// Pure helpers for the Coverage page (#74). Kept separate so they are unit-testable
// without rendering the server component.

export interface UseCaseRow {
  key: string
  label: string
  group: string
  regulations: string[]
  verification_methods: string[]
  mapped_controls: number
  atom_total: number
  atom_relevant: number
}

export interface CorpusDoc {
  source_regulation: string
  license_rule: number | null
  license_tier: string
  atom_count: number
  use_case: string | null
}

export interface LicenseSummaryRow {
  license_rule: number | null
  label: string
  atom_count: number
}

export interface LicenseCatalogEntry {
  source_id: string
  title: string
  publisher: string | null
  url: string | null
  version: string | null
  license_id: string | null
  license_name: string | null
  commercial_use: string | null
  ship_in_product: boolean | null
  terms_url: string | null
}

export interface CorpusOverview {
  license_summary: LicenseSummaryRow[]
  documents: CorpusDoc[]
  license_catalog: LicenseCatalogEntry[]
  totals: { documents: number; catalog_sources: number }
}

export const USE_CASE_GROUP_LABELS: Record<string, string> = {
  document: 'Dokument-Compliance',
  security: 'Security',
  cross_cutting: 'Querschnitt',
  product: 'Produkt / Sektor',
}

export function licenseTierBadgeClass(rule: number | null): string {
  switch (rule) {
    case 1:
      return 'bg-green-100 text-green-800'
    case 2:
      return 'bg-blue-100 text-blue-800'
    case 3:
      return 'bg-amber-100 text-amber-800'
    default:
      return 'bg-gray-100 text-gray-700'
  }
}

export function commercialBadgeClass(commercial: string | null): string {
  switch ((commercial || '').toLowerCase()) {
    case 'allowed':
      return 'bg-green-100 text-green-800'
    case 'restricted':
      return 'bg-amber-100 text-amber-800'
    case 'prohibited':
      return 'bg-red-100 text-red-800'
    default:
      return 'bg-gray-100 text-gray-700'
  }
}

export interface UseCaseGroup {
  group: string
  label: string
  rows: UseCaseRow[]
}

// Group use-cases by their registry group (stable order), each group's rows
// sorted by how many relevant obligations it carries (desc).
export function groupUseCases(rows: UseCaseRow[]): UseCaseGroup[] {
  const order = ['document', 'security', 'cross_cutting', 'product']
  const by: Record<string, UseCaseRow[]> = {}
  for (const r of rows) {
    ;(by[r.group] ||= []).push(r)
  }
  const groups = order.filter((g) => by[g]?.length)
  for (const g of Object.keys(by)) {
    if (!order.includes(g)) groups.push(g)
  }
  return groups.map((g) => ({
    group: g,
    label: USE_CASE_GROUP_LABELS[g] || g,
    rows: [...by[g]].sort((a, b) => b.atom_relevant - a.atom_relevant),
  }))
}