export type Category = {
  id: string
  nameFa: string
  nameEn: string
  children: Category[]
}

export const initialCategories: Category[] = [
  {
    id: '1',
    nameFa: 'شیرینی',
    nameEn: 'Pastries',
    children: [
      {
        id: '1-1',
        nameFa: 'شیرینی خشک',
        nameEn: 'Dry Cookies',
        children: [
          {
            id: '1-1-1',
            nameFa: 'شیرینی پسته',
            nameEn: 'Pistachio Cookie',
            children: [],
          },
          {
            id: '1-1-2',
            nameFa: 'شیرینی گردو',
            nameEn: 'Walnut Cookie',
            children: [],
          },
        ],
      },
      {
        id: '1-2',
        nameFa: 'شیرینی تر',
        nameEn: 'Soft Pastries',
        children: [],
      },
    ],
  },
  {
    id: '2',
    nameFa: 'کیک',
    nameEn: 'Cakes',
    children: [
      {
        id: '2-1',
        nameFa: 'کیک شکلاتی',
        nameEn: 'Chocolate Cake',
        children: [],
      },
      {
        id: '2-2',
        nameFa: 'چیزکیک',
        nameEn: 'Cheesecake',
        children: [],
      },
    ],
  },
  {
    id: '3',
    nameFa: 'نان',
    nameEn: 'Bread',
    children: [
      {
        id: '3-1',
        nameFa: 'کروسان',
        nameEn: 'Croissant',
        children: [],
      },
    ],
  },
  {
    id: '4',
    nameFa: 'باقلوا',
    nameEn: 'Baklava',
    children: [],
  },
]

export function createCategory(nameFa: string, nameEn: string): Category {
  return {
    id: `${Date.now()}-${Math.random().toString(36).slice(2, 7)}`,
    nameFa,
    nameEn,
    children: [],
  }
}

export function addChildCategory(
  categories: Category[],
  parentId: string,
  child: Category,
): Category[] {
  return categories.map((category) => {
    if (category.id === parentId) {
      return { ...category, children: [...category.children, child] }
    }
    if (category.children.length > 0) {
      return {
        ...category,
        children: addChildCategory(category.children, parentId, child),
      }
    }
    return category
  })
}

export function removeCategory(
  categories: Category[],
  targetId: string,
): Category[] {
  return categories
    .filter((category) => category.id !== targetId)
    .map((category) => ({
      ...category,
      children: removeCategory(category.children, targetId),
    }))
}

export type FlatCategoryOption = {
  id: string
  nameFa: string
  nameEn: string
  labelFa: string
  labelEn: string
  depth: number
}

export function flattenCategories(
  categories: Category[],
  prefix = '',
  depth = 0,
): FlatCategoryOption[] {
  return categories.flatMap((category) => {
    const labelFa = prefix ? `${prefix} / ${category.nameFa}` : category.nameFa
    const labelEn = prefix ? `${prefix} / ${category.nameEn}` : category.nameEn
    return [
      {
        id: category.id,
        nameFa: category.nameFa,
        nameEn: category.nameEn,
        labelFa,
        labelEn,
        depth,
      },
      ...flattenCategories(category.children, labelFa, depth + 1),
    ]
  })
}

export function findCategory(
  categories: Category[],
  id: string,
): Category | null {
  for (const category of categories) {
    if (category.id === id) return category
    const found = findCategory(category.children, id)
    if (found) return found
  }
  return null
}

export function findParentId(
  categories: Category[],
  targetId: string,
  parentId: string | null = null,
): string | null | undefined {
  for (const category of categories) {
    if (category.id === targetId) return parentId
    const found = findParentId(category.children, targetId, category.id)
    if (found !== undefined) return found
  }
  return undefined
}

export function updateCategory(
  categories: Category[],
  targetId: string,
  updates: { nameFa: string; nameEn: string },
): Category[] {
  return categories.map((category) => {
    if (category.id === targetId) {
      return { ...category, ...updates }
    }
    if (category.children.length > 0) {
      return {
        ...category,
        children: updateCategory(category.children, targetId, updates),
      }
    }
    return category
  })
}