# generate_manifest.py
import os
import json
import hashlib
from datetime import datetime

DWG_FOLDER = "/app/dwg_files"
DATABASE_FOLDER = "/app/database_files"
MANIFEST_FILE = "/app/manifest.json"

def generate_file_hash(file_path):
    """Generate SHA256 hash for a file."""
    hasher = hashlib.sha256()
    with open(file_path, "rb") as f:
        while chunk := f.read(8192):
            hasher.update(chunk)
    return hasher.hexdigest()

def process_directory(directory, manifest, prefix=""):
    """Process a directory and add its files to the manifest."""
    extensions = [".dwg", ".txt", ".csv"]
    # Whitelist of allowed files without extensions (matches app.py configuration)
    allowed_no_extension_files = ["version"]
    
    for root, _, files in os.walk(directory):
        for file in files:
            file_lower = file.lower()
            file_path = os.path.join(root, file)
            rel_path = os.path.relpath(file_path, directory)
            
            # Check if file has allowed extension or is in whitelist for files without extensions
            has_allowed_extension = any(file_lower.endswith(ext) for ext in extensions)
            is_allowed_no_extension = not os.path.splitext(file)[1] and file in allowed_no_extension_files
            
            if has_allowed_extension or is_allowed_no_extension:
                manifest[rel_path] = {
                    "size": os.path.getsize(file_path),
                    "modified": os.path.getmtime(file_path),
                    "hash": generate_file_hash(file_path),
                    "path": rel_path,
                    "remote_prefix": prefix
                }

def generate_manifest():
    """Scans the directories and creates a manifest file."""
    manifest = {}
    
    # Process DWG files directory
    if os.path.exists(DWG_FOLDER):
        process_directory(DWG_FOLDER, manifest, "dwg_files")
    
    # Process database files directory
    if os.path.exists(DATABASE_FOLDER):
        process_directory(DATABASE_FOLDER, manifest, "database_files")
    
    with open(MANIFEST_FILE, "w") as f:
        json.dump(manifest, f, indent=4)
    
    print("✅ Manifest updated successfully.")

if __name__ == "__main__":
    generate_manifest()