package valueobjects

import (
	"fmt"
	"time"

	"github.com/knowfoolery/backend/shared/errors"
	"github.com/knowfoolery/backend/shared/types"
)

type LeaderboardEntry struct {
	playerID     types.UserID
	playerName   string
	score        int32
	rank         int32
	achievedAt   time.Time
	sessionID    types.GameSessionID
	gamesPlayed  int32
	avgScore     float32
	lastActivity time.Time
	metadata     map[string]interface{}
}

func NewLeaderboardEntry(
	playerID types.UserID,
	playerName string,
	score int32,
	sessionID types.GameSessionID,
) (*LeaderboardEntry, error) {
	if playerID == "" {
		return nil, errors.ErrInvalidPlayerID
	}
	if playerName == "" {
		return nil, errors.ErrInvalidPlayerName
	}
	if score < 0 {
		return nil, errors.ErrInvalidScore
	}
	if sessionID == "" {
		return nil, errors.ErrInvalidSessionID
	}

	now := time.Now()
	return &LeaderboardEntry{
		playerID:     playerID,
		playerName:   playerName,
		score:        score,
		rank:         0,
		achievedAt:   now,
		sessionID:    sessionID,
		gamesPlayed:  1,
		avgScore:     float32(score),
		lastActivity: now,
		metadata:     make(map[string]interface{}),
	}, nil
}

func (le *LeaderboardEntry) PlayerID() types.UserID {
	return le.playerID
}

func (le *LeaderboardEntry) PlayerName() string {
	return le.playerName
}

func (le *LeaderboardEntry) Score() int32 {
	return le.score
}

func (le *LeaderboardEntry) Rank() int32 {
	return le.rank
}

func (le *LeaderboardEntry) AchievedAt() time.Time {
	return le.achievedAt
}

func (le *LeaderboardEntry) SessionID() types.GameSessionID {
	return le.sessionID
}

func (le *LeaderboardEntry) GamesPlayed() int32 {
	return le.gamesPlayed
}

func (le *LeaderboardEntry) AvgScore() float32 {
	return le.avgScore
}

func (le *LeaderboardEntry) LastActivity() time.Time {
	return le.lastActivity
}

func (le *LeaderboardEntry) Metadata() map[string]interface{} {
	result := make(map[string]interface{})
	for k, v := range le.metadata {
		result[k] = v
	}
	return result
}

func (le *LeaderboardEntry) UpdateScore(newScore int32, sessionID types.GameSessionID) error {
	if newScore < 0 {
		return errors.ErrInvalidScore
	}
	if sessionID == "" {
		return errors.ErrInvalidSessionID
	}

	if newScore > le.score {
		le.score = newScore
		le.sessionID = sessionID
		le.achievedAt = time.Now()
	}

	le.gamesPlayed++
	le.avgScore = (le.avgScore*float32(le.gamesPlayed-1) + float32(newScore)) / float32(le.gamesPlayed)
	le.lastActivity = time.Now()

	return nil
}

func (le *LeaderboardEntry) SetRank(rank int32) error {
	if rank <= 0 {
		return errors.ErrInvalidRank
	}
	le.rank = rank
	return nil
}

func (le *LeaderboardEntry) UpdatePlayerName(name string) error {
	if name == "" {
		return errors.ErrInvalidPlayerName
	}
	le.playerName = name
	return nil
}

func (le *LeaderboardEntry) SetMetadata(key string, value interface{}) error {
	if key == "" {
		return errors.ErrInvalidMetadata
	}
	le.metadata[key] = value
	return nil
}

func (le *LeaderboardEntry) RemoveMetadata(key string) {
	delete(le.metadata, key)
}

func (le *LeaderboardEntry) IsEqual(other *LeaderboardEntry) bool {
	if other == nil {
		return false
	}
	return le.playerID == other.playerID &&
		le.score == other.score &&
		le.sessionID == other.sessionID
}

func (le *LeaderboardEntry) String() string {
	return fmt.Sprintf("LeaderboardEntry{PlayerID: %s, Name: %s, Score: %d, Rank: %d}",
		le.playerID, le.playerName, le.score, le.rank)
}

type LeaderboardEntrySnapshot struct {
	PlayerID     types.UserID            `json:"player_id"`
	PlayerName   string                  `json:"player_name"`
	Score        int32                   `json:"score"`
	Rank         int32                   `json:"rank"`
	AchievedAt   time.Time               `json:"achieved_at"`
	SessionID    types.GameSessionID     `json:"session_id"`
	GamesPlayed  int32                   `json:"games_played"`
	AvgScore     float32                 `json:"avg_score"`
	LastActivity time.Time               `json:"last_activity"`
	Metadata     map[string]interface{}  `json:"metadata"`
}

func (le *LeaderboardEntry) ToSnapshot() LeaderboardEntrySnapshot {
	return LeaderboardEntrySnapshot{
		PlayerID:     le.playerID,
		PlayerName:   le.playerName,
		Score:        le.score,
		Rank:         le.rank,
		AchievedAt:   le.achievedAt,
		SessionID:    le.sessionID,
		GamesPlayed:  le.gamesPlayed,
		AvgScore:     le.avgScore,
		LastActivity: le.lastActivity,
		Metadata:     le.Metadata(),
	}
}

func (le *LeaderboardEntry) FromSnapshot(snapshot LeaderboardEntrySnapshot) error {
	if snapshot.PlayerID == "" {
		return errors.ErrInvalidPlayerID
	}
	if snapshot.PlayerName == "" {
		return errors.ErrInvalidPlayerName
	}
	if snapshot.Score < 0 {
		return errors.ErrInvalidScore
	}

	le.playerID = snapshot.PlayerID
	le.playerName = snapshot.PlayerName
	le.score = snapshot.Score
	le.rank = snapshot.Rank
	le.achievedAt = snapshot.AchievedAt
	le.sessionID = snapshot.SessionID
	le.gamesPlayed = snapshot.GamesPlayed
	le.avgScore = snapshot.AvgScore
	le.lastActivity = snapshot.LastActivity
	le.metadata = make(map[string]interface{})
	for k, v := range snapshot.Metadata {
		le.metadata[k] = v
	}

	return nil
}