import type { FormElementDto } from '~~/.api-client'

export function useFormElementDuplication() {
  function cloneElement(elementToClone: FormElementDto, existingElements: FormElementDto[]): FormElementDto {
    const newReference = elementToClone.reference
      ? generateNextReference(existingElements, elementToClone.reference)
      : undefined
    const isTextField = elementToClone.type === 'TEXTAREA' || elementToClone.type === 'TEXTFIELD'

    const clonedElement = JSON.parse(JSON.stringify(elementToClone)) as FormElementDto
    const resetOptions = clonedElement.options.map((option) => ({
      ...option,
      value: isTextField ? '' : option.value
    }))

    return {
      ...clonedElement,
      id: undefined,
      formElementSubSectionId: undefined,
      reference: newReference,
      options: resetOptions
    }
  }

  function generateNextReference(existingElements: FormElementDto[], baseReference: string): string {
    const { base } = extractReferenceBase(baseReference)

    const existingSuffixes = existingElements
      .filter((el) => el.reference && el.reference.startsWith(base))
      .map((el) => {
        const { suffix } = extractReferenceBase(el.reference!)
        return suffix
      })

    const maxSuffix = existingSuffixes.length > 0 ? Math.max(...existingSuffixes) : 0
    return `${base}_${maxSuffix + 1}`
  }

  function extractReferenceBase(reference: string): { base: string; suffix: number } {
    const match = reference.match(/^(.+?)_(\d+)$/)
    if (match && match[1] && match[2]) {
      return { base: match[1], suffix: parseInt(match[2], 10) }
    }
    return { base: reference, suffix: 1 }
  }

  return {
    cloneElement
  }
}