import { describe, it, expect } from 'vitest'
import { mkdtempSync, rmSync, existsSync, readFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import path from 'node:path'
import { cacheArtwork } from '../src/artwork.js'

function tempDir(): string {
  return mkdtempSync(path.join(tmpdir(), 'rs-artwork-'))
}

function imageFetch(calls: { count: number }): typeof fetch {
  return (async () => {
    calls.count++
    return new Response(new Uint8Array([0xff, 0xd8, 0xff, 0xe0]), {
      status: 200,
      headers: { 'content-type': 'image/jpeg' },
    })
  }) as typeof fetch
}

describe('cacheArtwork', () => {
  it('downloads and stores by url hash with content-type extension', async () => {
    const dir = tempDir()
    try {
      const calls = { count: 0 }
      const file = await cacheArtwork(dir, 'https://img.discogs.com/a.jpg', imageFetch(calls))
      expect(file).toMatch(/^[0-9a-f]{64}\.jpg$/)
      expect(existsSync(path.join(dir, file as string))).toBe(true)
    } finally {
      rmSync(dir, { recursive: true, force: true })
    }
  })

  it('second call for same url does not refetch', async () => {
    const dir = tempDir()
    try {
      const calls = { count: 0 }
      const fetcher = imageFetch(calls)
      await cacheArtwork(dir, 'https://img.discogs.com/a.jpg', fetcher)
      const again = await cacheArtwork(dir, 'https://img.discogs.com/a.jpg', fetcher)
      expect(calls.count).toBe(1)
      expect(again).not.toBeNull()
    } finally {
      rmSync(dir, { recursive: true, force: true })
    }
  })

  it('returns null for empty url and fetch failures without throwing', async () => {
    const dir = tempDir()
    try {
      expect(await cacheArtwork(dir, '', imageFetch({ count: 0 }))).toBeNull()
      const failing = (async () => {
        throw new TypeError('fetch failed')
      }) as unknown as typeof fetch
      expect(await cacheArtwork(dir, 'https://x/y.jpg', failing)).toBeNull()
      const notFound = (async () => new Response('nope', { status: 404 })) as unknown as typeof fetch
      expect(await cacheArtwork(dir, 'https://x/y.jpg', notFound)).toBeNull()
    } finally {
      rmSync(dir, { recursive: true, force: true })
    }
  })

  it('stores non-jpeg types with correct extension', async () => {
    const dir = tempDir()
    try {
      const fetcher = (async () =>
        new Response(new Uint8Array([0x89, 0x50]), {
          status: 200,
          headers: { 'content-type': 'image/png' },
        })) as typeof fetch
      const file = await cacheArtwork(dir, 'https://img.discogs.com/a.png', fetcher)
      expect(file).toMatch(/\.png$/)
      expect(readFileSync(path.join(dir, file as string)).length).toBeGreaterThan(0)
    } finally {
      rmSync(dir, { recursive: true, force: true })
    }
  })

  it('returns null when the response body fails mid-download', async () => {
    const dir = tempDir()
    try {
      const fetcher = (async () =>
        new Response(new ReadableStream({
          start(controller) {
            controller.enqueue(new Uint8Array([0xff]))
            controller.error(new TypeError('network error mid-body'))
          },
        }), { status: 200, headers: { 'content-type': 'image/jpeg' } })) as unknown as typeof fetch
      expect(await cacheArtwork(dir, 'https://x/abort.jpg', fetcher)).toBeNull()
    } finally {
      rmSync(dir, { recursive: true, force: true })
    }
  })
})