From e511da2e709192f32c94a43af10becab2cdd2a84 Mon Sep 17 00:00:00 2001
From: Bel LaPointe <breel@qualtrics.com>
Date: Thu, 26 Oct 2023 10:46:05 -0600
Subject: [PATCH] wip

---
 ana/prediction.go |  3 +++
 ana/predictor.go  | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 ana/prediction.go
 create mode 100644 ana/predictor.go

diff --git a/ana/prediction.go b/ana/prediction.go
new file mode 100644
index 0000000..2872af8
--- /dev/null
+++ b/ana/prediction.go
@@ -0,0 +1,3 @@
+package ana
+
+type Prediction []Predictor
diff --git a/ana/predictor.go b/ana/predictor.go
new file mode 100644
index 0000000..81180e3
--- /dev/null
+++ b/ana/predictor.go
@@ -0,0 +1,35 @@
+package ana
+
+import (
+	"maps"
+	"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)
+		}
+
+		for name := range result {
+			if !nameMatcher.MatchString(name) {
+				continue
+			}
+			for currency := range result[name] {
+				if !currencyMatcher.MatchString(string(currency)) {
+					continue
+				}
+				result[name][currency] *= 1.0 + apy/12.0
+			}
+		}
+		return result
+	}
+}