hnbot/sn/sn.go

package sn

import (
	"database/sql"
	"fmt"
	"log"
	"time"

	"github.com/dustin/go-humanize"
	sn "github.com/ekzyis/snappy"
	"gitlab.com/ekzyis/hnbot/db"
	"gitlab.com/ekzyis/hnbot/hn"
)

type DupesError = sn.DupesError

func CurateContent() (*[]hn.Item, error) {
	var (
		rows *sql.Rows
		err  error
	)
	if rows, err = db.Query(`
		SELECT t.id, time, title, url, author, score, ndescendants
		FROM (
			SELECT id, MIN(created_at) AS start, MAX(created_at) AS end
			FROM hn_items
			WHERE rank = 1 AND id NOT IN (SELECT hn_id FROM sn_items) AND length(title) >= 5
			GROUP BY id
			HAVING unixepoch(end) - unixepoch(start) >= 3600
			ORDER BY time ASC
			LIMIT 1
		) t JOIN hn_items ON t.id = hn_items.id AND t.end = hn_items.created_at;
	`); err != nil {
		err = fmt.Errorf("error querying hn_items: %w", err)
		return nil, err
	}
	defer rows.Close()

	var items []hn.Item
	for rows.Next() {
		var item hn.Item
		if err = rows.Scan(&item.ID, &item.Time, &item.Title, &item.Url, &item.By, &item.Score, &item.Descendants); err != nil {
			err = fmt.Errorf("error scanning hn_items: %w", err)
			return nil, err
		}
		items = append(items, item)
	}
	if err = rows.Err(); err != nil {
		err = fmt.Errorf("error iterating hn_items: %w", err)
		return nil, err
	}
	return &items, nil
}

type PostOptions struct {
	SkipDupes bool
}

func Post(item *hn.Item, options PostOptions) (int, error) {
	c := sn.NewClient()
	url := item.Url
	if url == "" {
		url = hn.ItemLink(item.ID)
	}
	log.Printf("post to SN: %s ...\n", url)

	if !options.SkipDupes {
		dupes, err := c.Dupes(url)
		if err != nil {
			return -1, err
		}
		if len(*dupes) > 0 {
			return -1, &sn.DupesError{Url: url, Dupes: *dupes}
		}
	}

	title := item.Title
	if len(title) > 80 {
		title = title[0:80]
	}

	comment := fmt.Sprintf(
		"This link was posted by [%s](%s) %s on [HN](%s). It received %d points and %d comments.",
		item.By,
		hn.UserLink(item.By),
		humanize.Time(time.Unix(int64(item.Time), 0)),
		hn.ItemLink(item.ID),
		item.Score, item.Descendants,
	)

	parentId, err := c.PostLink(url, title, comment, "tech")
	if err != nil {
		return -1, fmt.Errorf("error posting link: %w", err)
	}

	log.Printf("post to SN: %s ... OK \n", url)
	if err := db.SaveSnItem(parentId, item.ID); err != nil {
		return -1, err
	}

	return parentId, nil
}