diff --git a/analyzeMFT.py b/analyzeMFT.py
index 72e7df8..bda2bd4 100755
--- a/analyzeMFT.py
+++ b/analyzeMFT.py
@@ -1,10 +1,8 @@
-import asyncio
 import sys
+import asyncio
 from src.analyzeMFT.cli import main
 
 if __name__ == "__main__":
     if sys.platform == "win32":
-        # This sets the event loop policy to use the ProactorEventLoop on Windows
-        asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
-    
+        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
     asyncio.run(main())
\ No newline at end of file
diff --git a/src/analyzeMFT/__init__.py b/src/analyzeMFT/__init__.py
index c392eab..3fb9cbe 100644
--- a/src/analyzeMFT/__init__.py
+++ b/src/analyzeMFT/__init__.py
@@ -1,6 +1,18 @@
 from .windows_time import WindowsTime
 from .mft_record import MftRecord
 from .mft_analyzer import MftAnalyzer
-from .constants import VERSION
+from .file_writers import FileWriters
+from .constants import VERSION, CSV_HEADER
+from .cli import main
 
-__all__ = ['WindowsTime', 'MftRecord', 'MftAnalyzer', 'VERSION']
\ No newline at end of file
+__all__ = [
+    'WindowsTime',
+    'MftRecord',
+    'MftAnalyzer',
+    'FileWriters',
+    'VERSION',
+    'CSV_HEADER',
+    'main'
+]
+
+__version__ = VERSION
\ No newline at end of file
diff --git a/src/analyzeMFT/cli.py b/src/analyzeMFT/cli.py
index 0607e9e..d678fc6 100644
--- a/src/analyzeMFT/cli.py
+++ b/src/analyzeMFT/cli.py
@@ -36,16 +36,35 @@ async def main():
 
     (options, args) = parser.parse_args()
 
-    if not options.filename or not options.output_file:
+    if not options.filename:
         parser.print_help()
+        print("\nError: No input file specified. Use -f or --file to specify an MFT file.")
+        sys.exit(1)
+
+    if not options.output_file:
+        parser.print_help()
+        print("\nError: No output file specified. Use -o or --output to specify an output file.")
         sys.exit(1)
 
     if not options.export_format:
         options.export_format = "csv"  # Default to CSV if no format specified
 
-    analyzer = MftAnalyzer(options.filename, options.output_file, options.debug, options.compute_hashes, options.export_format)
-    await analyzer.analyze()
-    print(f"Analysis complete. Results written to {options.output_file}")
+    try:
+        analyzer = MftAnalyzer(options.filename, options.output_file, options.debug, options.compute_hashes, options.export_format)
+        await analyzer.analyze()
+        print(f"Analysis complete. Results written to {options.output_file}")
+    except FileNotFoundError:
+        print(f"Error: The file '{options.filename}' was not found.")
+        sys.exit(1)
+    except PermissionError:
+        print(f"Error: Permission denied when trying to read '{options.filename}' or write to '{options.output_file}'.")
+        sys.exit(1)
+    except Exception as e:
+        print(f"An unexpected error occurred: {str(e)}")
+        if options.debug:
+            import traceback
+            traceback.print_exc()
+        sys.exit(1)
 
 if __name__ == "__main__":
     asyncio.run(main())
\ No newline at end of file
diff --git a/src/analyzeMFT/mft_record.py b/src/analyzeMFT/mft_record.py
index 0f1370c..1bedd3c 100644
--- a/src/analyzeMFT/mft_record.py
+++ b/src/analyzeMFT/mft_record.py
@@ -4,7 +4,7 @@
 import zlib
 from .constants import *
 from .windows_time import WindowsTime
-from typing import Dict, Set, List, Optional, Any
+from typing import Dict, Set, List, Optional, Any,Union
 
 
 class MftRecord:
diff --git a/tests/constants.py b/tests/constants.py
new file mode 100644
index 0000000..58bc229
--- /dev/null
+++ b/tests/constants.py
@@ -0,0 +1,339 @@
+VERSION = '3.0.5'
+
+# File Record Flags
+FILE_RECORD_IN_USE = 0x0001
+FILE_RECORD_IS_DIRECTORY = 0x0002
+FILE_RECORD_IS_EXTENSION = 0x0004
+FILE_RECORD_HAS_SPECIAL_INDEX = 0x0008
+
+# Attribute Types
+STANDARD_INFORMATION_ATTRIBUTE = 0x10
+ATTRIBUTE_LIST_ATTRIBUTE = 0x20
+FILE_NAME_ATTRIBUTE = 0x30
+OBJECT_ID_ATTRIBUTE = 0x40
+SECURITY_DESCRIPTOR_ATTRIBUTE = 0x50
+VOLUME_NAME_ATTRIBUTE = 0x60
+VOLUME_INFORMATION_ATTRIBUTE = 0x70
+DATA_ATTRIBUTE = 0x80
+INDEX_ROOT_ATTRIBUTE = 0x90
+INDEX_ALLOCATION_ATTRIBUTE = 0xA0
+BITMAP_ATTRIBUTE = 0xB0
+REPARSE_POINT_ATTRIBUTE = 0xC0
+EA_INFORMATION_ATTRIBUTE = 0xD0
+EA_ATTRIBUTE = 0xE0
+LOGGED_UTILITY_STREAM_ATTRIBUTE = 0x100
+
+# Attribute Names
+ATTRIBUTE_NAMES = {
+    STANDARD_INFORMATION_ATTRIBUTE: "$STANDARD_INFORMATION",
+    ATTRIBUTE_LIST_ATTRIBUTE: "$ATTRIBUTE_LIST",
+    FILE_NAME_ATTRIBUTE: "$FILE_NAME",
+    OBJECT_ID_ATTRIBUTE: "$OBJECT_ID",
+    SECURITY_DESCRIPTOR_ATTRIBUTE: "$SECURITY_DESCRIPTOR",
+    VOLUME_NAME_ATTRIBUTE: "$VOLUME_NAME",
+    VOLUME_INFORMATION_ATTRIBUTE: "$VOLUME_INFORMATION",
+    DATA_ATTRIBUTE: "$DATA",
+    INDEX_ROOT_ATTRIBUTE: "$INDEX_ROOT",
+    INDEX_ALLOCATION_ATTRIBUTE: "$INDEX_ALLOCATION",
+    BITMAP_ATTRIBUTE: "$BITMAP",
+    REPARSE_POINT_ATTRIBUTE: "$REPARSE_POINT",
+    EA_INFORMATION_ATTRIBUTE: "$EA_INFORMATION",
+    EA_ATTRIBUTE: "$EA",
+    LOGGED_UTILITY_STREAM_ATTRIBUTE: "$LOGGED_UTILITY_STREAM"
+}
+
+# Standard Information Attribute
+STANDARD_INFORMATION = {
+    0x00: "Creation time",
+    0x08: "Last modification time",
+    0x10: "Last change time",
+    0x18: "Last access time",
+    0x20: "File attributes",
+    0x24: "Maximum versions",
+    0x28: "Version number",
+    0x2C: "Class ID",
+    0x30: "Owner ID",
+    0x34: "Security ID",
+    0x38: "Quota charged",
+    0x40: "Update sequence number (USN)"
+}
+
+# Attribute List
+ATTRIBUTE_LIST = {
+    0x00: "Attribute type",
+    0x04: "Record length",
+    0x06: "Name length (N)",
+    0x07: "Offset to Name",
+    0x08: "Starting VCN",
+    0x10: "Base File Reference of the attribute",
+    0x18: "Attribute ID",
+    0x1A: "Name in Unicode (if N > 0)"
+}
+
+# File Name Attribute
+FILE_NAME = {
+    0x00: "Parent directory file reference",
+    0x08: "Creation time",
+    0x10: "Last modification time",
+    0x18: "Last change time",
+    0x20: "Last access time",
+    0x28: "Allocated size",
+    0x30: "Real size",
+    0x38: "Flags",
+    0x3C: "Used by EAs and Reparse",
+    0x40: "Filename length in characters",
+    0x41: "Filename namespace",
+    0x42: "Filename (Unicode)"
+}
+
+# Object ID Attribute
+OBJECT_ID = {
+    0x00: "Object ID GUID",
+    0x10: "Birth Volume ID GUID",
+    0x20: "Birth Object ID GUID",
+    0x30: "Domain ID GUID"
+}
+
+# Security Descriptor Attribute Header
+SECURITY_DESCRIPTOR_HEADER = {
+    0x00: "Revision",
+    0x01: "Padding",
+    0x02: "Control Flags",
+    0x04: "Offset to Owner SID",
+    0x08: "Offset to Group SID",
+    0x0C: "Offset to SACL",
+    0x10: "Offset to DACL"
+}
+
+# Security Descriptor ACL
+SECURITY_DESCRIPTOR_ACL = {
+    0x00: "ACL Revision",
+    0x01: "Padding",
+    0x02: "ACL size",
+    0x04: "ACE count",
+    0x06: "Padding"
+}
+
+# Security Descriptor ACE
+SECURITY_DESCRIPTOR_ACE = {
+    0x00: "Type",
+    0x01: "Flags",
+    0x02: "Size",
+    0x04: "Access mask",
+    0x08: "SID"
+}
+
+# Volume Name Attribute
+VOLUME_NAME = {
+    0x00: "Volume name in Unicode"
+}
+
+# Volume Information Attribute
+VOLUME_INFORMATION = {
+    0x00: "Reserved (always zero?)",
+    0x08: "Major version",
+    0x09: "Minor version",
+    0x0A: "Flags",
+    0x0C: "Reserved (always zero?)"
+}
+
+# Data Attribute
+DATA = {
+    0x00: "Data content"
+}
+
+# Index Root Attribute
+INDEX_ROOT = {
+    0x00: "Attribute type",
+    0x04: "Collation rule",
+    0x08: "Bytes per index record",
+    0x0C: "Clusters per index record",
+    0x10: "Index node header"
+}
+
+# Index Allocation Attribute
+INDEX_ALLOCATION = {
+    0x00: "Data runs"
+}
+
+# Bitmap Attribute
+BITMAP = {
+    0x00: "Bit field"
+}
+
+# Reparse Point Attribute - Microsoft
+REPARSE_POINT_MS = {
+    0x00: "Reparse type and flags",
+    0x04: "Reparse data length",
+    0x06: "Padding",
+    0x08: "Reparse data"
+}
+
+# Reparse Point Attribute - Third Party
+REPARSE_POINT_3RD = {
+    0x00: "Reparse type and flags",
+    0x04: "Reparse data length",
+    0x06: "Padding",
+    0x08: "Reparse GUID",
+    0x18: "Reparse data"
+}
+
+# EA Information Attribute
+EA_INFORMATION = {
+    0x00: "Size of packed Extended Attributes",
+    0x02: "Number of EAs with NEED_EA set",
+    0x04: "Size of unpacked Extended Attributes"
+}
+
+# EA Attribute
+EA = {
+    0x00: "Offset to next EA",
+    0x04: "Flags",
+    0x05: "Name length",
+    0x06: "Value length",
+    0x08: "Name",
+    0x09: "Value"
+}
+
+# Logged Utility Stream
+LOGGED_UTILITY_STREAM = {
+    0x00: "Any data"
+}
+
+# Filename Namespaces
+FILENAME_NAMESPACE = {
+    0: "POSIX",
+    1: "Win32",
+    2: "DOS",
+    3: "Win32 & DOS"
+}
+
+# Index Entry Flags
+INDEX_ENTRY_NODE = 0x01
+INDEX_ENTRY_END = 0x02
+
+# MFT Record Size
+MFT_RECORD_SIZE = 1024
+
+# Attribute Flags
+ATTR_FLAG_COMPRESSED = 0x0001
+ATTR_FLAG_ENCRYPTED = 0x4000
+ATTR_FLAG_SPARSE = 0x8000
+
+# Collation Rules
+COLLATION_BINARY = 0x00
+COLLATION_FILENAME = 0x01
+COLLATION_UNICODE = 0x02
+COLLATION_ULONG = 0x10
+COLLATION_SID = 0x11
+COLLATION_SECURITY_HASH = 0x12
+COLLATION_ULONGS = 0x13
+
+# Byte order
+BYTE_ORDER = 'little'
+
+# Struct format strings
+STRUCT_STANDARD_INFORMATION = '<QQQQLLLQQQ'
+STRUCT_FILE_NAME = '<QQQQQQLLLLBB'
+STRUCT_OBJECT_ID = '<16s16s16s16s'
+
+# MFT Record header offsets and sizes
+MFT_RECORD_MAGIC_NUMBER_OFFSET = 0
+MFT_RECORD_UPDATE_SEQUENCE_OFFSET = 4
+MFT_RECORD_UPDATE_SEQUENCE_SIZE_OFFSET = 6
+MFT_RECORD_LOGFILE_SEQUENCE_NUMBER_OFFSET = 8
+MFT_RECORD_SEQUENCE_NUMBER_OFFSET = 16
+MFT_RECORD_HARD_LINK_COUNT_OFFSET = 18
+MFT_RECORD_FIRST_ATTRIBUTE_OFFSET = 20
+MFT_RECORD_FLAGS_OFFSET = 22
+MFT_RECORD_USED_SIZE_OFFSET = 24
+MFT_RECORD_ALLOCATED_SIZE_OFFSET = 28
+MFT_RECORD_FILE_REFERENCE_OFFSET = 32
+MFT_RECORD_NEXT_ATTRIBUTE_ID_OFFSET = 40
+MFT_RECORD_RECORD_NUMBER_OFFSET = 44
+
+# MFT Record header sizes
+MFT_RECORD_MAGIC_NUMBER_SIZE = 4
+MFT_RECORD_UPDATE_SEQUENCE_SIZE = 2
+MFT_RECORD_UPDATE_SEQUENCE_SIZE_SIZE = 2
+MFT_RECORD_LOGFILE_SEQUENCE_NUMBER_SIZE = 8
+MFT_RECORD_SEQUENCE_NUMBER_SIZE = 2
+MFT_RECORD_HARD_LINK_COUNT_SIZE = 2
+MFT_RECORD_FIRST_ATTRIBUTE_SIZE = 2
+MFT_RECORD_FLAGS_SIZE = 2
+MFT_RECORD_USED_SIZE_SIZE = 4
+MFT_RECORD_ALLOCATED_SIZE_SIZE = 4
+MFT_RECORD_FILE_REFERENCE_SIZE = 8
+MFT_RECORD_NEXT_ATTRIBUTE_ID_SIZE = 2
+MFT_RECORD_RECORD_NUMBER_SIZE = 4
+
+# MFT Record magic number
+MFT_RECORD_MAGIC = b'FILE'
+
+CSV_HEADER = [
+    # Basic Record Information
+    'Record Number', 
+    'Record Status',  # Instead of 'Good'/'Bad'
+    'Record Type',    # Instead of 'Active'/'Inactive'
+    'File Type',      # Instead of 'Record type'
+    'Sequence Number',
+    'Parent Record Number',
+    'Parent Record Sequence Number',
+    
+    # File Information
+    'Filename',
+    'Filepath',
+    
+    # Standard Information Times
+    'SI Creation Time',
+    'SI Modification Time',
+    'SI Access Time',
+    'SI Entry Time',
+    
+    # File Name Attribute Times
+    'FN Creation Time',
+    'FN Modification Time',
+    'FN Access Time',
+    'FN Entry Time',
+    
+    # Object ID Information
+    'Object ID',
+    'Birth Volume ID',
+    'Birth Object ID',
+    'Birth Domain ID',
+    
+    # Attribute Presence Flags
+    'Has Standard Information',
+    'Has Attribute List',
+    'Has File Name',
+    'Has Volume Name',
+    'Has Volume Information',
+    'Has Data',
+    'Has Index Root',
+    'Has Index Allocation',
+    'Has Bitmap',
+    'Has Reparse Point',
+    'Has EA Information',
+    'Has EA',
+    'Has Logged Utility Stream',
+    
+    # Detailed Attribute Information
+    'Attribute List Details',
+    'Security Descriptor',
+    'Volume Name',
+    'Volume Information',
+    'Data Attribute',
+    'Index Root',
+    'Index Allocation',
+    'Bitmap',
+    'Reparse Point',
+    'EA Information',
+    'EA',
+    'Logged Utility Stream',
+    
+    # Hash Information (if computed)
+    'MD5',
+    'SHA256',
+    'SHA512',
+    'CRC32'
+]
\ No newline at end of file
diff --git a/tests/generateMFT.py b/tests/generateMFT.py
index 8d1eceb..988ccee 100644
--- a/tests/generateMFT.py
+++ b/tests/generateMFT.py
@@ -3,7 +3,7 @@
 import os
 import uuid
 from datetime import datetime, timedelta
-from src.analyzeMFT.constants import *
+from constants import *
 
 def windows_time(dt):
     """Convert a datetime object to Windows filetime"""
@@ -61,11 +61,14 @@ def create_mft_record(record_number, flags, filename):
         windows_time(datetime.now() + timedelta(days=1)),  # Last modification time
         windows_time(datetime.now() + timedelta(days=2)),  # Last change time
         windows_time(datetime.now() + timedelta(days=3)),  # Last access time
-        1024, 1024,  # Allocated size, Real size
-        flags, 0,  # Flags, Reparse value
-        len(filename), 0  # Filename length, Namespace
+        1024,  # Allocated size
+        1024,  # Real size
+        flags,  # Flags
+        0,  # Reparse value
+        len(filename),  # Filename length
+        0,  # Namespace
+        0  
     ) + filename.encode('utf-16le')
-    offset = add_attribute(record, offset, FILE_NAME_ATTRIBUTE, fn_data)
     
     # $DATA attribute (resident)
     data = f"This is the content of {filename}".encode('utf-8')