add more code to env package

env/env.go

@@ -1,13 +1,121 @@
 package env
 
 import (
+	"fmt"
 	"log"
 	"os"
+	"strings"
 
 	"github.com/agentuity/go-common/logger"
 	"github.com/spf13/cobra"
 )
 
+type EnvLine struct {
+	Key string `json:"key"`
+	Val string `json:"val"`
+}
+
+// ParseEnvFile parses an environment file and returns a list of EnvLine structs.
+func ParseEnvFile(filename string) ([]EnvLine, error) {
+	if _, err := os.Stat(filename); os.IsNotExist(err) {
+		return []EnvLine{}, nil
+	}
+	buf, err := os.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return ParseEnvBuffer(buf)
+}
+
+func dequote(s string) string {
+	v := s
+	if strings.HasPrefix(v, "'") && strings.HasSuffix(v, "'") {
+		v = strings.TrimLeft(v, "'")
+		v = strings.TrimRight(v, "'")
+	} else if strings.HasPrefix(v, `"`) && strings.HasSuffix(v, `"`) {
+		v = strings.TrimLeft(v, `"`)
+		v = strings.TrimRight(v, `"`)
+	}
+	return v
+}
+
+func ParseEnvValue(key, val string) EnvLine {
+	return EnvLine{
+		Key: key,
+		Val: val,
+	}
+}
+
+// ProcessEnvLine processes an environment variable line and returns an EnvLine struct with the key, value, and secret flag set.
+func ProcessEnvLine(env string) EnvLine {
+	tok := strings.SplitN(env, "=", 2)
+	key := tok[0]
+	val := dequote(tok[1])
+	return ParseEnvValue(key, val)
+}
+
+// ParseEnvBuffer parses an environment file from a buffer and returns a list of EnvLine structs.
+func ParseEnvBuffer(buf []byte) ([]EnvLine, error) {
+	var envs []EnvLine
+	if len(buf) > 0 {
+		lines := strings.Split(string(buf), "\n")
+		for _, line := range lines {
+			line = strings.TrimSpace(line)
+			if line == "" || line[0] == '#' || !strings.Contains(line, "=") {
+				continue
+			}
+			envs = append(envs, ProcessEnvLine(line))
+		}
+	}
+	return envs, nil
+}
+
+func mustQuote(val string) bool {
+	if strings.Contains(val, `"`) {
+		return true
+	}
+	if strings.Contains(val, "\\n") {
+		return true
+	}
+	return false
+}
+
+type callback func(key, val string) string
+
+// EncodeOSEnvFunc encodes an environment variable for use in an OS environment using a custom sprintf function.
+func EncodeOSEnvFunc(key, val string, fn callback) string {
+	val = strings.ReplaceAll(val, "\n", "\\n")
+	val = strings.ReplaceAll(val, "'", "\\'")
+	if mustQuote(val) {
+		if strings.Contains(val, `"`) {
+			val = `'` + val + `'`
+		} else {
+			val = `"` + val + `"`
+		}
+	}
+	return fn(key, val)
+}
+
+// EncodeOSEnv encodes an environment variable for use in an OS environment.
+func EncodeOSEnv(key, val string) string {
+	return EncodeOSEnvFunc(key, val, func(key, val string) string {
+		return fmt.Sprintf(`%s=%s`, key, val)
+	})
+}
+
+// WriteEnvFile writes an environment file to a file.
+func WriteEnvFile(fn string, envs []EnvLine) error {
+	of, err := os.Create(fn)
+	if err != nil {
+		return err
+	}
+	defer of.Close()
+	for _, el := range envs {
+		fmt.Fprintln(of, EncodeOSEnv(el.Key, el.Val))
+	}
+	return of.Close()
+}
+
 // FlagOrEnv will try and get a flag from the cobra.Command and if not found, look it up in the environment
 // and fallback to defaultValue if non found
 func FlagOrEnv(cmd *cobra.Command, flagName string, envName string, defaultValue string) string {