package main

import (
    "fmt"
    "strings"
)

// Command is a chat command for the bot.
type Command struct {
    Name     string `json:"name"`
    Response string `json:"response"`
}

func main() {
    commands := make(map[string]*Command)

    // add a command to test against
    commands["music"] = &Command{
        Name:     "music",
        Response: "play that funky music!",
    }

    // faking what the message would be from twitch chat.
    message := "!music"

    // check the message
    if response, ok := Check(commands, message); ok {
        // send the response
        fmt.Printf("%s\n\r", response)
    } else {
        // no command was found in the message.
        fmt.Println("No command found.")
    }
}

// Check validates a message for a command and returns a response.
func Check(commands map[string]*Command, message string) (string, bool) {
    // take the first word from the message
    firstWord := strings.Split(message, " ")[0]

    // check if the word starts with an exclamation mark
    // and has at least one other character
    if strings.HasPrefix(firstWord, "!") && len(message) > 1 {
        // remove the exclamation mark from the word
        word := firstWord[1:]

        // perform an ok check on the map to see if it exists, and return
        // the response for it
        if cmd, ok := commands[word]; ok {
            return cmd.Response, true
        }
    }

    // we didn't find a command, so return no response and false.
    return "", false
}