Start investigating the maps

internal/maps/maps.go

@@ -0,0 +1,150 @@
+package maps
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/binary"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var (
+	expectedMagic         = []byte("\x08\x00WHMAP\x00")
+	expectedSetNameOffset = uint32(0x34)
+	notImplemented        = fmt.Errorf("Not implemented")
+)
+
+type Header struct {
+	IsCampaignMap uint32 // Tentatively: 0 = no, 1 = yes
+	MinWidth      uint32
+	MinLength     uint32
+	MaxWidth      uint32
+	MaxLength     uint32
+	Unknown1      uint32
+	Unknown2      uint32
+	Unknown3      uint32
+	Unknown4      uint32
+	Magic         [8]byte // "\x08\x00WHMAP\x00"
+	Unknown5      uint32
+	Unknown6      uint32
+	SetName       [8]byte // Or is it a null-terminated string?
+}
+
+func (h Header) Check() []error {
+	var out []error
+	if h.IsCampaignMap > 1 {
+		out = append(out, fmt.Errorf("Expected 0 or 1 for IsCampaignMap, got %v", h.IsCampaignMap))
+	}
+
+	if bytes.Compare(expectedMagic, h.Magic[:]) != 0 {
+		out = append(out, fmt.Errorf("Unexpected magic value: %v", h.Magic))
+	}
+
+	return out
+}
+
+type GameMap struct {
+	Header
+
+	// TODO: parse this into sections
+	Text string
+}
+
+// A game map contains a .txt and a .map. If they're in the same directory,
+// just pass the directory + basename to load both
+func LoadGameMap(prefix string) (*GameMap, error) {
+	for _, mapExt := range []string{".MAP", ".map"} {
+		for _, txtExt := range []string{".TXT", ".txt"} {
+			out, err := LoadGameMapByFiles(prefix+mapExt, prefix+txtExt)
+			if err != nil && !os.IsNotExist(err) {
+				return nil, err
+			}
+
+			if err == nil {
+				return out, nil
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("Couldn't find %s.{map,txt}, even ignoring case", prefix)
+}
+
+// A game map is composed of two files: .map and .txt
+func LoadGameMapByFiles(mapFile, txtFile string) (*GameMap, error) {
+	out, err := loadMapFile(mapFile)
+	if err != nil {
+		return nil, err
+	}
+
+	// TODO: load text and parse into sections
+	txt, err := ioutil.ReadFile(txtFile)
+	if err != nil {
+		return nil, err
+	}
+	out.Text = string(txt)
+
+	for _, err := range out.Check() {
+		log.Printf("%s: %v", mapFile, err)
+	}
+
+	return out, nil
+}
+
+func LoadGameMaps(dir string) (map[string]*GameMap, error) {
+	fis, err := ioutil.ReadDir(dir)
+	if err != nil {
+		return nil, err
+	}
+
+	out := make(map[string]*GameMap)
+
+	for _, fi := range fis {
+		filename := filepath.Join(dir, fi.Name())
+		basename := filepath.Base(filename)
+		extname := filepath.Ext(filename)
+
+		// Only pay attention to .MAP files. Assume they will have a .txt too
+		if !strings.EqualFold(extname, ".MAP") {
+			continue
+		}
+
+		prefix := filename[0 : len(filename)-4]
+
+		gameMap, err := LoadGameMap(prefix)
+		if err != nil {
+			return nil, fmt.Errorf("Error processing %v: %s", filename, err)
+		}
+
+		out[basename] = gameMap
+	}
+
+	return out, nil
+}
+
+func loadMapFile(filename string) (*GameMap, error) {
+	var out GameMap
+
+	mf, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	defer mf.Close()
+
+	zr, err := gzip.NewReader(mf)
+	if err != nil {
+		return nil, err
+	}
+
+	defer zr.Close()
+
+	if err := binary.Read(zr, binary.LittleEndian, &out.Header); err != nil {
+		return nil, fmt.Errorf("Error parsing %s: %v", filename, err)
+	}
+
+	return &out, nil
+}