// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
//go:build plus

package oss

import (
	rangeutils "github.com/TeaOSLab/EdgeNode/internal/utils/ranges"
	"strconv"
	"strings"
)

func httpRequestParseRangeHeader(rangeValue string) (result []rangeutils.Range, ok bool) {
	// 参考RFC：https://tools.ietf.org/html/rfc7233
	index := strings.Index(rangeValue, "=")
	if index == -1 {
		return
	}
	unit := rangeValue[:index]
	if unit != "bytes" {
		return
	}

	var rangeSetString = rangeValue[index+1:]
	if len(rangeSetString) == 0 {
		ok = true
		return
	}

	var pieces = strings.Split(rangeSetString, ", ")
	for _, piece := range pieces {
		index = strings.Index(piece, "-")
		if index == -1 {
			return
		}
		first := piece[:index]
		firstInt := int64(-1)

		var err error
		last := piece[index+1:]
		var lastInt = int64(-1)

		if len(first) > 0 {
			firstInt, err = strconv.ParseInt(first, 10, 64)
			if err != nil {
				return
			}

			if len(last) > 0 {
				lastInt, err = strconv.ParseInt(last, 10, 64)
				if err != nil {
					return
				}
				if lastInt < firstInt {
					return
				}
			}
		} else {
			if len(last) == 0 {
				return
			}

			lastInt, err = strconv.ParseInt(last, 10, 64)
			if err != nil {
				return
			}
			lastInt = -lastInt
		}

		result = append(result, [2]int64{firstInt, lastInt})
	}

	ok = true
	return
}