feat: investment accounts

2026-05-22 14:49:57 +00:00 · 2026-05-22 14:49:57 +00:00 · 7c24a8302d
commit 7c24a8302d
parent f444a074bc
25 changed files with 2205 additions and 56 deletions
--- a/internal/service/investment.go
+++ b/internal/service/investment.go
@ -0,0 +1,355 @@
+package service
+
+import (
+	"fmt"
+	"time"
+
+	"git.juancwu.dev/juancwu/budgit/internal/model"
+	"git.juancwu.dev/juancwu/budgit/internal/repository"
+	"github.com/google/uuid"
+	"github.com/shopspring/decimal"
+)
+
+// InvestmentService handles contribution rooms, holdings, trades, and the
+// summary view for investment-flagged accounts. Cash movement (contributions
+// and withdrawals) still goes through TransactionService / TransferService;
+// this service reads from those tables but never mutates them directly.
+type InvestmentService struct {
+	accountRepo repository.AccountRepository
+	roomRepo    repository.InvestmentContributionRoomRepository
+	holdingRepo repository.InvestmentHoldingRepository
+	tradeRepo   repository.InvestmentTradeRepository
+	txRepo      repository.TransactionRepository
+}
+
+func NewInvestmentService(
+	accountRepo repository.AccountRepository,
+	roomRepo repository.InvestmentContributionRoomRepository,
+	holdingRepo repository.InvestmentHoldingRepository,
+	tradeRepo repository.InvestmentTradeRepository,
+	txRepo repository.TransactionRepository,
+) *InvestmentService {
+	return &InvestmentService{
+		accountRepo: accountRepo,
+		roomRepo:    roomRepo,
+		holdingRepo: holdingRepo,
+		tradeRepo:   tradeRepo,
+		txRepo:      txRepo,
+	}
+}
+
+// ---------- Contribution room ----------
+
+func (s *InvestmentService) SetContributionRoom(accountID string, year int, room decimal.Decimal) error {
+	if accountID == "" {
+		return fmt.Errorf("account id is required")
+	}
+	if year < 1900 || year > 9999 {
+		return fmt.Errorf("year out of range")
+	}
+	if room.IsNegative() {
+		return fmt.Errorf("contribution room cannot be negative")
+	}
+	account, err := s.accountRepo.ByID(accountID)
+	if err != nil {
+		return fmt.Errorf("failed to load account: %w", err)
+	}
+	if !account.IsInvestment {
+		return fmt.Errorf("account is not an investment account")
+	}
+	now := time.Now()
+	return s.roomRepo.Upsert(&model.InvestmentContributionRoom{
+		AccountID:  accountID,
+		Year:       year,
+		RoomAmount: room,
+		CreatedAt:  now,
+		UpdatedAt:  now,
+	})
+}
+
+func (s *InvestmentService) GetContributionRoom(accountID string, year int) (*model.InvestmentContributionRoom, error) {
+	room, err := s.roomRepo.ByAccountAndYear(accountID, year)
+	if err != nil {
+		if err == repository.ErrContributionRoomNotFound {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("failed to load contribution room: %w", err)
+	}
+	return room, nil
+}
+
+func (s *InvestmentService) ListContributionRooms(accountID string) ([]*model.InvestmentContributionRoom, error) {
+	rooms, err := s.roomRepo.ByAccountID(accountID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to list contribution rooms: %w", err)
+	}
+	return rooms, nil
+}
+
+// ---------- Summary ----------
+
+// SummarizeAccount produces the rollup view for an investment account in the
+// given calendar year: contribution room, YTD cash flow, lifetime net
+// contributions, and total cost basis across all holdings.
+func (s *InvestmentService) SummarizeAccount(accountID string, year int) (*model.InvestmentAccountSummary, error) {
+	account, err := s.accountRepo.ByID(accountID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load account: %w", err)
+	}
+	if !account.IsInvestment {
+		return nil, fmt.Errorf("account is not an investment account")
+	}
+
+	ytdContrib, err := s.txRepo.SumByAccountYearType(accountID, year, model.TransactionTypeDeposit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to sum ytd contributions: %w", err)
+	}
+	ytdWithdraw, err := s.txRepo.SumByAccountYearType(accountID, year, model.TransactionTypeWithdrawal)
+	if err != nil {
+		return nil, fmt.Errorf("failed to sum ytd withdrawals: %w", err)
+	}
+	lifeContrib, err := s.txRepo.SumLifetimeByAccountType(accountID, model.TransactionTypeDeposit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to sum lifetime contributions: %w", err)
+	}
+	lifeWithdraw, err := s.txRepo.SumLifetimeByAccountType(accountID, model.TransactionTypeWithdrawal)
+	if err != nil {
+		return nil, fmt.Errorf("failed to sum lifetime withdrawals: %w", err)
+	}
+
+	summary := &model.InvestmentAccountSummary{
+		Account:          account,
+		Year:             year,
+		YTDContributions: ytdContrib,
+		YTDWithdrawals:   ytdWithdraw,
+		NetContributions: lifeContrib.Sub(lifeWithdraw),
+	}
+
+	room, err := s.roomRepo.ByAccountAndYear(accountID, year)
+	if err == nil {
+		amt := room.RoomAmount
+		summary.RoomAmount = &amt
+		rem := amt.Sub(ytdContrib)
+		summary.RoomRemaining = &rem
+	} else if err != repository.ErrContributionRoomNotFound {
+		return nil, fmt.Errorf("failed to load contribution room: %w", err)
+	}
+
+	positions, err := s.HoldingPositions(accountID)
+	if err != nil {
+		return nil, err
+	}
+	summary.HoldingCount = len(positions)
+	for _, p := range positions {
+		summary.TotalCostBasis = summary.TotalCostBasis.Add(p.CostBasis)
+	}
+	return summary, nil
+}
+
+// ---------- Holdings ----------
+
+func (s *InvestmentService) CreateHolding(accountID, symbol, displayName string) (*model.InvestmentHolding, error) {
+	if accountID == "" {
+		return nil, fmt.Errorf("account id is required")
+	}
+	if symbol == "" {
+		return nil, fmt.Errorf("symbol is required")
+	}
+	if displayName == "" {
+		displayName = symbol
+	}
+	account, err := s.accountRepo.ByID(accountID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load account: %w", err)
+	}
+	if !account.IsInvestment {
+		return nil, fmt.Errorf("account is not an investment account")
+	}
+	now := time.Now()
+	holding := &model.InvestmentHolding{
+		ID:          uuid.NewString(),
+		AccountID:   accountID,
+		Symbol:      symbol,
+		DisplayName: displayName,
+		CreatedAt:   now,
+		UpdatedAt:   now,
+	}
+	if err := s.holdingRepo.Create(holding); err != nil {
+		return nil, fmt.Errorf("failed to create holding: %w", err)
+	}
+	return holding, nil
+}
+
+func (s *InvestmentService) GetHolding(id string) (*model.InvestmentHolding, error) {
+	h, err := s.holdingRepo.ByID(id)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load holding: %w", err)
+	}
+	return h, nil
+}
+
+func (s *InvestmentService) UpdateHolding(id, symbol, displayName string) error {
+	if symbol == "" {
+		return fmt.Errorf("symbol is required")
+	}
+	if displayName == "" {
+		displayName = symbol
+	}
+	if err := s.holdingRepo.Update(id, symbol, displayName); err != nil {
+		return fmt.Errorf("failed to update holding: %w", err)
+	}
+	return nil
+}
+
+func (s *InvestmentService) DeleteHolding(id string) error {
+	return s.holdingRepo.Delete(id)
+}
+
+func (s *InvestmentService) ListHoldings(accountID string) ([]*model.InvestmentHolding, error) {
+	return s.holdingRepo.ByAccountID(accountID)
+}
+
+// ---------- Trades ----------
+
+type RecordTradeInput struct {
+	HoldingID    string
+	Type         model.InvestmentTradeType
+	Quantity     decimal.Decimal
+	PricePerUnit decimal.Decimal
+	Fees         *decimal.Decimal
+	OccurredAt   time.Time
+	Notes        *string
+}
+
+func (s *InvestmentService) RecordTrade(input RecordTradeInput) (*model.InvestmentTrade, error) {
+	if input.HoldingID == "" {
+		return nil, fmt.Errorf("holding id is required")
+	}
+	if !model.IsValidInvestmentTradeType(string(input.Type)) {
+		return nil, fmt.Errorf("invalid trade type: %s", input.Type)
+	}
+	if !input.Quantity.IsPositive() {
+		return nil, fmt.Errorf("quantity must be greater than zero")
+	}
+	if input.PricePerUnit.IsNegative() {
+		return nil, fmt.Errorf("price per unit cannot be negative")
+	}
+	if input.OccurredAt.IsZero() {
+		input.OccurredAt = time.Now()
+	}
+	trade := &model.InvestmentTrade{
+		ID:           uuid.NewString(),
+		HoldingID:    input.HoldingID,
+		Type:         input.Type,
+		Quantity:     input.Quantity,
+		PricePerUnit: input.PricePerUnit,
+		Fees:         input.Fees,
+		OccurredAt:   input.OccurredAt,
+		Notes:        input.Notes,
+		CreatedAt:    time.Now(),
+	}
+	if err := s.tradeRepo.Create(trade); err != nil {
+		return nil, fmt.Errorf("failed to record trade: %w", err)
+	}
+	return trade, nil
+}
+
+func (s *InvestmentService) UpdateTrade(id string, qty, price decimal.Decimal, fees *decimal.Decimal, occurredAt time.Time, notes *string) error {
+	if !qty.IsPositive() {
+		return fmt.Errorf("quantity must be greater than zero")
+	}
+	if price.IsNegative() {
+		return fmt.Errorf("price per unit cannot be negative")
+	}
+	return s.tradeRepo.Update(id, qty, price, fees, occurredAt, notes)
+}
+
+func (s *InvestmentService) DeleteTrade(id string) error {
+	return s.tradeRepo.Delete(id)
+}
+
+func (s *InvestmentService) GetTrade(id string) (*model.InvestmentTrade, error) {
+	return s.tradeRepo.ByID(id)
+}
+
+func (s *InvestmentService) ListTrades(holdingID string) ([]*model.InvestmentTrade, error) {
+	return s.tradeRepo.ByHoldingID(holdingID)
+}
+
+// HoldingPositions returns the derived position for every holding in the
+// account. Positions are computed by replaying each trade in chronological
+// order, maintaining a running weighted-average cost basis. Each sell reduces
+// the remaining quantity at the current avg cost; realized P/L accumulates on
+// each sell as (sell.price − avg cost) × qty − fees.
+func (s *InvestmentService) HoldingPositions(accountID string) ([]model.HoldingPosition, error) {
+	holdings, err := s.holdingRepo.ByAccountID(accountID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load holdings: %w", err)
+	}
+	out := make([]model.HoldingPosition, 0, len(holdings))
+	for _, h := range holdings {
+		pos, err := s.holdingPosition(*h)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, pos)
+	}
+	return out, nil
+}
+
+func (s *InvestmentService) HoldingPosition(holdingID string) (*model.HoldingPosition, error) {
+	h, err := s.holdingRepo.ByID(holdingID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load holding: %w", err)
+	}
+	pos, err := s.holdingPosition(*h)
+	if err != nil {
+		return nil, err
+	}
+	return &pos, nil
+}
+
+func (s *InvestmentService) holdingPosition(h model.InvestmentHolding) (model.HoldingPosition, error) {
+	trades, err := s.tradeRepo.ByHoldingID(h.ID)
+	if err != nil {
+		return model.HoldingPosition{}, fmt.Errorf("failed to load trades: %w", err)
+	}
+	pos := model.HoldingPosition{Holding: h}
+	qty := decimal.Zero
+	avgCost := decimal.Zero
+	for _, t := range trades {
+		fees := decimal.Zero
+		if t.Fees != nil {
+			fees = *t.Fees
+		}
+		pos.TotalFees = pos.TotalFees.Add(fees)
+		switch t.Type {
+		case model.InvestmentTradeTypeBuy:
+			newQty := qty.Add(t.Quantity)
+			if newQty.IsPositive() {
+				// weighted average including fees in cost basis
+				newCost := qty.Mul(avgCost).Add(t.Quantity.Mul(t.PricePerUnit)).Add(fees)
+				avgCost = newCost.Div(newQty)
+			}
+			qty = newQty
+			pos.TotalBuyQty = pos.TotalBuyQty.Add(t.Quantity)
+			price := t.PricePerUnit
+			pos.LastBuyPrice = &price
+		case model.InvestmentTradeTypeSell:
+			realized := t.PricePerUnit.Sub(avgCost).Mul(t.Quantity).Sub(fees)
+			pos.RealizedPL = pos.RealizedPL.Add(realized)
+			qty = qty.Sub(t.Quantity)
+			pos.TotalSellQty = pos.TotalSellQty.Add(t.Quantity)
+			price := t.PricePerUnit
+			pos.LastSellPrice = &price
+			if !qty.IsPositive() {
+				qty = decimal.Zero
+				avgCost = decimal.Zero
+			}
+		}
+	}
+	pos.Quantity = qty
+	pos.AvgCost = avgCost
+	pos.CostBasis = qty.Mul(avgCost)
+	return pos, nil
+}