Transfer first library files

go.mod

@@ -1,3 +1,17 @@
 module ersteller-lib
 
 go 1.24
+
+require (
+	github.com/jackc/pgx/v5 v5.7.5
+	github.com/mattn/go-sqlite3 v1.14.29
+	golang.org/x/crypto v0.40.0
+)
+
+require (
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	golang.org/x/sync v0.16.0 // indirect
+	golang.org/x/text v0.27.0 // indirect
+)

hash.go

@@ -0,0 +1,16 @@
+package ersteller_lib
+
+// https://medium.com/@rnp0728/secure-password-hashing-in-go-a-comprehensive-guide-5500e19e7c1f
+import "golang.org/x/crypto/bcrypt"
+
+// HashPassword generates a bcrypt hash for the given password.
+func HashPassword(password string) (string, error) {
+	bytes, err := bcrypt.GenerateFromPassword([]byte(password), 14)
+	return string(bytes), err
+}
+
+// VerifyPassword verifies if the given password matches the stored hash.
+func VerifyPassword(password, hash string) bool {
+	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
+	return err == nil
+}

logger.go

@@ -0,0 +1,32 @@
+package ersteller_lib
+
+import (
+	"fmt"
+	"strings"
+)
+
+func LogDebug(message string, a ...any) {
+	println(fmt.Sprintf(message, a...))
+}
+
+func Debug(a ...any) {
+	stringValue := joinStrings(a)
+	println(stringValue)
+}
+
+func joinStrings(a []any) string {
+	elementsToLog := []string{}
+
+	for i := 0; i < len(a); i++ {
+		elementsToLog = append(elementsToLog, strings.TrimSpace(fmt.Sprint(a[i])))
+	}
+	return strings.Join(elementsToLog, " ")
+}
+
+func LogError(message string, a ...any) {
+	println(fmt.Sprintf("Error: %v", fmt.Sprintf(message, a...)))
+}
+
+func Error(a ...any) {
+	println(fmt.Sprint("Error: ", joinStrings(a)))
+}

postgres.go

@@ -0,0 +1,54 @@
+package ersteller_lib
+
+import (
+	"context"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"time"
+)
+
+func CreatePostgresConnpool(dbUrl string) (*pgxpool.Pool, error) {
+	connPool, err := pgxpool.NewWithConfig(context.Background(), config(dbUrl))
+	if err != nil {
+		Error("Error while creating connection to the database!!", err)
+		return nil, err
+	}
+
+	connection, err := connPool.Acquire(context.Background())
+	if err != nil {
+		LogError("Error while acquiring connection from the database pool!! %v", err)
+		return nil, err
+	}
+	defer connection.Release()
+
+	err = connection.Ping(context.Background())
+	if err != nil {
+		LogError("Could not ping database")
+		return nil, err
+	}
+
+	return connPool, nil
+}
+
+func config(dbUrl string) *pgxpool.Config {
+	const defaultMaxConns = int32(4)
+	const defaultMinConns = int32(0)
+	const defaultMaxConnLifetime = time.Hour
+	const defaultMaxConnIdleTime = time.Minute * 30
+	const defaultHealthCheckPeriod = time.Minute
+	const defaultConnectTimeout = time.Second * 5
+
+	dbConfig, err := pgxpool.ParseConfig(dbUrl)
+	if err != nil {
+		Error("Failed to create a config, error: ", err)
+		return nil
+	}
+
+	dbConfig.MaxConns = defaultMaxConns
+	dbConfig.MinConns = defaultMinConns
+	dbConfig.MaxConnLifetime = defaultMaxConnLifetime
+	dbConfig.MaxConnIdleTime = defaultMaxConnIdleTime
+	dbConfig.HealthCheckPeriod = defaultHealthCheckPeriod
+	dbConfig.ConnConfig.ConnectTimeout = defaultConnectTimeout
+
+	return dbConfig
+}

sqlite.go

@@ -0,0 +1,29 @@
+package ersteller_lib
+
+import (
+	"context"
+	"database/sql"
+	_ "github.com/mattn/go-sqlite3"
+)
+
+// CreateSQLiteConnpool creates a new SQLite connection pool
+func CreateSQLiteConnpool(dbPath string) (*sql.DB, error) {
+	db, err := sql.Open("sqlite3", dbPath)
+	if err != nil {
+		Error("Error while creating connection to the SQLite database!!", err)
+		return nil, err
+	}
+
+	// Test the connection
+	err = db.PingContext(context.Background())
+	if err != nil {
+		LogError("Could not ping SQLite database: %v", err)
+		return nil, err
+	}
+
+	// Set connection pool settings
+	db.SetMaxOpenConns(4)
+	db.SetMaxIdleConns(2)
+
+	return db, nil
+}

strings.go

@@ -0,0 +1,37 @@
+package ersteller_lib
+
+import (
+	"bytes"
+	"fmt"
+	"regexp"
+	"strings"
+	"text/template"
+)
+
+func FirstLetterToUpper(name string) string {
+	return strings.ToUpper(name[:1]) + name[1:]
+}
+
+func FirstLetterToLower(name string) string {
+	return strings.ToLower(name[:1]) + name[1:]
+}
+
+func InlineTemplate(templateString string, data any) string {
+	dollarRegex := regexp.MustCompile(`\$(\w+)\$`)
+	templateString = dollarRegex.ReplaceAllStringFunc(templateString, func(s string) string {
+		if strings.HasPrefix(s, "$.") || strings.HasPrefix(s, "$end") || strings.HasPrefix(s, "$else") {
+			return s
+		}
+		return dollarRegex.ReplaceAllString(s, "$.$1$")
+	})
+	tmpl, err := template.New("inline").Delims("$", "$").Parse(templateString)
+	if err != nil {
+		return fmt.Sprint("Failed to parse template ", err)
+	}
+	var buf bytes.Buffer
+	err = tmpl.Execute(&buf, data)
+	if err != nil {
+		return fmt.Sprint("Failed to execute template ", err)
+	}
+	return buf.String()
+}

tracing.go

@@ -0,0 +1,14 @@
+package ersteller_lib
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+func Trace(object any) string {
+	marshalled, err := json.Marshal(object)
+	if err != nil {
+		return fmt.Sprint(object)
+	}
+	return string(marshalled)
+}