export const CAPTION_STYLES = ['descriptive', 'klein_prompt', 'delta', 'tags']

export const DELTA_LOCKED_LOOK =
  'short light-brown bob, pink tank, light blue shorts, open green Slytherin robe with red-gold trim, barefoot'

export function captionStylePrompt(style) {
  switch (style) {
    case 'klein_prompt':
      return 'Write one self-contained image generation prompt for Flux Klein. Include subject, pose, clothing, setting, lighting, and camera. No preamble or quotes.'
    case 'delta':
      return `The character's locked baseline look is: ${DELTA_LOCKED_LOOK}. Describe ONLY what changed from that baseline in this image. Do not restate the locked look.`
    case 'tags':
      return 'List comma-separated descriptive tags for this image. Tags only, no sentences.'
    case 'descriptive':
    default:
      return 'Describe this image in clear, detailed prose. Cover subject, appearance, clothing, pose, setting, and lighting.'
  }
}

export function validateCaptionRequest(raw) {
  const fail = message => { throw Object.assign(new Error(message), { statusCode: 400 }) }
  const body = raw || {}
  const style = String(body.captionStyle || body.style || 'descriptive')
  if (!CAPTION_STYLES.includes(style)) fail('Unknown caption style.')
  const folderId = String(body.folderId || '')
  if (!folderId) fail('Choose a folder.')
  const stillId = String(body.stillId || body.imageAId || '')
  const sourcePath = String(body.sourcePath || '')
  if (!stillId && !sourcePath) fail('Choose a still to describe.')
  return {
    mode: 'caption',
    folderId,
    stillId,
    sourcePath,
    captionStyle: style,
    promptSections: { action: `Describe · ${style}` },
    compiledPrompt: captionStylePrompt(style),
    engine: 'caption',
    imageStyles: { positive: [], negative: [] },
    hideOutput: false,
    lockFace: false,
    lockOutfit: false,
    hideInput: false,
    identityStillId: '',
    imageAId: stillId,
    imageBId: '',
    maskId: '',
    startClipId: '',
    endStillId: '',
    guides: [],
    batch: [],
    settings: {
      aspect: 'auto',
      fps: 24,
      width: 0,
      height: 0,
      steps: 1,
      cfg: 0,
      seedMode: 'random',
      seed: 0,
      duration: 0,
      turbo: true,
      loraStack: []
    }
  }
}