import ast
from langchain.schema import Document 

def chunk_python_source_code(source_code, references):
    """
    Entry point method to process the Python file.
    It invokes the iterate_ast function.
    """
    print(f"Processing file: {references}")

    for source_code, reference in zip(source_code, references):
        print(f"Processing text: {source_code} with reference: {reference}")
        iterate_ast(source_code, reference)
    

def iterate_ast(source_code, reference):
    """
    Parses the AST of the given Python file and delegates
    handling to specific methods based on node types.
    """
    # Parse the source code into an abstract syntax tree (AST)
    tree = ast.parse(source_code, filename=reference)

    # Gather all top-level imports for later use
    imports_dict = extract_imports(tree)
    
    # Iterate over first-level nodes
    for first_level_node in ast.iter_child_nodes(tree):
        if isinstance(first_level_node, ast.ClassDef):
            handle_first_level_class(first_level_node, source_code, imports_dict)
        elif isinstance(first_level_node, ast.FunctionDef):
            handle_first_level_func(first_level_node, source_code, imports_dict)

def extract_imports(tree):
    """
    Extracts all import statements from the AST tree and organizes them
    into a dictionary keyed by their fully qualified names for later analysis.
    """
    imports_dict = {}
    for node in ast.walk(tree):
        if isinstance(node, ast.Import):
            for alias in node.names:
                imports_dict[alias.name] = alias.name
        elif isinstance(node, ast.ImportFrom):
            module = node.module if node.module else ""
            for alias in node.names:
                full_name = f"{module}.{alias.name}" if module else alias.name
                imports_dict[alias.name] = full_name
    return imports_dict

def analyze_imports(node, imports_dict):
    """
    Analyzes the given node's body and signature to find relevant imports.
    """
    relevant_imports = set()
    for sub_node in ast.walk(node):
        if isinstance(sub_node, ast.Name) and sub_node.id in imports_dict:
            relevant_imports.add(imports_dict[sub_node.id])
    return list(relevant_imports)

def handle_first_level_class(class_node, source_code, imports_dict):
    """
    Handles classes at the first level of the AST by processing
    the class and its methods. Stores each class method in a Document object.
    """
    print(f"Class detected: {class_node.name}")

    # Extract relevant imports for this class
    class_imports = analyze_imports(class_node, imports_dict)
    
    # Extract the class source code
    class_start_line = class_node.lineno
    class_end_line = max(
        [n.end_lineno for n in ast.walk(class_node) if hasattr(n, "end_lineno")], default=class_node.lineno
    )
    class_source = '\n'.join(source_code.splitlines()[class_start_line - 1:class_end_line])

    # Store the class-level Document
    class_doc = Document(
        page_content=class_source,
        metadata={
            "type": "class",
            "class_name": class_node.name,
            "imports": class_imports
        }
    )
    print(f"Stored Class Document: {class_doc}\n")
    
    # Process methods within the class
    for second_level_node in ast.iter_child_nodes(class_node):
        if isinstance(second_level_node, ast.FunctionDef):
            handle_class_method(second_level_node, class_node.name, source_code, imports_dict)

def handle_class_method(method_node, class_name, source_code, imports_dict):
    """
    Handles methods within a class by storing them in a Document object.
    """
    print(f"Method detected: {method_node.name} in class {class_name}")
    
    # Extract method source code
    method_start_line = (
        method_node.decorator_list[0].lineno
        if method_node.decorator_list else method_node.lineno
    )
    method_end_line = method_node.end_lineno
    method_source = '\n'.join(source_code.splitlines()[method_start_line - 1:method_end_line])
    
    # Determine visibility metadata
    visibility = "internal" if method_node.name.startswith("_") else "public"
    
    # Extract relevant imports for this method
    method_imports = analyze_imports(method_node, imports_dict)
    
    # Store the method-level Document
    method_doc = Document(
        page_content=method_source,
        metadata={
            "type": "method",
            "class_name": class_name,
            "method_name": method_node.name,
            "visibility": visibility,
            "imports": method_imports
        }
    )
    print(f"Stored Method Document: {method_doc}\n")

def handle_first_level_func(function_node, source_code, imports_dict):
    """
    Handles functions at the first level of the AST by storing them
    in a Document object with metadata, including relevant imports.
    """
    print(f"Function detected: {function_node.name}")

    # Extract function source code
    function_start_line = (
        function_node.decorator_list[0].lineno
        if function_node.decorator_list else function_node.lineno
    )
    function_end_line = function_node.end_lineno
    function_source = '\n'.join(source_code.splitlines()[function_start_line - 1:function_end_line])
    
    # Determine visibility metadata
    visibility = "internal" if function_node.name.startswith("_") else "public"
    
    # Extract relevant imports for this function
    function_imports = analyze_imports(function_node, imports_dict)
    
    # Store the function-level Document
    function_doc = Document(
        page_content=function_source,
        metadata={
            "type": "function",
            "function_name": function_node.name,
            "visibility": visibility,
            "imports": function_imports
        }
    )
    print(f"Stored Function Document: {function_doc}\n")