from __future__ import with_statement
import calendar
import collections
import datetime
import functools
import itertools
import locale
import math
import operator
import psycopg2
import sys
import time

locale.setlocale(locale.LC_ALL, "")

Nickset = None
SlowReqThreshold = 1000
DefaultTimeBucket = datetime.timedelta(minutes=5)
ConnStr = "dbname=dumpfm user=postgres password=root"

def fetch_nicks():
    try:
        print "fetching user nicknames from db"
        conn = psycopg2.connect(ConnStr)
        cur = conn.cursor()
        cur.execute("select nick from users")
        return set(n for (n,) in cur.fetchall())
    except Exception, e:
        print "Error fetching user nicknames: %s" % e
        print "Profile urls will be incorrectly classified as 'Other'"
        return set()

def comma_format(i):
    return locale.format('%d', i, True)

def format_unit(val, units, factors):
    for unit, factor in zip(units, factors):
        if factor in (0, 1):
            return "%s%s" % (val, unit)
        elif val >= factor:
            return "%0.2f%s" % (float(val) / factor, unit)
    raise ValueError('Cannot format %s with any of %s' % (val, unit))

def format_time(t):
    return t.strftime('%Y/%m/%d %H:%M')

def format_ms(ms):
    return format_unit(ms, ['m', 's', 'ms'], [60 * 1000, 1000, 0])

def format_bytes(bytes):
    return format_unit(bytes,
                       ['GB', 'MB', 'KB', 'B'],
                       [1024 ** i for i in range(3, -1, -1)])

def median(pool):
    copy = sorted(pool)
    size = len(copy)
    if size % 2 == 1:
        return copy[(size - 1) / 2]
    else:
        return (copy[size/2 - 1] + copy[size/2]) / 2

def mean(pool):
    return sum(pool) / len(pool)
    

def percentile(N, percent, key=lambda x:x):
    """
    From http://code.activestate.com/recipes/511478-finding-the-percentile-of-the-values/
    Find the percentile of a list of values.

    @parameter N - is a list of values. Note N MUST BE already sorted.
    @parameter percent - a float value from 0.0 to 1.0.
    @parameter key - optional key function to compute value from each element of N.

    @return - the percentile of the values
    """
    if not N:
        return None
    k = (len(N)-1) * percent
    f = math.floor(k)
    c = math.ceil(k)
    if f == c:
        return key(N[int(k)])
    d0 = key(N[int(f)]) * (k-f)
    d1 = key(N[int(c)]) * (c-k)
    return d0+d1

def ninety_percentile(N):
    return percentile(N, .9)

def gather_by_key(rs, key):
    d = collections.defaultdict(list)
    for r in rs:
        group = r[key]
        d[group].append(r)
    return d

def group_by_time_interval(xs, interval, timekey):
    if len(xs) == 0:
        raise ValueError("Cannot group empty list")
    start = xs[0][timekey]
    end = xs[-1][timekey]
    interval_seconds = int(interval.seconds)
    span = int((end - start).seconds) / interval_seconds + 1
    res = [[] for i in range(span)]
    
    for x in xs:
        idx = int((x[timekey] - start).seconds) / interval_seconds
        res[idx].append(x)
    return res

def get_report_title(entries):
    start_time = entries[0]['ts']
    end_time = entries[-1]['ts']
    return "Dump Report: " + format_time(start_time) + " to " + format_time(end_time)

def build_js_array(start_time, interval, values):
    pairs = []
    for i, val in enumerate(values):
        t = start_time + interval * i
        unix_time = calendar.timegm(t.timetuple()) * 1000
        pairs.append('[%s, %s]' % (unix_time, val))
    return '[%s]' % ','.join(pairs)

SlowReportCount = 10
IpReportCount = 10

class ConsoleWriter(object):
            
    def section(self, label):
        print "\n----- %s -----" % label
    
    def paragraph(self, text):
        print text

    def list(self, entries):
        for e in entries:
            print "- %s" % e

    def table(self, headers, data):
        for row in data:
            label = row[0]
            if label:
                print "\n%s:" % label
            for h, d in zip(headers, row[1:]):
                print "  - %s: %s" % (h, d)

    def graph(self, *args, **kwds):
        pass

    def close(self):
        pass

HtmlTemplate = """
<html>
<head>
<title>%s</title>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript" src="http://dump.fm/static/js/jquery.flot.js"></script>
<style>
table {
    margin: 0;
    cellpadding: 1px;
}

th { text-align: left; }

tr:hover { background-color: #AFF; }

</style>
</head>
<body>%s</body>
</html>
"""

JqueryTemplate = """
$(function () {
    $.plot($("#%s"),
           [ { data: %s, label: "%s" } ],
           { xaxis: { mode: 'time' },
             yaxis: { min: 0 },
             legend: { position: 'sw' } });
});

"""

class HtmlWriter(object):
    
    def __init__(self, path, title):
        self.path = path
        self.title = title
        self.content = ""
        
    def section(self, label):
        self.content += "<h2>%s</h2>\n" % label

    def paragraph(self, text):
        self.content += "<p>%s</p>\n" % text

    def list(self, entries):
        self.content += "<ul>\n"
        for e in entries:
            self.content += "<li>%s</li>\n" % e
        self.content += "</ul>\n"

    def table(self, headers, data):
        self.content += "<table><tr><th></th>"
        for h in headers:
            self.content += "<th>%s</th>" % h
        self.content += "</tr>\n"
        for row in data:
            self.content += "<tr>"
            
            for i, val in enumerate(row):
                if i == 0:
                    self.content += "<th>%s</th>" % val
                else:
                    self.content += "<td>%s</td>" % val
            self.content += "</tr>\n"
        self.content += "</table>\n"

    def graph(self, label, graph_id, data):
        self.content += '<div id="%s" style="width: 100%%; height: 350px;"></div>' % graph_id
        js_array = "var %s = %s;" % (graph_id, data)
        graph_command = JqueryTemplate % (graph_id, graph_id, label)
        self.content += '<script>%s\n%s</script>' % (js_array, graph_command)
        
    def _assemble(self):
        return HtmlTemplate % (self.title or 'Untitled', self.content)

    def close(self):
        print "writing report to %s" % self.path
        text = self._assemble()
        with open(self.path, 'w') as f:
            f.write(text)
        

class Report(object):

    def __init__(self, writer, good, bad):
        self.writer = writer
        self.good = good
        self.bad = bad
        self.count = len(good)
        self.start = self.good[0]['ts']
        self.end = self.good[-1]['ts']
    
    def output_group_stats(self):
        self.writer.section('URL group stats')
        grouped = gather_by_key(self.good, 'urlgroup')

        headers = ['#', 'min', 'median', 'mean', '90%', 'max', '# slow', 'bytes sent', 'bytes/req']
        data = []

        for url_group in sorted(grouped.keys()):
            vals = sorted(r['time'] for r in grouped[url_group])
            slow_count = sum(1 for v in vals if v > SlowReqThreshold)
            bytes_sent = sum(r['total_bytes'] for r in grouped[url_group])
            data.append([url_group,
                         comma_format(len(vals)),
                         format_ms(min(vals)),
                         format_ms(median(vals)),
                         format_ms(mean(vals)),
                         format_ms(ninety_percentile(vals)),
                         format_ms(max(vals)),
                         slow_count,
                         format_bytes(bytes_sent),
                         format_bytes(bytes_sent / len(vals))])
        self.writer.table(headers, data)
        
    def output_activity_graphs(self, interval=DefaultTimeBucket):
        self.writer.section('Activity Rates')
        buckets = group_by_time_interval(self.good, interval, 'ts')

        def second_avg(count): return float(count) / interval.seconds
        
        def avg_bucket_rate(bs, cond):
            return [second_avg(sum(1 for r in b if cond(r))) for b in bs]

        reqs_per_sec = avg_bucket_rate(buckets, lambda r: True)
        images_per_sec = avg_bucket_rate(buckets, lambda r: r['urlgroup'] in ('Images', 'Avatars'))
        dumps_per_sec = avg_bucket_rate(buckets, lambda r: r['urlgroup'] in ('Post', 'Upload'))
        chat_users_per_sec = avg_bucket_rate(buckets, lambda r: r['urlgroup'] == 'ChatUpdate')


        self.writer.graph('Reqs / sec', 'reqs_per_sec',
                          build_js_array(self.start, interval, reqs_per_sec))
        self.writer.graph('Images / sec', 'images_per_sec',
                          build_js_array(self.start, interval, images_per_sec))
        self.writer.graph('Dumps / sec', 'dumps_per_sec',
                          build_js_array(self.start, interval, dumps_per_sec))
        self.writer.graph('Chat users / sec', 'chat_users_per_sec',
                          build_js_array(self.start, interval, chat_users_per_sec))

        self.writer.section('Response Time')
        
        def calc_bucket_resp_time(bs, func):
            return [func([r['time'] for r in b]) for b in bs]

        mean_resp_time = calc_bucket_resp_time(buckets, mean)
        median_resp_time = calc_bucket_resp_time(buckets, median)
        ninety_pct_time = calc_bucket_resp_time(buckets, ninety_percentile)
        max_resp_time = calc_bucket_resp_time(buckets, max)

        self.writer.graph('Mean response time (ms)', 'mean_resp_time',
                          build_js_array(self.start, interval, mean_resp_time))
        self.writer.graph('Median response time (ms)', 'median_per_sec',
                          build_js_array(self.start, interval, median_resp_time))
        self.writer.graph('90% response time (ms)', 'ninety_pct_time',
                          build_js_array(self.start, interval, ninety_pct_time))
        self.writer.graph('Max response time (ms)', 'max_resp_time',
                          build_js_array(self.start, interval, max_resp_time))
                          

    def output_slow_requests(self):
        self.writer.section('Slow URLs')
        slow = sorted((r for r in self.good if r['time'] > SlowReqThreshold),
                      key=lambda r: r['time'] * -1)
        entries = []
        for r in slow[:SlowReportCount]:
            e = "%s: %s, %s sent" % (r['url'],
                                     format_ms(r['time']),
                                     format_bytes(r['total_bytes']))
            entries.append(e)
        self.writer.list(entries)

    def output_unclassified_urls(self):
        unclassified = set(g['url'] for g in self.good if g['urlgroup'] == 'Other')
        unclassified_str = ', '.join(sorted(unclassified)[:100])
        if len(unclassified) > 100:
            unclassified_str += '...'
        self.writer.section('Unclassified URLs (%s)' % len(unclassified))
        self.writer.paragraph(unclassified_str)

    def output_ip_usage(self):
        grouped = gather_by_key(self.good, 'addr')
        sum_bytes = lambda reqs: sum(r['total_bytes'] for r in reqs)
        addr_bytes_gen = reversed(sorted((sum_bytes(reqs), addr) for addr, reqs in grouped.iteritems()))
        self.writer.section('Heaviest Users by IP')
        
        l = []
        for count, addr in itertools.islice(addr_bytes_gen, IpReportCount):
            bytes = sum(r['total_bytes'] for r in grouped[addr])
            l.append("%s: %s reqs, %s sent" % (addr,
                                               comma_format(count),
                                               format_bytes(bytes)))
        self.writer.list(l)

    def output_report(self):
        l = ["Interval: %s EST to %s EST (%s)" % (format_time(self.start),
                                          format_time(self.end),
                                          self.end - self.start),
             "%s Total Requests (%.02f r/s)" \
                 % (comma_format(self.count), self.count / (self.end - self.start).seconds),
             "Bytes sent %s" % format_bytes(sum(r['total_bytes'] for r in self.good))]
        self.writer.section('Overview')
        self.writer.list(l)
        self.output_activity_graphs()
        self.output_group_stats()
        self.output_slow_requests()
        self.output_ip_usage()
        self.output_unclassified_urls()


def parse_time(s):
    # Parse times such as 02/Jul/2010:22:21:25 -0400
    return datetime.datetime.strptime(s[:17], '%d/%b/%Y:%H:%M')
    
InfoUrls = ['/about_us', '/privacy', '/help', '/search', '/privacy', '/terms', '/hall',
            '/register', '/reset-request']
StaticUrls = ['/favicon.ico', '/robots.txt', '/']

def _classify_profile_url(url, nickset):
    if url.startswith('/u/'):
        url = url[2:]
    comps = url.split('/')
    comps.remove('')
    if len(comps) == 0 or comps[0] not in nickset:
        return None
    else:
        if len(comps) == 1:
            return 'Profile'
        elif comps[1] == 'popular':
            return 'Popular'
        elif comps[1] == 'favorites':
            return 'Favorites'
        elif comps[1] == 'log':
            return 'Log'
        else:
            return 'Profile'

def classify_url(method, url):
    profile_classification = _classify_profile_url(url, Nickset)
    if profile_classification:
        return profile_classification
    elif url.startswith('/avatars/'):
        return 'Avatars'
    elif url.startswith('/refresh'):
        return 'ChatUpdate'
    elif url.startswith('/chat') or url.startswith('/browser'):
        return 'ChatLoad'
    elif url.startswith('/json/') and url.endswith('/favorites'):
        return 'JsonFavs'
    elif url.startswith('/log'):
        return 'RoomLog'
    elif url.startswith('/login') or url.startswith('/logout'):
        return 'Login'
    elif url in InfoUrls or url.startswith('/m/') or url.startswith('/directory'):
        return 'InfoPages'
    elif url == '/msg':
        return 'Post'
    elif url == '/submit-registration':
        return 'Register'
    elif url.startswith('/cmd/ghettosearch/'):
        return 'Search'
    elif url.startswith('/static/') or url in StaticUrls:
        return 'Static'
    elif url.startswith('/images/'):
        return 'Images'
    elif url == '/cmd/tag/add':
        return 'TagAdd'
    elif url == '/cmd/tag/rm':
        return 'TagRemove'
    elif url == '/upload/message':
        return 'Upload'
    elif url.startswith('/p/'):
        return 'ViewDump'
    else:
        return 'Other'

def parse_ms(ms):
    return int(float(ms) * 1000)

def parse_request(s):
    method, url, httpversion = s.split(' ')
    url_group = classify_url(method, url)
    return {'method': method,
            'httpversion': httpversion,
            'urlgroup': url_group,
            'url': url }

def parse_status(s):
    code = int(s)
    # This works because statuses are parsed after urls.
    if code == 302:
        return {'code': 302, 'urlgroup': 'Redirect'}
    elif code == 404:
        return {'code': 404, 'urlgroup': '404'}
    elif code >= 500:
        return {'code': code, 'urlgroup': 'Error'}
    else:
        return code

LineFormat = [('addr', str),
              ('ts', parse_time),
              ('request', parse_request),
              ('pipe', str),
              ('status', parse_status),
              ('time', parse_ms),
              ('total_bytes', int),
              ('body_bytes', int),
              ('refer', str),
              ('agent', str)]

def parse_line(l):
    comps = [c.strip() for c in l.split('|')]
    if len(comps) != len(LineFormat):
        raise ValueError("Invalid number of log components (%s instead of %s): %s"
                         % (len(comps), len(LineFormat), l))
    r = {}
    for (label, f), v in zip(LineFormat, comps):
        try:
            res = f(v)
            if isinstance(res, dict):
                r.update(res)
            else:
                r[label] = f(v)
        except Exception, e:
            return "Unable to convert %s field '%s': %s (%s)" % (label, v, e, l.strip())
    return r

def parse_log(path):
    print 'reading %s' % path
    lines = [parse_line(l) for l in open(path, 'r')]
    good_lines = [l for l in lines if isinstance(l, dict)]
    bad_lines = [l for l in lines if not isinstance(l, dict)]
    return good_lines, bad_lines


if __name__ == "__main__":
    if len(sys.argv) < 1:
        print "usage: logreport.py logfile [outfile]"
        sys.exit(1)
    logpath = sys.argv[1]
    outpath = sys.argv[2] if len(sys.argv) > 2 else None        

    Nickset = fetch_nicks()
    good_lines, bad_lines = parse_log(logpath)
    if len(good_lines) == 0:
        print "Log file is empty or cannot be read!"
        sys.exit(1)

    if outpath:
        report_title = get_report_title(good_lines)
        writer = HtmlWriter(outpath, report_title)
    else:
        writer = ConsoleWriter()

    report = Report(writer, good_lines, bad_lines)
    report.output_report()
    writer.close()