Added go text template writier (#1)

feat(templ): ✨ added templ to command line that reads go template and outputs code

Reviewed-on: #1
Co-authored-by: Hein <hein.puth@gmail.com>
Co-committed-by: Hein <hein.puth@gmail.com>

pkg/writers/template/formatters.go

@@ -0,0 +1,157 @@
+package template
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+// ToJSON converts a value to JSON string
+// Usage: {{ .Database | toJSON }}
+func ToJSON(v interface{}) string {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return fmt.Sprintf("{\"error\": \"failed to marshal: %v\"}", err)
+	}
+	return string(data)
+}
+
+// ToJSONPretty converts a value to pretty-printed JSON string
+// Usage: {{ .Database | toJSONPretty "  " }}
+func ToJSONPretty(v interface{}, indent string) string {
+	data, err := json.MarshalIndent(v, "", indent)
+	if err != nil {
+		return fmt.Sprintf("{\"error\": \"failed to marshal: %v\"}", err)
+	}
+	return string(data)
+}
+
+// ToYAML converts a value to YAML string
+// Usage: {{ .Database | toYAML }}
+func ToYAML(v interface{}) string {
+	data, err := yaml.Marshal(v)
+	if err != nil {
+		return fmt.Sprintf("error: failed to marshal: %v", err)
+	}
+	return string(data)
+}
+
+// Indent indents each line of a string by the specified number of spaces
+// Usage: {{ .Column.Description | indent 4 }}
+func Indent(s string, spaces int) string {
+	if s == "" {
+		return ""
+	}
+
+	prefix := strings.Repeat(" ", spaces)
+	lines := strings.Split(s, "\n")
+	for i, line := range lines {
+		if line != "" {
+			lines[i] = prefix + line
+		}
+	}
+	return strings.Join(lines, "\n")
+}
+
+// IndentWith indents each line of a string with a custom prefix
+// Usage: {{ .Column.Description | indentWith "    " }}
+func IndentWith(s string, prefix string) string {
+	if s == "" {
+		return ""
+	}
+
+	lines := strings.Split(s, "\n")
+	for i, line := range lines {
+		if line != "" {
+			lines[i] = prefix + line
+		}
+	}
+	return strings.Join(lines, "\n")
+}
+
+// Escape escapes special characters in a string for use in code
+// Usage: {{ .Column.Default | escape }}
+func Escape(s string) string {
+	s = strings.ReplaceAll(s, "\\", "\\\\")
+	s = strings.ReplaceAll(s, "\"", "\\\"")
+	s = strings.ReplaceAll(s, "\n", "\\n")
+	s = strings.ReplaceAll(s, "\r", "\\r")
+	s = strings.ReplaceAll(s, "\t", "\\t")
+	return s
+}
+
+// EscapeQuotes escapes only quote characters
+// Usage: {{ .Column.Comment | escapeQuotes }}
+func EscapeQuotes(s string) string {
+	s = strings.ReplaceAll(s, "\"", "\\\"")
+	s = strings.ReplaceAll(s, "'", "\\'")
+	return s
+}
+
+// Comment adds comment prefix to a string
+// Supports: "//" (Go, C++, etc.), "#" (Python, shell), "--" (SQL), "/* */" (block)
+// Usage: {{ .Table.Description | comment "//" }}
+func Comment(s string, style string) string {
+	if s == "" {
+		return ""
+	}
+
+	lines := strings.Split(s, "\n")
+
+	switch style {
+	case "//":
+		for i, line := range lines {
+			lines[i] = "// " + line
+		}
+		return strings.Join(lines, "\n")
+
+	case "#":
+		for i, line := range lines {
+			lines[i] = "# " + line
+		}
+		return strings.Join(lines, "\n")
+
+	case "--":
+		for i, line := range lines {
+			lines[i] = "-- " + line
+		}
+		return strings.Join(lines, "\n")
+
+	case "/* */", "/**/":
+		if len(lines) == 1 {
+			return "/* " + lines[0] + " */"
+		}
+		result := "/*\n"
+		for _, line := range lines {
+			result += " * " + line + "\n"
+		}
+		result += " */"
+		return result
+
+	default:
+		// Default to // style
+		for i, line := range lines {
+			lines[i] = "// " + line
+		}
+		return strings.Join(lines, "\n")
+	}
+}
+
+// QuoteString adds quotes around a string
+// Usage: {{ .Column.Default | quoteString }}
+func QuoteString(s string) string {
+	return "\"" + s + "\""
+}
+
+// UnquoteString removes quotes from a string
+// Usage: {{ .Value | unquoteString }}
+func UnquoteString(s string) string {
+	if len(s) >= 2 {
+		if (s[0] == '"' && s[len(s)-1] == '"') || (s[0] == '\'' && s[len(s)-1] == '\'') {
+			return s[1 : len(s)-1]
+		}
+	}
+	return s
+}