/**
 * History display utilities for edit pages.
 *
 * Extracted from pages/component/[id]/edit.vue, pieces/[id]/edit.vue,
 * product/[id]/edit.vue – each had an identical copy.
 */

// ---------------------------------------------------------------------------
// Formatters
// ---------------------------------------------------------------------------

export const historyActionLabel = (action: string): string => {
  if (action === 'create') return 'Création'
  if (action === 'delete') return 'Suppression'
  if (action === 'restore') return 'Restauration'
  return 'Modification'
}

const historyDateFormatter = new Intl.DateTimeFormat('fr-FR', {
  dateStyle: 'medium',
  timeStyle: 'short',
})

export const formatHistoryDate = (value: string): string => {
  const date = new Date(value)
  if (Number.isNaN(date.getTime())) return value
  return historyDateFormatter.format(date)
}

export const formatHistoryValue = (value: unknown): string => {
  if (value === null || value === undefined || value === '') return '—'
  if (Array.isArray(value)) {
    if (value.length === 0) return '—'
    return value.map((item) => formatHistoryValue(item)).join(', ')
  }
  if (typeof value === 'object') {
    const maybeRecord = value as Record<string, unknown>
    const name = typeof maybeRecord.name === 'string' ? maybeRecord.name : null
    const id = typeof maybeRecord.id === 'string' ? maybeRecord.id : null
    if (name && id) return `${name} (#${id})`
    if (name) return name
    if (id) return `#${id}`
    try {
      return JSON.stringify(value)
    } catch {
      return String(value)
    }
  }
  return String(value)
}

// ---------------------------------------------------------------------------
// Diff entries
// ---------------------------------------------------------------------------

interface DiffChange {
  from?: unknown
  to?: unknown
}

export interface HistoryDiffEntry {
  field: string
  label: string
  fromLabel: string
  toLabel: string
}

export const historyDiffEntries = (
  entry: { diff?: Record<string, DiffChange> | null },
  fieldLabels: Record<string, string>,
): HistoryDiffEntry[] => {
  const diff = entry.diff ?? {}
  return Object.entries(diff).map(([field, change]) => ({
    field,
    label: fieldLabels[field] ?? field,
    fromLabel: formatHistoryValue(change?.from),
    toLabel: formatHistoryValue(change?.to),
  }))
}