# -*- coding: utf-8 -*-
# !/usr/bin/env python

"""
用于测量性能的中间件
"""
# Original version taken from http://www.djangosnippets.org/snippets/186/
# Original author: udfalkso
# Modified by: Shwagroo Team and Gun.io


import sys
import os
import re
import hotshot, hotshot.stats
import tempfile
from six import StringIO

from django.conf import settings

words_re = re.compile(r'\s+')

group_prefix_re = [
    re.compile("^.*/django/[^/]+"),
    re.compile("^(.*)/[^/]+$"),  # extract module path
    re.compile(".*"),  # catch strange entries
]


class ProfileMiddleware(object):
    """
    Displays hotshot profiling for any view.
    http://yoursite.com/yourview/?prof
    Add the "prof" key to query string by appending ?prof (or &prof=)
    and you'll see the profiling results in your browser.
    It's set up to only be available in django's debug mode, is available for superuser otherwise,
    but you really shouldn't add this middleware to any production configuration.
    WARNING: It uses hotshot profiler which is not thread safe.
    """

    def process_request(self, request):
        if settings.DEBUG and 'prof' in request.GET:
            self.tmpfile = tempfile.mktemp()
            self.prof = hotshot.Profile(self.tmpfile)

    def process_view(self, request, callback, callback_args, callback_kwargs):
        if settings.DEBUG and 'prof' in request.GET:
            return self.prof.runcall(callback, request, *callback_args, **callback_kwargs)

    def get_group(self, file_):
        for g in group_prefix_re:
            name = g.findall(file_)
            if name:
                return name[0]

    def get_summary(self, results_dict, total):
        list_ = [(item[1], item[0]) for item in results_dict.items()]
        list_.sort(reverse = True)
        list_ = list_[:40]

        res = "      tottime\n"
        for item in list_:
            res += "%4.1f%% %7.3f %s\n" % (100 * item[0] / total if total else 0, item[0], item[1])

        return res

    def summary_for_files(self, stats_str):
        stats_str = stats_str.split("\n")[5:]

        stats = {}
        groups = {}

        total = 0

        for s in stats_str:
            fields = words_re.split(s)
            if len(fields) == 7:
                time = float(fields[2])
                total += time
                file_ = fields[6].split(":")[0]

                if not file_ in stats:
                    stats[file_] = 0
                stats[file_] += time

                group = self.get_group(file_)
                if not group in groups:
                    groups[group] = 0
                groups[group] += time

        return "<pre>" + \
               " ---- By file ----\n\n" + self.get_summary(stats, total) + "\n" + \
               " ---- By group ---\n\n" + self.get_summary(groups, total) + \
               "</pre>"

    def process_response(self, request, response):
        if settings.DEBUG and 'prof' in request.GET:
            self.prof.close()

            out = StringIO()
            old_stdout = sys.stdout
            sys.stdout = out

            stats = hotshot.stats.load(self.tmpfile)
            stats.sort_stats('time', 'calls')
            stats.print_stats()

            sys.stdout = old_stdout
            stats_str = out.getvalue()

            if response and response.content and stats_str:
                response.content = "<pre>" + stats_str + "</pre>"

            response.content = "\n".join(response.content.split("\n")[:40])

            response.content += self.summary_for_files(stats_str)

            os.unlink(self.tmpfile)

        return response