frontend: implement tag

1 files changed, 42 insertions, 0 deletions

diff --git a/textproto/types.go b/textproto/types.go
index 2109517..9a1731b 100644
--- a/textproto/types.go
+++ b/textproto/types.go
@@ -2,10 +2,13 @@ package textproto
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 )
 
+// BUG(lukeshu): Only supports the "raw" date format (not "rfc2822" or
+// "now")
 type UserTime struct {
 	Name  string
 	Email string
@@ -28,6 +31,45 @@ func (ut UserTime) String() string {
 	}
 }
 
+func ParseUserTime(str string) (UserTime, error) {
+	ret := UserTime{}
+	lt := strings.IndexAny(str, "<>")
+	if lt < 0 || str[lt] != '<' {
+		return ret, fmt.Errorf("Missing < in ident string: %v", str)
+	}
+	if lt > 0 {
+		if str[lt-1] != ' ' {
+			return ret, fmt.Errorf("Missing space before < in ident string: %v", str)
+		}
+		ret.Name = str[:lt-1]
+	}
+	gt := lt + 1 + strings.IndexAny(str[lt+1:], "<>")
+	if gt < lt+1 || str[gt] != '>' {
+		return ret, fmt.Errorf("Missing > in ident string: %v", str)
+	}
+	if str[gt+1] != ' ' {
+		return ret, fmt.Errorf("Missing space after > in ident string: %v", str)
+	}
+	ret.Email = str[lt+1 : gt]
+
+	strWhen := str[gt+2:]
+	sp := strings.IndexByte(strWhen, ' ')
+	if sp < 0 {
+		return ret, fmt.Errorf("missing time zone in when: %v", str)
+	}
+	sec, err := strconv.ParseInt(strWhen[:sp], 10, 64)
+	if err != nil {
+		return ret, err
+	}
+	tzt, err := time.Parse("-0700", strWhen[sp+1:])
+	if err != nil {
+		return ret, err
+	}
+	ret.Time = time.Unix(sec, 0).In(tzt.Location())
+
+	return ret, nil
+}
+
 type Mode uint32 // 18 bits
 
 var (