export type ItemType = 'E' | 'F' | 'U' | 'T' | 'B'

export interface HierarchyInfo {
  fullPath: string
  items: { type: ItemType; number: number }[]
  epicCode: string | null
  featureCode: string | null
  itemCode: string | null
}

const TYPE_LABELS: Record<ItemType, string> = {
  E: 'Épica',
  F: 'Feature',
  U: 'HU',
  T: 'Tarea',
  B: 'Bug',
}

const TYPE_COLORS: Record<ItemType, string> = {
  E: 'bg-purple-100 text-purple-700 dark:bg-purple-900/30 dark:text-purple-400',
  F: 'bg-blue-100 text-blue-700 dark:bg-blue-900/30 dark:text-blue-400',
  U: 'bg-emerald-100 text-emerald-700 dark:bg-emerald-900/30 dark:text-emerald-400',
  T: 'bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400',
  B: 'bg-rose-100 text-rose-700 dark:bg-rose-900/30 dark:text-rose-400',
}

const TYPE_ICONS: Record<ItemType, string> = {
  E: '📦',
  F: '⭐',
  U: '📋',
  T: '⚙️',
  B: '🐛',
}

export function getTypeLabel(type: ItemType): string {
  return TYPE_LABELS[type] || type
}

export function getTypeColor(type: ItemType): string {
  return TYPE_COLORS[type] || 'bg-muted text-muted-foreground'
}

export function getTypeIcon(type: ItemType): string {
  return TYPE_ICONS[type] || '📄'
}

const HIERARCHY_REGEX = /\[(([EFUTB]\d+)(?:-([EFUTB]\d+))?(?:-([EFUTB]\d+))?)\]/i

export function parseHierarchy(title: string): HierarchyInfo | null {
  const match = title.match(HIERARCHY_REGEX)
  if (!match) return null

  const fullPath = match[1].toUpperCase()
  const segments = [match[2]]
  if (match[3]) segments.push(match[3])
  if (match[4]) segments.push(match[4])

  const items = segments.map(s => ({
    type: s[0] as ItemType,
    number: parseInt(s.slice(1), 10),
  }))

  const epic = items.find(i => i.type === 'E')
  const feature = items.find(i => i.type === 'F')
  const item = items[items.length - 1]

  return {
    fullPath,
    items,
    epicCode: epic ? `E${String(epic.number).padStart(2, '0')}` : null,
    featureCode: feature ? `F${String(feature.number).padStart(2, '0')}` : null,
    itemCode: item ? `${item.type}${String(item.number).padStart(2, '0')}` : null,
  }
}

export function stripHierarchy(title: string): string {
  return title.replace(HIERARCHY_REGEX, '').trim()
}

export function getItemType(title: string): ItemType {
  const h = parseHierarchy(title)
  if (h?.items.length) return h.items[h.items.length - 1].type
  return 'U'
}

export function buildHierarchyPath(
  epicNum?: number,
  featureNum?: number,
  itemType?: ItemType,
  itemNum?: number,
): string {
  const parts: string[] = []
  if (epicNum !== undefined) parts.push(`E${String(epicNum).padStart(2, '0')}`)
  if (featureNum !== undefined) parts.push(`F${String(featureNum).padStart(2, '0')}`)
  if (itemType && itemNum !== undefined) parts.push(`${itemType}${String(itemNum).padStart(2, '0')}`)
  return parts.length ? `[${parts.join('-')}]` : ''
}

export function buildFullTitle(
  name: string,
  epicNum?: number,
  featureNum?: number,
  itemType?: ItemType,
  itemNum?: number,
): string {
  const path = buildHierarchyPath(epicNum, featureNum, itemType, itemNum)
  return path ? `${path} ${name}` : name
}

export function extractItemNumber(title: string, type: ItemType): number | null {
  const h = parseHierarchy(title)
  if (!h) return null
  const found = h.items.find(i => i.type === type)
  return found?.number ?? null
}