checkpoint 1

internal/parser/detector.go

@@ -1,55 +1,31 @@
-// internal/parser/detector.go
 package parser
 
 import (
-    "bytes"
-    "os"
+	"bytes"
+	"errors"
 )
 
-type FileType string
-
-const (
-    FileTypeFIT     FileType = "fit"
-    FileTypeTCX     FileType = "tcx"
-    FileTypeGPX     FileType = "gpx"
-    FileTypeUnknown FileType = "unknown"
+var (
+	// FIT file signature
+	fitSignature = []byte{0x0E, 0x10} // .FIT files start with 0x0E 0x10
 )
 
-func DetectFileType(filepath string) (FileType, error) {
-    file, err := os.Open(filepath)
-    if err != nil {
-        return FileTypeUnknown, err
-    }
-    defer file.Close()
-    
-    // Read first 512 bytes for detection
-    header := make([]byte, 512)
-    n, err := file.Read(header)
-    if err != nil && n == 0 {
-        return FileTypeUnknown, err
-    }
-    
-    header = header[:n]
-    
-    return DetectFileTypeFromData(header), nil
-}
+// DetectFileType detects the file type based on its content
+func DetectFileType(data []byte) (string, error) {
+	// Check FIT file signature
+	if len(data) >= 2 && bytes.Equal(data[:2], fitSignature) {
+		return ".fit", nil
+	}
 
-func DetectFileTypeFromData(data []byte) FileType {
-    // Check for FIT file signature
-    if len(data) >= 8 && bytes.Equal(data[8:12], []byte(".FIT")) {
-        return FileTypeFIT
-    }
-    
-    // Check for XML-based formats
-    if bytes.HasPrefix(data, []byte("<?xml")) {
-        if bytes.Contains(data[:200], []byte("<gpx")) ||
-           bytes.Contains(data[:200], []byte("topografix.com/GPX")) {
-            return FileTypeGPX
-        }
-        if bytes.Contains(data[:500], []byte("TrainingCenterDatabase")) {
-            return FileTypeTCX
-        }
-    }
-    
-    return FileTypeUnknown
+	// Check TCX file signature (XML with TrainingCenterDatabase root)
+	if bytes.Contains(data, []byte("<TrainingCenterDatabase")) {
+		return ".tcx", nil
+	}
+
+	// Check GPX file signature (XML with <gpx> root)
+	if bytes.Contains(data, []byte("<gpx")) {
+		return ".gpx", nil
+	}
+
+	return "", errors.New("unrecognized file format")
 }