mv /ana, /ledger to /src/

src/ledger/bpi.go

@@ -0,0 +1,64 @@
+package ledger
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"os"
+	"strconv"
+)
+
+type BPIs map[Currency]BPI
+
+type BPI map[string]float64
+
+func NewBPIs(p string) (BPIs, error) {
+	f, err := os.Open(p)
+	if os.IsNotExist(err) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	result := make(map[Currency]BPI)
+
+	r := bufio.NewReader(f)
+	for {
+		line, err := readTransactionLine(r)
+		if len(line) > 0 {
+			fields := bytes.Fields(line)
+			if len(fields) > 3 {
+				date := string(fields[1])
+				currency := Currency(fields[len(fields)-2])
+				value, err := strconv.ParseFloat(string(fields[len(fields)-1][1:]), 64)
+				if err != nil {
+					return nil, err
+				}
+				if _, ok := result[currency]; !ok {
+					result[currency] = make(BPI)
+				}
+				result[currency][date] = value
+			}
+		}
+		if err == io.EOF {
+			return result, nil
+		} else if err != nil {
+			return result, err
+		}
+	}
+}
+
+func (bpi BPI) Lookup(date string) float64 {
+	var closestWithoutGoingOver string
+	for k := range bpi {
+		if k <= date && k > closestWithoutGoingOver {
+			closestWithoutGoingOver = k
+		}
+	}
+	if closestWithoutGoingOver == "" {
+		return 0
+	}
+	return bpi[closestWithoutGoingOver]
+}