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package server
import (
"sort"
"strings"
)
type CommandSender interface {
OnCommandOutput(from *Server, output string)
OnCommandError(from *Server, err string)
}
type commandCtx struct {
server *Server
sender CommandSender
arg arguments
auth authLevel
}
type commandHandler func(commandCtx) (err string)
func isCommand(message string) (isCmd bool, text string) {
text = message
if message[0] == '/' {
text = message[1:]
// an additional slash escapes the second //not command -> /not command
isCmd = len(text) != 0 && text[0] != '/'
}
return
}
func executeCommand(
s *Server, auth authLevel, from CommandSender, command string) {
ctx := commandCtx {
server: s,
sender: from,
arg: parseArgs(command),
auth: auth,
}
cmd, _ := ctx.arg.nextArg()
handler := commands[cmd]
var err string
if commandAuth[cmd] > auth {
err = "Permission denied"
} else if handler == nil {
err = "Unknown command: /" + cmd
} else {
err = handler(ctx)
}
if err != "" {
from.OnCommandError(s, err)
}
}
func usage(cmd string) string {
if help[cmd] != nil {
return "Usage: " + help[cmd][0]
} else {
return "Invalid usage"
}
}
var commands = map[string]commandHandler {
"op": func(ctx commandCtx) string {
name, ok := ctx.arg.nextArg()
if !ok {
return usage("op")
}
if !playerNameRegex.Match([]byte(name)) {
return "Unknown player."
}
ctx.server.changePlayerAuth(name, opAuth, func(ok bool) {
if ok {
ctx.sender.OnCommandOutput(ctx.server, "Opped.")
} else {
ctx.sender.OnCommandError(ctx.server, "Unknown player")
}
})
return ""
},
"deop": func(ctx commandCtx) string {
name, ok := ctx.arg.nextArg()
if !ok {
return usage("op")
}
ctx.server.changePlayerAuth(name, defaultAuth, func(ok bool) {
if ok {
ctx.sender.OnCommandOutput(ctx.server, "Deopped.")
} else {
ctx.sender.OnCommandError(ctx.server, "Unknown player")
}
})
return ""
},
"stop": func(ctx commandCtx) string {
ctx.server.Stop(nil)
return ""
},
"save": func(ctx commandCtx) string {
ctx.server.Save(nil)
return ""
},
"help": func(ctx commandCtx) string {
cmd, ok := ctx.arg.nextArg()
if !ok {
var usages []string
for cmd, helpMessages := range help {
if commandAuth[cmd] <= ctx.auth {
usages = append(usages, helpMessages[0])
}
}
sort.Strings(usages)
ctx.sender.OnCommandOutput(ctx.server, "Available commands:")
for _, usage := range usages {
ctx.sender.OnCommandOutput(ctx.server, "* " + usage)
}
return ""
}
if help[cmd] == nil {
return "Unknown command: /" + cmd
}
for n, line := range help[cmd] {
if n == 0 {
line = "Usage: " + line
} else {
line = " " + line
}
ctx.sender.OnCommandOutput(ctx.server, line)
}
return ""
},
}
var commandAuth = map[string]authLevel {
"op": opAuth,
"deop": opAuth,
"save": opAuth,
"stop": opAuth,
}
var help = map[string][]string {
"op": []string {
"/op <player>",
"Grant operator status",
},
"deop": []string {
"/deop <player>",
"Revoke operator status",
},
"save": []string {
"/save",
"Save all levels",
},
"stop": []string {
"/stop",
"Stop the server",
},
"help": []string {
"/help [command]",
},
}
type arguments struct {
rd *strings.Reader
}
func parseArgs(command string) arguments {
return arguments {strings.NewReader(command)}
}
func (arg *arguments) nextArg() (string, bool) {
var out strings.Builder
for {
b, err := arg.rd.ReadByte()
if err != nil {
return "", false
}
if b != ' ' {
arg.rd.UnreadByte()
break
}
}
var splitChar byte = ' '
b, err := arg.rd.ReadByte()
if err != nil {
return "", false
}
if b == '"' {
splitChar = '"'
} else {
arg.rd.UnreadByte()
}
for {
b, err = arg.rd.ReadByte()
if err != nil {
if out.Len() > 0 {
break
}
return "", false
}
if b == splitChar {
break
}
if b == '\\' {
b, err = arg.rd.ReadByte()
if err != nil {
b = '\\'
}
}
out.WriteByte(b)
}
return out.String(), true
}
func (arg *arguments) allArgs() []string {
var (a string; ok bool; args []string)
for {
a, ok = arg.nextArg()
if !ok {
break
}
args = append(args, a)
}
return args
}
|
