package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"os"

	"github.com/joho/godotenv"
)

type BotMessage struct {
	User struct {
		ID   int    `json:"id"`
		Name string `json:"name"`
	} `json:"user"`

	Room struct {
		ID   int    `json:"id"`
		Name string `json:"name"`
	} `json:"room"`

	Message struct {
		ID   int `json:"id"`
		Body struct {
			HTML  string `json:"html"`
			Plain string `json:"plain"`
		} `json:"body"`
	} `json:"message"`
}

var userLastCommandType = make(map[string]string)

func init() {
	registerPlugin(PingPlugin{})
	registerPlugin(MathPlugin{})
	registerPlugin(HiPlugin{})
	registerPlugin(TracePlugin{})
	registerPlugin(HelpPlugin{})
	registerPlugin(TimerPlugin{})
}

func main() {
	godotenv.Load()
	fmt.Println("Sox started")
	http.HandleFunc("/", commandHandler)

	port := os.Getenv("PORT")
	if port == "" {
		port = "4567"
	}

	panic(http.ListenAndServe(":"+port, nil))
}

func commandHandler(w http.ResponseWriter, r *http.Request) {
	var msg BotMessage
	err := json.NewDecoder(r.Body).Decode(&msg)
	if err != nil {
		errorResponse(w, http.StatusBadRequest, "invalid request body")
		return
	}

	fmt.Fprintln(w, executeCommand(msg))
}

func executeCommand(msg BotMessage) string {
	command, arguments := SplitFirstWord(msg.Message.Body.Plain)

	if p, ok := registry[command]; ok {
		if command != "help" {
			userLastCommandType[msg.User.Name] = command
		}
		return p.Execute(msg, arguments)
	}

	// Fall back to last command, treating full message as new args
	if last, ok := userLastCommandType[msg.User.Name]; ok {
		if p, ok := registry[last]; ok {
			return p.Execute(msg, msg.Message.Body.Plain)
		}
	}

	return "Not sure what to do... Try `help` to see what I can do!"
}

func errorResponse(w http.ResponseWriter, status int, msg string) {
	w.WriteHeader(status)
	fmt.Fprintf(w, "Error: %s", msg)
}