Files
mailgoserver/internal/mailstore/rules.go
T

109 lines
3.4 KiB
Go

package mailstore
import (
"strings"
"mailgoserver/internal/db"
)
// FilterAction is the outcome of evaluating a mailbox's filter rules against one
// incoming message.
type FilterAction struct {
Folder string // non-empty: store here instead of INBOX
MarkRead bool
Drop bool // don't store at all
// ForwardTo: non-empty means also relay a copy of this message out to this
// address — see smtpserver's deliverLocally, which actually sends it (this
// package has no outbound SMTP capability of its own). KeepCopy controls whether
// the recipient's own local copy is still stored too.
ForwardTo string
KeepCopy bool
}
// ApplyRules evaluates a mailbox's filter rules in priority order and returns the
// first match's action (zero value if none match, meaning "store in INBOX, unread").
// headers should have "from"/"to"/"subject"/"body"/"has_attachment"/"recipient_type"
// keys — rules run at delivery time, before the message is encrypted and stored, so
// real header/body values are available, not just the plaintext cache columns used
// for fast IMAP listing. has_attachment is "yes"/"no" and recipient_type is
// "to"/"cc"/"bcc", both computed by the caller rather than being real headers.
func (s *Store) ApplyRules(mailboxID int64, headers map[string]string) (FilterAction, error) {
rules, err := s.DB.ListRulesForMailbox(mailboxID)
if err != nil {
return FilterAction{}, err
}
for _, r := range rules {
if !r.IsActive {
continue
}
if !ruleMatches(r, headers) {
continue
}
switch r.Action {
case "move_to_folder":
return FilterAction{Folder: r.ActionValue}, nil
case "mark_as_spam":
// Reuses the same Junk folder score-based quarantine already delivers
// into (see smtpserver/session.go) — from the mailbox owner's
// perspective it's the same "goes to Junk" outcome either way.
return FilterAction{Folder: "Junk"}, nil
case "delete":
return FilterAction{Drop: true}, nil
case "mark_read":
return FilterAction{MarkRead: true}, nil
case "forward":
return FilterAction{ForwardTo: r.ActionValue, KeepCopy: r.ActionOptions().KeepCopy}, nil
}
}
return FilterAction{}, nil
}
// ruleMatches combines a rule's conditions per its match type: "all" requires every
// condition to match (AND), "any" requires at least one (OR).
func ruleMatches(r db.MailboxFilterRule, headers map[string]string) bool {
conditions, matchType := r.Conditions()
if matchType == "any" {
for _, c := range conditions {
if matchCondition(c.Op, headers[c.Field], c.Value) {
return true
}
}
return false
}
for _, c := range conditions {
if !matchCondition(c.Op, headers[c.Field], c.Value) {
return false
}
}
return true
}
// matchCondition compares a header's actual value against a condition's target.
// target may hold several "\n"-joined values (the rule builder's chip input, e.g.
// multiple From addresses or multiple subject keywords) — matches if any one does,
// mirroring how a real mail client's "is any of" condition works.
func matchCondition(op, value, target string) bool {
value = strings.ToLower(value)
for _, t := range strings.Split(target, "\n") {
t = strings.ToLower(strings.TrimSpace(t))
if t == "" {
continue
}
switch op {
case "contains":
if strings.Contains(value, t) {
return true
}
case "equals":
if value == t {
return true
}
case "starts_with":
if strings.HasPrefix(value, t) {
return true
}
}
}
return false
}