package mux

import (
	"fmt"
	"sort"
	"strconv"

	"git.mgmcomp.net/thisnthat/discordgo"
)

func (r *Router) helpCommandHandler(s *discordgo.Session, m *discordgo.Message, ctx *Context) {
	displayPrefix := ""

	switch ctx.Method {
	case DirectMethod:
		displayPrefix = ""
	case PrefixMethod:
		displayPrefix = r.prefix
	case MentionMethod:
		displayPrefix = fmt.Sprintf("@%s ", s.State.User.Username)
	}

	// Sort commands
	maxDisplayLen := 0
	keys := make([]string, 0, len(r.routes))
	cmdmap := make(map[string]*route)

	for _, v := range r.routes {
		// Only display commands with a description
		if v.Description == "" {
			continue
		}

		// Calculate the max length of command+args string
		l := len(v.Name) // TODO: Add the +args part :)
		if l > maxDisplayLen {
			maxDisplayLen = l
		}

		cmdmap[v.Name] = v

		// help and about are added separately below.
		if v.Name == "help" || v.Name == "about" {
			continue
		}

		keys = append(keys, v.Name)
	}

	sort.Strings(keys)

	// TODO: Learn more link needs to be configurable
	resp := "```autoit\n"

	v, ok := cmdmap["help"]
	if ok {
		keys = append([]string{v.Name}, keys...)
	}

	v, ok = cmdmap["about"]
	if ok {
		keys = append([]string{v.Name}, keys...)
	}

	// Add sorted result to help msg
	for _, k := range keys {
		v := cmdmap[k]
		resp += fmt.Sprintf("%s%-"+strconv.Itoa(maxDisplayLen)+"s # %s\n", displayPrefix, v.Name, v.Description)
	}

	resp += "```\n"
	s.ChannelMessageSend(m.ChannelID, resp)

	return
}