import type { IngestSegment } from '../ingest/segment.js'
import type { ReleaseIdentity } from '../release/index.js'
import type { AggregatedFile } from '../aggregate/index.js'

/**
 * A complete file as a seeding node reports it (CONCEPT.md D37): what the
 * file, its release and its binary need, once per file, and the segments
 * as [part number, message-id, bytes].
 */
export interface SeedFile {
  fileKey: string
  name: string
  poster: string
  subject: string
  totalParts: number
  groups: string[]
  /** Earliest post date of its articles, ISO 8601. */
  postedAt: string | null
  release: ReleaseIdentity | null
  segments: [number, string, number][]
}

/** A segment of a file that didn't complete on the node, for the regular ingest path. */
export type SeedFragment = Omit<IngestSegment, 'postedAt' | 'articleNumber'> & { postedAt?: string; articleNumber?: number }

/** What a node sends per batch: the article it has reached, and what it found up to there. */
export interface SeedBatch {
  /** First article number not covered yet (everything below it, from the range start, is in this or earlier batches). */
  next: number
  headers: number
  obfuscated: number
  deferred: number
  files: SeedFile[]
  fragments: SeedFragment[]
}

export function toSeedFile(file: AggregatedFile<IngestSegment>): SeedFile {
  const first = file.segments[0]
  const times = file.segments.map((s) => s.postedAt?.getTime()).filter((t): t is number => Number.isFinite(t))
  return {
    fileKey: file.fileKey,
    name: first.name,
    poster: first.poster,
    subject: first.subject,
    totalParts: first.totalParts,
    groups: first.groups,
    postedAt: times.length > 0 ? new Date(Math.min(...times)).toISOString() : null,
    release: first.release ?? null,
    segments: file.segments.map((s) => [s.number, s.messageId, s.bytes]),
  }
}

export function toFragment(segment: IngestSegment): SeedFragment {
  const { postedAt, articleNumber, ...rest } = segment
  const date = postedAt && !Number.isNaN(postedAt.getTime()) ? postedAt.toISOString() : undefined
  return { ...rest, postedAt: date, articleNumber: articleNumber === undefined ? undefined : Number(articleNumber) }
}

export function fromFragment(fragment: SeedFragment): IngestSegment {
  // The JSON body parser turns empty strings into null; the columns want ''.
  return {
    ...fragment,
    poster: fragment.poster ?? '',
    subject: fragment.subject ?? '',
    name: fragment.name ?? '',
    postedAt: fragment.postedAt ? new Date(fragment.postedAt) : undefined,
  }
}

/** A file from a node's JSON, with empty strings back where the body parser made them null. */
export function normalizeSeedFile(file: SeedFile): SeedFile {
  return { ...file, name: file.name ?? '', poster: file.poster ?? '', subject: file.subject ?? '' }
}