Planner/core/expenses.go
Manuel Forcén Muñoz 54d7d14ef9 Added expenses to plan
2025-04-09 18:37:02 +02:00

137 lines
3 KiB
Go

package core
import (
"encoding/json"
"errors"
"github.com/shopspring/decimal"
"gorm.io/gorm"
)
type DebtType int
const (
ProportionalDebt DebtType = iota
AbsoluteDebt = iota
)
func (dt DebtType) String() string {
return [...]string{"proportional", "absolute"}[dt]
}
func (dt DebtType) MarshalJSON() ([]byte, error) {
return json.Marshal(dt.String())
}
func (dt *DebtType) UnmarshalJSON(data []byte) error {
var s string
if err := json.Unmarshal(data, &s); err != nil {
return nil
}
if s == "proportional" {
*dt = ProportionalDebt
} else if s == "absolute" {
*dt = AbsoluteDebt
} else {
return errors.New("Invalid value for debt type")
}
return nil
}
type DebtSpec struct {
Member Member `json:"member"`
Amount decimal.Decimal `json:"amount"`
DebtType DebtType `json:"debt_type"`
}
func CreateExpense(db *gorm.DB, plan Plan, payer Member, amount decimal.Decimal) (*Expense, error) {
expense := new(Expense)
expense.Plan = plan
expense.Payer = payer
expense.Amount = amount
err := db.Create(&expense).Error
if err != nil {
return nil, err
}
return expense, nil
}
func (e *Expense) GetDebt(db *gorm.DB) ([]Debt, error) {
var debts []Debt
if err := db.Model(e).Association("Debts").Find(&debts); err != nil {
return []Debt{}, err
}
return debts, nil
}
func (e *Expense) SetDebt(db *gorm.DB, debtSpec []DebtSpec) error {
abs_paid := decimal.Decimal{}
debts := make([]Debt, 0)
var prop_payers int64 = 0
for _, debt := range debtSpec {
if debt.DebtType == ProportionalDebt {
prop_payers += 1
} else {
debts = append(debts, Debt{
Amount: debt.Amount,
Paid: decimal.Decimal{},
ExpenseID: e.ID,
DebtorID: debt.Member.ID,
})
abs_paid.Add(debt.Amount)
}
}
if abs_paid.Cmp(e.Amount) > 0 {
return errors.New("Absolute pay amount is larger than debt")
}
prop_debt := e.Amount.Sub(abs_paid).DivRound(decimal.NewFromInt(prop_payers), 2)
return db.Transaction(func(tx *gorm.DB) error {
for _, debt := range debts {
if err := db.Create(&debt).Error; err != nil {
return err
}
}
for _, debt := range debtSpec {
if debt.DebtType != ProportionalDebt {
continue
}
if err := db.Create(&Debt{
Amount: prop_debt,
Paid: decimal.Decimal{},
ExpenseID: e.ID,
DebtorID: debt.Member.ID,
}).Error; err != nil {
return err
}
}
return nil
})
}
func (e *Expense) Delete(db *gorm.DB) error {
return db.Transaction(func(tx *gorm.DB) error {
if err := db.Model(e).Association("Debts").Delete(&[]Debt{}); err != nil {
return err
}
return db.Delete(e, e).Error
})
}
func ListExpenses(db *gorm.DB, plan Plan) ([]Expense, error) {
var expenses []Expense
if err := db.Where("plan_id = ?", plan.ID).Find(&expenses).Error; err != nil {
return []Expense{}, err
}
return expenses, nil
}
func GetExpense(db *gorm.DB, expense_id uint) (*Expense, error) {
expense := new(Expense)
expense.ID = expense_id
if err := db.Take(expense).Error; err != nil {
return nil, err
}
return expense, nil
}