import fs from 'fs';
import os from 'os';
import path from 'path';
import YAML from 'yaml';
import { describe, it, expect, beforeEach, afterEach } from 'vitest';
import { persistSubreddits } from '../src/config/persistence.js';

const SAMPLE = `# top-level note that must survive
reddit:
  # weights bias picking
  subreddits:
    - { name: AverageNudes, weight: 4, tone: 'direct' }    # validation seekers
    - { name: gonewild40plus, weight: 4, tone: 'gentle' }  # mature
    - { name: normalnudes, weight: 3 }                     # real bodies
    - { name: tightandtoned, weight: 1 }

  pollIntervalMs: 30000
  userAgent: "ua"
`;

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

  beforeEach(() => {
    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'rb-config-'));
    configPath = path.join(tmpDir, 'config.yaml');
    fs.writeFileSync(configPath, SAMPLE, 'utf-8');
  });

  afterEach(() => {
    fs.rmSync(tmpDir, { recursive: true, force: true });
  });

  it('mutates an existing row in place and preserves its inline comment', () => {
    persistSubreddits(
      [
        { name: 'AverageNudes', type: 'image', weight: 4, tone: 'playful' },
        { name: 'gonewild40plus', type: 'image', weight: 4, tone: 'gentle' },
        { name: 'normalnudes', type: 'image', weight: 3, tone: 'default' },
        { name: 'tightandtoned', type: 'image', weight: 1, tone: 'default' },
      ],
      configPath,
    );
    const out = fs.readFileSync(configPath, 'utf-8');
    expect(out).toMatch(/tone:\s*['"]?playful['"]?/);
    expect(out).toContain('# validation seekers');
    expect(out).toContain('# top-level note that must survive');
    expect(out).toContain('# weights bias picking');
    expect(out).toContain('# mature');
    expect(out).toContain('pollIntervalMs: 30000');
  });

  it('drops removed rows (and their attached comments)', () => {
    persistSubreddits(
      [
        { name: 'AverageNudes', type: 'image', weight: 4, tone: 'direct' },
        { name: 'tightandtoned', type: 'image', weight: 1, tone: 'default' },
      ],
      configPath,
    );
    const out = fs.readFileSync(configPath, 'utf-8');
    expect(out).not.toContain('gonewild40plus');
    expect(out).not.toContain('normalnudes');
    expect(out).not.toContain('# mature');
    expect(out).toContain('AverageNudes');
    expect(out).toContain('tightandtoned');
    expect(out).toContain('# validation seekers');
  });

  it('appends new rows in caller order', () => {
    persistSubreddits(
      [
        { name: 'AverageNudes', type: 'image', weight: 4, tone: 'direct' },
        { name: 'gonewild40plus', type: 'image', weight: 4, tone: 'gentle' },
        { name: 'normalnudes', type: 'image', weight: 3, tone: 'default' },
        { name: 'tightandtoned', type: 'image', weight: 1, tone: 'default' },
        { name: 'NewSub', type: 'chat', weight: 2, tone: 'playful' },
      ],
      configPath,
    );
    const parsed = YAML.parse(fs.readFileSync(configPath, 'utf-8'));
    const subs = parsed.reddit.subreddits;
    expect(subs[subs.length - 1]).toMatchObject({
      name: 'NewSub',
      type: 'chat',
      weight: 2,
      tone: 'playful',
    });
  });

  it("omits 'default' tone and 'image' type on write to match on-disk style", () => {
    persistSubreddits(
      [{ name: 'OnlyOne', type: 'image', weight: 1, tone: 'default' }],
      configPath,
    );
    const out = fs.readFileSync(configPath, 'utf-8');
    expect(out).not.toMatch(/tone:\s*default/);
    expect(out).not.toMatch(/type:\s*image/);
  });

  it('atomic write — tmp file not left behind on success', () => {
    persistSubreddits(
      [{ name: 'OnlyOne', type: 'image', weight: 1, tone: 'direct' }],
      configPath,
    );
    expect(fs.existsSync(configPath + '.tmp')).toBe(false);
  });

  it('reorders rows according to input order', () => {
    persistSubreddits(
      [
        { name: 'tightandtoned', type: 'image', weight: 1, tone: 'default' },
        { name: 'AverageNudes', type: 'image', weight: 4, tone: 'direct' },
        { name: 'gonewild40plus', type: 'image', weight: 4, tone: 'gentle' },
        { name: 'normalnudes', type: 'image', weight: 3, tone: 'default' },
      ],
      configPath,
    );
    const parsed = YAML.parse(fs.readFileSync(configPath, 'utf-8'));
    expect(parsed.reddit.subreddits.map((s: { name: string }) => s.name)).toEqual([
      'tightandtoned',
      'AverageNudes',
      'gonewild40plus',
      'normalnudes',
    ]);
  });
});