U
    ڲg                     @  s   d dl mZ d dlZd dlZd dlmZmZmZ d dlmZm	Z	m
Z
 d dlmZmZmZ erhd dlmZ dZddd	d
dddZd
ddddZG dd dZG dd deZG dd deZG dd deZdS )    )annotationsN)datetime	timedeltatimezone)
formatdate	parsedateparsedate_tz)TYPE_CHECKINGAnyMapping)HTTPResponsez%a, %d %b %Y %H:%M:%S GMTr   zdatetime | Noner   )deltadatereturnc                 C  s   |pt tj}||  S N)r   nowr   utc)r   r    r   ;/tmp/pip-unpacked-wheel-rew7nuve/cachecontrol/heuristics.pyexpire_after   s    r   str)dtr   c                 C  s   t t|  S r   )r   calendartimegm	timetuple)r   r   r   r   datetime_to_header   s    r   c                   @  s<   e Zd ZdddddZdddddZdddd	d
ZdS )BaseHeuristicr   
str | Noneresponser   c                 C  s   dS )a!  
        Return a valid 1xx warning header value describing the cache
        adjustments.

        The response is provided too allow warnings like 113
        http://tools.ietf.org/html/rfc7234#section-5.5.4 where we need
        to explicitly say response is over 24 hours old.
        z110 - "Response is Stale"r   selfr   r   r   r   warning   s    	zBaseHeuristic.warningdict[str, str]c                 C  s   i S )zUpdate the response headers with any new headers.

        NOTE: This SHOULD always include some Warning header to
              signify that the response was cached by the client, not
              by way of the provided headers.
        r   r    r   r   r   update_headers'   s    zBaseHeuristic.update_headersc                 C  s@   |  |}|r<|j| | |}|d k	r<|jd|i |S )NWarning)r$   headersupdater"   )r!   r   Zupdated_headersZwarning_header_valuer   r   r   apply0   s    

zBaseHeuristic.applyN)__name__
__module____qualname__r"   r$   r(   r   r   r   r   r      s   	r   c                   @  s    e Zd ZdZdddddZdS )OneDayCachezM
    Cache the response by providing an expires 1 day in the
    future.
    r   r#   r   c                 C  sZ   i }d|j krVt|j d }ttddt|d d dtjid}t||d< d|d	< |S )
Nexpiresr      )days   tzinfo)r   publiccache-control)r&   r   r   r   r   r   r   r   )r!   r   r&   r   r-   r   r   r   r$   B   s    
zOneDayCache.update_headersN)r)   r*   r+   __doc__r$   r   r   r   r   r,   <   s   r,   c                   @  s@   e Zd ZdZdddddZddd	d
dZddd	ddZdS )ExpiresAfterz;
    Cache **all** requests for a defined time period.
    r
   None)kwr   c                 K  s   t f || _d S r   )r   r   )r!   r7   r   r   r   __init__U   s    zExpiresAfter.__init__r   r#   r   c                 C  s   t | j}t|ddS )Nr2   )r-   r3   )r   r   r   )r!   r   r-   r   r   r   r$   X   s    
zExpiresAfter.update_headersr   c                 C  s   d}|| j  S )Nz:110 - Automatically cached for %s. Response might be stale)r   )r!   r   tmplr   r   r   r"   \   s    zExpiresAfter.warningN)r)   r*   r+   r4   r8   r$   r"   r   r   r   r   r5   P   s   r5   c                   @  sJ   e Zd ZdZdddddddd	d
ddhZdddddZdddddZdS )LastModifieda  
    If there is no Expires header already, fall back on Last-Modified
    using the heuristic from
    http://tools.ietf.org/html/rfc7234#section-4.2.2
    to calculate a reasonable value.

    Firefox also does something like this per
    https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching_FAQ
    http://lxr.mozilla.org/mozilla-release/source/netwerk/protocol/http/nsHttpResponseHead.cpp#397
    Unlike mozilla we limit this to 24-hr.
                i,  i-  i  i  i  i  i  r   r#   )respr   c                 C  s   |j }d|kri S d|kr*|d dkr*i S |j| jkr:i S d|ksJd|krNi S t|d }|d k	sftt|d d }t|d }|d kri S t }t	d|| }|t| }t	dt
|d d	}	|	|kri S ||	 }
dttt|
iS )
Nr-   r3   r2   r   zlast-modifiedr0   r   
   iQ )r&   statuscacheable_by_default_statusesr   AssertionErrorr   r   r   timemaxminstrftimeTIME_FMTgmtime)r!   r?   r&   Z
time_tupler   Zlast_modifiedr   current_ager   freshness_lifetimer-   r   r   r   r$   |   s.    zLastModified.update_headersr   c                 C  s   d S r   r   )r!   r?   r   r   r   r"      s    zLastModified.warningN)r)   r*   r+   r4   rB   r$   r"   r   r   r   r   r:   a   s    r:   )N)
__future__r   r   rD   r   r   r   email.utilsr   r   r   typingr	   r
   r   urllib3r   rH   r   r   r   r,   r5   r:   r   r   r   r   <module>   s   !