import { computed } from 'vue'
import { useLocalStorageRef } from '~/utils/useLocalStorageRef'

/* ── Types ── */

export type ServiceTierId = string

export interface ServiceTier {
  id: ServiceTierId
  name: string
  color: string
  icon: string
  description: string
  minScore: number
  benefits: string[]
}

export interface AttentionRule {
  id: string
  field: 'premium' | 'policy_count' | 'commission' | 'collectivo_member' | 'multi_line' | 'tenure_years' | 'has_private_policies'
  operator: 'gte' | 'lte' | 'eq' | 'gt' | 'lt'
  value: number | boolean
  points: number
  label: string
}

export interface CustomerAttentionConfig {
  tiers: ServiceTier[]
  rules: AttentionRule[]
  autoClassify: boolean
}

/* ── Defaults ── */

function defaultTiers(): ServiceTier[] {
  return [
    {
      id: 'platinum',
      name: 'Platinum',
      color: '#7c3aed',
      icon: 'i-heroicons-star',
      description: 'VIP multi-line clients with highest lifetime value',
      minScore: 80,
      benefits: ['Priority claims handling', 'Dedicated account manager', 'Annual review', 'Renewal negotiation priority'],
    },
    {
      id: 'gold',
      name: 'Gold',
      color: '#d4a017',
      icon: 'i-heroicons-trophy',
      description: 'Established clients with strong portfolio',
      minScore: 55,
      benefits: ['Priority support', 'Proactive renewal outreach', 'Cross-sell consultation'],
    },
    {
      id: 'silver',
      name: 'Silver',
      color: '#6b7280',
      icon: 'i-heroicons-shield-check',
      description: 'Active clients with growth potential',
      minScore: 30,
      benefits: ['Standard support', 'Regular check-ins'],
    },
    {
      id: 'standard',
      name: 'Standard',
      color: '#01696f',
      icon: 'i-heroicons-user',
      description: 'All active customers',
      minScore: 0,
      benefits: ['Standard service'],
    },
  ]
}

function defaultRules(): AttentionRule[] {
  return [
    { id: 'r1', field: 'premium', operator: 'gte', value: 5000, points: 25, label: 'Annual premium >= $5,000' },
    { id: 'r2', field: 'premium', operator: 'gte', value: 10000, points: 40, label: 'Annual premium >= $10,000' },
    { id: 'r3', field: 'policy_count', operator: 'gte', value: 3, points: 15, label: '3+ active policies' },
    { id: 'r4', field: 'policy_count', operator: 'gte', value: 5, points: 25, label: '5+ active policies' },
    { id: 'r5', field: 'multi_line', operator: 'gte', value: 3, points: 20, label: 'Multi-line (3+ different lines)' },
    { id: 'r6', field: 'tenure_years', operator: 'gte', value: 3, points: 10, label: 'Client for 3+ years' },
    { id: 'r7', field: 'tenure_years', operator: 'gte', value: 5, points: 20, label: 'Client for 5+ years' },
    { id: 'r8', field: 'collectivo_member', operator: 'eq', value: true, points: 15, label: 'Collectivo member with private policies' },
    { id: 'r9', field: 'commission', operator: 'gte', value: 1000, points: 10, label: 'Annual commission >= $1,000' },
  ]
}

function defaultConfig(): CustomerAttentionConfig {
  return {
    tiers: defaultTiers(),
    rules: defaultRules(),
    autoClassify: true,
  }
}

/* ── Customer input shape ── */

export interface CustomerAttentionInput {
  totalPremium: number
  policyCount: number
  lineCount: number
  tenureYears: number
  isCollectivoMember: boolean
  hasPrivatePolicies: boolean
  estimatedCommission: number
}

/* ── Rule evaluation ── */

function evaluateRule(rule: AttentionRule, customer: CustomerAttentionInput): boolean {
  let fieldValue: number | boolean

  switch (rule.field) {
    case 'premium':
      fieldValue = customer.totalPremium
      break
    case 'policy_count':
      fieldValue = customer.policyCount
      break
    case 'commission':
      fieldValue = customer.estimatedCommission
      break
    case 'multi_line':
      fieldValue = customer.lineCount
      break
    case 'tenure_years':
      fieldValue = customer.tenureYears
      break
    case 'collectivo_member':
      // Special: collectivo member rule only matches if also has private policies
      return rule.value === true && customer.isCollectivoMember && customer.hasPrivatePolicies
    case 'has_private_policies':
      return typeof rule.value === 'boolean' ? customer.hasPrivatePolicies === rule.value : false
    default:
      return false
  }

  if (typeof fieldValue === 'boolean' || typeof rule.value === 'boolean') return false

  switch (rule.operator) {
    case 'gte': return (fieldValue as number) >= (rule.value as number)
    case 'gt':  return (fieldValue as number) > (rule.value as number)
    case 'lte': return (fieldValue as number) <= (rule.value as number)
    case 'lt':  return (fieldValue as number) < (rule.value as number)
    case 'eq':  return (fieldValue as number) === (rule.value as number)
    default:    return false
  }
}

/* ── Composable ── */

export function useCustomerAttention() {
  const config = useLocalStorageRef<CustomerAttentionConfig>('policy-ui-customer-attention-v1', defaultConfig)

  const tiers = computed(() => [...config.value.tiers].sort((a, b) => b.minScore - a.minScore))

  const rules = computed(() => config.value.rules)

  function getScoreForCustomer(customer: CustomerAttentionInput): number {
    let score = 0
    for (const rule of config.value.rules) {
      if (evaluateRule(rule, customer)) {
        score += rule.points
      }
    }
    return score
  }

  function getTierForCustomer(customer: CustomerAttentionInput): ServiceTier {
    const score = getScoreForCustomer(customer)
    const sorted = [...config.value.tiers].sort((a, b) => b.minScore - a.minScore)
    for (const tier of sorted) {
      if (score >= tier.minScore) return tier
    }
    // Fallback to lowest tier
    return sorted[sorted.length - 1] ?? config.value.tiers[0]
  }

  /* ── Tier CRUD ── */

  function addTier(tier: ServiceTier) {
    config.value.tiers.push(tier)
  }

  function updateTier(id: string, patch: Partial<ServiceTier>) {
    const idx = config.value.tiers.findIndex(t => t.id === id)
    if (idx !== -1) {
      config.value.tiers[idx] = { ...config.value.tiers[idx], ...patch }
    }
  }

  function removeTier(id: string) {
    config.value.tiers = config.value.tiers.filter(t => t.id !== id)
  }

  /* ── Rule CRUD ── */

  function addRule(rule: AttentionRule) {
    config.value.rules.push(rule)
  }

  function updateRule(id: string, patch: Partial<AttentionRule>) {
    const idx = config.value.rules.findIndex(r => r.id === id)
    if (idx !== -1) {
      config.value.rules[idx] = { ...config.value.rules[idx], ...patch }
    }
  }

  function removeRule(id: string) {
    config.value.rules = config.value.rules.filter(r => r.id !== id)
  }

  return {
    config,
    tiers,
    rules,
    getScoreForCustomer,
    getTierForCustomer,
    addTier,
    updateTier,
    removeTier,
    addRule,
    updateRule,
    removeRule,
  }
}