package repository

import (
	"code.30cm.net/digimon/app-cloudep-permission-server/pkg/domain"
	"code.30cm.net/digimon/app-cloudep-permission-server/pkg/domain/entity"
	"code.30cm.net/digimon/app-cloudep-permission-server/pkg/domain/repository"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/zeromicro/go-zero/core/stores/redis"
	"time"
)

// TokenRepositoryParam token 需要的參數
type TokenRepositoryParam struct {
	Redis *redis.Redis
}

// TokenRepository 用於操作 token 的存儲庫
type TokenRepository struct {
	TokenRepositoryParam
}

// NewTokenRepository 初始化並返回一個 TokenRepository 實例
func NewTokenRepository(param TokenRepositoryParam) repository.TokenRepo {
	return &TokenRepository{
		TokenRepositoryParam: param,
	}
}

// ====================== 私有工具函數 =======================

// runPipeline 執行 Redis pipeline 操作
func (repo *TokenRepository) runPipeline(ctx context.Context, pipelineFunc func(tx redis.Pipeliner) error) error {
	return repo.Redis.PipelinedCtx(ctx, pipelineFunc)
}

// setToken 使用 Redis pipeline 存儲 token 並設定 TTL
func (repo *TokenRepository) setToken(ctx context.Context, tx redis.Pipeliner, id string, body []byte, ttl time.Duration) error {
	return tx.Set(ctx, domain.GetAccessTokenRedisKey(id), body, ttl).Err()
}

// setRefreshToken 若 token 中有 refresh token，則存儲之（使用 pipeline）
func (repo *TokenRepository) setRefreshToken(ctx context.Context, tx redis.Pipeliner, token entity.Token, ttl time.Duration) error {
	if token.RefreshToken == "" {
		return nil
	}
	return tx.Set(ctx, domain.GetRefreshTokenRedisKey(token.RefreshToken), token.ID, ttl).Err()
}

// setTokenRelation 在 Redis 中設定 token 與 UID/Device 之間的關聯，並設定過期時間
func (repo *TokenRepository) setTokenRelation(ctx context.Context, tx redis.Pipeliner, uid, deviceID, tokenID string, ttl time.Duration) error {
	// 定義需要執行的操作列表
	operations := []struct {
		key string
		op  func() error
	}{
		{
			key: domain.GetUIDTokenRedisKey(uid),
			op: func() error {
				return tx.SAdd(ctx, domain.GetUIDTokenRedisKey(uid), tokenID).Err()
			},
		},
		{
			key: domain.GetDeviceTokenRedisKey(deviceID),
			op: func() error {
				return tx.SAdd(ctx, domain.GetDeviceTokenRedisKey(deviceID), tokenID).Err()
			},
		},
	}

	// 執行每個操作，並為對應 key 設置過期時間
	for _, operation := range operations {
		if err := operation.op(); err != nil {
			return fmt.Errorf("failed to create token relaction: %w", err)
		}
		if err := tx.Expire(ctx, operation.key, ttl).Err(); err != nil {
			return fmt.Errorf("failed to set expire: %w", err)
		}
	}

	return nil
}

// retrieveToken 根據指定 key 從 Redis 中獲取 token
func (repo *TokenRepository) retrieveToken(ctx context.Context, key string) (entity.Token, error) {
	body, err := repo.Redis.GetCtx(ctx, key)
	if err != nil {
		return entity.Token{}, err
	}

	if body == "" {
		return entity.Token{}, fmt.Errorf("failed to found token")
	}

	var token entity.Token
	if err := json.Unmarshal([]byte(body), &token); err != nil {
		return entity.Token{}, fmt.Errorf("failed to unmarshal token JSON: %w", err)
	}

	return token, nil
}

// getTokensBySet 根據集合 key 獲取所有 token
func (repo *TokenRepository) getTokensBySet(ctx context.Context, setKey string) ([]entity.Token, error) {
	ids, err := repo.Redis.Smembers(setKey)
	if err != nil {
		if errors.Is(err, redis.Nil) {
			return nil, nil
		}
		return nil, err
	}

	tokens := make([]entity.Token, 0, len(ids))
	var tokensToDelete []string
	now := time.Now().UnixNano()
	for _, id := range ids {
		token, err := repo.retrieveToken(ctx, domain.GetAccessTokenRedisKey(id))
		if err != nil {
			tokensToDelete = append(tokensToDelete, id)
			continue
		}

		if token.ExpiresIn < now {
			tokensToDelete = append(tokensToDelete, id)
			continue
		}
		tokens = append(tokens, token)
	}

	// 清除過期或錯誤的 token
	if len(tokensToDelete) > 0 {
		_ = repo.DeleteAccessTokenByID(ctx, tokensToDelete)
	}

	return tokens, nil
}

// getCountBySet 獲取集合中元素的數量
func (repo *TokenRepository) getCountBySet(ctx context.Context, setKey string) (int, error) {
	count, err := repo.Redis.ScardCtx(ctx, setKey)
	if err != nil {
		return 0, err
	}

	return int(count), nil
}

// deleteKeysAndRelations 刪除指定的 Redis key 並移除相關關聯（UID 與 DeviceID）
func (repo *TokenRepository) deleteKeysAndRelations(ctx context.Context, keys []string, uid, deviceID, tokenID string) error {
	err := repo.Redis.Pipelined(func(tx redis.Pipeliner) error {
		// 移除 UID 與 DeviceID 關聯中的 tokenID
		_ = tx.SRem(ctx, domain.GetUIDTokenRedisKey(uid), tokenID)
		_ = tx.SRem(ctx, domain.GetDeviceTokenRedisKey(deviceID), tokenID)

		// 刪除所有指定的 keys
		for _, key := range keys {
			_ = tx.Del(ctx, key)
		}

		return nil
	})

	return err
}

// batchDeleteKeys 批量刪除 Redis keys
func (repo *TokenRepository) batchDeleteKeys(ctx context.Context, keys ...string) error {
	return repo.Redis.Pipelined(func(tx redis.Pipeliner) error {
		for _, key := range keys {
			if err := tx.Del(ctx, key).Err(); err != nil {
				return err
			}
		}
		return nil
	})
}

// ====================== 公開方法 =======================

// Create 創建新的 token
func (repo *TokenRepository) Create(ctx context.Context, token entity.Token) error {
	binToken, err := json.Marshal(token)
	if err != nil {
		return err
	}
	// 根據 token 設定 refresh 過期秒數計算 TTL
	refreshTTL := time.Duration(token.RedisRefreshExpiredSec()) * time.Second

	return repo.runPipeline(ctx, func(tx redis.Pipeliner) error {
		if err := repo.setToken(ctx, tx, token.ID, binToken, refreshTTL); err != nil {
			return err
		}
		if err := repo.setRefreshToken(ctx, tx, token, refreshTTL); err != nil {
			return err
		}

		if err := repo.setTokenRelation(ctx, tx, token.UID, token.DeviceID, token.ID, refreshTTL); err != nil {
			return err
		}
		return nil
	})
}

// CreateOneTimeToken 創建一次性 token
func (repo *TokenRepository) CreateOneTimeToken(ctx context.Context, key string, ticket entity.Ticket, dt time.Duration) error {
	body, err := json.Marshal(ticket)
	if err != nil {
		return err
	}

	_, err = repo.Redis.SetnxExCtx(ctx, domain.GetRefreshTokenRedisKey(key), string(body), int(dt.Seconds()))
	return err
}

// GetAccessTokenByOneTimeToken 根據一次性 token 獲取 access token
func (repo *TokenRepository) GetAccessTokenByOneTimeToken(ctx context.Context, oneTimeToken string) (entity.Token, error) {
	return repo.retrieveToken(ctx, domain.GetRefreshTokenRedisKey(oneTimeToken))
}

// GetAccessTokenByID 根據 token ID 獲取 access token
func (repo *TokenRepository) GetAccessTokenByID(ctx context.Context, id string) (entity.Token, error) {
	return repo.retrieveToken(ctx, domain.GetAccessTokenRedisKey(id))
}

// GetAccessTokensByUID 根據 UID 獲取所有 access tokens
func (repo *TokenRepository) GetAccessTokensByUID(ctx context.Context, uid string) ([]entity.Token, error) {
	return repo.getTokensBySet(ctx, domain.GetUIDTokenRedisKey(uid))
}

// GetAccessTokenCountByUID 根據 UID 獲取 access token 的數量
func (repo *TokenRepository) GetAccessTokenCountByUID(ctx context.Context, uid string) (int, error) {
	return repo.getCountBySet(ctx, domain.GetUIDTokenRedisKey(uid))
}

// GetAccessTokensByDeviceID 根據 DeviceID 獲取所有 access tokens
func (repo *TokenRepository) GetAccessTokensByDeviceID(ctx context.Context, deviceID string) ([]entity.Token, error) {
	return repo.getTokensBySet(ctx, domain.GetDeviceTokenRedisKey(deviceID))
}

// GetAccessTokenCountByDeviceID 根據 DeviceID 獲取 access token 的數量
func (repo *TokenRepository) GetAccessTokenCountByDeviceID(ctx context.Context, deviceID string) (int, error) {
	return repo.getCountBySet(ctx, domain.GetDeviceTokenRedisKey(deviceID))
}

// Delete 刪除指定的 token
func (repo *TokenRepository) Delete(ctx context.Context, token entity.Token) error {
	keys := []string{
		domain.GetAccessTokenRedisKey(token.ID),
		domain.GetRefreshTokenRedisKey(token.RefreshToken),
	}
	return repo.deleteKeysAndRelations(ctx, keys, token.UID, token.DeviceID, token.ID)
}

// DeleteAccessTokenByID 根據 token ID 刪除 access token
func (repo *TokenRepository) DeleteAccessTokenByID(ctx context.Context, ids []string) error {
	for _, tokenID := range ids {
		token, err := repo.GetAccessTokenByID(ctx, tokenID)
		if err != nil {
			continue
		}
		keys := []string{
			domain.GetAccessTokenRedisKey(token.ID),
			domain.GetRefreshTokenRedisKey(token.RefreshToken),
		}
		_ = repo.deleteKeysAndRelations(ctx, keys, token.UID, token.DeviceID, token.ID)
	}
	return nil
}

// DeleteAccessTokensByUID 根據 UID 刪除所有 access tokens
func (repo *TokenRepository) DeleteAccessTokensByUID(ctx context.Context, uid string) error {
	tokens, err := repo.GetAccessTokensByUID(ctx, uid)
	if err != nil {
		return err
	}
	for _, token := range tokens {
		if err := repo.Delete(ctx, token); err != nil {
			return err
		}
	}
	return nil
}

// DeleteAccessTokensByDeviceID 根據 DeviceID 刪除所有 access tokens
func (repo *TokenRepository) DeleteAccessTokensByDeviceID(ctx context.Context, deviceID string) error {
	tokens, err := repo.GetAccessTokensByDeviceID(ctx, deviceID)
	if err != nil {
		return err
	}

	// 預分配 keys：每個 token 包含兩個 key
	keys := make([]string, 0, len(tokens)*2)
	for _, token := range tokens {
		keys = append(keys, domain.GetAccessTokenRedisKey(token.ID))
		keys = append(keys, domain.GetRefreshTokenRedisKey(token.RefreshToken))
	}

	// 移除 UID 關聯中的 tokenID
	if err := repo.runPipeline(ctx, func(tx redis.Pipeliner) error {
		for _, token := range tokens {
			_ = tx.SRem(ctx, domain.GetUIDTokenRedisKey(token.UID), token.ID)
		}
		return nil
	}); err != nil {
		return err
	}

	if err := repo.batchDeleteKeys(ctx, keys...); err != nil {
		return err
	}

	_, err = repo.Redis.Del(domain.GetDeviceTokenRedisKey(deviceID))
	return err
}

// DeleteOneTimeToken 刪除一次性 token（支持多個 key 一併刪除）
func (repo *TokenRepository) DeleteOneTimeToken(ctx context.Context, ids []string, tokens []entity.Token) error {
	totalKeys := len(ids) + len(tokens)
	keys := make([]string, 0, totalKeys)

	for _, id := range ids {
		keys = append(keys, domain.GetRefreshTokenRedisKey(id))
	}
	for _, token := range tokens {
		keys = append(keys, domain.GetRefreshTokenRedisKey(token.RefreshToken))
	}

	return repo.batchDeleteKeys(ctx, keys...)
}