package backend

import (
	"errors"

	"github.com/bwmarrin/discordgo"

	"TerraOceanBot/db"
	"TerraOceanBot/discord/config"
)

var trustCache = make(map[string]float64)

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

func GetTrust(s *discordgo.Session, discordID string) (float64, error) {
	rawScore, err := GetRawTrust(s, discordID)
	if err != nil {
		return 0.0, err
	}

	//Calculate active level
	totalLevel, err := db.GetTotalActiveLevel()
	if err != nil {
		return rawScore, nil
	}
	if totalLevel < 1000000 {
		return rawScore, nil
	}
	activeLevel, err := db.GetActiveLevel(discordID)
	if err != nil && err != db.ErrNotFound {
		//ErrNotFound is allowed. It just means the player hasn't played yet.
		return 0.0, err
	}
	activeBuff := float64(activeLevel) / float64(totalLevel)

	return rawScore * (1 + activeBuff), nil
}

func GetRawTrust(s *discordgo.Session, discordID string) (float64, error) {
	if v, ok := trustCache[discordID]; ok {
		return v, nil
	}
	member, err := s.GuildMember(config.GuildID, discordID)
	if err != nil {
		return 0.0, err
	}
	isMember := false
	for _, role := range member.Roles {
		if role == config.MemberRoleID {
			isMember = true
		}
	}
	if !isMember {
		return 0.0, ErrNotMember
	}
	votes, err := db.GetTrustVote(discordID)
	if err != nil {
		return 0.0, err
	}
	if len(votes) == 0 {
		return 0.0, nil
	}
	var total float64
	for _, v := range votes {
		total += float64(v)
	}

	rawScore := total / float64(len(votes))
	trustCache[discordID] = rawScore
	return rawScore, 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 == config.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 := db.UpdateTrust(sourceID, targetID, voteValue, false)
	if err != nil {
		return err
	}
	delete(trustCache, targetID)
	return nil
}