Response Content Processing

def collect(response, collector):
    """
    Incrementally collect the body of the response.
    
    This function may only be called once for a given response.
    If the collector raises an exception, it will be set as the error
    value on the response Deferred and the HTTP transport will be closed.
    
    Parameters:
    - response: IResponse - The HTTP response to collect body from
    - collector: callable - Function called with each data chunk (bytes)
    
    Returns:
    Deferred that fires with None when entire body has been read
    """

def content(response):
    """
    Read the complete contents of an HTTP response.
    
    This function may be called multiple times for a response, it uses
    a WeakKeyDictionary to cache the contents of the response.
    
    Parameters:
    - response: IResponse - The HTTP response to get contents of
    
    Returns:
    Deferred that fires with complete content as bytes
    """

def text_content(response, encoding="ISO-8859-1"):
    """
    Read and decode HTTP response contents as text.
    
    The charset is automatically detected from the Content-Type header.
    If no charset is specified, the provided encoding is used as fallback.
    
    Parameters:
    - response: IResponse - The HTTP response to decode
    - encoding: str - Fallback encoding if none detected (default: ISO-8859-1)
    
    Returns:
    Deferred that fires with decoded text as str
    """

def json_content(response, **kwargs):
    """
    Read and parse HTTP response contents as JSON.
    
    This function relies on text_content() and may be called multiple
    times for a given response. JSON content is automatically decoded
    as UTF-8 per RFC 7159.
    
    Parameters:
    - response: IResponse - The HTTP response to parse
    - **kwargs: Additional keyword arguments for json.loads()
    
    Returns:
    Deferred that fires with parsed JSON data
    """

import treq
from twisted.internet import defer

@defer.inlineCallbacks
def get_content():
    response = yield treq.get('https://httpbin.org/get')
    
    # Get raw bytes
    raw_data = yield treq.content(response)
    print(f"Raw data: {raw_data[:100]}...")
    
    # Get decoded text
    text_data = yield treq.text_content(response)
    print(f"Text data: {text_data[:100]}...")
    
    # Parse as JSON
    json_data = yield treq.json_content(response)
    print(f"JSON data: {json_data}")

@defer.inlineCallbacks
def stream_large_file():
    response = yield treq.get('https://httpbin.org/bytes/10000')
    
    chunks = []
    def collector(data):
        chunks.append(data)
        print(f"Received chunk of {len(data)} bytes")
    
    yield treq.collect(response, collector)
    total_data = b''.join(chunks)
    print(f"Total received: {len(total_data)} bytes")

@defer.inlineCallbacks
def handle_different_types():
    # JSON API response  
    json_response = yield treq.get('https://httpbin.org/json')
    data = yield treq.json_content(json_response)
    
    # Plain text response
    text_response = yield treq.get('https://httpbin.org/robots.txt')
    text = yield treq.text_content(text_response)
    
    # Binary data (image, file, etc.)
    binary_response = yield treq.get('https://httpbin.org/bytes/1024')
    binary_data = yield treq.content(binary_response)
    
    # Custom JSON parsing with parameters
    json_response = yield treq.get('https://httpbin.org/json')
    # Parse with custom options
    data = yield treq.json_content(json_response, parse_float=float, parse_int=int)

@defer.inlineCallbacks
def handle_content_errors():
    try:
        response = yield treq.get('https://httpbin.org/status/500')
        
        # Content functions work regardless of HTTP status
        content = yield treq.text_content(response)
        print(f"Error response content: {content}")
        
    except Exception as e:
        print(f"Request failed: {e}")
    
    try:
        response = yield treq.get('https://httpbin.org/html')
        
        # This will raise an exception if content is not valid JSON
        json_data = yield treq.json_content(response)
        
    except ValueError as e:
        print(f"JSON parsing failed: {e}")
        # Fall back to text content
        text_data = yield treq.text_content(response)

@defer.inlineCallbacks
def use_response_methods():
    response = yield treq.get('https://httpbin.org/json')
    
    # These are equivalent to the module-level functions
    content_bytes = yield response.content()
    text_content = yield response.text()
    json_data = yield response.json()
    
    # Incremental collection
    chunks = []
    yield response.collect(chunks.append)

# Collector function type for incremental processing
CollectorFunction = Callable[[bytes], None]

# Encoding detection return type
Optional[str]  # Charset name or None if not detected

# Content function return types
Deferred[bytes]    # For content()
Deferred[str]      # For text_content()
Deferred[Any]      # For json_content()
Deferred[None]     # For collect()