init - add project files

tools/jet-2.12.0/generator/postgres/postgres_generator.go

@@ -0,0 +1,93 @@
+package postgres
+
+import (
+	"database/sql"
+	"fmt"
+	"net/url"
+	"path"
+	"strconv"
+
+	"github.com/go-jet/jet/v2/generator/metadata"
+	"github.com/go-jet/jet/v2/generator/template"
+	"github.com/go-jet/jet/v2/postgres"
+	"github.com/jackc/pgconn"
+)
+
+// DBConnection contains postgres connection details
+type DBConnection struct {
+	Host     string
+	Port     int
+	User     string
+	Password string
+	SslMode  string
+	Params   string
+
+	DBName     string
+	SchemaName string
+}
+
+// Generate generates jet files at destination dir from database connection details
+func Generate(destDir string, dbConn DBConnection, genTemplate ...template.Template) (err error) {
+	dsn := fmt.Sprintf("postgresql://%s:%s@%s:%s/%s?sslmode=%s",
+		url.PathEscape(dbConn.User),
+		url.PathEscape(dbConn.Password),
+		dbConn.Host,
+		strconv.Itoa(dbConn.Port),
+		url.PathEscape(dbConn.DBName),
+		dbConn.SslMode,
+	)
+
+	return GenerateDSN(dsn, dbConn.SchemaName, destDir, genTemplate...)
+}
+
+// GenerateDSN generates jet files using dsn connection string
+func GenerateDSN(dsn, schema, destDir string, templates ...template.Template) error {
+	cfg, err := pgconn.ParseConfig(dsn)
+	if err != nil {
+		return fmt.Errorf("failed to parse config: %w", err)
+	}
+	if cfg.Database == "" {
+		return fmt.Errorf("database name is required")
+	}
+	db, err := openConnection(dsn)
+	if err != nil {
+		return fmt.Errorf("failed to open db connection: %w", err)
+	}
+	defer db.Close()
+
+	fmt.Println("Retrieving schema information...")
+	generatorTemplate := template.Default(postgres.Dialect)
+	if len(templates) > 0 {
+		generatorTemplate = templates[0]
+	}
+
+	schemaMetadata, err := metadata.GetSchema(db, &postgresQuerySet{}, schema)
+	if err != nil {
+		return fmt.Errorf("failed to get '%s' schema metadata: %w", schema, err)
+	}
+
+	dirPath := path.Join(destDir, cfg.Database)
+
+	err = template.ProcessSchema(dirPath, schemaMetadata, generatorTemplate)
+	if err != nil {
+		return fmt.Errorf("failed to generate schema %s: %d", schemaMetadata.Name, err)
+	}
+
+	return nil
+}
+
+func openConnection(dsn string) (*sql.DB, error) {
+	fmt.Println("Connecting to postgres database...")
+
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open db connection: %w", err)
+	}
+
+	err = db.Ping()
+	if err != nil {
+		return nil, fmt.Errorf("failed to ping database: %w", err)
+	}
+
+	return db, nil
+}