package utils

import (
	"regexp"
)

// Patch is the patch object to provider a converter function
type Patch interface {
	Patch([]byte) []byte
}

// RegexpPatcher a patch object to provider a converter function from regular expression
type RegexpPatcher struct {
	pattern     *regexp.Regexp
	replacement string
}

// NewRegexpPatcher will return a patch object to provider a converter function from regular expression
func NewRegexpPatcher(regex string, repl string) *RegexpPatcher {
	return &RegexpPatcher{
		pattern:     regexp.MustCompile(regex),
		replacement: repl,
	}
}

// Patch will convert a bytes to another bytes with patch rules
func (p *RegexpPatcher) Patch(body []byte) []byte {
	// TODO: ensure why the pattern will be disabled when there are multiple goroutines for bytes replacement
	return []byte(p.PatchString(string(body)))
}

// PatchString will convert a string to another string with patch rules
func (p *RegexpPatcher) PatchString(body string) string {
	return p.pattern.ReplaceAllString(body, p.replacement)
}

// RetCodePatcher will convert `RetCode` as integer
var RetCodePatcher = NewRegexpPatcher(`"RetCode":\s?"(\d+)"`, `"RetCode": $1`)

// PortPatcher will convert `Port` as integer
var PortPatcher = NewRegexpPatcher(`"Port":\s?"(\d+)"`, `"Port": $1`)

// FrequencePatcher will convert `Frequence` as float64
var FrequencePatcher = NewRegexpPatcher(`"Frequence":\s?"([\d.]+)"`, `"Frequence": $1`)