import { monthlyPayroll } from '~/types/members'

export function useCushionForecast() {
  const cashStore = useCashStore()
  const membersStore = useMembersStore()
  const policiesStore = usePoliciesStore()
  const budgetStore = useBudgetStore()
  
  // Savings progress calculation
  const savingsProgress = computed(() => {
    const current = cashStore.currentSavings || 0
    const targetMonths = policiesStore.savingsTargetMonths || 3
    const monthlyBurn = getMonthlyBurn()
    const target = targetMonths * monthlyBurn
    
    return {
      current,
      target,
      targetMonths,
      progressPct: target > 0 ? Math.min(100, (current / target) * 100) : 0,
      gap: Math.max(0, target - current),
      status: getProgressStatus(current, target)
    }
  })
  
  // 13-week cushion breach forecast
  const cushionForecast = computed(() => {
    const minCushion = policiesStore.minCashCushionAmount || 5000
    const currentBalance = cashStore.currentCash || 0
    const monthlyBurn = getMonthlyBurn()
    const weeklyBurn = monthlyBurn / 4.33 // Convert monthly to weekly
    
    const weeks = []
    let runningBalance = currentBalance
    
    for (let week = 1; week <= 13; week++) {
      // Simple projection: subtract weekly burn
      runningBalance -= weeklyBurn
      
      const breachesCushion = runningBalance < minCushion
      
      weeks.push({
        week,
        balance: runningBalance,
        breachesCushion,
        cushionAmount: minCushion
      })
    }
    
    const firstBreachWeek = weeks.find(w => w.breachesCushion)?.week
    const breachesWithin13Weeks = Boolean(firstBreachWeek)
    
    return {
      weeks,
      firstBreachWeek,
      breachesWithin13Weeks,
      minCushion,
      weeksUntilBreach: firstBreachWeek || null
    }
  })
  
  function getMonthlyBurn() {
    const operatingMode = policiesStore.operatingMode || 'minimum'
    const payrollCost = monthlyPayroll(membersStore.members, operatingMode)
    const oncostPct = policiesStore.payrollOncostPct || 0
    const totalPayroll = payrollCost * (1 + oncostPct / 100)
    const overheadCost = budgetStore.overheadCosts.reduce((sum, cost) => sum + (cost.amount || 0), 0)
    
    return totalPayroll + overheadCost
  }
  
  function getProgressStatus(current: number, target: number): 'green' | 'yellow' | 'red' {
    if (target === 0) return 'green'
    const pct = (current / target) * 100
    if (pct >= 80) return 'green'
    if (pct >= 50) return 'yellow'
    return 'red'
  }
  
  // Alert conditions (matching CLAUDE.md)
  const alerts = computed(() => ({
    savingsBelowTarget: savingsProgress.value.current < savingsProgress.value.target,
    cushionBreach: cushionForecast.value.breachesWithin13Weeks,
  }))
  
  return {
    savingsProgress,
    cushionForecast,
    alerts,
    getMonthlyBurn
  }
}