage | Error>>): Backend {
  return {
    async listUserRepos() {
      return [];
    },
    async getRawFile(owner, repo, path) {
      const repoPages = pages[`${owner}/${repo}`];
      if (!repoPages) return null;
      const v = repoPages[path];
      if (v === undefined) return null;
      if (v instanceof Error) throw v;
      return v.body;
    },
    async getFileWithSha(): Promise<FileWithSha | null> {
      return null;
    },
    async commitFile(_a: CommitFileArgs) {
      throw new Error('not used');
    },
  };
}

async function seedCache(projects: CacheFile['projects']) {
  const file: CacheFile = {
    schemaVersion: 3,
    synced_at: '2026-04-30T00:00:00Z',
    synced_from: 'https://g',
    machine: 'm',
    projects,
    errors: [],
  };
  await writeCache(cacheFile, file);
}

function call(
  tools: ReturnType<typeof makeKnowledgeTools>,
  name: string,
  args: Record<string, unknown>,
) {
  const t = tools.find((x) => x.name === name);
  if (!t) throw new Error(`tool ${name} missing`);
  return t.handler(args);
}

const sampleIndex = `# Wiki Index

## Concepts

- [yarn-on-windows](concepts/yarn-on-windows.md) — Yarn on Windows
- [other](concepts/other.md) — Other Concept

## Raw

- [pdf-dump](raw/pdf-dump.md) — Heavy PDF
`;

describe('knowledge.ask_projects', () => {
  it('returns matches across listed projects with snippets', async () => {
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': {
        '.wiki/concepts/yarn-on-windows.md': {
          body: '---\ntitle: Yarn on Windows\n---\n\nyarn install on windows is fiddly',
        },
      },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'yarn',
      projects: ['u/foo'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.asked_projects).toEqual(['u/foo']);
    expect(parsed.results).toHaveLength(1);
    expect(parsed.results[0].project).toBe('u/foo');
    expect(parsed.results[0].matches).toHaveLength(1);
    expect(parsed.results[0].matches[0].slug).toBe('concepts/yarn-on-windows');
    expect(parsed.results[0].matches[0].type).toBe('concepts');
    expect(parsed.results[0].matches[0].title).toBe('Yarn on Windows');
    expect(parsed.results[0].matches[0].snippet).toContain('yarn');
  });

  it('routes fetches to the correct owner across multiple owners (cross-owner)', async () => {
    await seedCache([
      {
        name: 'victor/books',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
      {
        name: 'OpeItcLoc03/common',
        default_branch: 'master',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const calls: Array<{ owner: string; repo: string }> = [];
    const backend: Backend = {
      async listUserRepos() {
        return [];
      },
      async getRawFile(owner, repo, path) {
        calls.push({ owner, repo });
        if (owner === 'victor' && repo === 'books') {
          return path === '.wiki/concepts/yarn-on-windows.md' ? 'victor body about yarn' : null;
        }
        if (owner === 'OpeItcLoc03' && repo === 'common') {
          return path === '.wiki/concepts/yarn-on-windows.md' ? 'common body about yarn' : null;
        }
        // Reject acting-identity routing — proves the bug is gone.
        throw new Error(`unexpected fetch ${owner}/${repo}`);
      },
      async getFileWithSha(): Promise<FileWithSha | null> {
        return null;
      },
      async commitFile() {
        throw new Error('not used');
      },
    };
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'OpeItcLoc03',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'yarn',
      projects: ['victor/books', 'OpeItcLoc03/common'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results).toHaveLength(2);
    const victorResult = parsed.results.find((x: { project: string }) => x.project === 'victor/books');
    const commonResult = parsed.results.find((x: { project: string }) => x.project === 'OpeItcLoc03/common');
    expect(victorResult.matches[0].snippet).toContain('victor body');
    expect(commonResult.matches[0].snippet).toContain('common body');
    // Owner extracted from projectName, not from acting giteaUser.
    expect(calls.some((c) => c.owner === 'victor' && c.repo === 'books')).toBe(true);
    expect(calls.some((c) => c.owner === 'OpeItcLoc03' && c.repo === 'common')).toBe(true);
  });

  it('rejects bare project name with parseTargetProject hint', async () => {
    await seedCache([]);
    const backend = makeBackend({});
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'x',
      projects: ['books'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results).toHaveLength(1);
    expect(parsed.results[0].project).toBe('books');
    expect(parsed.results[0].error).toContain('must be qualified');
  });

  it('continues with valid projects when one is bare', async () => {
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': {
        '.wiki/concepts/yarn-on-windows.md': { body: 'yarn body' },
      },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'yarn',
      projects: ['books', 'u/foo'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results).toHaveLength(2);
    expect(parsed.results[0].error).toContain('must be qualified');
    expect(parsed.results[1].matches).toHaveLength(1);
  });

  it('rejects agenda literal with explanatory error', async () => {
    await seedCache([]);
    const backend = makeBackend({});
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'x',
      projects: ['agenda'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results[0].error).toContain('agenda not supported');
  });

  it('reports "no wiki" for projects without wiki_index', async () => {
    await seedCache([
      {
        name: 'u/no-wiki',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
      },
    ]);
    const backend = makeBackend({});
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'anything',
      projects: ['u/no-wiki'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results).toEqual([
      { project: 'u/no-wiki', error: 'no wiki — repo has no .wiki/index.md' },
    ]);
  });

  it('reports "unknown project" when project not in cache', async () => {
    await seedCache([]);
    const backend = makeBackend({});
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'x',
      projects: ['u/ghost'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results).toEqual([
      { project: 'u/ghost', error: 'unknown project — run sync first' },
    ]);
  });

  it('excludes raw type by default', async () => {
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': {
        '.wiki/raw/pdf-dump.md': { body: 'pdf about pdf' },
      },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'pdf',
      projects: ['u/foo'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results[0].matches).toEqual([]);
  });

  it('includes raw when explicitly asked', async () => {
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': { '.wiki/raw/pdf-dump.md': { body: 'pdf body' } },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'pdf',
      projects: ['u/foo'],
      types: ['raw'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results[0].matches).toHaveLength(1);
    expect(parsed.results[0].matches[0].slug).toBe('raw/pdf-dump');
  });

  it('respects limit per project', async () => {
    const wideIndex = `# Wiki Index\n\n## Concepts\n\n- [a](concepts/a.md) — A\n- [b](concepts/b.md) — B\n- [c](concepts/c.md) — C\n`;
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: wideIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': {
        '.wiki/concepts/a.md': { body: '' },
        '.wiki/concepts/b.md': { body: '' },
        '.wiki/concepts/c.md': { body: '' },
      },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: '',
      projects: ['u/foo'],
      limit: 2,
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results[0].matches).toHaveLength(2);
  });

  it('marks snippet as "(fetch failed)" when live fetch throws', async () => {
    await seedCache([
      {
        name: 'u/foo',
        default_branch: 'main',
        fetched_at: '2026-04-30T00:00:00Z',
        active_tasks: [],
        all_tasks_count: 0,
        raw: '',
        wiki_index: sampleIndex,
      },
    ]);
    const backend = makeBackend({
      'u/foo': {
        '.wiki/concepts/yarn-on-windows.md': new Error('boom'),
      },
    });
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend,
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'yarn',
      projects: ['u/foo'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.results[0].matches[0].snippet).toBe('(fetch failed)');
    expect(parsed.results[0].matches[0].slug).toBe('concepts/yarn-on-windows');
  });

  it('returns error when backend not configured', async () => {
    await seedCache([]);
    const tools = makeKnowledgeTools({ wikiRoot, projectCwd, cacheFile });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'x',
      projects: ['u/foo'],
    });
    expect(r.isError).toBe(true);
    expect(r.content[0].text).toContain('disabled');
  });

  it('next_action_hint mentions both knowledge.get_from and tasks.create', async () => {
    await seedCache([]);
    const tools = makeKnowledgeTools({
      wikiRoot,
      projectCwd,
      cacheFile,
      backend: makeBackend({}),
      giteaUser: 'u',
    });
    const r = await call(tools, 'knowledge.ask_projects', {
      query: 'x',
      projects: ['u/foo'],
    });
    const parsed = JSON.parse(r.content[0].text);
    expect(parsed.next_action_hint).toContain('knowledge.get_from');
    expect(parsed.next_action_hint).toContain('tasks.create');
  });
});