// Copyright (C) 2020 Marius Schellenberger

package pve

import (
	"bytes"
	"encoding/json"
	"errors"
	"io"
	"net/http"
	"net/url"
	"strings"
)

type data struct {
	Data   json.RawMessage `json:"data"`
	Errors json.RawMessage `json:"errors"`
}

func unwrapData(resp *http.Response, v interface{}) error {
	if resp.Body == nil {
		return nil
	}
	var d data
	err := json.NewDecoder(resp.Body).Decode(&d)
	if err != nil {
		return err
	}
	if d.Errors != nil {
		return errors.New(string(d.Errors))
	}
	if v == nil {
		return nil
	}
	return json.Unmarshal(d.Data, &v)
}

type httpbody map[string]string

func (b httpbody) Reader() io.Reader {
	data := url.Values{}
	for k, v := range b {
		data.Set(k, v)
	}
	return strings.NewReader(data.Encode())
}

type unreadBuffer struct {
	b    *bytes.Buffer
	save []byte
}

func newUnreadBuffer() (ub *unreadBuffer, buf *bytes.Buffer) {
	buf = new(bytes.Buffer)
	ub = &unreadBuffer{b: buf}
	return
}

func (u *unreadBuffer) Save() {
	u.save = u.b.Bytes()
}

func (u *unreadBuffer) Reset(b **bytes.Buffer) {
	if u.save != nil && b != nil {
		u.b = bytes.NewBuffer(u.save)
		*b = u.b
	}
}