transmet/news/news.go

188 lines
5.1 KiB
Go

package news
import (
"time"
"database/sql"
_ "github.com/lib/pq"
"fmt"
"github.com/dballard/transmet/categories"
)
type News struct {
news_id int
Url string
Title string
Category_id int
Date time.Time
Notes string
Expoerted bool
}
/* Storage Node containing:
* Name - categry name
* News children
* Category - category of this node
* Children - sub containers: mapped to sub categories
*/
type NewsContainer struct {
Name string
News []News
Category *categories.Category
Children map[int]*NewsContainer
}
// Insert News item into DB
func (news *News) Insert(db *sql.DB) error {
_, err := db.Exec("INSERT INTO news (url, title, category_id, notes) VALUES($1, $2, $3, $4)", news.Url, news.Title, news.Category_id, news.Notes );
if err != nil {
fmt.Println("Error inserting news: ", err)
return err
}
return nil
}
func nullStringToString(str *sql.NullString) string {
if str.Valid {
return str.String
} else {
return ""
}
}
// Init and add a news container to the Data Structs
func addContainer(category_id int, flat, tree map[int]*NewsContainer) {
container := &NewsContainer{ Category: categories.CategoriesFlat[category_id], Name: categories.CategoriesFlat[category_id].Name, News: []News{}, Children: map[int]*NewsContainer{} }
flat[category_id] = container
parent := categories.CategoriesFlat[category_id].Parent
if parent.Valid {
if _, ok := flat[int(parent.Int64)]; !ok {
addContainer(int(parent.Int64), flat, tree)
}
flat[int(parent.Int64)].Children[category_id] = container
} else {
tree[category_id] = container
}
}
// Load and return in NewsContainer format all the unexported news items
func LoadPage(db *sql.DB, offset, amount int) ([]News, int, error) {
categories.LoadCategories(db) // required by addContainer
rows, err := db.Query("SELECT url, title, category_id, timestamp, notes FROM news WHERE exported is null order by category_id ASC")
if err != nil {
fmt.Println("DB errpr reading LoadPage news: ", err)
return nil, 0, err
}
defer rows.Close()
return convertSqlToNews(rows)
}
// Load and return in NewsContainer format all the unexported news items
func Unexported(db *sql.DB) (map[int]*NewsContainer, int, error) {
categories.LoadCategories(db) // required by addContainer
rows, err := db.Query("SELECT url, title, category_id, timestamp, notes FROM news WHERE exported is null order by category_id ASC")
if err != nil {
fmt.Println("DB errpr reading unexported news: ", err)
return nil, 0, err
}
defer rows.Close()
return convertSqlToNewsContainer(rows)
}
func convertSqlToNews(rows *sql.Rows) ([]News, int, error) {
news := []News{}
count := 0
for rows.Next() {
newsItem := News{}
var url, title, notes sql.NullString
var date, category_id sql.NullInt64
err := rows.Scan(&url, &title, &category_id, &newsItem.Date, &notes)
if err != nil {
fmt.Println("Error reading news from DB: " + err.Error())
return nil, 0, err
}
newsItem.Url = nullStringToString(&url)
newsItem.Title = nullStringToString(&title)
newsItem.Notes = nullStringToString(&notes)
if date.Valid {
newsItem.Date = time.Unix(date.Int64, 0)
} else {
newsItem.Date = time.Now()
}
if category_id.Valid {
newsItem.Category_id = int(category_id.Int64)
} else {
continue // needs a category id
}
news = append(news, newsItem)
count++
}
return news, count, nil
}
func convertSqlToNewsContainer(rows *sql.Rows) (map[int]*NewsContainer, int, error) {
newsTree := map[int]*NewsContainer{}
newsFlat := map[int]*NewsContainer{}
count := 0
for rows.Next() {
news := News{}
var url, title, notes sql.NullString
var date, category_id sql.NullInt64
err := rows.Scan(&url, &title, &category_id, &news.Date, &notes)
if err != nil {
fmt.Println("Error reading news from DB: " + err.Error())
return nil, 0, err
}
news.Url = nullStringToString(&url)
news.Title = nullStringToString(&title)
news.Notes = nullStringToString(&notes)
if date.Valid {
news.Date = time.Unix(date.Int64, 0)
} else {
news.Date = time.Now()
}
if category_id.Valid {
news.Category_id = int(category_id.Int64)
} else {
continue // needs a category id
}
if _, ok := newsFlat[news.Category_id]; !ok {
addContainer(news.Category_id, newsFlat, newsTree)
}
container := newsFlat[news.Category_id]
container.News = append(container.News, news)
count++
}
return newsTree, count, nil
}
// Helper fn - formating - math
func (this *NewsContainer) HeaderDepth(start int) int {
return start + this.Category.Depth()
}
// Mark the current batch (news.exported is null) as exported in this batch (exported = now())
func MarkExported(db *sql.DB) error {
now := time.Now()
_, err := db.Exec("UPDATE news SET exported=$1 WHERE exported is null", now)
if err != nil {
fmt.Println("DB errror: news.MarkExported():", err)
}
return err
}