// Copyright 2019 Yunion
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package vmdkutils

import (
	"bufio"
	"fmt"
	"io"
	"regexp"
	"strconv"
	"strings"

	"yunion.io/x/pkg/utils"
)

type SVMDKInfo struct {
	ExtentFile       string
	Heads            int64
	Sectors          int64
	Cylinders        int64
	CID              string
	LongCID          string
	UUID             string
	AdapterType      string
	VirtualHWVersion string
}

func (info SVMDKInfo) Size() int64 {
	return info.Heads * info.Sectors * info.Cylinders * 512
}

const (
	//RW 20971520 VMFS "89334fec-7013-46cb-8d7b-8271cbe1a175_1-flat.vmdk"
	//RW 62914560 SESPARSE "89334fec-7013-46cb-8d7b-8271cbe1a175-sesparse.vmdk"
	extentPatternString = `^RW \d+ (VMFS|SESPARSE)\w* \"(?P<fn>[^"]+)`
)

var (
	extentPatternRegexp = regexp.MustCompile(extentPatternString)
)

func Parse(content string) (*SVMDKInfo, error) {
	return ParseStream(strings.NewReader(content))
}

func ParseStream(stream io.Reader) (*SVMDKInfo, error) {
	info := SVMDKInfo{}
	scanner := bufio.NewScanner(stream)
	findExtent := false
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		matches := extentPatternRegexp.FindStringSubmatch(line)
		if len(matches) > 0 {
			// log.Debugf("%#v", matches)
			info.ExtentFile = matches[2]
			findExtent = true
		} else {
			equalPos := strings.IndexByte(line, '=')
			if equalPos > 0 {
				key := strings.TrimSpace(line[:equalPos])
				value := utils.Unquote(strings.TrimSpace(line[equalPos+1:]))
				switch key {
				case "CID":
					info.CID = value
				case "ddb.uuid":
					info.UUID = value
				case "ddb.geometry.cylinders":
					info.Cylinders, _ = strconv.ParseInt(value, 10, 64)
				case "ddb.geometry.heads":
					info.Heads, _ = strconv.ParseInt(value, 10, 64)
				case "ddb.geometry.sectors":
					info.Sectors, _ = strconv.ParseInt(value, 10, 64)
				case "ddb.longContentID":
					info.LongCID = value
				case "ddb.adapterType":
					info.AdapterType = value
				case "ddb.virtualHWVersion":
					info.VirtualHWVersion = value
				}
			}
		}
	}
	if !findExtent {
		return nil, fmt.Errorf("not a vmdk file")
	}
	return &info, nil
}