import logging
import mimetypes
mimetypes.init()
mimetypes.types_map['.dwg'] = 'image/x-dwg'
mimetypes.types_map['.ico'] = 'image/x-icon'
mimetypes.types_map['.bz2'] = 'application/x-bzip2'
mimetypes.types_map['.gz'] = 'application/x-gzip'

import os
import re
import stat
import time
from urllib import unquote

import cherrypy
from cherrypy.lib import cptools, httputil, file_generator_limited


def serve_file(path, content_type=None, disposition=None, name=None, debug=False):
    """Set status, headers, and body in order to serve the given path.
    
    The Content-Type header will be set to the content_type arg, if provided.
    If not provided, the Content-Type will be guessed by the file extension
    of the 'path' argument.
    
    If disposition is not None, the Content-Disposition header will be set
    to "<disposition>; filename=<name>". If name is None, it will be set
    to the basename of path. If disposition is None, no Content-Disposition
    header will be written.
    """
    
    response = cherrypy.serving.response
    
    # If path is relative, users should fix it by making path absolute.
    # That is, CherryPy should not guess where the application root is.
    # It certainly should *not* use cwd (since CP may be invoked from a
    # variety of paths). If using tools.staticdir, you can make your relative
    # paths become absolute by supplying a value for "tools.staticdir.root".
    if not os.path.isabs(path):
        msg = "'%s' is not an absolute path." % path
        if debug:
            cherrypy.log(msg, 'TOOLS.STATICFILE')
        raise ValueError(msg)
    
    try:
        st = os.stat(path)
    except OSError:
        if debug:
            cherrypy.log('os.stat(%r) failed' % path, 'TOOLS.STATIC')
        raise cherrypy.NotFound()
    
    # Check if path is a directory.
    if stat.S_ISDIR(st.st_mode):
        # Let the caller deal with it as they like.
        if debug:
            cherrypy.log('%r is a directory' % path, 'TOOLS.STATIC')
        raise cherrypy.NotFound()
    
    # Set the Last-Modified response header, so that
    # modified-since validation code can work.
    response.headers['Last-Modified'] = httputil.HTTPDate(st.st_mtime)
    cptools.validate_since()
    
    if content_type is None:
        # Set content-type based on filename extension
        ext = ""
        i = path.rfind('.')
        if i != -1:
            ext = path[i:].lower()
        content_type = mimetypes.types_map.get(ext, None)
    if content_type is not None:
        response.headers['Content-Type'] = content_type
    if debug:
        cherrypy.log('Content-Type: %r' % content_type, 'TOOLS.STATIC')
    
    cd = None
    if disposition is not None:
        if name is None:
            name = os.path.basename(path)
        cd = '%s; filename="%s"' % (disposition, name)
        response.headers["Content-Disposition"] = cd
    if debug:
        cherrypy.log('Content-Disposition: %r' % cd, 'TOOLS.STATIC')
    
    # Set Content-Length and use an iterable (file object)
    #   this way CP won't load the whole file in memory
    content_length = st.st_size
    fileobj = open(path, 'rb')
    return _serve_fileobj(fileobj, content_type, content_length, debug=debug)

def serve_fileobj(fileobj, content_type=None, disposition=None, name=None,
                  debug=False):
    """Set status, headers, and body in order to serve the given file object.
    
    The Content-Type header will be set to the content_type arg, if provided.
    
    If disposition is not None, the Content-Disposition header will be set
    to "<disposition>; filename=<name>". If name is None, 'filename' will
    not be set. If disposition is None, no Content-Disposition header will
    be written.

    CAUTION: If the request contains a 'Range' header, one or more seek()s will
    be performed on the file object.  This may cause undesired behavior if
    the file object is not seekable.  It could also produce undesired results
    if the caller set the read position of the file object prior to calling
    serve_fileobj(), expecting that the data would be served starting from that
    position.
    """
    
    response = cherrypy.serving.response
    
    try:
        st = os.fstat(fileobj.fileno())
    except AttributeError:
        if debug:
            cherrypy.log('os has no fstat attribute', 'TOOLS.STATIC')
        content_length = None
    else:
        # Set the Last-Modified response header, so that
        # modified-since validation code can work.
        response.headers['Last-Modified'] = httputil.HTTPDate(st.st_mtime)
        cptools.validate_since()
        content_length = st.st_size
    
    if content_type is not None:
        response.headers['Content-Type'] = content_type
    if debug:
        cherrypy.log('Content-Type: %r' % content_type, 'TOOLS.STATIC')
    
    cd = None
    if disposition is not None:
        if name is None:
            cd = disposition
        else:
            cd = '%s; filename="%s"' % (disposition, name)
        response.headers["Content-Disposition"] = cd
    if debug:
        cherrypy.log('Content-Disposition: %r' % cd, 'TOOLS.STATIC')
    
    return _serve_fileobj(fileobj, content_type, content_length, debug=debug)

def _serve_fileobj(fileobj, content_type, content_length, debug=False):
    """Internal. Set response.body to the given file object, perhaps ranged."""
    response = cherrypy.serving.response
    
    # HTTP/1.0 didn't have Range/Accept-Ranges headers, or the 206 code
    request = cherrypy.serving.request
    if request.protocol >= (1, 1):
        response.headers["Accept-Ranges"] = "bytes"
        r = httputil.get_ranges(request.headers.get('Range'), content_length)
        if r == []:
            response.headers['Content-Range'] = "bytes */%s" % content_length
            message = "Invalid Range (first-byte-pos greater than Content-Length)"
            if debug:
                cherrypy.log(message, 'TOOLS.STATIC')
            raise cherrypy.HTTPError(416, message)
        
        if r:
            if len(r) == 1:
                # Return a single-part response.
                start, stop = r[0]
                if stop > content_length:
                    stop = content_length
                r_len = stop - start
                if debug:
                    cherrypy.log('Single part; start: %r, stop: %r' % (start, stop),
                                 'TOOLS.STATIC')
                response.status = "206 Partial Content"
                response.headers['Content-Range'] = (
                    "bytes %s-%s/%s" % (start, stop - 1, content_length))
                response.headers['Content-Length'] = r_len
                fileobj.seek(start)
                response.body = file_generator_limited(fileobj, r_len)
            else:
                # Return a multipart/byteranges response.
                response.status = "206 Partial Content"
                import mimetools
                boundary = mimetools.choose_boundary()
                ct = "multipart/byteranges; boundary=%s" % boundary
                response.headers['Content-Type'] = ct
                if "Content-Length" in response.headers:
                    # Delete Content-Length header so finalize() recalcs it.
                    del response.headers["Content-Length"]
                
                def file_ranges():
                    # Apache compatibility:
                    yield "\r\n"
                    
                    for start, stop in r:
                        if debug:
                            cherrypy.log('Multipart; start: %r, stop: %r' % (start, stop),
                                         'TOOLS.STATIC')
                        yield "--" + boundary
                        yield "\r\nContent-type: %s" % content_type
                        yield ("\r\nContent-range: bytes %s-%s/%s\r\n\r\n"
                               % (start, stop - 1, content_length))
                        fileobj.seek(start)
                        for chunk in file_generator_limited(fileobj, stop - start):
                            yield chunk
                        yield "\r\n"
                    # Final boundary
                    yield "--" + boundary + "--"
                    
                    # Apache compatibility:
                    yield "\r\n"
                response.body = file_ranges()
            return response.body
        else:
            if debug:
                cherrypy.log('No byteranges requested', 'TOOLS.STATIC')
    
    # Set Content-Length and use an iterable (file object)
    #   this way CP won't load the whole file in memory
    response.headers['Content-Length'] = content_length
    response.body = fileobj
    return response.body

def serve_download(path, name=None):
    """Serve 'path' as an application/x-download attachment."""
    # This is such a common idiom I felt it deserved its own wrapper.
    return serve_file(path, "application/x-download", "attachment", name)


def _attempt(filename, content_types, debug=False):
    if debug:
        cherrypy.log('Attempting %r (content_types %r)' % 
                     (filename, content_types), 'TOOLS.STATICDIR')
    try:
        # you can set the content types for a
        # complete directory per extension
        content_type = None
        if content_types:
            r, ext = os.path.splitext(filename)
            content_type = content_types.get(ext[1:], None)
        serve_file(filename, content_type=content_type, debug=debug)
        return True
    except cherrypy.NotFound:
        # If we didn't find the static file, continue handling the
        # request. We might find a dynamic handler instead.
        if debug:
            cherrypy.log('NotFound', 'TOOLS.STATICFILE')
        return False

def staticdir(section, dir, root="", match="", content_types=None, index="",
              debug=False):
    """Serve a static resource from the given (root +) dir.
    
    If 'match' is given, request.path_info will be searched for the given
    regular expression before attempting to serve static content.
    
    If content_types is given, it should be a Python dictionary of
    {file-extension: content-type} pairs, where 'file-extension' is
    a string (e.g. "gif") and 'content-type' is the value to write
    out in the Content-Type response header (e.g. "image/gif").
    
    If 'index' is provided, it should be the (relative) name of a file to
    serve for directory requests. For example, if the dir argument is
    '/home/me', the Request-URI is 'myapp', and the index arg is
    'index.html', the file '/home/me/myapp/index.html' will be sought.
    """
    request = cherrypy.serving.request
    if request.method not in ('GET', 'HEAD'):
        if debug:
            cherrypy.log('request.method not GET or HEAD', 'TOOLS.STATICDIR')
        return False
    
    if match and not re.search(match, request.path_info):
        if debug:
            cherrypy.log('request.path_info %r does not match pattern %r' % 
                         (request.path_info, match), 'TOOLS.STATICDIR')
        return False
    
    # Allow the use of '~' to refer to a user's home directory.
    dir = os.path.expanduser(dir)

    # If dir is relative, make absolute using "root".
    if not os.path.isabs(dir):
        if not root:
            msg = "Static dir requires an absolute dir (or root)."
            if debug:
                cherrypy.log(msg, 'TOOLS.STATICDIR')
            raise ValueError(msg)
        dir = os.path.join(root, dir)
    
    # Determine where we are in the object tree relative to 'section'
    # (where the static tool was defined).
    if section == 'global':
        section = "/"
    section = section.rstrip(r"\/")
    branch = request.path_info[len(section) + 1:]
    branch = unquote(branch.lstrip(r"\/"))
    
    # If branch is "", filename will end in a slash
    filename = os.path.join(dir, branch)
    if debug:
        cherrypy.log('Checking file %r to fulfill %r' % 
                     (filename, request.path_info), 'TOOLS.STATICDIR')
    
    # There's a chance that the branch pulled from the URL might
    # have ".." or similar uplevel attacks in it. Check that the final
    # filename is a child of dir.
    if not os.path.normpath(filename).startswith(os.path.normpath(dir)):
        raise cherrypy.HTTPError(403) # Forbidden
    
    handled = _attempt(filename, content_types)
    if not handled:
        # Check for an index file if a folder was requested.
        if index:
            handled = _attempt(os.path.join(filename, index), content_types)
            if handled:
                request.is_index = filename[-1] in (r"\/")
    return handled

def staticfile(filename, root=None, match="", content_types=None, debug=False):
    """Serve a static resource from the given (root +) filename.
    
    If 'match' is given, request.path_info will be searched for the given
    regular expression before attempting to serve static content.
    
    If content_types is given, it should be a Python dictionary of
    {file-extension: content-type} pairs, where 'file-extension' is
    a string (e.g. "gif") and 'content-type' is the value to write
    out in the Content-Type response header (e.g. "image/gif").
    """
    request = cherrypy.serving.request
    if request.method not in ('GET', 'HEAD'):
        if debug:
            cherrypy.log('request.method not GET or HEAD', 'TOOLS.STATICFILE')
        return False
    
    if match and not re.search(match, request.path_info):
        if debug:
            cherrypy.log('request.path_info %r does not match pattern %r' % 
                         (request.path_info, match), 'TOOLS.STATICFILE')
        return False
    
    # If filename is relative, make absolute using "root".
    if not os.path.isabs(filename):
        if not root:
            msg = "Static tool requires an absolute filename (got '%s')." % filename
            if debug:
                cherrypy.log(msg, 'TOOLS.STATICFILE')
            raise ValueError(msg)
        filename = os.path.join(root, filename)
    
    return _attempt(filename, content_types, debug=debug)
