initial database definition

Signed-off-by: Tobias Erbshäußer <tobias@tesoft.dev>
2026-05-24 09:22:20 +02:00
parent 333211d4d0
commit af43e23fe6
2 changed files with 290 additions and 0 deletions
@@ -1 +1,2 @@
 .idea
+*.sqlite
@@ -0,0 +1,289 @@
+package main
+
+import (
+	"database/sql"
+	"errors"
+	"log"
+	"strconv"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type Database struct {
+	db *sql.DB
+}
+
+func NewDatabase(path string) (*Database, error) {
+	log.Println("Opening database '" + path + "'")
+
+	db, err := sql.Open("sqlite3", path)
+	if err != nil {
+		return nil, err
+	}
+
+	err = migrate(db)
+	if err != nil {
+		_ = db.Close()
+		return nil, err
+	}
+
+	return &Database{db}, nil
+}
+
+func (db *Database) Close() {
+	err := db.db.Close()
+	if err != nil {
+		log.Println("Error closing database:", err.Error())
+	}
+}
+
+func (db *Database) CreateBlogArticle() (int64, func(*Article) error, error) {
+	tx, err := db.db.Begin()
+	if err != nil {
+		return -1, nil, err
+	}
+
+	res, err := tx.Exec(
+		"INSERT INTO blog_article(status, title, date, content) VALUES (?, ?, ?, ?)",
+		ArticleStatusDraft,
+		"",
+		time.DateOnly,
+		"",
+	)
+	if err != nil {
+		return -1, nil, err
+	}
+
+	id, err := res.LastInsertId()
+	if err != nil {
+		return -1, nil, err
+	}
+
+	return id, func(article *Article) error {
+		if article == nil {
+			return tx.Rollback()
+		}
+
+		var modificationDate *string
+		if article.ModificationDate != nil {
+			tmp := article.ModificationDate.Format(time.DateOnly)
+			modificationDate = &tmp
+		}
+
+		_, err := tx.Exec(
+			"UPDATE blog_article SET title = ?, date = ?, modification_date = ?, content = ? WHERE id = ?",
+			article.Title,
+			article.ReleaseDate.Format(time.DateOnly),
+			modificationDate,
+			article.Content,
+			id,
+		)
+		if err != nil {
+			_ = tx.Rollback()
+			return err
+		}
+
+		for _, tag := range article.Tags {
+			tagId, err := createOrGetTag(tx, tag)
+			if err != nil {
+				_ = tx.Rollback()
+				return err
+			}
+
+			_, err = tx.Exec(
+				"INSERT INTO blog_article_to_tag(tag_id, article_id) VALUES (?, ?)",
+				tagId,
+				id,
+			)
+			if err != nil {
+				return err
+			}
+		}
+
+		for _, file := range article.Files {
+			_, err = tx.Exec(
+				"INSERT INTO blog_file(id, articleId, data) VALUES (?, ?, ?)",
+				file.Id,
+				id,
+				file.Data,
+			)
+			if err != nil {
+				return err
+			}
+		}
+
+		return tx.Commit()
+	}, err
+}
+
+func (db *Database) GetBlogArticles(showAll bool, offset int, limit int) ([]ArticleProperties, error) {
+	inner := "SELECT id FROM blog_article"
+	if !showAll {
+		inner = inner + " WHERE status = " + strconv.Itoa(ArticleStatusPublished)
+	}
+	inner = inner + " ORDER BY date DESC LIMIT ? OFFSET ?"
+	outer := "SELECT blog_article.id, blog_article.status, blog_article.title, blog_article.date, blog_article.modification_date, blog_tag.name" +
+		" FROM blog_article" +
+		" LEFT JOIN blog_article_to_tag ON blog_article.id = blog_article_to_tag.article_id" +
+		" LEFT JOIN blog_tag ON blog_article_to_tag.tag_id = blog_tag.id" +
+		" WHERE blog_article.id IN (" + inner + ")" +
+		" ORDER BY blog_article.date DESC, blog_article.id"
+
+	rows, err := db.db.Query(
+		outer,
+		limit,
+		offset,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	articles := make([]ArticleProperties, 0)
+	for rows.Next() {
+		var id int64
+		var status ArticleStatus
+		var title string
+		var dateStr string
+		var modificationDateStr *string
+		var tag *string
+		err := rows.Scan(&id, &status, &title, &dateStr, &modificationDateStr, &tag)
+		if err != nil {
+			_ = rows.Close()
+			return nil, err
+		}
+
+		if tag != nil && len(articles) > 0 && articles[len(articles)-1].Id == id {
+			articles[len(articles)-1].Tags = append(articles[len(articles)-1].Tags, *tag)
+			continue
+		}
+
+		date, _ := time.Parse(time.DateOnly, dateStr)
+		var modificationDate *time.Time
+		if modificationDateStr != nil {
+			tmp, _ := time.Parse(time.DateOnly, *modificationDateStr)
+			modificationDate = &tmp
+		}
+
+		tags := make([]string, 0)
+		if tag != nil {
+			tags = append(tags, *tag)
+		}
+
+		articles = append(articles, ArticleProperties{
+			id,
+			title,
+			status,
+			tags,
+			date,
+			modificationDate,
+		})
+	}
+
+	err = rows.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	return articles, nil
+}
+
+func migrate(db *sql.DB) error {
+	tx, err := db.Begin()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	log.Println("Checking database schema version")
+	var curVersion int
+	err = tx.QueryRow("SELECT version FROM schema_info").Scan(&curVersion)
+	if err != nil {
+		curVersion = -1
+	}
+
+	if curVersion == -1 {
+		log.Println("Database is empty")
+
+		err = createV1Tables(tx)
+		if err != nil {
+			_ = tx.Rollback()
+			return err
+		}
+	} else {
+		log.Println("Database schema version is", curVersion)
+
+		if curVersion != 1 {
+			log.Fatalln("Unsupported database schema version")
+		}
+	}
+
+	return tx.Commit()
+}
+
+func createV1Tables(tx *sql.Tx) error {
+	log.Println("Creating tables for schema version 1")
+
+	_, err := tx.Exec(`
+		CREATE TABLE schema_info(
+		    id INTEGER PRIMARY KEY CHECK(id = 0),
+		    version INTEGER NOT NULL
+		);
+		INSERT INTO schema_info(
+			id,
+			version
+		) VALUES (
+		 	0,
+		  	1
+		);
+
+		CREATE TABLE blog_tag(
+		    id INTEGER PRIMARY KEY,
+		    name TEXT NOT NULL UNIQUE
+		);
+		CREATE TABLE blog_article(
+		    id INTEGER PRIMARY KEY,
+		    status INTEGER NOT NULL,
+		    title TEXT NOT NULL UNIQUE,
+		    date TEXT NOT NULL,
+		    modification_date TEXT,
+		    content TEXT NOT NULL
+		);
+		CREATE TABLE blog_article_to_tag(
+		    tag_id INTEGER NOT NULL,
+		    article_id INTEGER NOT NULL,
+		    PRIMARY KEY(tag_id, article_id)
+		);
+		CREATE TABLE blog_file(
+		    id INTEGER NOT NULL,
+		    articleId INTEGER NOT NULL,
+		    data BLOB NOT NULL,
+		    PRIMARY KEY(id, articleId),
+		    FOREIGN KEY(articleId) REFERENCES blog_article(id)
+		);
+	`)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func createOrGetTag(tx *sql.Tx, name string) (int64, error) {
+	var id int64
+	err := tx.QueryRow("SELECT id FROM blog_tag WHERE name = ?", name).Scan(&id)
+	if err == nil {
+		return id, nil
+	} else if !errors.Is(err, sql.ErrNoRows) {
+		return -1, err
+	}
+
+	res, err := tx.Exec(
+		"INSERT INTO blog_tag(name) VALUES (?)",
+		name,
+	)
+	if err != nil {
+		return -1, err
+	}
+
+	return res.LastInsertId()
+}