package model

import (
    "time"
    "crypto/sha256"
    "encoding/hex"
)


// TODO docstring
type Article struct {
    SourceUrl   string
    PublishDate time.Time
    FetchDate   time.Time
    Title       string
    Content     string
    Author      string
}

// TODO docstring
type ArticleViewModel struct {
    Title       string
    Author      string
    PublishDate string
    SourceUrl   string
    Summary     string
}


// TODO docstring
func (a *Article) ViewModel() *ArticleViewModel {
    summary := a.Content
    if len(a.Content) > 300 {
        summary = summary[:300]
    }

    return &ArticleViewModel{
        Title: a.Title,
        Author: a.Author,
        PublishDate: a.PublishDate.Local().Format("02.01.2006 03:04"),
        SourceUrl: a.SourceUrl,
        Summary: summary,
    }
}


// --- implement IIdentifiable interface ---

// Generates a hash based on the source url of the article. Can be used to
// identify the article.
func (article *Article) Id() string {
    hash := sha256.Sum256([]byte(article.SourceUrl))
    return hex.EncodeToString(hash[:])
}