package mapblockparser

import (
	"compress/zlib"
	"bufio"
	"bytes"
	"strings"
	"errors"
	"strconv"
	"io"
	log "github.com/sirupsen/logrus"
)

const (
	INVENTORY_TERMINATOR = "EndInventory"
	INVENTORY_END = "EndInventoryList"
	INVENTORY_START = "List"
)

func readU16(data []byte, offset int) int {
	return (int(data[offset]) << 8) | int(data[offset + 1])
}

func readU32(data []byte, offset int) int {
	return int(data[offset]) << 24 |
		int(data[offset+1]) << 16 |
		int(data[offset+2]) << 8 |
		int(data[offset+3])
}


func parseMetadata(mapblock *MapBlock, data []byte) (int, error) {
	log.WithFields(log.Fields{
		"data-length": len(data),
	}).Debug("Parsing metadata")

	r := bytes.NewReader(data)

	cr := new(CountedReader)
	cr.Reader = r

	z, err := zlib.NewReader(cr)
	if err != nil {
		return 0, err
	}

	defer z.Close()

	buf := new(bytes.Buffer)
	io.Copy(buf, z)

	metadata := buf.Bytes()

	offset := 0
	version := metadata[offset]

	if version != 2 {
		return 0, errors.New("Wrong metadata version: " + strconv.Itoa(int(version)))
	}

	offset++;
	count := readU16(metadata, offset)

	log.WithFields(log.Fields{
		"count": count,
		"version": version,
	}).Debug("Parsed metadata-header")

	offset+=2

	log.Println("Metadata", buf.String())//XXX

	for i := 0; i < count; i++ {
		position := readU16(metadata, offset);
		pairsMap := mapblock.Metadata.GetPairsMap(position)

		offset+=2
		valuecount := readU32(metadata, offset)

		offset+=4
		for j := 0; j < valuecount; j++ {
			keyLength := readU16(metadata, offset);
	                offset+=2;

			key := string(metadata[offset:keyLength+offset])
			offset+=keyLength

			valueLength := readU32(metadata, offset)
			offset+=4;

			value := string(metadata[offset:keyLength+offset])
			offset+=valueLength

			pairsMap[key] = &value

			offset++

			log.Println("MD item", i, offset, position, valuecount, valueLength, keyLength, pairsMap)//XXX

		}

		var currentInventoryName *string = nil
		var currentInventory *Inventory = nil


		scanner := bufio.NewScanner(bytes.NewReader(metadata[offset:]))
		for scanner.Scan() {
			txt := scanner.Text()
			offset += len(txt) + 1;

			log.Println("inv", txt)

			if txt == INVENTORY_END {
				currentInventoryName = nil
				currentInventory = nil
			}

			if txt == INVENTORY_TERMINATOR {
				break
			}

			if strings.HasPrefix(txt, INVENTORY_START) {
				pairs := strings.Split(txt, " ")
				currentInventoryName = &pairs[1]
				currentInventory = mapblock.Metadata.GetInventory(position, *currentInventoryName)
				currentInventory.Size = 0
			}
		}

		//TODO
		
	}

	return cr.Count, nil
}