aerc/lib/format/format.go
Reto Brunner f1a0fd20d6 improve date parsing for notmuch/maildir
If a message date would fail to parse, the worker would never receive
the MessageInfo it asked for, and so it wouldn't display the message.

The problem is the spec for date formats is too lax, so trying to ensure
we can parse every weird date format out there is not a strategy we want
to pursue. On the other hand, preventing the user from reading and
working with a message due to the error format is also not a solution.

The maildir and notmuch workers will now fallback to the internal date, which
is based on the received header if we can't parse the format of the Date header.

The UI will also fallback to the received header whenever the date header can't
be parsed.

This patch is based on the work done by Lyudmil Angelov <lyudmilangelov@gmail.com>
But tries to handle a parsing error a bit more gracefully instead of just returning
the zero date.
2020-08-10 08:00:52 +02:00

353 lines
8.3 KiB
Go

package format
import (
"errors"
"fmt"
gomail "net/mail"
"strings"
"time"
"unicode"
"git.sr.ht/~sircmpwn/aerc/models"
)
func parseAddress(address string) *gomail.Address {
addrs, err := gomail.ParseAddress(address)
if err != nil {
return nil
}
return addrs
}
func ParseMessageFormat(
fromAddress string,
format string, timestampformat string,
accountName string, number int, msg *models.MessageInfo,
marked bool) (string,
[]interface{}, error) {
retval := make([]byte, 0, len(format))
var args []interface{}
accountFromAddress := parseAddress(fromAddress)
var c rune
for i, ni := 0, 0; i < len(format); {
ni = strings.IndexByte(format[i:], '%')
if ni < 0 {
ni = len(format)
retval = append(retval, []byte(format[i:ni])...)
break
}
ni += i + 1
// Check for fmt flags
if ni == len(format) {
goto handle_end_error
}
c = rune(format[ni])
if c == '+' || c == '-' || c == '#' || c == ' ' || c == '0' {
ni++
}
// Check for precision and width
if ni == len(format) {
goto handle_end_error
}
c = rune(format[ni])
for unicode.IsDigit(c) {
ni++
c = rune(format[ni])
}
if c == '.' {
ni++
c = rune(format[ni])
for unicode.IsDigit(c) {
ni++
c = rune(format[ni])
}
}
retval = append(retval, []byte(format[i:ni])...)
// Get final format verb
if ni == len(format) {
goto handle_end_error
}
c = rune(format[ni])
switch c {
case '%':
retval = append(retval, '%')
case 'a':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0]
retval = append(retval, 's')
args = append(args,
fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host))
case 'A':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
var addr *models.Address
if len(msg.Envelope.ReplyTo) == 0 {
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender or reply-to")
} else {
addr = msg.Envelope.From[0]
}
} else {
addr = msg.Envelope.ReplyTo[0]
}
retval = append(retval, 's')
args = append(args,
fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host))
case 'C':
retval = append(retval, 'd')
args = append(args, number)
case 'd':
date := msg.Envelope.Date
if date.IsZero() {
date = msg.InternalDate
}
retval = append(retval, 's')
args = append(args,
dummyIfZeroDate(date, timestampformat))
case 'D':
date := msg.Envelope.Date
if date.IsZero() {
date = msg.InternalDate
}
retval = append(retval, 's')
args = append(args,
dummyIfZeroDate(date, timestampformat))
case 'f':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0].Format()
retval = append(retval, 's')
args = append(args, addr)
case 'F':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0]
var val string
if addr.Name == accountFromAddress.Name && len(msg.Envelope.To) != 0 {
addr = msg.Envelope.To[0]
}
if addr.Name != "" {
val = addr.Name
} else {
val = fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host)
}
retval = append(retval, 's')
args = append(args, val)
case 'g':
retval = append(retval, 's')
args = append(args, strings.Join(msg.Labels, ", "))
case 'i':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
retval = append(retval, 's')
args = append(args, msg.Envelope.MessageId)
case 'n':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0]
var val string
if addr.Name != "" {
val = addr.Name
} else {
val = fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host)
}
retval = append(retval, 's')
args = append(args, val)
case 'r':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
addrs := models.FormatAddresses(msg.Envelope.To)
retval = append(retval, 's')
args = append(args, addrs)
case 'R':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
addrs := models.FormatAddresses(msg.Envelope.Cc)
retval = append(retval, 's')
args = append(args, addrs)
case 's':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
retval = append(retval, 's')
args = append(args, msg.Envelope.Subject)
case 't':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.To) == 0 {
return "", nil,
errors.New("found no address for recipient")
}
addr := msg.Envelope.To[0]
retval = append(retval, 's')
args = append(args,
fmt.Sprintf("%s@%s", addr.Mailbox, addr.Host))
case 'T':
retval = append(retval, 's')
args = append(args, accountName)
case 'u':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0]
retval = append(retval, 's')
args = append(args, addr.Mailbox)
case 'v':
if msg.Envelope == nil {
return "", nil,
errors.New("no envelope available for this message")
}
if len(msg.Envelope.From) == 0 {
return "", nil,
errors.New("found no address for sender")
}
addr := msg.Envelope.From[0]
// check if message is from current user
if addr.Name != "" {
retval = append(retval, 's')
args = append(args,
strings.Split(addr.Name, " ")[0])
}
case 'Z':
// calculate all flags
var readReplyFlag = ""
var delFlag = ""
var flaggedFlag = ""
var markedFlag = ""
seen := false
recent := false
answered := false
for _, flag := range msg.Flags {
if flag == models.SeenFlag {
seen = true
} else if flag == models.RecentFlag {
recent = true
} else if flag == models.AnsweredFlag {
answered = true
}
if flag == models.DeletedFlag {
delFlag = "D"
// TODO: check if attachments
}
if flag == models.FlaggedFlag {
flaggedFlag = "!"
}
// TODO: check gpg stuff
}
if seen {
if answered {
readReplyFlag = "r" // message has been replied to
}
} else {
if recent {
readReplyFlag = "N" // message is new
} else {
readReplyFlag = "O" // message is old
}
}
if marked {
markedFlag = "*"
}
retval = append(retval, '4', 's')
args = append(args, readReplyFlag+delFlag+flaggedFlag+markedFlag)
// Move the below cases to proper alphabetical positions once
// implemented
case 'l':
// TODO: number of lines in the message
retval = append(retval, 'd')
args = append(args, msg.Size)
case 'e':
// TODO: current message number in thread
fallthrough
case 'E':
// TODO: number of messages in current thread
fallthrough
case 'H':
// TODO: spam attribute(s) of this message
fallthrough
case 'L':
// TODO:
fallthrough
case 'X':
// TODO: number of attachments
fallthrough
case 'y':
// TODO: X-Label field
fallthrough
case 'Y':
// TODO: X-Label field and some other constraints
fallthrough
default:
// Just ignore it and print as is
// so %k in index format becomes %%k to Printf
retval = append(retval, '%')
retval = append(retval, byte(c))
}
i = ni + 1
}
return string(retval), args, nil
handle_end_error:
return "", nil,
errors.New("reached end of string while parsing message format")
}
func dummyIfZeroDate(date time.Time, format string) string {
if date.IsZero() {
return strings.Repeat("?", len(format))
}
return date.Format(format)
}