// @vitest-environment node
import { mkdtempSync } from 'node:fs';
import { tmpdir } from 'node:os';
import { join } from 'node:path';
import { test, expect } from 'vitest';
import { cleanPrefValue, cleanPrefsPatch, mergePrefs } from './prefs.js';

const NOW = 1_800_000_000_000;

test('only known preferences with valid values are accepted', () => {
  expect(cleanPrefValue('theme', 'dark')).toBe('dark');
  expect(cleanPrefValue('theme', 'neon')).toBeUndefined();
  expect(cleanPrefValue('translation', 'ESV')).toBe('ESV');
  expect(cleanPrefValue('translation', 'KJV')).toBeUndefined();
  expect(cleanPrefValue('layout', 'flow')).toBe('flow');
  expect(cleanPrefValue('commentarySource', 'tyndale')).toBe('tyndale');
  expect(cleanPrefValue('startPage', 'reader')).toBe('reader');
  expect(cleanPrefValue('startPage', 'admin')).toBeUndefined();
  expect(cleanPrefValue('planTranslation', 'same')).toBe('same');
  expect(cleanPrefValue('planTranslation', 'NASB')).toBe('NASB');
  expect(cleanPrefValue('planTranslation', 'KJV')).toBeUndefined();
  expect(cleanPrefValue('fontSize', 2)).toBeUndefined(); // not a synced preference
});

test('position needs a real book and chapter, and the book is normalised', () => {
  expect(cleanPrefValue('position', { book: 'jhn', chapter: 3 })).toEqual({ book: 'JHN', chapter: 3 });
  expect(cleanPrefValue('position', { book: 'JOHN', chapter: 3 })).toBeUndefined();
  expect(cleanPrefValue('position', { book: 'JHN', chapter: 0 })).toBeUndefined();
  expect(cleanPrefValue('position', { book: 'JHN', chapter: '3' })).toBeUndefined();
  expect(cleanPrefValue('position', null)).toBeUndefined();
});

test('cleanPrefsPatch drops unknown keys, bad values and silly timestamps', () => {
  const patch = cleanPrefsPatch({ prefs: {
    theme: { v: 'sepia', at: NOW },
    layout: { v: 'nope', at: NOW },
    evil: { v: 'x', at: NOW },
    translation: { v: 'NLT', at: 'yesterday' },
    commentarySource: { v: 'tyndale', at: NOW + 5 * 86_400_000 }, // far in the future
    position: { v: { book: 'GEN', chapter: 2 }, at: NOW - 10 },
  } }, NOW);
  expect(patch).toEqual({ theme: { v: 'sepia', at: NOW }, position: { v: { book: 'GEN', chapter: 2 }, at: NOW - 10 } });
  expect(cleanPrefsPatch(null)).toEqual({});
  expect(cleanPrefsPatch({ prefs: [] })).toEqual({});
});

test('the newest change to each preference wins, independently', () => {
  const existing = { theme: { v: 'dark', at: 100 }, layout: { v: 'flow', at: 500 } };
  const patch = { theme: { v: 'paper', at: 200 }, layout: { v: 'verses', at: 300 }, translation: { v: 'ESV', at: 50 } };
  expect(mergePrefs(existing, patch)).toEqual({
    theme: { v: 'paper', at: 200 }, // patch is newer
    layout: { v: 'flow', at: 500 }, // stored is newer
    translation: { v: 'ESV', at: 50 }, // new key
  });
  expect(mergePrefs({ theme: { v: 'dark', at: 100 } }, { theme: { v: 'paper', at: 100 } }).theme.v).toBe('dark'); // tie keeps stored
});

test('the database keeps one row per user', async () => {
  process.env.DATA_DIR = mkdtempSync(join(tmpdir(), 'prefs-'));
  const db = await import('./db.js');
  db.initDb();
  db.createUser({ id: 'u1', email: 'a@example.test', passwordHash: 'x' });
  db.createUser({ id: 'u2', email: 'b@example.test', passwordHash: 'x' });
  expect(db.getUserPrefs('u1')).toEqual({});
  db.setUserPrefs('u1', { theme: { v: 'dark', at: 1 } });
  db.setUserPrefs('u1', { theme: { v: 'sepia', at: 2 } });
  expect(db.getUserPrefs('u1')).toEqual({ theme: { v: 'sepia', at: 2 } });
  expect(db.getUserPrefs('u2')).toEqual({});
});

test('study templates are kept only when well-formed, and trimmed to sane sizes', async () => {
  const { cleanPrefValue } = await import('./prefs.js');
  const good = { id: 'user-abc1', name: ' Lesson ', description: 'x', prompts: { observation: 'Look', junk: 'no' }, starters: { generalNotes: 'Context:', bogus: 'no' } };
  expect(cleanPrefValue('studyTemplates', [good, { id: 'other', name: 'bad id' }, { id: 'user-2' }, null])).toEqual([
    { id: 'user-abc1', name: 'Lesson', description: 'x', prompts: { observation: 'Look' }, starters: { generalNotes: 'Context:' } },
  ]);
  expect(cleanPrefValue('studyTemplates', 'nope')).toBeUndefined();
  expect(cleanPrefValue('studyTemplates', Array.from({ length: 30 }, (_, i) => ({ id: `user-${i}`, name: `T${i}` }))).length).toBe(12);
  expect(cleanPrefValue('studyTemplates', [{ id: 'user-a', name: 'x', starters: { observation: 'y'.repeat(5000) } }])[0].starters.observation.length).toBe(2000);
});