# -*- test-case-name: mv3d.test.util.test_patch -*-
# Copyright (C) 2010-2012 Mortal Coil Games
# See LICENSE for details.
"""
Automated patching for MV3D clients.

@author:  mike


"""

from ConfigParser import ConfigParser
from urlparse import urlparse
import httplib
import os
import zipfile
import sys
try:
    from cStringIO import StringIO
except ImportError:
    from StringIO import StringIO
from hashlib import sha1


class Patcher(object):
    """
    Handles patching MV3D up to date. Use *before* other modules are loaded.
    """
    def __init__(self):
        self.patches = ConfigParser()
        self.loadedFiles = []
        self.baseDir = os.path.abspath(os.path.expanduser("~/.mv3d/test"))


    def _getPage(self, url):
        """
        Download a single url and return the data
        """
        urlChunks = urlparse(url)
        _scheme, host, path, _parameters, _query, _fragment = urlChunks
        connection = httplib.HTTPConnection(host, 80)
        connection.connect()
        connection.request("GET", path)
        response = connection.getresponse()
        if response.status < 200 or response.status > 299:
            raise ValueError("Bad http response: %d" % response.status)
        data = response.read()
        connection.close()
        return data


    def downloadPatchFile(self, url):
        """
        Downloads a patch file.
        """
        data = self._getPage(url)
        self.patches.readfp(StringIO(data))
        self.loadedFiles.append(url)


    def gatherDependencyList(self):
        """
        Check the dependencies of the patch files loaded and gather patch files
        from dependents.
        """
        missingPatchFiles = True
        while missingPatchFiles:
            deps = []
            for section in self.patches.sections():
                if self.patches.has_option(section, "Dependencies"):
                    deps.extend(self.patches.get(section, "Dependencies").split(
                        ","))
            missingPatchFiles = False
            for dep in deps[:]:
                if not dep in self.loadedFiles and dep:
                    self.downloadPatchFile(dep)
                    deps.remove(dep)
                    missingPatchFiles = True


    def checkCRC(self, localFile, crc):
        """
        Check the CRC of a file against the one specified
        """
        fil = open(localFile, "rb")
        hash = sha1()
        count = 0
        while True:
            count += 1
            data = fil.read(2 ** 20)
            if not data:
                break
            hash.update(data)
        fil.close()
        if hash.hexdigest() == crc:
            return True
        return False


    def getMissingFiles(self):
        """
        Figure out what files are missing.
        """
        self.gatherDependencyList()
        files = {}
        for section in self.patches.sections():
            if self.patches.has_option(section, "Download"):
                download = dict(url=self.patches.get(section, "Download"))
                download["localfile"] = os.path.join(self.baseDir,
                    download["url"].split("/")[-1])
                if os.path.exists(download["localfile"]):
                    if self.patches.has_option(section, "CRC"):
                        download["CRC"] = self.patches.get(section, "CRC")
                        download["needed"] = not self.checkCRC(
                            download["localfile"], download["CRC"])
                    else:
                        download["needed"] = False
                else:
                    download["needed"] = True
                if self.patches.has_option(section, "Unzip"):
                    download["unzip"] = self.patches.getboolean(section,
                        "Unzip")
                else:
                    download["unzip"] = True
                if not download["needed"] and not download["unzip"]:
                    sys.path.append(download["localfile"])
                files[section] = download
        return [(section, file)
            for section, file in files.items() if file["needed"]]


    def download(self):
        """
        Calculate current dependencies and download everything.
        """
        if not os.path.exists(self.baseDir):
            os.makedirs(self.baseDir)
        files = self.getMissingFiles()
        for _section, file in files:
            data = self._getPage(file["url"])
            fil = open(file["localfile"], "wb")
            fil.write(data)
            fil.close()
            if file["unzip"]:
                sio = StringIO(data)
                zippy = zipfile.ZipFile(sio, "r")
                try:
                    zippy.extractall(self.baseDir)
                except AttributeError: #extractall = 2.6
                    #http://stackoverflow.com/questions/1774434/download-a-zip-file-to-a-local-drive-and-extract-all-files-to-a-destination-folde
                    for n in zippy.namelist():
                        dest = os.path.join(self.baseDir, n)
                        destdir = os.path.dirname(dest)
                        if not os.path.isdir(destdir):
                            os.makedirs(destdir)
                        data = zippy.read(n)
                        f = open(dest, 'wb')
                        f.write(data)
                        f.close()
                zippy.close()
            else:
                sys.path.append(file["localfile"])



    def run(self):
        """
        Find which section has the ExecFunction attribute and exec it.
        """
        results = []
        sys.path.insert(0, self.baseDir)
        os.chdir(self.baseDir)
        try:
            # TODO: this is probably never going to work.
            reactorName = base.appRunner.getToken("reactor")
        except:
            reactorName = "wx"
        if reactorName == "wx":
            from twisted.internet import wxreactor
            wxreactor.install()
        else:
            from twisted.internet import selectreactor
            selectreactor.install()
        for section in self.patches.sections():
            if self.patches.has_option(section, "ExecFunction"):
                fullPath = self.patches.get(section, "ExecFunction")
                fname = fullPath.split(".")[-1]
                mname = ".".join(fullPath.split(".")[:-1])
                mod = __import__(mname, fromlist=[fname])
                func = getattr(mod, fname)
                if self.patches.has_option(section, "ExecArgs"):
                    args = self.patches.get(section, "ExecArgs").split(",")
                else:
                    args = []
                results.append(func(*args))
        return results