ana-ledger/ana/predictor.go

129 lines
3.4 KiB
Go

package ana
import (
"maps"
"math"
"regexp"
"time"
"gogs.inhome.blapointe.com/ana-ledger/ledger"
)
type Predictor func(ledger.Balances, time.Duration) ledger.Balances
func NewInterestPredictor(namePattern string, currencyPattern string, apy float64) Predictor {
nameMatcher := regexp.MustCompile(namePattern)
currencyMatcher := regexp.MustCompile(currencyPattern)
return func(given ledger.Balances, delta time.Duration) ledger.Balances {
result := maps.Clone(given)
for k, v := range result {
result[k] = maps.Clone(v)
}
monthsPassed := float64(delta) / float64(time.Hour*24.0*365.0/12.0)
scalar := math.Pow(1.0+apy/12.0, monthsPassed)
for name := range result {
if !nameMatcher.MatchString(name) {
continue
}
for currency := range result[name] {
if !currencyMatcher.MatchString(string(currency)) {
continue
}
result[name][currency] *= scalar
}
}
return result
}
}
func NewContributionPredictor(reg ledger.Register) Predictor {
monthlyRate := getMonthlyContributionRates(reg)
return newContributionPredictor(monthlyRate)
}
func newContributionPredictor(monthlyRate map[string]ledger.Balance) Predictor {
return func(given ledger.Balances, delta time.Duration) ledger.Balances {
month := time.Hour * 24 * 365 / 12
months := float64(delta) / float64(month)
result := make(ledger.Balances)
for k, v := range given {
result[k] = maps.Clone(v)
}
for name := range monthlyRate {
if _, ok := result[name]; !ok {
result[name] = make(ledger.Balance)
}
for currency := range monthlyRate[name] {
result[name][currency] += monthlyRate[name][currency] * months
}
}
return result
}
}
func getMonthlyContributionRates(reg ledger.Register) map[string]ledger.Balance {
window := time.Hour * 24 * 365 / 2
contributions := getRecentContributions(reg, window)
result := make(map[string]ledger.Balance)
for name := range contributions {
result[name] = getMonthlyContributionRate(contributions[name], window, name)
}
return result
}
// TODO better than average
func getMonthlyContributionRate(contributions []ledger.Balance, window time.Duration, name string) ledger.Balance {
sumPerCurrency := map[ledger.Currency]float64{}
for _, balance := range contributions {
for currency, v := range balance {
sumPerCurrency[currency] += v
}
}
result := make(ledger.Balance)
for currency, summed := range sumPerCurrency {
result[currency] = summed / (float64(window) / float64(time.Hour*24.0*365.0/12.0))
}
return result
}
func getRecentContributions(reg ledger.Register, window time.Duration) map[string][]ledger.Balance {
return getContributions(reg.Between(time.Now().Add(-1*window), time.Now()))
}
func getContributions(reg ledger.Register) map[string][]ledger.Balance {
contributions := make(map[string][]ledger.Balance)
for _, name := range reg.Names() {
contributions[name] = getContributionsFor(reg, name)
}
return contributions
}
func getContributionsFor(reg ledger.Register, name string) []ledger.Balance {
result := make([]ledger.Balance, 0)
var last ledger.Balance
for _, date := range reg.Dates() {
if _, ok := reg[date][name]; !ok {
continue
}
if last == nil {
last = reg[date][name]
continue
}
result = append(result, make(ledger.Balance))
this := result[len(result)-1]
for k, v := range last {
this[k] = -1 * v
}
for k, v := range reg[date][name] {
this[k] += v
}
last = reg[date][name]
}
return result
}