init

.gitignore

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+reddit.db
+top-of-reddit
+

README.md

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+# Top of Reddit
+
+- Every post that makes it to the front page of [r/all](http://reddit.com/r/all).
+- Updated daily.
+- Sorted by highest score achieved.
+- GoLang 
+- [BoltDB](https://github.com/boltdb/bolt) for persistance.
+
+Inspired by [github-trending](https://github.com/josephyzhou/github-trending).

main.go

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+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/boltdb/bolt"
+	"github.com/tidwall/gjson"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"sort"
+	"strconv"
+	"time"
+)
+
+const (
+	REDDIT_URL  string = "https://www.reddit.com/r/"
+	USER_AGENT  string = "top-of-reddit:bot"
+	DATE_FORMAT string = "01-02-2006"
+)
+
+var (
+	// buckets
+	DAILY_BUCKET []byte = []byte("daily_bucket")
+	MAIN_BUCKET  []byte = []byte("main") // main bucket for keeping track of the current day
+
+	// keys
+	TODAY_KEY []byte = []byte("today_date")
+)
+
+type RedditPost struct {
+	Subreddit    string  `json:"subreddit"`
+	ID           string  `json:"id"`
+	Gilded       int     `json:"gilded"`
+	Score        int     `json:"score"`
+	Author       string  `json:"author"`
+	Domain       string  `json:"domain"`
+	Over_18      bool    `json:"over_18"`
+	Thumbnail    string  `json:"thumbnail"`
+	Permalink    string  `json:"permalink"`
+	Url          string  `json:"url"`
+	Title        string  `json:"title"`
+	Created      float64 `json:"created"`
+	Created_utc  float64 `json:"created_utc"`
+	Num_comments int     `json:"num_comments"`
+	Ups          int     `json:"ups"`
+
+	// extra fields
+	TopPosition int // highest achieved position on front page
+}
+
+func main() {
+	// start database connection
+	db := openDbSession()
+	defer db.Close()
+
+	// start main program loop
+	for {
+		fmt.Println("Updating...")
+		// send http request for json data
+		response, err := getPosts("all")
+		if err != nil {
+			log.Println(err.Error())
+		} else {
+			// create RedditPost slice
+			posts, err := convertPosts(response)
+			if err != nil {
+				log.Println(err.Error())
+			} else {
+				// update the daily bucket with posts
+				updateDailyPosts(db, DAILY_BUCKET, getTodayBucket(), posts)
+				checkDateChange(db)
+			}
+
+		}
+
+		time.Sleep(time.Second * 30)
+	}
+}
+
+// start the main database session
+func openDbSession() *bolt.DB {
+	database, err := bolt.Open("reddit.db", 0600, &bolt.Options{Timeout: 1 * time.Second})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return database
+}
+
+// returns the post bucket for today
+func getTodayBucket() []byte {
+	return []byte(time.Now().Format(DATE_FORMAT))
+}
+
+// returns the post bucket for today
+func getYesterdayBucket() []byte {
+	yesterday := time.Now().AddDate(0, 0, -1)
+	return []byte(yesterday.Format(DATE_FORMAT))
+}
+
+func checkDateChange(db *bolt.DB) {
+	err := db.Update(func(tx *bolt.Tx) error {
+
+		b, err := tx.CreateBucketIfNotExists(MAIN_BUCKET)
+
+		if err != nil {
+			return err
+		}
+
+		storedDay := b.Get(TODAY_KEY)
+
+		// if the day changes
+		if storedDay == nil || string(getTodayBucket()) != string(storedDay) {
+			// set today's date in database
+			err := b.Put(TODAY_KEY, []byte(getTodayBucket()))
+
+			if err != nil {
+				return err
+			}
+
+			if storedDay == nil {
+				storedDay = getTodayBucket()
+			}
+
+			// if there was a previous stored key todayDate - create markdown file
+			fmt.Println("Creating markdown!")
+
+			storedPosts, err := getStoredPosts(db, DAILY_BUCKET, storedDay)
+
+			if err != nil {
+				return err
+			}
+
+			err = writePostsToFile(string(storedDay), storedPosts)
+
+			if err != nil {
+				return err
+			}
+
+			// push to github
+			err = pushToGithub()
+
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		log.Println(err)
+		return
+	}
+}
+
+func writePostsToFile(fileName string, posts []RedditPost) error {
+	// create new markdown file
+	file, err := os.Create(fileName + ".md")
+	defer file.Close()
+
+	if err != nil {
+		return err
+	}
+
+	for index, p := range posts {
+		permalink := "http://reddit.com" + p.Permalink
+		file.WriteString("## " + strconv.Itoa(index+1) + ". [" + p.Title + "](" + permalink + ") - " + strconv.Itoa(p.Score) + "\n")
+		file.WriteString("#### [r/" + p.Subreddit + "](http://reddit.com/r/" + p.Subreddit + ")")
+		file.WriteString(" - [u/" + p.Author + "](http://reddit.com/u/" + p.Author + ") - ")
+		file.WriteString(strconv.Itoa(p.Num_comments) + " Comments - ")
+		file.WriteString("Top position achieved: " + strconv.Itoa(p.TopPosition) + "\n\n")
+
+		// don't show thumbnail if NSFW
+		if p.Over_18 {
+			file.WriteString("<a href=\"" + p.Url + "\"><img src=\"https://github.com/mgerb/top-of-reddit/raw/master/nsfw.jpg\"></img></a>\n\n")
+		} else {
+			file.WriteString("<a href=\"" + p.Url + "\"><img src=\"" + p.Thumbnail + "\"></img></a>\n\n")
+		}
+	}
+
+	file.Sync()
+
+	return nil
+}
+
+// get a RedditPost slice
+func getStoredPosts(db *bolt.DB, bucket []byte, day []byte) ([]RedditPost, error) {
+
+	posts := []RedditPost{}
+
+	err := db.View(func(tx *bolt.Tx) error {
+		tx.Bucket(bucket).Bucket(day).ForEach(func(_, v []byte) error {
+			tempPost := RedditPost{}
+			err := json.Unmarshal(v, &tempPost)
+			posts = append(posts, tempPost)
+			sort.Sort(ByScore(posts))
+
+			if err != nil {
+				return err
+			}
+
+			return nil
+		})
+
+		return nil
+	})
+
+	if err != nil {
+		return []RedditPost{}, err
+	}
+
+	return posts, nil
+}
+
+// stores new posts in the bucket only if they do not exist
+func updateDailyPosts(db *bolt.DB, bucket []byte, day []byte, redditPosts []RedditPost) error {
+	err := db.Update(func(tx *bolt.Tx) error {
+
+		daily_bucket, err := tx.CreateBucketIfNotExists(bucket)
+		if err != nil {
+			return err
+		}
+
+		today, err := daily_bucket.CreateBucketIfNotExists(day)
+		if err != nil {
+			return err
+		}
+
+		for index, post := range redditPosts {
+			// check if post was in yesterdays top posts
+			yesterday := daily_bucket.Bucket(getYesterdayBucket())
+			if yesterday != nil && yesterday.Get([]byte(post.ID)) != nil {
+				continue
+			}
+
+			post.TopPosition = index + 1
+
+			// get value stored in database
+			storedPostString := today.Get([]byte(post.ID))
+
+			// if post is already stored in database - check to update highest score
+			if storedPostString != nil {
+				storedPost := RedditPost{}
+				err := json.Unmarshal(storedPostString, &storedPost)
+				if err != nil {
+					return err
+				}
+
+				// only store the highest score a post receives
+				if storedPost.Score > post.Score {
+					post.Score = storedPost.Score
+				}
+
+				// only store the highest position a post receives
+				if storedPost.TopPosition > index+1 {
+					post.TopPosition = storedPost.TopPosition
+				}
+			} else {
+				fmt.Println("Updating new post: " + post.Title)
+			}
+
+			// serialize json
+			postString, err := json.Marshal(post)
+			if err != nil {
+				return err
+			}
+
+			// store in database
+			err = today.Put([]byte(post.ID), []byte(postString))
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// convert reddit response string to RedditPost slice
+func convertPosts(postString string) ([]RedditPost, error) {
+	posts := []RedditPost{}
+
+	for _, p := range gjson.Get(postString, "data.children").Array() {
+		tempPost := RedditPost{}
+
+		err := json.Unmarshal([]byte(p.Get("data").String()), &tempPost)
+		if err != nil {
+			return posts, err
+		}
+
+		posts = append(posts, tempPost)
+	}
+
+	return posts, nil
+}
+
+// send http request to reddit and obtain the response string
+func getPosts(subreddit string) (string, error) {
+	client := &http.Client{}
+
+	req, err := http.NewRequest("GET", REDDIT_URL+subreddit+".json", nil)
+
+	req.Header.Add("User-Agent", USER_AGENT)
+
+	response, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+
+	defer response.Body.Close()
+
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return "", err
+	}
+
+	return string(body), nil
+}
+
+func pushToGithub() error {
+	fmt.Println("Pushing to Github...")
+	commitMessage := "Adding posts for " + string(getTodayBucket())
+
+	out, err := exec.Command("git", "add", ".").Output()
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(out))
+
+	out, err = exec.Command("git", "commit", "-m", commitMessage).Output()
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(out))
+
+	out, err = exec.Command("git", "push", "origin", "master").Output()
+	if err != nil {
+		return err
+	}
+	fmt.Println(string(out))
+
+	return nil
+}
+
+// sorting
+type ByScore []RedditPost
+
+func (s ByScore) Len() int {
+	return len(s)
+}
+
+func (s ByScore) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+func (s ByScore) Less(i, j int) bool {
+	return s[i].Score > s[j].Score
+}