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justguestbook/guestbook.go

100 lines
2.8 KiB
Go

package justguestbook
import (
"errors"
"time"
)
const (
// DateFormat is a format of the date and time used in a guestbook.
DateFormat = "2006-01-02 15:04:05"
// Reply holds a reply for a guestbook's entry.
type Reply struct {
// ID of a guestbook's entry is used when update of a reply is performed.
//
// Not present in JSON because a reply comes within its corresponding entry.
ID int64 `json:"-"`
// Created holds a date and time when a reply was created.
Created time.Time `json:"created,omitempty"`
// Message holds a reply's message.
Message string `json:"message"`
}
// NewReply creates a new reply and, before that, verifies that a passed message
// is not empty.
func NewReply(entryID int64, message string) (*Reply, error) {
if message == "" {
return nil, errors.New("empty message field")
}
return &Reply{
ID: entryID,
Created: time.Now().UTC(),
Message: message}, nil
}
// Entry holds a guestbook entry.
type Entry struct {
// ID of an entry.
ID int64 `json:"entry_id"`
// Created holds the date and time when an entry was created.
Created time.Time `json:"created"`
// Name holds a nick-/name of a guest who posted an entry.
Name string `json:"name"`
// Website of a guest. Can be empty.
Website string `json:"website,omitempty"`
// HideWebsite tells wether to hide or show guest's website.
HideWebsite bool `json:"hide_website,omitempty"`
// Message that a guest wrote.
Message string `json:"message"`
// Reply holds a reply for this entry.
Reply *Reply `json:"reply,omitempty"`
}
// NewEntry creates a new Entry and, before that, verifies if the name and message
// aren't empty and the website field do not exceed the limit.
func NewEntry(name, message, website string, hideWebsite bool) (*Entry, error) {
if name == "" || message == "" {
return nil, errors.New("name and message field are required")
}
return &Entry{
Created: time.Now().UTC(),
Name: name,
Website: website,
HideWebsite: hideWebsite,
Message: message}, nil
}
// Guestbook is an interface that should be implemented by a DB.
type Guestbook interface {
// Entries returns a slice of guestbook entries.
Entries(page, pageSize int64) ([]*Entry, error)
// Count returns how much entries are in a DB.
Count() (int64, error)
// NewEntry inserts a given Entry into a DB.
NewEntry(entry *Entry) error
// EditEntry modifies the fields of an existing entry.
EditEntry(entry *Entry) error
// DeleteEntry removes an Entry with a given ID.
DeleteEntry(entryID int64) error
// NewReply inserts a given Reply into a DB.
NewReply(reply *Reply) error
// EditReply modifies a message field of a given Reply.
EditReply(reply *Reply) error
// DeleteReply removes a Reply with a given ID of an Entry.
DeleteReply(entryID int64) error
// Close closes a DB.
Close() error
}