import type { Collection, CollectionWithCount, Generation } from './db';

/**
 * The one place a database row becomes JSON.
 *
 * Every API serialiser lives in this file — a structural choice, not tidiness: it is the one place
 * that can enforce snake_case across every endpoint. See the standalone repo's test for the incident
 * this guarded against (`serialize.test.ts`, ported below).
 *
 * Snake case throughout, because the response body is deliberately OpenAI-shaped and OpenAI is snake.
 */

/**
 * `/files/<name>`, relative from this plugin's own mount — NOT an absolute `PUBLIC_URL` any more.
 *
 * The standalone service served images unauthenticated with a durable absolute URL; inside Officer the
 * route is behind the permission gate like everything else, so there is no host to bake in and no
 * reason to. An API caller already holding a bearer token re-fetches this path with the same
 * `Authorization` header they used to get here. The Officer frontend (which cannot set that header on
 * an `<img src>`) appends its own `?token=` — see `plugins/atelier/web/lib/api.ts` — the same escape
 * hatch `FileViewer` and the music plugin already use for exactly this reason.
 */
const imageUrl = (row: Generation) => (row.imagePath ? `/files/${row.imagePath}` : null);

/** What every image reports about itself, wherever it appears. */
const measured = (row: Generation) => ({
  width: row.width,
  height: row.height,
  // `has_alpha` is whether the file carries an alpha channel; `opaque` is whether every pixel in it is
  // fully opaque. Both, because an alpha channel the model never used is the failure worth catching.
  has_alpha: row.hasAlpha,
  opaque: row.opaque,
  cost_usd: row.costUsd,
  duration_ms: row.durationMs,
});

/** The compact form, for `atelier.images[]` — no prompt, which at n:10 would repeat 32000 chars ten times. */
export const serializeGenerationImage = (row: Generation) => ({
  id: row.id,
  status: row.status,
  url: imageUrl(row),
  ...measured(row),
  error: row.error,
});

/**
 * The full row, for history and collections.
 *
 * `prompt`, `options` and `input_images` are here deliberately and are not to be normalised or
 * truncated: every disappointing result so far has been traced to what was asked for, and these three
 * are what make that diagnosis possible after the fact.
 */
export const serializeGeneration = (row: Generation) => ({
  id: row.id,
  request_id: row.requestId,
  index: row.index,
  operation: row.operation,
  status: row.status,
  provider: row.provider,
  model: row.model,
  prompt: row.prompt,
  options: row.options,
  input_images: row.inputImages,
  mask_image: row.maskImage,
  image_path: row.imagePath,
  url: imageUrl(row),
  ...measured(row),
  error: row.error,
  created_at: row.createdAt,
  started_at: row.startedAt,
  finished_at: row.finishedAt,
});

/**
 * A collection, as the API returns it.
 *
 * Drizzle hands back camelCase because that is what the schema declares in TypeScript. Returning the
 * row untouched is how a camelCase field would reach the wire in a snake_case API — this is where one
 * becomes the other.
 */
export const serializeCollection = (row: Collection) => ({
  id: row.id,
  name: row.name,
  description: row.description,
  created_at: row.createdAt,
  updated_at: row.updatedAt,
});

/** The list form, with the counts the index screen needs. */
export const serializeCollectionSummary = (row: CollectionWithCount) => ({
  ...serializeCollection(row),
  item_count: row.itemCount,
  cover_image_path: row.coverImagePath,
  cover_url: row.coverImagePath ? `/files/${row.coverImagePath}` : null,
});