# -*- coding: utf-8 -*-
# $Id: webutils.py 56762 2015-07-03 01:41:28Z vboxsync $

"""
Common Web Utility Functions.
"""

__copyright__ = \
"""
Copyright (C) 2012-2015 Oracle Corporation

This file is part of VirtualBox Open Source Edition (OSE), as
available from http://www.virtualbox.org. This file is free software;
you can redistribute it and/or modify it under the terms of the GNU
General Public License (GPL) as published by the Free Software
Foundation, in version 2 as it comes in the "COPYING" file of the
VirtualBox OSE distribution. VirtualBox OSE is distributed in the
hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.

The contents of this file may alternatively be used under the terms
of the Common Development and Distribution License Version 1.0
(CDDL) only, as it comes in the "COPYING.CDDL" file of the
VirtualBox OSE distribution, in which case the provisions of the
CDDL are applicable instead of those of the GPL.

You may elect to license modified versions of this file under the
terms and conditions of either the GPL or the CDDL or both.
"""
__version__ = "$Revision: 56762 $"

# Standard Python imports.
import os;
import shutil;
import sys;
import unittest;

# Validation Kit imports.
from common import utils;

# Python 3 hacks:
if sys.version_info[0] < 3:
    from urllib         import urlopen      as urllib_urlopen;
    from urllib2        import quote        as urllib_quote;
    from urllib         import urlencode    as urllib_urlencode;
else:
    from urllib.parse   import quote        as urllib_quote;        # pylint: disable=F0401,E0611
    from urllib.parse   import urlencode    as urllib_urlencode;    # pylint: disable=F0401,E0611
    from urllib.request import urlopen      as urllib_urlopen;      # pylint: disable=F0401,E0611


def escapeElem(sText):
    """
    Escapes special character to HTML-safe sequences.
    """
    sText = sText.replace('&', '&amp;')
    sText = sText.replace('<', '&lt;')
    return sText.replace('>', '&gt;')

def escapeAttr(sText):
    """
    Escapes special character to HTML-safe sequences.
    """
    sText = sText.replace('&', '&amp;')
    sText = sText.replace('<', '&lt;')
    sText = sText.replace('>', '&gt;')
    return sText.replace('"', '&quot;')

def escapeElemToStr(oObject):
    """
    Stringifies the object and hands it to escapeElem.
    """
    if utils.isString(oObject):
        return escapeElem(oObject);
    return escapeElem(str(oObject));

def escapeAttrToStr(oObject):
    """
    Stringifies the object and hands it to escapeAttr.  May return unicode string.
    """
    if utils.isString(oObject):
        return escapeAttr(oObject);
    return escapeAttr(str(oObject));

def escapeAttrJavaScriptStringDQ(sText):
    """ Escapes a javascript string that is to be emitted between double quotes. """
    if '"' not in sText:
        chMin = min(sText);
        if ord(chMin) >= 0x20:
            return sText;

    sRet = '';
    for ch in sText:
        if ch == '"':
            sRet += '\\"';
        elif ord(ch) >= 0x20:
            sRet += ch;
        elif ch == '\n':
            sRet += '\\n';
        elif ch == '\r':
            sRet += '\\r';
        elif ch == '\t':
            sRet += '\\t';
        else:
            sRet += '\\x%02x' % (ch,);
    return sRet;

def quoteUrl(sText):
    """
    See urllib.quote().
    """
    return urllib_quote(sText);

def encodeUrlParams(dParams):
    """
    See urllib.urlencode().
    """
    return urllib_urlencode(dParams, doseq=True)

def hasSchema(sUrl):
    """
    Checks if the URL has a schema (e.g. http://) or is file/server relative.
    Returns True if schema is present, False if not.
    """
    iColon = sUrl.find(':');
    if iColon > 0:
        sSchema = sUrl[0:iColon];
        if len(sSchema) >= 2 and len(sSchema) < 16 and sSchema.islower() and sSchema.isalpha():
            return True;
    return False;

def getFilename(sUrl):
    """
    Extracts the filename from the URL.
    """
    ## @TODO This isn't entirely correct. Use the urlparser instead!
    sFilename = os.path.basename(sUrl.replace('/', os.path.sep));
    return sFilename;


def downloadFile(sUrlFile, sDstFile, sLocalPrefix, fnLog, fnError = None, fNoProxies=True):
    """
    Downloads the given file if an URL is given, otherwise assume it's
    something on the build share and copy it from there.

    Raises no exceptions, returns log + success indicator instead.

    Note! This method may use proxies configured on the system and the
          http_proxy, ftp_proxy, no_proxy environment variables.

    @todo Fixed build burn here. Please set default value for fNoProxies
          to appropriate one.
    """
    if fnError is None:
        fnError = fnLog;

    if  sUrlFile.startswith('http://') \
     or sUrlFile.startswith('https://') \
     or sUrlFile.startswith('ftp://'):
        # Download the file.
        fnLog('Downloading "%s" to "%s"...' % (sUrlFile, sDstFile));
        try:
            ## @todo We get 404.html content instead of exceptions here, which is confusing and should be addressed.
            if fNoProxies:
                oSrc = urllib_urlopen(sUrlFile);
            else:
                oSrc = urllib_urlopen(sUrlFile, proxies = dict());
            oDst = utils.openNoInherit(sDstFile, 'wb');
            oDst.write(oSrc.read());
            oDst.close();
            oSrc.close();
        except Exception, oXcpt:
            fnError('Error downloading "%s" to "%s": %s' % (sUrlFile, sDstFile, oXcpt));
            return False;
    else:
        # Assumes file from the build share.
        sSrcPath = os.path.join(sLocalPrefix, sUrlFile);
        fnLog('Copying "%s" to "%s"...' % (sSrcPath, sDstFile));
        try:
            shutil.copyfile(sSrcPath, sDstFile);
        except Exception, oXcpt:
            fnError('Error copying "%s" to "%s": %s' % (sSrcPath, sDstFile, oXcpt));
            return False;

    return True;



#
# Unit testing.
#

# pylint: disable=C0111
class CommonUtilsTestCase(unittest.TestCase):
    def testHasSchema(self):
        self.assertTrue(hasSchema('http://www.oracle.com/'));
        self.assertTrue(hasSchema('https://virtualbox.com/'));
        self.assertFalse(hasSchema('://virtualbox.com/'));
        self.assertFalse(hasSchema('/usr/bin'));
        self.assertFalse(hasSchema('usr/bin'));
        self.assertFalse(hasSchema('bin'));
        self.assertFalse(hasSchema('C:\\WINNT'));

if __name__ == '__main__':
    unittest.main();
    # not reached.