package main

import (
	"errors"

	"github.com/bwmarrin/discordgo"
)

var trustCache map[string]float64

var errNotMember = errors.New("trust: only members have trust value")

func getTrust(s *discordgo.Session, discordID string) (float64, error) {
	if v, ok := trustCache[discordID]; ok {
		return v, nil
	}
	member, err := s.GuildMember(guildID, discordID)
	if err != nil {
		return 0.0, err
	}
	isMember := false
	for _, role := range member.Roles {
		if role == memberRoleID {
			isMember = true
		}
	}
	if !isMember {
		return 0.0, errNotMember
	}
	votes, err := getTrustVote(discordID)
	if err != nil {
		return 0.0, err
	}
	votes = append(votes, 3)
	var total float64
	for _, v := range votes {
		total += float64(v)
	}
	return total / float64(len(votes)), nil
}

func getTotalTrust(s *discordgo.Session) (float64, error) {
	members, err := getAllMembers(s)
	if err != nil {
		return 0.0, err
	}
	var total float64
	for _, member := range members {
		isMember := false
		for _, role := range member.Roles {
			if role == memberRoleID {
				isMember = true
			}
		}
		if !isMember {
			continue
		}
		trust, err := getTrust(s, member.User.ID)
		if err != nil {
			return 0.0, err
		}
		total += trust
	}
	return total, nil
}

func updateTrust(sourceID, targetID string, voteValue int) error {
	err := updateDbTrust(sourceID, targetID, voteValue, false)
	if err != nil {
		return err
	}
	delete(trustCache, targetID)
	return nil
}