post.go

package blog

import (
	"html/template"
	"strconv"
	"time"

	"github.com/blevesearch/bleve"
	"github.com/pkg/errors"
)

const (
	layoutUnix = "Mon Jan 2 15:04:05 -07 2006"
	layoutISO  = "2006-01-02"
)

// PostService is the interface that wraps method related to a blog post
type PostService interface {
	GetAllPosts() []*Post
	GetPostByURI(uri string) *Post
	GetLatestPosts(days int) []*Post
	GetRelatedPosts(currentPost *Post) []*Post
	GetAllCategories() map[string][]*Post
	GetPostsPerTag() map[string]int
	GetAllTags() []string
	GetImageAddresses() []string
	GetPostURIByImage() map[string]string
	GetPostsByCategory(category string) []*Post
	GetPostsByTag(tag string) []*Post
	GetPreviousAndNextPost(currentPost *Post) (previousPost, nextPost *Post)
	GetYears() []string
	GetMonthsInYear() map[string][]string
	GetPostsByDate(year, month, date string) []*Post
	GetPostsByMonth() map[string]map[string][]*Post
	GetPostsByYear(year string) []*Post
}

// SearchService is the interface that wraps methods related to search
type SearchService interface {
	GetIndex() bleve.Index
	Index(*Post, *bleve.Batch) error
	Search(value string) ([]*Post, error)
	CloseIndex() error
}

// Post represents a blog post
type Post struct {
	ID          int
	URI         string
	Title       string
	Date        publishDate
	Description string
	Images      []string
	Content     template.HTML
	Summary     template.HTML
	Truncated   bool
	Categories  []string
	Tags        []string
	HasPrev     bool
	HasNext     bool
}

type publishDate struct {
	time.Time
}

func (d *publishDate) UnmarshalYAML(unmarshal func(interface{}) error) error {
	var pd string
	if err := unmarshal(&pd); err != nil {
		return err
	}

	layouts := []string{layoutUnix, layoutISO}
	for _, layout := range layouts {
		date, err := time.Parse(layout, pd)
		if err == nil {
			d.Time = date
			return nil
		}
	}

	return errors.Errorf("Unrecognized date format: %s", pd)
}

// ToISODate converts date to ISO layout
func ToISODate(d publishDate) string {
	return d.Time.Format(layoutISO)
}

// ToMonthName converts month from string number to name
func ToMonthName(month string) string {
	m, _ := strconv.Atoi(month)
	return time.Month(m).String()
}

// Contains checks if a slice of strings contains a string
func Contains(s []string, e string) bool {
	for _, v := range s {
		if v == e {
			return true
		}
	}
	return false
}

// GetYear gets year from publish date
func (d *publishDate) GetYear() string {
	return strconv.Itoa(d.Time.Year())
}

// GetMonth gets month from publish date
func (d *publishDate) GetMonth() string {
	month := int(d.Time.Month())
	if month < 10 {
		return "0" + strconv.Itoa(month)
	}

	return strconv.Itoa(month)
}

// GetDay gets day from publish date
func (d *publishDate) GetDay() string {
	day := d.Time.Day()
	if day < 10 {
		return "0" + strconv.Itoa(day)
	}

	return strconv.Itoa(day)
}