package domain

import (
	"encoding/base64"
	"time"
)

const (
	serverMaxLen = 10
)

type Session struct {
	ID        int64
	UserID    int64
	ServerKey string
	SID       string
	CreatedAt time.Time
	UpdatedAt time.Time
}

type CreateSessionParams struct {
	userID    int64
	serverKey string
	sid       string
}

func NewCreateSessionParams(serverKey, sid string, userID int64) (CreateSessionParams, error) {
	if serverKey == "" {
		return CreateSessionParams{}, ValidationError{
			Field: "ServerKey",
			Err:   ErrRequired,
		}
	}

	if len(serverKey) > serverMaxLen {
		return CreateSessionParams{}, ValidationError{
			Field: "ServerKey",
			Err: MaxLengthError{
				Max: serverMaxLen,
			},
		}
	}

	if sid == "" {
		return CreateSessionParams{}, ValidationError{
			Field: "SID",
			Err:   ErrRequired,
		}
	}

	if !isBase64(sid) {
		return CreateSessionParams{}, ValidationError{
			Field: "SID",
			Err:   ErrBase64,
		}
	}

	if userID < userIDMin {
		return CreateSessionParams{}, ValidationError{
			Field: "UserID",
			Err: MinError{
				Min: userIDMin,
			},
		}
	}

	return CreateSessionParams{userID: userID, serverKey: serverKey, sid: sid}, nil
}

func (c CreateSessionParams) UserID() int64 {
	return c.userID
}

func (c CreateSessionParams) ServerKey() string {
	return c.serverKey
}

func (c CreateSessionParams) SID() string {
	return c.sid
}

func isBase64(s string) bool {
	_, err := base64.StdEncoding.DecodeString(s)
	return err == nil
}