import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import { mkdtemp, mkdir, writeFile, rm } from 'node:fs/promises';
import { join } from 'node:path';
import { tmpdir } from 'node:os';
import {
  loadSpecDomains,
  readSpec,
  fileToSpecDomain,
} from './lib/openlore-context-injector-helpers.ts';

// ─── Fixtures ─────────────────────────────────────────────────────────────────

const SPEC_CONTENT = `# Auth Specification

> Generated by openlore

## Purpose

Handles authentication and session management.

## Requirements

### Requirement: Login

The system SHALL authenticate users via JWT.

#### Scenario: ValidCredentials
- **GIVEN** valid credentials
- **WHEN** login is called
- **THEN** a JWT is returned
`;

async function createSpec(tmpDir: string, domain: string, content = SPEC_CONTENT) {
  const specDir = join(tmpDir, 'openspec', 'specs', domain);
  await mkdir(specDir, { recursive: true });
  await writeFile(join(specDir, 'spec.md'), content);
}

// ─── loadSpecDomains ──────────────────────────────────────────────────────────

describe('loadSpecDomains', () => {
  let tmpDir: string;

  beforeEach(async () => {
    tmpDir = await mkdtemp(join(tmpdir(), 'openlore-injector-test-'));
  });

  afterEach(async () => {
    await rm(tmpDir, { recursive: true, force: true });
  });

  it('returns empty array when openspec/specs/ does not exist', () => {
    const result = loadSpecDomains(tmpDir);
    expect(result).toEqual([]);
  });

  it('returns empty array when openspec/specs/ has no subdirectories', async () => {
    await mkdir(join(tmpDir, 'openspec', 'specs'), { recursive: true });
    const result = loadSpecDomains(tmpDir);
    expect(result).toEqual([]);
  });

  it('loads a single spec domain', async () => {
    await createSpec(tmpDir, 'auth');
    const result = loadSpecDomains(tmpDir);
    expect(result).toHaveLength(1);
    expect(result[0].name).toBe('auth');
    expect(result[0].purpose).toBe('Handles authentication and session management.');
    expect(result[0].path).toContain('spec.md');
  });

  it('loads multiple spec domains', async () => {
    await createSpec(tmpDir, 'auth');
    await createSpec(tmpDir, 'api', `# Api\n\n## Purpose\n\nProvides REST endpoints.\n`);
    const result = loadSpecDomains(tmpDir);
    expect(result).toHaveLength(2);
    const names = result.map((d) => d.name).sort();
    expect(names).toEqual(['api', 'auth']);
  });

  it('skips a domain with missing spec.md', async () => {
    await mkdir(join(tmpDir, 'openspec', 'specs', 'empty-domain'), { recursive: true });
    await createSpec(tmpDir, 'auth');
    const result = loadSpecDomains(tmpDir);
    expect(result).toHaveLength(1);
    expect(result[0].name).toBe('auth');
  });

  it('extracts purpose even with [PARTIAL SPEC] prefix', async () => {
    await createSpec(
      tmpDir,
      'analyzer',
      `# Analyzer\n\n## Purpose\n\n[PARTIAL SPEC — file too large] Analyzes codebase.\n`
    );
    const result = loadSpecDomains(tmpDir);
    expect(result[0].purpose).toBe('Analyzes codebase.');
  });

  it('returns empty purpose when ## Purpose section is missing', async () => {
    await createSpec(tmpDir, 'nopurpose', `# No Purpose\n\n## Requirements\n\nSomething.\n`);
    const result = loadSpecDomains(tmpDir);
    expect(result[0].purpose).toBe('');
  });
});

// ─── readSpec ─────────────────────────────────────────────────────────────────

describe('readSpec', () => {
  let tmpDir: string;

  beforeEach(async () => {
    tmpDir = await mkdtemp(join(tmpdir(), 'openlore-injector-test-'));
  });

  afterEach(async () => {
    await rm(tmpDir, { recursive: true, force: true });
  });

  it('returns empty string when spec file does not exist', () => {
    const domain = { name: 'auth', path: join(tmpDir, 'nonexistent.md'), purpose: '' };
    expect(readSpec(domain)).toBe('');
  });

  it('returns full content when under maxChars', async () => {
    await createSpec(tmpDir, 'auth');
    const [domain] = loadSpecDomains(tmpDir);
    const result = readSpec(domain);
    expect(result).toBe(SPEC_CONTENT);
  });

  it('truncates at a section boundary when over maxChars', async () => {
    const longContent = SPEC_CONTENT + '\n## Section2\n\n' + 'x'.repeat(5000);
    await createSpec(tmpDir, 'auth', longContent);
    const [domain] = loadSpecDomains(tmpDir);
    const result = readSpec(domain, 200);
    expect(result).toContain('spec truncated');
    expect(result.length).toBeLessThan(longContent.length);
  });

  it('truncates without section boundary when content has no ## headers after truncation point', async () => {
    const flatContent = 'a'.repeat(500);
    await createSpec(tmpDir, 'auth', flatContent);
    const [domain] = loadSpecDomains(tmpDir);
    const result = readSpec(domain, 100);
    expect(result).toContain('spec truncated');
  });
});

// ─── fileToSpecDomain ─────────────────────────────────────────────────────────

describe('fileToSpecDomain', () => {
  let tmpDir: string;
  const domains = [
    { name: 'auth', path: '', purpose: '' },
    { name: 'api', path: '', purpose: '' },
    { name: 'analyzer', path: '', purpose: '' },
  ];

  beforeEach(async () => {
    tmpDir = await mkdtemp(join(tmpdir(), 'openlore-injector-test-'));
    await mkdir(join(tmpDir, '.openlore', 'analysis'), { recursive: true });
  });

  afterEach(async () => {
    await rm(tmpDir, { recursive: true, force: true });
  });

  it('returns null when no match is found', () => {
    const result = fileToSpecDomain('src/unknown/mystery.ts', domains, tmpDir);
    expect(result).toBeNull();
  });

  it('matches by domain name in file path (heuristic)', () => {
    const result = fileToSpecDomain('src/auth/middleware.ts', domains, tmpDir);
    expect(result).toBe('auth');
  });

  it('matches by parent directory name', () => {
    const result = fileToSpecDomain('src/api/routes.ts', domains, tmpDir);
    expect(result).toBe('api');
  });

  it('uses mapping.json when available (array form)', async () => {
    const mapping = [{ file: 'src/core/analyzer/engine.ts', domain: 'analyzer' }];
    await writeFile(join(tmpDir, '.openlore', 'analysis', 'mapping.json'), JSON.stringify(mapping));
    const result = fileToSpecDomain('src/core/analyzer/engine.ts', domains, tmpDir);
    expect(result).toBe('analyzer');
  });

  it('uses mapping.json when available (object form)', async () => {
    const mapping = {
      'req-1': { filePath: 'src/api/server.ts', spec: 'api' },
    };
    await writeFile(join(tmpDir, '.openlore', 'analysis', 'mapping.json'), JSON.stringify(mapping));
    const result = fileToSpecDomain('src/api/server.ts', domains, tmpDir);
    expect(result).toBe('api');
  });

  it('falls back to heuristic when mapping.json has no match', async () => {
    const mapping = [{ file: 'src/other.ts', domain: 'api' }];
    await writeFile(join(tmpDir, '.openlore', 'analysis', 'mapping.json'), JSON.stringify(mapping));
    const result = fileToSpecDomain('src/auth/service.ts', domains, tmpDir);
    expect(result).toBe('auth');
  });

  it('handles malformed mapping.json without throwing', async () => {
    await writeFile(join(tmpDir, '.openlore', 'analysis', 'mapping.json'), 'not valid json');
    const result = fileToSpecDomain('src/auth/service.ts', domains, tmpDir);
    expect(result).toBe('auth');
  });
});