From a4a83e4b549e858d4f8c821591bfb74706d846e8 Mon Sep 17 00:00:00 2001
From: Vidhu Kant Sharma <vidhukant@protonmail.ch>
Date: Sat, 28 May 2022 14:45:09 +0530
Subject: Moved the blog to new repository

---
 src/blog/controller.go | 164 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 164 insertions(+)
 create mode 100644 src/blog/controller.go

(limited to 'src/blog/controller.go')

diff --git a/src/blog/controller.go b/src/blog/controller.go
new file mode 100644
index 0000000..8355e87
--- /dev/null
+++ b/src/blog/controller.go
@@ -0,0 +1,164 @@
+/*
+ * vidhublog: Vidhu Kant's Blog
+ * Copyright (C) 2022  Vidhu Kant Sharma <vidhukant@protonmail.ch>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package blog
+
+import (
+  "strconv"
+  "fmt"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+type Post struct {
+  ID        int
+  CreatedAt string
+  UpdatedAt *string
+  Title     string
+  Content   string
+  Tags      []Tag
+}
+
+type Tag struct {
+  ID   int
+  Name string
+}
+
+func (db *dbhandler) getPostCount(tag *int) int {
+  var query string
+  if tag != nil {
+    query = "SELECT COUNT(DISTINCT(PostID)) FROM Post_Tags WHERE TagID = " + strconv.Itoa(*tag)
+  } else {
+	// because some posts might not even have tags
+    query = "SELECT COUNT(*) FROM Posts"
+  }
+
+  rows, err := db.connection.Prepare(query)
+  if err != nil {
+    panic(err.Error())
+  }
+  defer rows.Close()
+
+  var count int
+  if err := rows.QueryRow().Scan(&count); err != nil {
+    panic(err)
+  }
+
+  return count
+}
+
+// start = read from nth row, limit = read n rows
+func (db *dbhandler) getPosts(start, limit int, reversed bool, tags string) []Post {
+  var qry string
+  if len(tags) < 1 {
+    qry = "SELECT ID, DATE_FORMAT(CreatedAt, '%D %M %Y'), Title FROM Posts"
+  } else {
+    qry = `SELECT DISTINCT Posts.ID, DATE_FORMAT(Posts.CreatedAt, '%D %M %Y'), Posts.Title
+    FROM Post_Tags 
+    INNER JOIN Posts ON Post_Tags.PostID = Posts.ID
+    WHERE Post_Tags.TagID IN (` + tags + `)`
+  }
+  if reversed {
+    qry = qry + " ORDER BY ID DESC"
+  }
+  qry = fmt.Sprintf("%s LIMIT %d,%d", qry, start, limit)
+
+  rows, err := db.connection.Query(qry) 
+  if err != nil {
+    panic(err)
+  }
+  defer rows.Close()
+
+  var posts []Post
+  for rows.Next() {
+    var p Post
+    err := rows.Scan(&p.ID, &p.CreatedAt, &p.Title)
+    if err != nil {
+      panic(err)
+    }
+    // load post's tags
+    p.Tags = db.getPostTags(p.ID)
+    posts = append(posts, p)
+  }
+
+  return posts
+}
+
+func (db *dbhandler) getPost(id int) Post {
+  rows, err := db.connection.Prepare(
+    `SELECT ID, DATE_FORMAT(CreatedAt, "%D %M %Y"), DATE_FORMAT(UpdatedAt, "%D %M %Y"), Title, Content FROM Posts WHERE ID = ?`,
+  )
+  if err != nil {
+    panic(err.Error())
+  }
+  defer rows.Close()
+
+  var post Post
+  if err := rows.QueryRow(id).Scan(&post.ID, &post.CreatedAt, &post.UpdatedAt, &post.Title, &post.Content); err != nil {
+    // TODO: handle error when rows are empty
+    post.Content = "404"
+    // panic(err)
+  }
+
+  return post
+}
+
+func (db *dbhandler) getPostTags(id int) []Tag {
+  rows, err := db.connection.Query(
+    `SELECT Tags.ID, Tags.Name FROM Post_Tags 
+    INNER JOIN Tags ON Post_Tags.TagID = Tags.ID 
+    WHERE Post_Tags.PostID = ` + strconv.Itoa(id),
+  ) 
+  if err != nil {
+		panic(err.Error())
+	}
+	defer rows.Close()
+
+  var tags []Tag
+  for rows.Next() {
+    var tag Tag
+    err := rows.Scan(&tag.ID, &tag.Name)
+    if err != nil {
+      panic(err)
+    }
+    tags = append(tags, tag)
+  }
+
+  return tags
+}
+
+// returns all tags
+func (db *dbhandler) getTags() []Tag {
+  rows, err := db.connection.Query("SELECT ID, Name FROM Tags") 
+  if err != nil {
+    panic(err.Error())
+  }
+  defer rows.Close()
+
+  var tags []Tag
+  for rows.Next() {
+    var t Tag
+    err := rows.Scan(&t.ID, &t.Name)
+    if err != nil {
+      panic(err)
+    }
+    tags = append(tags, t)
+  }
+
+  return tags
+}
-- 
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