// WS-4 Settlement Report: client wrapper + row-level rendering helpers
// 의존: supabase, settlement_reconciliation_v1 view, settlement_distribution_cycles

import { supabase } from './supabase'

// ─── Types ──────────────────────────────────────────────────────────────────

export type ParticipantType = 'citizen' | 'enterprise' | 'platform' | 'reserve'
export type PayoutStatus = 'pending' | 'sent' | 'confirmed' | 'failed'
export type CycleStatus = 'pending' | 'completed' | 'failed' | 'compensating'

export interface SettlementParticipantRow {
  rowId: string
  cycleId: string
  tradeId: string
  cycleKey: string
  cycleStatus: CycleStatus
  grossProceeds: bigint
  platformFee: bigint
  beneficiaryPool: bigint
  citizenPool: bigint
  reservePool: bigint
  roundingResidual: bigint
  ruleSetVersion: string
  participantId: string
  participantType: ParticipantType
  participantName: string
  basisLabel: string | null
  co2Grams: bigint | null
  contributionWeight: number | null
  grossAmount: bigint
  withholdingTax: bigint
  netAmount: bigint
  ledgerTxnId: string | null
  idempotencyKey: string
  payoutStatus: PayoutStatus
  distributedAt: string
}

export interface SettlementSummary {
  cycleId: string
  tradeId: string
  cycleKey: string
  cycleStatus: CycleStatus
  grossProceeds: bigint
  platformFee: bigint
  beneficiaryPool: bigint
  citizenPool: bigint
  reservePool: bigint
  roundingResidual: bigint
  ruleSetVersion: string
  participantCounts: { citizen: number; enterprise: number; platform: number; reserve: number }
  totalDistributed: bigint
  invariantOk: boolean
}

export interface DistributeResult {
  cycleId: string
  cycleKey: string
  status: string
  grossProceeds: number
  platformFee: number
  beneficiaryPool: number
  citizenPool: number
  reservePool: number
  roundingResidual: number
  totalDistributed: number
  ruleSetVersion: string
}

// ─── Raw DB row mapping ──────────────────────────────────────────────────────

// eslint-disable-next-line @typescript-eslint/no-explicit-any
function mapRow(r: any): SettlementParticipantRow {
  return {
    rowId:               r.row_id,
    cycleId:             r.cycle_id,
    tradeId:             r.trade_id,
    cycleKey:            r.cycle_key,
    cycleStatus:         r.cycle_status as CycleStatus,
    grossProceeds:       BigInt(r.gross_proceeds ?? 0),
    platformFee:         BigInt(r.platform_fee ?? 0),
    beneficiaryPool:     BigInt(r.beneficiary_pool ?? 0),
    citizenPool:         BigInt(r.citizen_pool ?? 0),
    reservePool:         BigInt(r.reserve_pool ?? 0),
    roundingResidual:    BigInt(r.rounding_residual ?? 0),
    ruleSetVersion:      r.rule_set_version ?? 'v1.0',
    participantId:       r.participant_id,
    participantType:     r.participant_type as ParticipantType,
    participantName:     r.participant_name,
    basisLabel:          r.basis_label ?? null,
    co2Grams:            r.co2_grams != null ? BigInt(r.co2_grams) : null,
    contributionWeight:  r.contribution_weight != null ? Number(r.contribution_weight) : null,
    grossAmount:         BigInt(r.gross_amount ?? 0),
    withholdingTax:      BigInt(r.withholding_tax ?? 0),
    netAmount:           BigInt(r.net_amount ?? 0),
    ledgerTxnId:         r.ledger_txn_id ?? null,
    idempotencyKey:      r.idempotency_key,
    payoutStatus:        r.payout_status as PayoutStatus,
    distributedAt:       r.distributed_at,
  }
}

// ─── API ─────────────────────────────────────────────────────────────────────

/**
 * RPC 호출: 거래 대금을 원자적으로 분배한다.
 * 동일 trade_id 재호출 시 idempotent.
 */
export async function distributeProceeds(tradeId: string): Promise<DistributeResult> {
  const { data, error } = await supabase.rpc('distribute_sale_proceeds', {
    p_trade_id: tradeId,
  })
  if (error) throw error
  return data as DistributeResult
}

/**
 * 특정 거래의 전체 정산 행을 조회한다.
 */
export async function getReconciliationRows(tradeId: string): Promise<SettlementParticipantRow[]> {
  const { data, error } = await supabase
    .from('settlement_reconciliation_v1')
    .select('*')
    .eq('trade_id', tradeId)
    .order('participant_type')
    .order('gross_amount', { ascending: false })
  if (error) throw error
  return (data ?? []).map(mapRow)
}

/**
 * 특정 시민 참여자의 모든 정산 내역을 조회한다.
 * APP-14 "이번 정산 예상 분배" 프리뷰 카드에 사용.
 */
export async function getCitizenSettlements(
  userId: string,
  limit = 20,
): Promise<SettlementParticipantRow[]> {
  const { data, error } = await supabase
    .from('settlement_reconciliation_v1')
    .select('*')
    .eq('participant_id', userId)
    .eq('participant_type', 'citizen')
    .order('distributed_at', { ascending: false })
    .limit(limit)
  if (error) throw error
  return (data ?? []).map(mapRow)
}

/**
 * 거래 정산 요약 (집계)을 반환한다.
 * 불변 검증: sum(net_amount) + rounding_residual == gross_proceeds
 */
export function buildSummary(rows: SettlementParticipantRow[]): SettlementSummary | null {
  if (rows.length === 0) return null

  const first = rows[0]
  const counts = { citizen: 0, enterprise: 0, platform: 0, reserve: 0 }
  let totalDistributed = 0n

  for (const r of rows) {
    counts[r.participantType]++
    totalDistributed += r.netAmount
  }

  const invariantOk =
    totalDistributed + first.roundingResidual === first.grossProceeds

  return {
    cycleId:          first.cycleId,
    tradeId:          first.tradeId,
    cycleKey:         first.cycleKey,
    cycleStatus:      first.cycleStatus,
    grossProceeds:    first.grossProceeds,
    platformFee:      first.platformFee,
    beneficiaryPool:  first.beneficiaryPool,
    citizenPool:      first.citizenPool,
    reservePool:      first.reservePool,
    roundingResidual: first.roundingResidual,
    ruleSetVersion:   first.ruleSetVersion,
    participantCounts: counts,
    totalDistributed,
    invariantOk,
  }
}

// ─── Rendering helpers ───────────────────────────────────────────────────────

const KRW_LOCALE: Intl.NumberFormatOptions = {
  style: 'currency',
  currency: 'KRW',
  maximumFractionDigits: 0,
}

export function formatKrw(amount: bigint | number): string {
  return new Intl.NumberFormat('ko-KR', KRW_LOCALE).format(Number(amount))
}

export function participantTypeLabel(t: ParticipantType): string {
  const MAP: Record<ParticipantType, string> = {
    citizen: '시민',
    enterprise: '수혜 기업',
    platform: '플랫폼',
    reserve: '준비금',
  }
  return MAP[t]
}

export function payoutStatusBadge(s: PayoutStatus): { label: string; color: string } {
  const MAP: Record<PayoutStatus, { label: string; color: string }> = {
    pending:   { label: '대기', color: 'text-amber-600 bg-amber-50' },
    sent:      { label: '발송', color: 'text-blue-600 bg-blue-50' },
    confirmed: { label: '확정', color: 'text-green-600 bg-green-50' },
    failed:    { label: '실패', color: 'text-red-600 bg-red-50' },
  }
  return MAP[s]
}