pepebot/discord/commands.go
2021-06-03 14:07:11 +02:00

106 lines
2.9 KiB
Go

package main
import (
"strings"
"github.com/bwmarrin/discordgo"
)
/* The Command interface is a template for the implementation of a command of the discord bot.
The actual command will be executed in the Execute function.
All the actual Command objects will be (similarly to Handlers in the net/http package) put into a CommandMux */
type Command interface {
Execute(s *discordgo.Session, m *discordgo.MessageCreate)
}
type HandlerFunc func(s *discordgo.Session, m *discordgo.MessageCreate)
func (f HandlerFunc) Execute(s *discordgo.Session, m *discordgo.MessageCreate) {
f(s, m)
}
/* The CommandMux struct is a type of mux for Discord commands. It's modelled after the net/http ServeMux */
type CommandMux struct {
m map[string]muxEntry
prefix string
}
func NewCommandMux() *CommandMux { return new(CommandMux) }
func (c *CommandMux) removeFirst(command string) string {
split := strings.SplitN(strings.TrimSpace(command), " ", 2)
if len(split) > 1 {
return split[1]
}
return ""
}
func (c *CommandMux) firstCommand(command string) string {
split := strings.SplitN(strings.TrimSpace(command), " ", 2)
if len(split) > 0 {
return split[0]
}
return ""
}
func (c *CommandMux) Handler(m *discordgo.MessageCreate) (cmd Command, pattern string) {
if strings.HasPrefix(m.Content, c.prefix) {
/* Special case for this bot alone. It has a command that is only it's prefix
So we check if the whole message is only the prefix before proceding.
So please don't forget to add the command, since it's totally hardcoded here. */
if strings.TrimSpace(m.Content) == c.prefix {
return c.m[c.prefix].h, c.m[c.prefix].pattern
}
m := c.removeFirst(m.Content) /* Here the prefix is removed, so we're left with only the first keyword */
cmd, ok := c.m[c.firstCommand(m)]
if ok {
return cmd.h, cmd.pattern
}
}
/* Here is where I might add the whole checking for bad words part */
return nil, ""
}
func (c *CommandMux) Execute(s *discordgo.Session, m *discordgo.MessageCreate) {
h, _ := c.Handler(m)
if h == nil {
//log.Printf("There exists no handler for %s\n", m.Content)
return
}
h.Execute(s, m)
}
func (c *CommandMux) Handle(pattern string, handler Command) {
if pattern == "" {
panic("commandmux: invalid pattern")
}
if handler == nil {
panic("commandmux: nil handler")
}
if _, exist := c.m[pattern]; exist {
panic("commandmux: multiple registrations for " + pattern)
}
if c.m == nil {
c.m = make(map[string]muxEntry)
}
e := muxEntry{h: handler, pattern: pattern}
c.m[pattern] = e
}
func (c *CommandMux) HandleFunc(pattern string, handler func(s *discordgo.Session, m *discordgo.MessageCreate)) {
if handler == nil {
panic("commandmux: nil handler")
}
c.Handle(pattern, HandlerFunc(handler))
}
/* The muxEntry struct contains the actual Command implementation as well as the pattern (discord command)
it will be matched against */
type muxEntry struct {
h Command
pattern string
}