package main

import (
	"errors"
	"fmt"
	"strings"

	"github.com/bwmarrin/discordgo"
)

const guildID = "626424729234046987"
const memberRoleID = "626434632614805526"
const auditChannel = "631789849929711627"

var errMemberNotFound = errors.New("messageutil: the requested member was not found")

func enforceDM(s *discordgo.Session, m *discordgo.MessageCreate) bool {
	if m.GuildID != "" {
		//This command can only be used in DM to protect the invite creator.
		s.ChannelMessageDelete(m.ChannelID, m.ID)
		s.ChannelMessageSend(
			m.ChannelID,
			m.Author.Mention()+"，这个指令只能在私信中使用。\n"+m.Author.Mention()+", this command can only be used in DM.",
		)
		return false
	}
	return true
}

func membersOnly(s *discordgo.Session, m *discordgo.MessageCreate) bool {
	member, err := s.GuildMember(guildID, m.Author.ID)
	if err != nil {
		s.ChannelMessageSend(
			m.ChannelID,
			m.Author.Mention()+"，请在成为会员后才使用这个指令。\n"+m.Author.Mention()+", please use this command after you become a member.",
		)
		return false
	}
	for _, v := range member.Roles {
		if v == memberRoleID {
			return true
		}
	}
	s.ChannelMessageSend(
		m.ChannelID,
		m.Author.Mention()+"，请在成为会员后才使用这个指令。\n"+m.Author.Mention()+", please use this command after you become a member.",
	)
	return false
}

func nonMembersOnly(s *discordgo.Session, m *discordgo.MessageCreate) bool {
	member, err := s.GuildMember(guildID, m.Author.ID)
	if err != nil {
		return false
	}
	for _, v := range member.Roles {
		if v == memberRoleID {
			s.ChannelMessageSend(
				m.ChannelID,
				m.Author.Mention()+"，该指令只能被非会员使用。\n"+m.Author.Mention()+", this command can only be used by non-member.",
			)
			return false
		}
	}
	return true
}

func sendPrivateMessage(s *discordgo.Session, recipient, message string) error {
	channel, err := s.UserChannelCreate(recipient)
	if err != nil {
		return err
	}
	_, err = s.ChannelMessageSend(channel.ID, message)
	return err
}

func auditLog(s *discordgo.Session, message string) {
	_, err := s.ChannelMessageSend(auditChannel, message)
	if err != nil {
		fmt.Println("==Audit Log==")
		fmt.Println(message)
		fmt.Println(err)
	}
}

func getMemberFromUserFriendlyName(s *discordgo.Session, user string) (*discordgo.Member, error) {
	allMembers, err := getAllMembers(s)
	if err != nil {
		return nil, err
	}
	if strings.HasPrefix(user, "@") {
		user = strings.TrimPrefix(user, "@")
	} else if strings.HasSuffix(user, ">") {
		if strings.HasPrefix(user, "<@!") {
			user = strings.TrimSuffix(strings.TrimPrefix(user, "<@!"), ">")
		} else if strings.HasPrefix(user, "<@") {
			user = strings.TrimSuffix(strings.TrimPrefix(user, "<@"), ">")
		}
	}
	if strings.ContainsRune(user, '#') {
		list := strings.Split(user, "#")
		username := strings.Join(list[:len(list)-1], "#")
		discriminator := list[len(list)-1]
		for _, v := range allMembers {
			if v.User.Username == username && v.User.Discriminator == discriminator {
				return v, nil
			}
		}
	}
	for _, v := range allMembers {
		if v.User.ID == user {
			return v, nil
		}
	}
	for _, v := range allMembers {
		if v.Nick == user {
			return v, nil
		}
	}
	for _, v := range allMembers {
		if v.User.Username == user {
			return v, nil
		}
	}
	return nil, errMemberNotFound
}

func getAllMembers(s *discordgo.Session) ([]*discordgo.Member, error) {
	initial, err := s.GuildMembers(guildID, "", 1000)
	if err != nil {
		return nil, err
	}
	next := initial[len(initial)-1].User.ID
	for next != "" {
		nextArray, err := s.GuildMembers(guildID, next, 1000)
		if err != nil {
			return nil, err
		}
		if len(nextArray) == 0 {
			next = ""
		} else {
			next = nextArray[len(nextArray)-1].User.ID
			initial = append(initial, nextArray...)
		}
	}
	return initial, nil
}