import { useState, useCallback } from 'react'
import * as api from '@/services/api'
import type { ProposedDayApplyItem, PlanApplyResponse } from '@/types'

interface UsePlanApplyResult {
  response: PlanApplyResponse | null
  isLoading: boolean
  error: string | null
  apply: (workspaceId: string, days: ProposedDayApplyItem[], replace: boolean) => Promise<PlanApplyResponse>
}

/**
 * Applies a plan (persists proposed days as real planned days).
 * Returns the full response including collision info, rejections, and created counts.
 */
export function usePlanApply(): UsePlanApplyResult {
  const [response, setResponse] = useState<PlanApplyResponse | null>(null)
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const apply = useCallback(
    async (workspaceId: string, days: ProposedDayApplyItem[], replace: boolean) => {
      setIsLoading(true)
      setError(null)
      try {
        const result = await api.applyPlan(workspaceId, days, replace)
        setResponse(result)
        return result
      } catch (err: unknown) {
        const message = err instanceof Error ? err.message : 'Kunde inte använda plan'
        setError(message)
        setResponse(null)
        throw err
      } finally {
        setIsLoading(false)
      }
    },
    [],
  )

  return { response, isLoading, error, apply }
}