ana-ledger/ana/predictor.go

101 lines
2.9 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)
_ = monthlyRate
return func(given ledger.Balances, delta time.Duration) ledger.Balances {
panic(nil)
}
}
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)
}
return result
}
// TODO better than average
func getMonthlyContributionRate(contributions []ledger.Balance, window time.Duration) 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*365/12))
}
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 _, date := range reg.Dates() {
for name := range reg[date] {
contributions[name] = append(contributions[name], make(ledger.Balance))
if len(contributions[name]) > 1 {
for k := range contributions[name][len(contributions[name])-2] {
contributions[name][len(contributions[name])-1][k] = 0
}
}
balance := contributions[name][len(contributions[name])-1]
for currency, value := range reg[date][name] {
balance[currency] = value
}
if forName := contributions[name]; len(forName) > 1 {
lastBalance := forName[len(forName)-2]
for currency := range lastBalance {
balance[currency] -= lastBalance[currency]
}
}
}
}
return contributions
}