alllllmost

ledger/file.go

@@ -1,6 +1,7 @@
 package ledger
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"io"
@@ -66,14 +67,18 @@ type transaction struct {
 	recipients  []transactionRecipient
 }
 
+func (t transaction) empty() bool {
+	return fmt.Sprint(t) == fmt.Sprint(transaction{})
+}
+
 type transactionRecipient struct {
 	name     string
 	value    float64
 	currency string
 }
 
-func (t transaction) empty() bool {
-	return fmt.Sprint(t) == fmt.Sprint(transaction{})
+func (t transactionRecipient) empty() bool {
+	return t == (transactionRecipient{})
 }
 
 func (file File) transactions() ([]transaction, error) {
@@ -83,9 +88,11 @@ func (file File) transactions() ([]transaction, error) {
 	}
 	defer f.Close()
 
+	var r io.Reader = f
+
 	result := make([]transaction, 0)
 	for {
-		one, err := readTransaction(f)
+		newr, one, err := readTransaction(r)
 		if !one.empty() {
 			result = append(result, one)
 		}
@@ -95,51 +102,161 @@ func (file File) transactions() ([]transaction, error) {
 		if err != nil {
 			return result, err
 		}
+		r = newr
 	}
 }
 
-func readTransaction(r io.Reader) (transaction, error) {
+func readTransaction(r io.Reader) (io.Reader, transaction, error) {
 	result := transaction{}
 	var err error
 
+	if r, err = readTransactionLeadingWhitespace(r); err != nil {
+		return r, transaction{}, err
+	}
+
 	if result.date, err = readTransactionDate(r); err != nil {
-		return result, fmt.Errorf("did not find transaction date: %w", err)
+		if err == io.EOF {
+			return r, transaction{}, err
+		}
+		return nil, result, fmt.Errorf("did not find transaction date: %w", err)
 	}
 
 	if result.description, err = readTransactionDescription(r); err != nil {
-		return result, fmt.Errorf("did not find transaction description: %w", err)
+		return nil, result, fmt.Errorf("did not find transaction description: %w", err)
 	}
 
-	return transaction{}, errors.New("not impl: reading payee, recipients")
+	for {
+		newR, recipient, err := readTransactionRecipient(r)
+		r = newR
+		if !recipient.empty() {
+			result.recipients = append(result.recipients, recipient)
+		}
+		if err != nil || recipient.empty() {
+			return r, result, err
+		}
+	}
 }
 
+// from "\s*.* read \s*"
+func readTransactionLeadingWhitespace(r io.Reader) (io.Reader, error) {
+	for {
+		b, err := readOne(r)
+		if err != nil {
+			return r, err
+		}
+		if b != 0 && !isSpaceByte(b) {
+			return io.MultiReader(bytes.NewReader([]byte{b}), r), nil
+		}
+	}
+}
+
+// from "20yy-mm-dd.* read "20yy-mm-dd"
 func readTransactionDate(r io.Reader) (string, error) {
-	var firstByte [1]byte
-	for firstByte[0] < '0' || firstByte[0] > '9' {
-		if _, err := r.Read(firstByte[:]); err != nil {
+	startOfDate := []byte{}
+	for len(startOfDate) == 0 {
+		b, err := readOne(r)
+		if err != nil {
 			return "", err
 		}
+		if '0' <= b && b <= '9' {
+			startOfDate = append(startOfDate, b)
+		}
 	}
 
-	restOfDate := make([]byte, len("2006-01-02")-1)
+	restOfDate := make([]byte, len("2006-01-02")-len(startOfDate))
 	if _, err := r.Read(restOfDate); err != nil {
 		return "", err
 	}
 
-	return fmt.Sprintf("%s%s", firstByte, restOfDate), nil
+	return fmt.Sprintf("%s%s", startOfDate, restOfDate), nil
 }
 
+// from "\s*.*\n.*" read \s*.*\n.*"
 func readTransactionDescription(r io.Reader) (string, error) {
 	result := make([]byte, 0, 16)
-	var firstByte [1]byte
 	for {
-		if _, err := r.Read(firstByte[:]); err != nil {
+		b, err := readOne(r)
+		if err != nil {
 			return "", err
 		}
-		if firstByte[0] == '\n' {
+		if b == '\n' {
 			break
 		}
-		result = append(result, firstByte[0])
+		result = append(result, b)
 	}
 	return strings.TrimSpace(string(result)), nil
 }
+
+// from "\s+.*\n?.*" read "\s+.*\n?"
+func readTransactionRecipient(r io.Reader) (io.Reader, transactionRecipient, error) {
+	if b, err := readOne(r); err != nil {
+		return r, transactionRecipient{}, err
+	} else if !isSpaceByte(b) {
+		return r, transactionRecipient{}, fmt.Errorf("didnt find leading whitespace for transaction recipient")
+	}
+
+	r, err := readTransactionLeadingWhitespace(r)
+	if err != nil {
+		return r, transactionRecipient{}, err
+	}
+
+	result := transactionRecipient{}
+	for {
+		b, err := readOne(r)
+		if err != nil {
+			if result.empty() {
+				return nil, result, err
+			}
+			return nil, result, fmt.Errorf("failed to read transaction recipient name after skipping whitespace: %w", err)
+		} else if !isSpaceByte(b) {
+			result.name += string([]byte{b})
+			continue
+		}
+		break
+	}
+	if result.name == "" {
+		return nil, result, fmt.Errorf("did not parse any name for transaction recipient")
+	}
+
+	for {
+		b, err := readOne(r)
+		if err != nil {
+			return r, result, err
+		}
+		if isSpaceByte(b) && b != '\n' {
+			continue
+		}
+		break
+	}
+
+	if b, err := readOne(r); err != nil {
+		return r, result, err
+	} else if isSpaceByte(b) {
+		return r, result, err
+	} else if newr, value, currency, err := readTransactionValueCurrency(io.MultiReader(bytes.NewReader([]byte{b}), r)); err != nil {
+		return r, result, fmt.Errorf("failed to read transaction recipient's value and currency: %w", err)
+	} else {
+		r = newr
+		result.value = value
+		result.currency = currency
+	}
+	return r, result, err
+}
+
+func readOne(r io.Reader) (byte, error) {
+	var firstByte [1]byte
+	_, err := r.Read(firstByte[:])
+	return firstByte[0], err
+}
+
+func isSpaceByte(b byte) bool {
+	return len(bytes.TrimSpace([]byte{b})) == 0
+}
+
+func isNumericByte(b byte) bool {
+	return '0' <= b && b <= '9' || b == '.' || b == '-'
+}
+
+func readTransactionValueCurrency(r io.Reader) (io.Reader, float64, string, error) {
+	return nil, 0, "", errors.New("not impl read a value currency")
+}

ledger/file_test.go

@@ -115,7 +115,7 @@ func TestReadTransaction(t *testing.T) {
 	for name, d := range cases {
 		c := d
 		t.Run(name, func(t *testing.T) {
-			got, err := readTransaction(strings.NewReader(c.input))
+			_, got, err := readTransaction(strings.NewReader(c.input))
 			if err != c.err {
 				t.Error(err)
 			}