import { computed } from 'vue'
import { storeToRefs } from 'pinia'
import { allocatePayroll } from '~/types/members'

export function usePayrollAllocation() {
  const membersStore = useMembersStore()
  const policiesStore = usePoliciesStore()
  const budgetStore = useBudgetStore()
  
  const { members, payPolicy } = storeToRefs(membersStore)
  const { equalHourlyWage, payrollOncostPct } = storeToRefs(policiesStore)
  const { capacityTotals } = storeToRefs(membersStore)
  
  // Calculate base payroll budget from hours and wage
  const basePayrollBudget = computed(() => {
    const totalHours = capacityTotals.value.targetHours || 0
    const wage = equalHourlyWage.value || 0
    return totalHours * wage
  })
  
  // Allocate payroll to members based on policy
  const allocatedMembers = computed(() => {
    if (members.value.length === 0 || basePayrollBudget.value === 0) {
      return members.value
    }
    
    return allocatePayroll(
      members.value,
      payPolicy.value,
      basePayrollBudget.value
    )
  })
  
  // Total payroll with oncosts
  const totalPayrollWithOncosts = computed(() => {
    return basePayrollBudget.value * (1 + payrollOncostPct.value / 100)
  })
  
  // Update member planned pay when allocation changes
  watchEffect(() => {
    allocatedMembers.value.forEach(member => {
      membersStore.setPlannedPay(member.id, member.monthlyPayPlanned || 0)
    })
  })
  
  return {
    basePayrollBudget,
    allocatedMembers,
    totalPayrollWithOncosts,
    payPolicy
  }
}