package envs

import (
	"strings"
)

// Error conforms to a stdlib error interface.
func (e *EnvErrNoVal) Error() (errStr string) {

	var sb *strings.Builder = new(strings.Builder)

	sb.WriteString("the variable '")
	sb.WriteString(e.VarName)
	sb.WriteString("' was ")
	if sb.WasFound {
		sb.WriteString("found")
	} else {
		sb.WriteString("not found")
	}
	if e.WasRequiredNonEmpty && e.WasFound {
		sb.WriteString(" but is empty and was required to be non-empty") 
	}

	errStr = sb.String()

	return
}