package error

import (
	"strings"

	"github.com/yusing/go-proxy/internal/utils/strutils/ansi"
)

type withSubject struct {
	Subject string `json:"subject"`
	Err     error  `json:"err"`
}

const subjectSep = " > "

func highlight(subject string) string {
	return ansi.HighlightRed + subject + ansi.Reset
}

func PrependSubject(subject string, err error) *withSubject {
	switch err := err.(type) {
	case *withSubject:
		return err.Prepend(subject)
	case *baseError:
		return PrependSubject(subject, err.Err)
	default:
		return &withSubject{subject, err}
	}
}

func (err withSubject) Prepend(subject string) *withSubject {
	if subject != "" {
		err.Subject = subject + subjectSep + err.Subject
	}
	return &err
}

func (err *withSubject) Is(other error) bool {
	return err.Err == other
}

func (err *withSubject) Unwrap() error {
	return err.Err
}

func (err *withSubject) Error() string {
	subjects := strings.Split(err.Subject, subjectSep)
	subjects[len(subjects)-1] = highlight(subjects[len(subjects)-1])
	return strings.Join(subjects, subjectSep) + ": " + err.Err.Error()
}