package errors

import (
	"errors"
	"fmt"
	"strings"
	"time"

	"google.golang.org/grpc/codes"
	pb "github.com/topfans/backend/pkg/proto/common"
)

// 业务错误类型
var (
	ErrUserNotFound            = errors.New("user not found")
	ErrUserAlreadyExists       = errors.New("user already exists")
	ErrInvalidPassword         = errors.New("invalid password")
	ErrInvalidOldPassword      = errors.New("old password is incorrect")
	ErrSameAsOldPassword       = errors.New("new password is same as old")
	ErrInvalidVerifyToken      = errors.New("invalid verify token")
	ErrInvalidToken            = errors.New("invalid token")
	ErrTokenExpired            = errors.New("token expired")
	ErrTokenMismatch           = errors.New("token mismatch")
	ErrUserInactive            = errors.New("user is inactive")
	ErrFanProfileNotFound      = errors.New("fan profile not found")
	ErrFanProfileAlreadyExists = errors.New("fan profile already exists")
	ErrNicknameAlreadyExists   = errors.New("该昵称已被注册")
	ErrInvalidNickname         = errors.New("invalid nickname format")
	ErrStarNotFound            = errors.New("star not found")
	ErrInvalidMobile           = errors.New("invalid mobile format")
	ErrPasswordTooShort        = errors.New("password too short")
	ErrInvalidStarID           = errors.New("invalid star_id")
	ErrInvalidUserID           = errors.New("invalid user_id")
	ErrMaxIdentitiesReached    = errors.New("maximum number of identities reached")
	ErrInternalServer          = errors.New("internal server error")

	// 社交服务相关错误
	ErrCannotAddSelf           = errors.New("不能添加自己为好友")
	ErrCannotSearchSelf        = errors.New("不能查找自己")
	ErrNotFanOfStar            = errors.New("对方不是该明星的粉丝")
	ErrAlreadyFriends          = errors.New("你们已经是好友了")
	ErrRequestAlreadyPending   = errors.New("已有待处理的好友请求")
	ErrRequestInCooldown       = errors.New("请求已被拒绝，请稍后再试")
	ErrInvalidFriendUserID     = errors.New("friend_user_id不能为空")
	ErrFriendRequestNotFound   = errors.New("好友请求不存在")
	ErrCannotProcessOwnRequest = errors.New("不能处理自己发送的请求")
	ErrRequestAlreadyProcessed = errors.New("该请求已被处理")
	ErrRequestExpired          = errors.New("好友请求已过期")
	ErrInvalidAction           = errors.New("无效的操作")
	ErrNotFriends              = errors.New("你们不是好友")
	ErrMaxFriendsReached      = errors.New("已达到最大好友数量限制")

	// 资产服务相关错误
	ErrAssetNotFound          = errors.New("资产不存在")
	ErrMintOrderNotFound      = errors.New("铸造订单不存在")
	ErrInsufficientCrystal    = errors.New("水晶余额不足")
	ErrInsufficientMintTimes  = errors.New("铸造次数不足")
	ErrAssetAccessDenied      = errors.New("无权访问该资产")
	ErrMintOrderAccessDenied  = errors.New("无权访问该订单")
	ErrInvalidAssetStatus     = errors.New("资产状态无效")
	ErrInvalidMintOrderStatus = errors.New("订单状态无效")

	// 账号状态相关错误
	ErrAccountFrozen         = errors.New("账号已被冻结")
	ErrAccountBanned        = errors.New("账号已被封禁")

	// 活动服务相关错误
	ErrActivityNotFound  = errors.New("活动不存在")
	ErrActivityItemNotFound = errors.New("活动道具不存在")

	// 星册服务相关错误
	ErrCollectionAssetNotFound  = errors.New("典藏藏品不存在")
	ErrActivityAssetNotFound    = errors.New("活动藏品不存在")
	ErrAssetRegistryNotFound    = errors.New("资产索引不存在")
	ErrInvalidAssetType         = errors.New("无效的资产类型")
)

// ToGRPCCode 将错误转换为 google.rpc.Code 数字
// 用 errors.Is 而非 == 比较,以便识别 fmt.Errorf("%w: ...", ErrXxx, ...) 包装后的错误
//
// 映射表:
//   codes.OK                (0)  - 成功
//   codes.NotFound          (5)  - ErrUserNotFound / ErrFanProfileNotFound / ErrStarNotFound / ErrFriendRequestNotFound / ErrAssetNotFound / ErrMintOrderNotFound / ErrActivityNotFound / ErrActivityItemNotFound / ErrCollectionAssetNotFound / ErrActivityAssetNotFound / ErrAssetRegistryNotFound
//   codes.InvalidArgument   (3)  - 参数/数据校验错
//   codes.Unauthenticated   (16) - ErrInvalidPassword / ErrInvalidToken / ErrTokenExpired / ErrTokenMismatch
//   codes.PermissionDenied  (7)  - ErrAccountFrozen / ErrAccountBanned / ErrUserInactive / ErrAssetAccessDenied / ErrMintOrderAccessDenied
//   codes.ResourceExhausted (8)  - ErrRequestInCooldown
//   codes.Internal          (13) - 未识别的 error
func ToGRPCCode(err error) codes.Code {
	if err == nil {
		return codes.OK
	}

	switch {
	case errors.Is(err, ErrUserNotFound), errors.Is(err, ErrFanProfileNotFound), errors.Is(err, ErrStarNotFound):
		return codes.NotFound
	case errors.Is(err, ErrUserAlreadyExists), errors.Is(err, ErrFanProfileAlreadyExists), errors.Is(err, ErrNicknameAlreadyExists):
		return codes.InvalidArgument
	case errors.Is(err, ErrInvalidPassword), errors.Is(err, ErrInvalidToken), errors.Is(err, ErrTokenExpired), errors.Is(err, ErrTokenMismatch):
		return codes.Unauthenticated
	case errors.Is(err, ErrAccountFrozen), errors.Is(err, ErrAccountBanned), errors.Is(err, ErrUserInactive):
		return codes.PermissionDenied
	case errors.Is(err, ErrInvalidMobile), errors.Is(err, ErrPasswordTooShort),
		errors.Is(err, ErrInvalidOldPassword), errors.Is(err, ErrSameAsOldPassword),
		errors.Is(err, ErrInvalidVerifyToken),
		errors.Is(err, ErrInvalidStarID), errors.Is(err, ErrInvalidUserID),
		errors.Is(err, ErrMaxIdentitiesReached), errors.Is(err, ErrInvalidNickname):
		return codes.InvalidArgument
	case errors.Is(err, ErrCannotAddSelf), errors.Is(err, ErrCannotSearchSelf), errors.Is(err, ErrNotFanOfStar), errors.Is(err, ErrAlreadyFriends),
		errors.Is(err, ErrRequestAlreadyPending), errors.Is(err, ErrInvalidFriendUserID), errors.Is(err, ErrCannotProcessOwnRequest),
		errors.Is(err, ErrRequestAlreadyProcessed), errors.Is(err, ErrRequestExpired), errors.Is(err, ErrInvalidAction), errors.Is(err, ErrNotFriends):
		return codes.InvalidArgument
	case errors.Is(err, ErrRequestInCooldown):
		return codes.ResourceExhausted
	case errors.Is(err, ErrFriendRequestNotFound), errors.Is(err, ErrAssetNotFound), errors.Is(err, ErrMintOrderNotFound):
		return codes.NotFound
	case errors.Is(err, ErrInsufficientCrystal), errors.Is(err, ErrInsufficientMintTimes), errors.Is(err, ErrInvalidAssetStatus), errors.Is(err, ErrInvalidMintOrderStatus):
		return codes.InvalidArgument
	case errors.Is(err, ErrAssetAccessDenied), errors.Is(err, ErrMintOrderAccessDenied):
		return codes.PermissionDenied
	case errors.Is(err, ErrActivityNotFound), errors.Is(err, ErrActivityItemNotFound), errors.Is(err, ErrCollectionAssetNotFound), errors.Is(err, ErrActivityAssetNotFound), errors.Is(err, ErrAssetRegistryNotFound):
		return codes.NotFound
	case errors.Is(err, ErrInvalidAssetType):
		return codes.InvalidArgument
	default:
		return codes.Internal
	}
}

// FormatErrorResponse 格式化错误响应
// code 字段填 google.rpc.Code 数字(uint32)
func FormatErrorResponse(err error) *pb.BaseResponse {
	if err == nil {
		return &pb.BaseResponse{
			Code:      uint32(codes.OK),
			Message:   "",
			Timestamp: getCurrentTimestamp(),
		}
	}

	return &pb.BaseResponse{
		Code:      uint32(ToGRPCCode(err)),
		Message:   err.Error(),
		Timestamp: getCurrentTimestamp(),
	}
}

// FormatSuccessResponse 格式化成功响应
func FormatSuccessResponse() *pb.BaseResponse {
	return &pb.BaseResponse{
		Code:      uint32(codes.OK),
		Message:   "",
		Timestamp: getCurrentTimestamp(),
	}
}

// BuildBaseResponse 构建基础响应（FormatErrorResponse的别名）
func BuildBaseResponse(err error) *pb.BaseResponse {
	return FormatErrorResponse(err)
}

// NewError 创建新的业务错误,带 google.rpc.Code
// 推荐用法:appErrors.NewError(codes.Unauthenticated, "token 过期")
func NewError(code codes.Code, message string) error {
	return fmt.Errorf("[%s] %s", code.String(), message)
}

// NewRequestInCooldownError 创建冷静期错误，包含剩余天数
// 用 fmt.Errorf("%w: ...") 保留 wrap 关系,让 errors.Is(err, ErrRequestInCooldown) 仍能识别
func NewRequestInCooldownError(days int) error {
	return fmt.Errorf("%w: %d 天后再试", ErrRequestInCooldown, days)
}

// BuildBaseResponseWithMessage 构建带有自定义消息的响应
// code 是 google.rpc.Code 数字
func BuildBaseResponseWithMessage(code codes.Code, message string) *pb.BaseResponse {
	return &pb.BaseResponse{
		Code:      uint32(code),
		Message:   message,
		Timestamp: getCurrentTimestamp(),
	}
}

// getCurrentTimestamp 获取当前时间戳（毫秒）
func getCurrentTimestamp() int64 {
	return time.Now().UnixMilli()
}

// NewAccountBannedError 返回 ErrAccountBanned,可选地把 reason 拼到 message 里
// 用 fmt.Errorf("%w: ...") 保留 wrap 关系,让 errors.Is(err, ErrAccountBanned) 仍能识别
func NewAccountBannedError(reason string) error {
	if reason != "" {
		return fmt.Errorf("%w: %s", ErrAccountBanned, reason)
	}
	return ErrAccountBanned
}

// NewAccountFrozenError 返回 ErrAccountFrozen,把 reason / frozenUntil 拼到 message 里
// frozenUntil 为 nil 表示永久冻结
func NewAccountFrozenError(reason string, frozenUntil *int64) error {
	parts := []string{}
	if reason != "" {
		parts = append(parts, "原因:"+reason)
	}
	if frozenUntil != nil {
		parts = append(parts, "解封时间:"+time.UnixMilli(*frozenUntil).Format("2006-01-02 15:04:05"))
	}
	if len(parts) > 0 {
		return fmt.Errorf("%w: %s", ErrAccountFrozen, strings.Join(parts, ", "))
	}
	return ErrAccountFrozen
}