irc/message.go

137 lines
2.9 KiB
Go

package main
import (
"fmt"
"strings"
)
type Message struct {
Tags map[string]string
Source string
Command command
Parameters []string
Raw string
parseIndex int
}
func (m *Message) ParseMessage() error {
m.parseIndex = 0
m.consumeSpaces()
if m.consume('@') {
m.Tags, _ = m.parseTags()
}
m.consumeSpaces()
if m.consume(':') {
m.Source, _ = m.parseSource()
}
m.consumeSpaces()
m.Command, _ = m.parseCommand()
m.consumeSpaces()
m.Parameters, _ = m.parseParameters()
return nil
}
func (m *Message) parseTags() (map[string]string, error) {
tags := make(map[string]string)
for {
next := m.findNext("=", ";")
if next == -1 {
break
} else if m.Raw[m.parseIndex+next] == '=' {
key := m.Raw[m.parseIndex : m.parseIndex+next]
m.parseIndex += next + 1
eot := m.findNext(";", " ")
tags[key] = m.Raw[m.parseIndex : m.parseIndex+eot]
m.parseIndex += len(tags[key]) + 1
} else if m.Raw[m.parseIndex+next] == ';' {
key := m.Raw[m.parseIndex : m.parseIndex+next]
m.parseIndex += next + 1
tags[key] = ""
} else {
break
}
}
return tags, nil
}
func (m *Message) parseSource() (string, error) {
start := m.parseIndex
endofparse := strings.Index(m.Raw[m.parseIndex:], " ")
if endofparse == -1 {
return "", fmt.Errorf("end of string encountered while parsing tags")
}
m.parseIndex += endofparse
return m.Raw[start:m.parseIndex], nil
}
func (m *Message) parseCommand() (command, error) {
start := m.parseIndex
endofparse := strings.Index(m.Raw[m.parseIndex:], " ")
if endofparse == -1 {
return "", fmt.Errorf("end of string encountered while parsing command")
}
m.parseIndex += endofparse
return command(m.Raw[start:m.parseIndex]), nil
}
func (m *Message) parseParameters() ([]string, error) {
params := []string{}
for m.parseIndex <= len(m.Raw) {
m.consumeSpaces()
if m.consume(':') { // "run until end of line"
params = append(params, m.Raw[m.parseIndex:])
break
}
endofparse := strings.Index(m.Raw[m.parseIndex:], " ")
if endofparse == -1 { // no further params after this one
p := strings.TrimSuffix(m.Raw[m.parseIndex:], " ")
if len(p) > 0 { // reject empty trailing params
params = append(params, p)
}
break
}
params = append(params, m.Raw[m.parseIndex:m.parseIndex+endofparse])
m.parseIndex += endofparse
}
return params, nil
}
func (m *Message) consumeSpaces() {
if len(m.Raw) <= m.parseIndex {
return
}
for len(m.Raw) > m.parseIndex && m.Raw[m.parseIndex] == ' ' {
m.parseIndex++
}
}
func (m *Message) consume(r byte) bool {
if len(m.Raw) <= m.parseIndex {
return false
}
if m.Raw[m.parseIndex] == r {
m.parseIndex++
return true
}
return false
}
func (m *Message) findNext(bs ...string) int {
if len(bs) == 0 {
return 0
}
r := -1
for _, b := range bs {
i := strings.Index(m.Raw[m.parseIndex:], b)
if r == -1 || (i != -1 && i < r) {
r = i
}
}
return r
}
func (m *Message) ToBytes() []byte {
return nil
}