import type { Operation } from './usePrintQueue'

export interface PrintTemplate {
  id: string
  name: string
  description?: string
  operations: Operation[]
  createdAt: number
  updatedAt: number
}

const STORAGE_KEY = 'printercentral-templates'

export function useTemplates() {
  const templates = useState<PrintTemplate[]>('templates', () => [])
  const initialized = useState('templatesInitialized', () => false)

  // Cargar de localStorage al iniciar (solo cliente)
  if (import.meta.client && !initialized.value) {
    const stored = localStorage.getItem(STORAGE_KEY)
    if (stored) {
      try {
        templates.value = JSON.parse(stored)
      } catch (e) {
        console.error('Error parsing templates:', e)
      }
    }
    initialized.value = true
  }

  // Guardar en localStorage cuando cambie
  watch(templates, (val) => {
    if (import.meta.client) {
      localStorage.setItem(STORAGE_KEY, JSON.stringify(val))
    }
  }, { deep: true })

  function saveTemplate(name: string, description: string, operations: Operation[]): PrintTemplate {
    const template: PrintTemplate = {
      id: crypto.randomUUID(),
      name,
      description,
      operations: JSON.parse(JSON.stringify(operations)),
      createdAt: Date.now(),
      updatedAt: Date.now()
    }
    templates.value = [...templates.value, template]
    return template
  }

  function updateTemplate(id: string, updates: Partial<Omit<PrintTemplate, 'id' | 'createdAt'>>) {
    const idx = templates.value.findIndex(t => t.id === id)
    if (idx !== -1) {
      templates.value = templates.value.map((t, i) =>
        i === idx ? { ...t, ...updates, updatedAt: Date.now() } : t
      )
    }
  }

  function deleteTemplate(id: string) {
    templates.value = templates.value.filter(t => t.id !== id)
  }

  function loadTemplate(id: string): Operation[] | null {
    const template = templates.value.find(t => t.id === id)
    return template ? JSON.parse(JSON.stringify(template.operations)) : null
  }

  function duplicateTemplate(id: string): PrintTemplate | null {
    const template = templates.value.find(t => t.id === id)
    if (!template) return null
    return saveTemplate(
      `${template.name} (copia)`,
      template.description || '',
      template.operations
    )
  }

  return {
    templates: readonly(templates),
    saveTemplate,
    updateTemplate,
    deleteTemplate,
    loadTemplate,
    duplicateTemplate
  }
}