/**
 * frontend-writes.test.ts — the ONE write loop of the frontend primitive
 * scaffolders (theme, layout, ui-primitives, dashboard, auth).
 *
 * Audit 2026-09-24, B-WARN-11: five identical loops in five `main()` bodies,
 * none of them testable. The contract they all claimed in prose is pinned
 * here once.
 */
import { describe, it, expect, beforeEach, afterEach } from 'vitest'
import { existsSync, mkdirSync, mkdtempSync, readFileSync, rmSync, statSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join, resolve } from 'node:path'
import { deepMerge, writeFrontendFiles } from '../frontend-writes.js'

let root: string
beforeEach(() => { root = mkdtempSync(join(tmpdir(), 'ss-frontend-writes-')) })
afterEach(() => rmSync(root, { recursive: true, force: true }))

function seed(rel: string, content: string): string {
  const abs = join(root, rel)
  mkdirSync(join(abs, '..'), { recursive: true })
  writeFileSync(abs, content, 'utf-8')
  return abs
}

describe('writeFrontendFiles — overwrite strategy', () => {
  it('creates a missing file (nested folders included) and reports it ABSOLUTE', () => {
    const r = writeFrontendFiles([{ path: 'src/components/ui/PageTemplate.tsx', content: 'export {}\n' }], { projectPath: root })
    expect(r.filesCreated).toEqual([resolve(root, 'src/components/ui/PageTemplate.tsx')])
    expect(r.filesModified).toEqual([])
    expect(r.skipped).toEqual([])
    expect(r.malformed).toEqual([])
    expect(readFileSync(join(root, 'src/components/ui/PageTemplate.tsx'), 'utf-8')).toBe('export {}\n')
  })

  it('rewrites a drifted generated file and reports it under filesModified', () => {
    seed('src/index.css', '/* old */\n')
    const r = writeFrontendFiles([{ path: 'src/index.css', content: '/* new */\n' }], { projectPath: root })
    expect(r.filesModified).toEqual([resolve(root, 'src/index.css')])
    expect(r.filesCreated).toEqual([])
    expect(readFileSync(join(root, 'src/index.css'), 'utf-8')).toBe('/* new */\n')
  })

  it('an identical file is a NO-OP (not written, not reported) unless force', () => {
    const abs = seed('src/index.css', '/* same */\n')
    const before = statSync(abs).mtimeMs
    const r = writeFrontendFiles([{ path: 'src/index.css', content: '/* same */\n' }], { projectPath: root })
    expect(r.filesModified).toEqual([])
    expect(r.filesCreated).toEqual([])
    expect(statSync(abs).mtimeMs).toBe(before)

    const forced = writeFrontendFiles([{ path: 'src/index.css', content: '/* same */\n' }], { projectPath: root, force: true })
    expect(forced.filesModified).toEqual([resolve(root, 'src/index.css')])
  })

  it('NEVER overwrites a @customised file (all three comment forms) — skipped as given, even with force', () => {
    seed('src/index.css', '/* @customised */\n.x{}\n')
    seed('src/components/ui/PageTemplate.tsx', '// @customised — hand-owned\nexport {}\n')
    seed('src/x.html', '<!-- @customised -->\n<p/>\n')
    const files = [
      { path: 'src/index.css', content: 'new' },
      { path: 'src/components/ui/PageTemplate.tsx', content: 'new' },
      { path: 'src/x.html', content: 'new' },
    ]
    for (const force of [false, true]) {
      const r = writeFrontendFiles(files, { projectPath: root, force })
      expect(r.skipped).toEqual(['src/index.css', 'src/components/ui/PageTemplate.tsx', 'src/x.html'])
      expect(r.filesModified).toEqual([])
    }
    expect(readFileSync(join(root, 'src/index.css'), 'utf-8')).toBe('/* @customised */\n.x{}\n')
  })

  it('refuses a path that escapes the project root (traversal) before writing anything', () => {
    expect(() => writeFrontendFiles([{ path: '../escape.css', content: 'x' }], { projectPath: root })).toThrow()
    expect(existsSync(resolve(root, '..', 'escape.css'))).toBe(false)
  })
})

describe('writeFrontendFiles — deep-merge-json strategy (i18n catalogues)', () => {
  const patch = JSON.stringify({ entityLookup: { search: 'Rechercher', empty: 'Aucun' } }, null, 2)

  it('a NEW catalogue is written verbatim (it is already a complete document)', () => {
    const r = writeFrontendFiles([{ path: 'src/locales/fr/common.json', content: patch, strategy: 'deep-merge-json' }], { projectPath: root })
    expect(r.filesCreated).toEqual([resolve(root, 'src/locales/fr/common.json')])
    expect(readFileSync(join(root, 'src/locales/fr/common.json'), 'utf-8')).toBe(patch)
  })

  it('an EXISTING catalogue is deep-merged — sibling namespaces and sibling keys survive', () => {
    seed('src/locales/fr/common.json', JSON.stringify({
      auth: { login: 'Connexion' },
      entityLookup: { search: 'OLD', placeholder: 'Choisir…' },
    }, null, 2) + '\n')
    const r = writeFrontendFiles([{ path: 'src/locales/fr/common.json', content: patch, strategy: 'deep-merge-json' }], { projectPath: root })
    expect(r.filesModified).toEqual([resolve(root, 'src/locales/fr/common.json')])
    const merged = JSON.parse(readFileSync(join(root, 'src/locales/fr/common.json'), 'utf-8'))
    expect(merged).toEqual({
      auth: { login: 'Connexion' },
      entityLookup: { search: 'Rechercher', placeholder: 'Choisir…', empty: 'Aucun' },
    })
  })

  it('an already-merged catalogue is a NO-OP unless force', () => {
    seed('src/locales/fr/common.json', JSON.stringify({ entityLookup: { search: 'Rechercher', empty: 'Aucun' } }, null, 2) + '\n')
    const r = writeFrontendFiles([{ path: 'src/locales/fr/common.json', content: patch, strategy: 'deep-merge-json' }], { projectPath: root })
    expect(r.filesModified).toEqual([])
    const forced = writeFrontendFiles([{ path: 'src/locales/fr/common.json', content: patch, strategy: 'deep-merge-json' }], { projectPath: root, force: true })
    expect(forced.filesModified).toHaveLength(1)
  })

  it('a MALFORMED catalogue is refused — reported absolute, never replaced by the patch (B-WARN-22)', () => {
    const abs = seed('src/locales/fr/common.json', '{ "auth": { "login": "Connexion" ')
    const r = writeFrontendFiles([{ path: 'src/locales/fr/common.json', content: patch, strategy: 'deep-merge-json' }], { projectPath: root })
    expect(r.malformed).toEqual([resolve(root, 'src/locales/fr/common.json')])
    expect(r.filesModified).toEqual([])
    expect(readFileSync(abs, 'utf-8')).toBe('{ "auth": { "login": "Connexion" ')
  })
})

describe('deepMerge', () => {
  it('merges objects key by key; arrays and primitives in the patch replace the base', () => {
    expect(deepMerge({ a: { b: 1, c: [1] }, d: 'x' }, { a: { c: [2], e: null }, f: 2 }))
      .toEqual({ a: { b: 1, c: [2], e: null }, d: 'x', f: 2 })
    expect(deepMerge([1, 2], { a: 1 })).toEqual({ a: 1 })
    expect(deepMerge({ a: 1 }, 'scalar')).toBe('scalar')
  })
})