[golang] bootstrapped a client in yet another language

golang/pkg/database/migrations.go

@@ -0,0 +1,78 @@
+package database
+
+import (
+	"context"
+	"database/sql"
+	"embed"
+	"io/fs"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+type DB struct {
+	ctx context.Context
+	db  *sql.DB
+}
+
+//go:embed sql/*.sql
+var schemaFiles embed.FS
+
+func DBInit(ctx context.Context, url string) (myDB *DB, err error) {
+	var db *sql.DB
+	if db, err = sql.Open("sqlite3", url); err != nil {
+		return nil, err
+	}
+	defer func() {
+		if err != nil {
+			_ = db.Close()
+		}
+	}()
+
+	if _, err = db.ExecContext(ctx, "PRAGMA foreign_keys = ON"); err != nil {
+		return nil, err
+	}
+	if _, err = db.ExecContext(ctx, "PRAGMA journal_mode = WAL"); err != nil {
+		return nil, err
+	}
+
+	var version int
+	if err = db.QueryRowContext(ctx, `SELECT version FROM schema_version;`).Scan(&version); err != nil {
+		if err.Error() == "no such table: schema_version" {
+			version = 0
+		} else {
+			return nil, err
+		}
+	}
+
+	statements := make([]string, 0)
+	err = fs.WalkDir(schemaFiles, ".", func(path string, d fs.DirEntry, err error) error {
+		if d.IsDir() || err != nil {
+			return err
+		}
+		var stmts []byte
+		if stmts, err = schemaFiles.ReadFile(path); err != nil {
+			return err
+		} else {
+			statements = append(statements, string(stmts))
+		}
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	for version < len(statements) {
+		if _, err = db.ExecContext(ctx, statements[version]); err != nil {
+			return nil, err
+		}
+		version++
+	}
+	if _, err = db.ExecContext(ctx, `DELETE FROM schema_version; INSERT INTO schema_version (version) VALUES (?);`, version); err != nil {
+		return nil, err
+	}
+	return &DB{ctx: ctx, db: db}, nil
+}
+
+func (db *DB) Close() error {
+	return db.db.Close()
+}

golang/pkg/database/sql/000_init.sql

@@ -0,0 +1,7 @@
+CREATE TABLE schema_version (
+	version INTEGER NOT NULL
+);
+CREATE TABLE tokens (
+	id INTEGER PRIMARY KEY,
+	data TEXT NOT NULL
+);

golang/pkg/database/tokens.go

@@ -0,0 +1,14 @@
+package database
+
+func (db DB) AddToken(token string) error {
+	_, err := db.db.ExecContext(db.ctx, `INSERT INTO tokens(data) VALUES (?);`, token)
+	return err
+}
+
+func (db DB) GetToken() (string, error) {
+	var token string
+	if err := db.db.QueryRowContext(db.ctx, `SELECT data FROM tokens;`).Scan(&token); err != nil {
+		return "", err
+	}
+	return token, nil
+}