common

Documentation

Overview

Common functions, constants, and structures package for the backend.

Index

• Constants
• func FlushUserData(users *map[string]models.User, callerID string) *map[string]models.User
• func UnmarshalRequestData[T any](r *http.Request, model *T) error
• func WriteResponse(w http.ResponseWriter, resp interface{}, code int) error
• type APIResponse
• type Logger
  • func NewLogger(r *http.Request, worker string) *Logger
  • func (l *Logger) Error(err error) *Logger
  • func (l *Logger) Log() *Logger
  • func (l *Logger) Msg(msg string) *Logger
  • func (l *Logger) Payload(pl interface{}) *Logger
  • func (l *Logger) Println(msg string, code int) bool
  • func (l *Logger) RemovePrefix() *Logger
  • func (l *Logger) ResetTimer() *Logger
  • func (l *Logger) SetPrefix(prefix string) *Logger
  • func (l *Logger) Status(code int) *Logger
  • func (l *Logger) Write(w http.ResponseWriter)
• type LoggerInterface

Constants

const (
	HDR_PAGE_NO      = "X-Page-No"
	HDR_HIDE_REPLIES = "X-Hide-Replies"
	HDR_DUMP_TOKEN   = "X-Dump-Token"
	DHR_API_TOKEN    = "X-API-Token"
)

Header names.

const (
	// Auth-related error messages
	ERR_AUTH_FAIL           = "wrong credentials entered, or such user does not exist"
	ERR_AUTH_ACC_TOKEN_FAIL = "could not generate new access token"
	ERR_AUTH_REF_TOKEN_FAIL = "could not generate new refresh token"
	ERR_TOKEN_SAVE_FAIL     = "could not save new token to database"

	// Generic error messages
	ERR_CALLER_BLANK      = "callerID cannot be empty"
	ERR_CALLER_FAIL       = "could not get caller's name"
	ERR_CALLER_NOT_FOUND  = "caller not found in the database"
	ERR_USER_NOT_FOUND    = "user not found in the database"
	ERR_PAGENO_INCORRECT  = "pageNo has to be specified as integer/number"
	ERR_PAGE_EXPORT_NIL   = "could not get more pages, one exported map is nil!"
	ERR_INPUT_DATA_FAIL   = "could not process the input data, try again"
	ERR_API_TOKEN_BLANK   = "blank API token sent"
	ERR_API_TOKEN_INVALID = "invalid API token sent"
	ERR_NO_SERVER_SECRET  = "missing the server's secret (APP_PEPPER)"

	// Image-processing-related error messages
	ERR_IMG_DECODE_FAIL      = "image: could not decode to byte stream"
	ERR_IMG_ENCODE_FAIL      = "image: could not re-encode"
	ERR_IMG_ORIENTATION_FAIL = "image: could not fix the orientation"
	ERR_IMG_GIF_TO_WEBP_FAIL = "image: could not convert GIF to WebP"
	ERR_IMG_UNKNOWN_TYPE     = "image: unsupported format entered"
	ERR_IMG_SAVE_FILE_FAIL   = "image: could not save to a file"
	ERR_IMG_THUMBNAIL_FAIL   = "image: could not re-encode the thumbnail"

	// Poll-related error messages
	ERR_POLL_AUTHOR_MISMATCH    = "you cannot post a foreigner's poll"
	ERR_POLL_SAVE_FAIL          = "could not save the poll, try again"
	ERR_POLL_POST_FAIL          = "could not save a post about the new poll"
	ERR_POLL_NOT_FOUND          = "such poll not found in the database (may be deleted)"
	ERR_POLL_SELF_VOTE          = "you cannot vote in yours own poll"
	ERR_POLL_EXISTING_VOTE      = "you have already voted on such poll"
	ERR_POLL_DELETE_FOREIGN     = "you cannot delete a foreigner's poll"
	ERR_POLL_DELETE_FAIL        = "could not delete the poll, try again"
	ERR_POLLID_BLANK            = "pollID param is required"
	ERR_POLL_INVALID_VOTE_COUNT = "you can pass only one vote per poll"
	ERR_POLL_DUPLICIT_OPTIONS   = "all options (inc. the very question) have to be unique"

	// Post-related error messages
	ERR_POST_BLANK          = "post has got no content"
	ERR_POSTER_INVALID      = "you can add yours posts only"
	ERR_POST_SAVE_FAIL      = "could not save the post, try again"
	ERR_POST_NOT_FOUND      = "could not find the post (may be deleted)"
	ERR_POST_SELF_RATE      = "you cannot rate your own posts"
	ERR_POST_UPDATE_FOREIGN = "you cannot update a foreigner's post"
	ERR_POST_DELETE_FOREIGN = "you cannot delete a foreigner's post"
	ERR_POST_DELETE_FAIL    = "could not delete the post, try again"
	ERR_POST_DELETE_THUMB   = "could not delete associated thumbnail"
	ERR_POST_DELETE_FULLIMG = "could not delete associated full image"
	ERR_POSTID_BLANK        = "postID param is required"
	ERR_HASHTAG_BLANK       = "hashtag param is required"

	// Push-related (non-)error messages
	MSG_WEBPUSH_GW_RESPONSE         = "push goroutine: webpush gateway:"
	ERR_DEVICE_NOT_FOUND            = "devices not found in the database"
	ERR_SUBSCRIPTION_SAVE_FAIL      = "could not save the subscription to database"
	ERR_SUBSCRIPTION_NOT_FOUND      = "such subscription not found in the database"
	ERR_DEVICE_SUBSCRIBED_ALREADY   = "this device has been already registered"
	ERR_PUSH_SELF_NOTIF             = "will not notify oneself"
	ERR_PUSH_DISABLED_NOTIF         = "will not notify original poster"
	ERR_PUSH_UUID_BLANK             = "device's UUID cannot be sent empty"
	ERR_PUSH_BODY_COMPOSE_FAIL      = "failed to compose the notification body"
	ERR_NOTIFICATION_NOT_SENT       = "notification could not be sent"
	ERR_NOTIFICATION_RESP_BODY_FAIL = "failed to read the notification's response body"
	ERR_DEVICE_LIST_UPDATE_FAIL     = "failed to save the updated device list"
	ERR_UUID_BLANK                  = "uuid param is required"

	// User-related error messages
	ERR_USER_DELETE_FOREIGN       = "you cannot delete a foreigner's account"
	ERR_USER_DELETE_FAIL          = "could not delete the user from user database, try again"
	ERR_SUBSCRIPTION_DELETE_FAIL  = "could not delete the user from subscriptions, try again"
	ERR_MISSING_IMG_CONTENT       = "no image data received, try again"
	ERR_REGISTRATION_DISABLED     = "registration is disabled at the moment"
	ERR_RESTRICTED_NICKNAME       = "this nickname is restricted"
	ERR_USER_NICKNAME_TAKEN       = "this nickname has been already taken"
	ERR_NICKNAME_CHARSET_MISMATCH = "the nickname can only consist of characters a-z, A-Z and numbers 0-9"
	ERR_NICKNAME_TOO_LONG_SHORT   = "nickname is too long (>12 runes), or too short (<3 runes)"
	ERR_WRONG_EMAIL_FORMAT        = "wrong format of the e-mail address"
	ERR_EMAIL_ALREADY_USED        = "this e-mail address has been already used"
	ERR_USER_SAVE_FAIL            = "could not save new user to database"
	ERR_POSTREG_POST_SAVE_FAIL    = "could not save a new post about the new user's addition"
	ERR_USER_UPDATE_FOREIGN       = "could not update a foreign's account"
	ERR_USERID_BLANK              = "userID param is required"
	ERR_USER_UPDATE_FAIL          = "could not update the user in database"
	ERR_USER_PASSPHRASE_FOREIGN   = "you can change yours passphrase only"
	ERR_PASSPHRASE_REQ_INCOMPLETE = "passphrase change request is partly or completely empty"
	ERR_PASSPHRASE_CURRENT_WRONG  = "current passphrase sent is wrong"
	ERR_NO_EMAIL_MATCH            = "could not find a match for such e-mail address"
	ERR_MAIL_COMPOSITION_FAIL     = "could not compose the mail properly, try again"
	ERR_MAIL_NOT_SENT             = "could not send the mail, try again"
	ERR_REQUEST_UUID_BLANK        = "could not process blank request's UUID"
	ERR_REQUEST_EMAIL_BLANK       = "could not process blank request's e-mail address"
	ERR_REQUEST_UUID_INVALID      = "entered UUID is invalid"
	ERR_REQUEST_UUID_EXPIRED      = "entered UUID has expired"
	ERR_REQUEST_DELETE_FAIL       = "could not delete the request from database, try again"
	ERR_PASSPHRASE_UPDATE_FAIL    = "could not update the passphrase in database, try again"
	ERR_TARGET_USER_NOT_PRIVATE   = "target user is not private, no need to file new follow requests"
	ERR_USER_AVATAR_FOREIGN       = "you can update yours avatar only"
	ERR_ACTIVATION_MAIL_FAIL      = "the activation mail was not sent, try again"
	ERR_USER_NOT_ACTIVATED        = "user has not been activated yet, check your mail inbox"
)

(Non-)Error messages.

const (
	// Localhost as the IPv4 address.
	LOCALHOST4 = "127.0.0.1"

	// Localhost as the IPv6 address.
	LOCALHOST6 = "::1"
)

const (
	// Refresh token's TTL.
	TOKEN_TTL = time.Hour * 168 * 4
)

Token consts.

Functions

func FlushUserData

func FlushUserData(users *map[string]models.User, callerID string) *map[string]models.User

helper function to flush sensitive user data in the export for response

func UnmarshalRequestData

func UnmarshalRequestData[T any](r *http.Request, model *T) error

UnmarshalRequestData is a helper function that combines reading the request body and data structure unmarshalling from a JSON stream.

func WriteResponse

func WriteResponse(w http.ResponseWriter, resp interface{}, code int) error

Types

type APIResponse

type APIResponse struct {
	// Common fields for all responses
	Message   string `json:"message"`
	Timestamp int64  `json:"timestamp"`

	// Data field for any payload
	Data interface{} `json:"data"`
}

new generic API response schema idea

type Logger

type Logger struct {
	// CallerID is a nickname of the user calling the API.
	CallerID string `json:"-"`

	// Code integer is a HTTP return code.
	Code int `json:"code" validation:"required"`

	// IPAddress string is basically an user's IPv4/IPv6 address (beware of proxies).
	IPAddress string `json:"-"`

	// Message string holds a custom message returned by a various HTTP handler.
	Message string `json:"message" validation:"required"`

	// Prefix stands at the start of the logger output before the very message.
	Prefix string `json:"-"`

	// Method string hold a HTTP method name.
	Method string `json:"method"`

	// Route string is the very route called by user.
	Route string `json:"route"`

	// Version is the tagged version of the client's SW (compiled in).
	Version string `json:"version"`

	// WorkerName string is the name of a worker processing such request.
	WorkerName string `json:"worker_name" validation:"required"`

	// Response is a helper field to hold the prepared API response for sending.
	Response *APIResponse `json:"-"`

	// Err is a helper error field to hold the error type from the BE logging callback procedure.
	Err error `json:"-"`

	// TimerStart holds the starting point of the time measurement. To be subtracted and written to the JSON output afterwards.
	TimerStart time.Time `json:"request_start"`

	// TimeStop is the very stop time mark in terms of the system/application process duration.
	TimerStop time.Time `json:"request_stop"`

	// TimeDurationNS hold the difference between the start and stop time points regarding the application process making its duration (in nanoseconds).
	TimerDurationNS time.Duration `json:"request_duration_ns"`
}

func NewLogger

func NewLogger(r *http.Request, worker string) *Logger

NewLogger takes the HTTP request structure in (can be nil), and the worker's name (required string) to prepare a new Logger instance. Returns a pointer to the new Logger instance.

func (*Logger) Error

func (l *Logger) Error(err error) *Logger

Error takes an error and holds it in the Logger structure for the possible output.

func (*Logger) Log

func (l *Logger) Log() *Logger

Log write the logger's JSON output to the stdout.

func (*Logger) Msg

func (l *Logger) Msg(msg string) *Logger

Msg writes the input <msg> string to the Logger struct for its following output.

func (*Logger) Payload

func (l *Logger) Payload(pl interface{}) *Logger

Payload takes and prepares the HTTP response's body payload. The input can be nil.

func (*Logger) Println

func (l *Logger) Println(msg string, code int) bool

Deprecated. Println formats the encoded Logger struct into an output string to stdin.

func (*Logger) RemovePrefix

func (l *Logger) RemovePrefix() *Logger

RemovePrefix remove preiously prepended string from the Logger struct.

func (*Logger) ResetTimer

func (l *Logger) ResetTimer() *Logger

ResetTimer resets the TimerStart timestamp. Usable in the procedures where the logger is passed (???) or not to log the whole HTTP server uptime (the gracefully HTTP server shutdown goroutine).

func (*Logger) SetPrefix

func (l *Logger) SetPrefix(prefix string) *Logger

SetPrefix sets the log's prefix according to the input <prefix> string.

func (*Logger) Status

func (l *Logger) Status(code int) *Logger

Status writes the HTTP Status code (as integer) for the following logger output.

func (*Logger) Write

func (l *Logger) Write(w http.ResponseWriter)

Write writes the HTTP headers and sends the response to the client.

type LoggerInterface

type LoggerInterface interface {
	// Basic methods.
	Msg(message string) *Logger
	Status(code int) *Logger
	Error(err error) *Logger

	// Prefix-related methods.
	SetPrefix(prefix string) *Logger
	RemovePrefix() *Logger

	// Timer-related methods.
	ResetTimer() *Logger

	// Data-related methods.
	Log() *Logger
	Payload(pl interface{}) *Logger
	Write(w http.ResponseWriter)
}