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|
package command
import (
"fmt"
"strings"
"github.com/ProtonMail/gluon/rfcparser"
)
type Builder interface {
FromParser(p *rfcparser.Parser) (Payload, error)
}
// Parser parses IMAP Commands.
type Parser struct {
parser *rfcparser.Parser
scanner *rfcparser.Scanner
commands map[string]Builder
lastTag string
lastCmd string
}
func NewParser(s *rfcparser.Scanner) *Parser {
return NewParserWithLiteralContinuationCb(s, nil)
}
func NewParserWithLiteralContinuationCb(s *rfcparser.Scanner, cb func() error) *Parser {
return &Parser{
scanner: s,
parser: rfcparser.NewParserWithLiteralContinuationCb(s, cb),
commands: map[string]Builder{
"list": &ListCommandParser{},
"append": &AppendCommandParser{},
"search": &SearchCommandParser{},
"fetch": &FetchCommandParser{},
"capability": &CapabilityCommandParser{},
"idle": &IdleCommandParser{},
"noop": &NoopCommandParser{},
"logout": &LogoutCommandParser{},
"check": &CheckCommandParser{},
"close": &CloseCommandParser{},
"expunge": &ExpungeCommandParser{},
"unselect": &UnselectCommandParser{},
"starttls": &StartTLSCommandParser{},
"status": &StatusCommandParser{},
"select": &SelectCommandParser{},
"examine": &ExamineCommandParser{},
"create": &CreateCommandParser{},
"delete": &DeleteCommandParser{},
"subscribe": &SubscribeCommandParser{},
"unsubscribe": &UnsubscribeCommandParser{},
"rename": &RenameCommandParser{},
"lsub": &LSubCommandParser{},
"login": &LoginCommandParser{},
"store": &StoreCommandParser{},
"copy": &CopyCommandParser{},
"move": &MoveCommandParser{},
"uid": NewUIDCommandParser(),
"id": &IDCommandParser{},
},
}
}
func (p *Parser) LastParsedTag() string {
return p.lastTag
}
func (p *Parser) LastParsedCommand() string {
return p.lastCmd
}
// ConsumeInvalidInput will consume all remaining scanner input until a new line has been reached.
func (p *Parser) ConsumeInvalidInput() error {
_, err := p.scanner.ConsumeUntilNewLine()
return err
}
func (p *Parser) Parse() (Command, error) {
result := Command{}
p.lastTag = ""
p.lastCmd = ""
p.parser.ResetOffsetCounter()
if err := p.parser.Advance(); err != nil {
return result, err
}
tag, err := p.parseTag()
if err != nil {
return result, err
}
// Done command does not have a tag.
if strings.ToLower(tag.Value) == "done" {
p.lastCmd = "done"
result.Tag = ""
result.Payload = &Done{}
} else {
result.Tag = tag.Value
p.lastTag = tag.Value
if err := p.parser.Consume(rfcparser.TokenTypeSP, "Expected space after tag"); err != nil {
return result, err
}
payload, err := p.parseCommand()
if err != nil {
return result, err
}
result.Payload = payload
}
if err := p.parser.Consume(rfcparser.TokenTypeCR, "expected CR"); err != nil {
return Command{}, err
}
// Can't fully consume the last new line here or we will hang forever as the clients don't send the next token.
// In the next loop, the call to advance will ensure the next token in the stream gets loaded properly.
if !p.parser.Check(rfcparser.TokenTypeLF) {
return Command{}, p.parser.MakeError("expected LF after CR")
}
return result, nil
}
func (p *Parser) parseCommand() (Payload, error) {
var commandBytes []byte
commandOffset := p.parser.CurrentToken().Offset
for {
if ok, err := p.parser.Matches(rfcparser.TokenTypeChar); err != nil {
return nil, err
} else if ok {
commandBytes = append(commandBytes, rfcparser.ByteToLower(p.parser.PreviousToken().Value))
} else {
break
}
}
p.lastCmd = string(commandBytes)
builder, ok := p.commands[p.lastCmd]
if !ok {
return nil, p.parser.MakeErrorAtOffset(fmt.Sprintf("unknown command '%v'", p.lastCmd), commandOffset)
}
return builder.FromParser(p.parser)
}
func (p *Parser) parseTag() (rfcparser.String, error) {
// tag = 1*<any ASTRING-CHAR except "+">
isTagChar := func(tt rfcparser.TokenType) bool {
return rfcparser.IsAStringChar(tt) && tt != rfcparser.TokenTypePlus
}
if err := p.parser.ConsumeWith(isTagChar, "Invalid tag char detected"); err != nil {
return rfcparser.String{}, err
}
tag, err := p.parser.CollectBytesWhileMatchesWithPrevWith(isTagChar)
if err != nil {
return rfcparser.String{}, err
}
return tag.IntoString(), err
}
|
