mv /ana, /ledger to /src/

src/ledger/file.go

@@ -0,0 +1,151 @@
+package ledger
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"sort"
+	"unicode"
+)
+
+var filesAppendDelim = "\t"
+
+type Files []string
+
+func NewFiles(p string, q ...string) (Files, error) {
+	f := Files(append([]string{p}, q...))
+	_, err := f.Deltas()
+	return f, err
+}
+
+func (files Files) Add(payee string, delta Delta) error {
+	currencyValue := fmt.Sprintf("%s%.2f", delta.Currency, delta.Value)
+	if delta.Currency != USD {
+		currencyValue = fmt.Sprintf("%.2f %s", delta.Value, delta.Currency)
+	}
+	return files.append(fmt.Sprintf("%s   %s\n%s%s%s%s\n%s%s",
+		delta.Date, delta.Description,
+		filesAppendDelim, delta.Name, filesAppendDelim+filesAppendDelim+filesAppendDelim, currencyValue,
+		filesAppendDelim, payee,
+	))
+}
+
+func (files Files) append(s string) error {
+	if err := files.trimTrainlingWhitespace(); err != nil {
+		return err
+	}
+
+	f, err := os.OpenFile(string(files[0]), os.O_APPEND|os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	fmt.Fprintf(f, "\n%s", s)
+	return f.Close()
+}
+
+func (files Files) trimTrainlingWhitespace() error {
+	idx, err := files._lastNonWhitespacePos()
+	if err != nil {
+		return err
+	}
+	if idx < 1 {
+		return nil
+	}
+
+	f, err := os.OpenFile(string(files[0]), os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	return f.Truncate(int64(idx + 1))
+}
+
+func (files Files) _lastNonWhitespacePos() (int, error) {
+	f, err := os.Open(string(files[0]))
+	if os.IsNotExist(err) {
+		return -1, nil
+	}
+	if err != nil {
+		return -1, err
+	}
+	defer f.Close()
+
+	b, err := io.ReadAll(f)
+	if err != nil {
+		return -1, err
+	}
+	for i := len(b) - 1; i >= 0; i-- {
+		if !unicode.IsSpace(rune(b[i])) {
+			return i, nil
+		}
+	}
+	return len(b) - 1, nil
+}
+
+func (files Files) Deltas(like ...Like) (Deltas, error) {
+	transactions, err := files.transactions()
+	if err != nil {
+		return nil, err
+	}
+	sort.Slice(transactions, func(i, j int) bool {
+		return fmt.Sprintf("%s %s", transactions[i].date, transactions[i].description) < fmt.Sprintf("%s %s", transactions[j].date, transactions[j].description)
+	})
+
+	result := make(Deltas, 0, len(transactions)*2)
+	for _, transaction := range transactions {
+		sums := map[string]float64{}
+		for _, recipient := range transaction.recipients {
+			sums[recipient.currency] += recipient.value
+			delta := newDelta(
+				transaction.date,
+				transaction.description,
+				recipient.name,
+				recipient.value,
+				recipient.currency,
+				recipient.isSet,
+			)
+			result = append(result, delta)
+		}
+		for currency, value := range sums {
+			if value == 0 {
+				continue
+			}
+			if transaction.payee == "" {
+				//return nil, fmt.Errorf("didnt find net zero and no dumping ground payee set: %+v", transaction)
+			} else {
+				delta := newDelta(
+					transaction.date,
+					transaction.description,
+					transaction.payee,
+					-1.0*value,
+					currency,
+					false,
+				)
+				result = append(result, delta)
+			}
+		}
+	}
+
+	balances := make(Balances)
+	for i := range result {
+		if result[i].isSet {
+			var was float64
+			if m, ok := balances[result[i].Name]; ok {
+				was = m[result[i].Currency]
+			}
+			result[i].Value = result[i].Value - was
+			result[i].isSet = false
+		}
+		balances.Push(result[i])
+	}
+
+	for i := range result {
+		if result[i].isSet {
+			return nil, fmt.Errorf("failed to resolve isSet: %+v", result[i])
+		}
+	}
+	return result.Like(like...), nil
+}