Request and Response Handling

class Request:
    def __init__(self, environ, populate_request=True, shallow=False):
        """
        Create a new request wrapper.
        
        Parameters:
        - environ: WSGI environment dictionary
        - populate_request: Whether to parse form data immediately
        - shallow: Don't consume input stream for form parsing
        """
    
    # URL and path information
    method: str  # HTTP method (GET, POST, etc.)
    url: str  # Complete URL
    base_url: str  # URL without query string
    url_root: str  # Protocol, host, and script root
    path: str  # Path portion of URL  
    script_root: str  # SCRIPT_NAME from WSGI
    query_string: str  # Raw query string
    
    # Request data access
    args: MultiDict  # Parsed query parameters
    form: MultiDict  # Parsed form data (POST/PUT)
    files: MultiDict  # Uploaded files as FileStorage objects
    values: MultiDict  # Combined args and form data
    data: bytes  # Raw request body
    json: Any  # Parsed JSON data (if Content-Type is JSON)
    
    # Headers and metadata
    headers: Headers  # Request headers
    cookies: dict  # Request cookies
    authorization: Optional[Authorization]  # Authorization header
    # User-Agent header accessible via headers.get('User-Agent')
    
    # Accept headers for content negotiation
    accept_mimetypes: MIMEAccept  # Accept header
    accept_charsets: CharsetAccept  # Accept-Charset header
    accept_encodings: Accept  # Accept-Encoding header  
    accept_languages: LanguageAccept  # Accept-Language header
    
    # Conditional request headers
    cache_control: RequestCacheControl  # Cache-Control header
    if_match: Optional[ETags]  # If-Match header
    if_none_match: Optional[ETags]  # If-None-Match header
    if_modified_since: Optional[datetime]  # If-Modified-Since header
    if_unmodified_since: Optional[datetime]  # If-Unmodified-Since header
    range: Optional[Range]  # Range header
    
    # Content information
    content_type: Optional[str]  # Content-Type header
    content_length: Optional[int]  # Content-Length header
    mimetype: Optional[str]  # MIME type from Content-Type
    mimetype_params: dict  # Parameters from Content-Type
    
    # Request type checks
    is_json: bool  # True if Content-Type is JSON
    is_secure: bool  # True if request is over HTTPS
    is_xhr: bool  # True if X-Requested-With is XMLHttpRequest
    
    # Client and server information
    remote_addr: Optional[str]  # Client IP address
    remote_user: Optional[str]  # Authenticated username
    scheme: str  # URL scheme (http/https)
    host: str  # Host header value
    port: Optional[int]  # Port number
    
    def get_json(self, force=False, silent=False, cache=True):
        """
        Parse request body as JSON.
        
        Parameters:
        - force: Parse even if Content-Type is not JSON
        - silent: Return None instead of raising on parse errors
        - cache: Cache parsed result
        
        Returns:
        Parsed JSON data or None
        """

class Response:
    def __init__(self, response=None, status=None, headers=None, mimetype=None, content_type=None, direct_passthrough=False):
        """
        Create a new response object.
        
        Parameters:
        - response: Response body (string, bytes, or iterable)
        - status: HTTP status code or status line
        - headers: Response headers (dict, list, or Headers object)
        - mimetype: MIME type for Content-Type header
        - content_type: Complete Content-Type header value
        - direct_passthrough: Don't modify response body
        """
    
    # Response data and status
    data: bytes  # Response body as bytes
    status: str  # Complete status line (e.g., "200 OK")
    status_code: int  # Status code number
    headers: Headers  # Response headers
    
    # Content type information
    mimetype: Optional[str]  # MIME type portion
    content_type: Optional[str]  # Complete Content-Type header
    content_length: Optional[int]  # Content-Length header
    
    # Caching headers
    cache_control: ResponseCacheControl  # Cache-Control header
    expires: Optional[datetime]  # Expires header
    last_modified: Optional[datetime]  # Last-Modified header
    etag: Optional[str]  # ETag header
    
    # Other headers
    www_authenticate: Optional[WWWAuthenticate]  # WWW-Authenticate header
    location: Optional[str]  # Location header for redirects
    
    def set_cookie(self, key, value="", max_age=None, expires=None, path="/", domain=None, secure=False, httponly=False, samesite=None):
        """
        Set a cookie.
        
        Parameters:
        - key: Cookie name
        - value: Cookie value
        - max_age: Maximum age in seconds
        - expires: Expiration datetime or timestamp
        - path: Cookie path
        - domain: Cookie domain
        - secure: Only send over HTTPS
        - httponly: Don't allow JavaScript access
        - samesite: SameSite attribute ('Strict', 'Lax', or 'None')
        """
    
    def delete_cookie(self, key, path="/", domain=None, secure=False, httponly=False, samesite=None):
        """
        Delete a cookie by setting it to expire immediately.
        
        Parameters:
        - key: Cookie name to delete
        - path: Cookie path (must match original)
        - domain: Cookie domain (must match original)
        - secure: Secure flag (must match original)
        - httponly: HttpOnly flag (must match original)
        - samesite: SameSite attribute (must match original)
        """
    
    def set_etag(self, etag, weak=False):
        """
        Set the ETag header.
        
        Parameters:
        - etag: ETag value
        - weak: Whether this is a weak ETag
        """
    
    def make_conditional(self, request_or_environ, accept_ranges=False, complete_length=None):
        """
        Make response conditional based on request headers.
        
        Handles If-Match, If-None-Match, If-Modified-Since, If-Unmodified-Since
        and Range headers automatically.
        
        Parameters:
        - request_or_environ: Request object or WSGI environ
        - accept_ranges: Whether to accept Range requests
        - complete_length: Total content length for partial content
        
        Returns:
        Response object (may be modified for 304/416 responses)
        """
    
    def add_etag(self, overwrite=False, weak=False):
        """
        Add an ETag header based on response content.
        
        Parameters:
        - overwrite: Replace existing ETag
        - weak: Generate weak ETag
        """
    
    def freeze(self, no_etag=False):
        """
        Make response immutable and add ETag if missing.
        
        Parameters:
        - no_etag: Don't add ETag header
        """

class ResponseStream:
    def __init__(self, response):
        """
        Create a response stream wrapper.
        
        Parameters:
        - response: Response object to wrap
        """
    
    def write(self, data):
        """
        Write data to response stream.
        
        Parameters:
        - data: Data to write (string or bytes)
        """
    
    def writelines(self, lines):
        """
        Write multiple lines to response stream.
        
        Parameters:
        - lines: Iterable of lines to write
        """
    
    def close(self):
        """Close the response stream."""

from werkzeug.wrappers import Request, Response

def application(environ, start_response):
    request = Request(environ)
    
    # Access request data
    method = request.method
    path = request.path
    user_agent = request.headers.get('User-Agent')
    
    # Handle different content types
    if request.is_json:
        data = request.get_json()
        response = Response(f"Received JSON: {data}")
    elif request.method == 'POST':
        form_data = request.form
        response = Response(f"Form data: {dict(form_data)}")
    else:
        response = Response("Hello World!")
    
    return response(environ, start_response)

from werkzeug.wrappers import Request, Response
from werkzeug.utils import secure_filename
import os

def handle_upload(environ, start_response):
    request = Request(environ)
    
    if request.method == 'POST':
        uploaded_file = request.files.get('file')
        if uploaded_file and uploaded_file.filename:
            filename = secure_filename(uploaded_file.filename)
            upload_path = os.path.join('/uploads', filename)
            uploaded_file.save(upload_path)
            response = Response(f"File {filename} uploaded successfully")
        else:
            response = Response("No file uploaded", status=400)
    else:
        response = Response('''
        <form method="POST" enctype="multipart/form-data">
            <input type="file" name="file">
            <input type="submit" value="Upload">
        </form>
        ''', mimetype='text/html')
    
    return response(environ, start_response)

from werkzeug.wrappers import Request, Response
import json

def api_endpoint(environ, start_response):
    request = Request(environ)
    
    data = {"message": "Hello", "status": "success"}
    
    # Check what the client accepts
    if request.accept_mimetypes.accept_json:
        response = Response(
            json.dumps(data),
            mimetype='application/json'
        )
    elif request.accept_mimetypes.accept_html:
        html = f"<h1>{data['message']}</h1><p>Status: {data['status']}</p>"
        response = Response(html, mimetype='text/html')
    else:
        # Default to plain text
        response = Response(f"{data['message']} - {data['status']}")
    
    return response(environ, start_response)

from werkzeug.wrappers import Request, Response
from werkzeug.http import http_date
from datetime import datetime

def cached_content(environ, start_response):
    request = Request(environ)
    
    # Create response with content
    content = "This is cached content that changes infrequently"
    response = Response(content)
    
    # Set caching headers
    response.last_modified = datetime(2023, 1, 1)
    response.cache_control.max_age = 3600  # Cache for 1 hour
    response.add_etag()  # Generate ETag from content
    
    # Make response conditional (handles 304 Not Modified)
    response.make_conditional(request)
    
    return response(environ, start_response)

from werkzeug.wrappers import Request, Response

def session_example(environ, start_response):
    request = Request(environ)
    
    # Read existing session
    session_id = request.cookies.get('session_id')
    
    if session_id:
        response = Response(f"Welcome back! Session: {session_id}")
    else:
        # Create new session
        import uuid
        new_session_id = str(uuid.uuid4())
        response = Response(f"New session created: {new_session_id}")
        
        # Set secure session cookie
        response.set_cookie(
            'session_id', 
            new_session_id,
            max_age=3600,  # 1 hour
            secure=True,   # HTTPS only
            httponly=True, # No JavaScript access
            samesite='Lax' # CSRF protection
        )
    
    return response(environ, start_response)