#!/usr/bin/env python3

from collections import Counter, defaultdict
import csv
from dataclasses import dataclass
from datetime import datetime, timedelta
from pathlib import Path
import re
from sys import argv
from urllib.parse import urlparse
from typing import Dict, List, Tuple
from warnings import warn

import user_agents


ACCESS_RE = re.compile(' '.join((
    r'(?P<address>\S+)',
    r'\S+',
    r'\S+',
    r'(?P<date>\[\S+ \S+\])',
    r'"GET (?P<resource>[^ ?]+)(\?\S+)? [^"]+"',
    r'200 [0-9]+',
    r'"(?P<referer>[^"]+)(\?\S+)?"',
    r'"(?P<useragent>[^"]+)"'
)))

DATE_FMT = '[%d/%b/%Y:%H:%M:%S %z]'

VISIT_MAX_DURATION = timedelta(hours=1)

DOMAINS = {
    'quatuorbellefeuille.com',
    'quatuorbellefeuille.fr',
    'klg.uber.space'
}


def normalize_path(p):
    if p == '/':
        return '/index.html'
    return p


@dataclass
class Access:
    address: str
    useragent: str
    referrer: str
    time: datetime
    resource: str

    @classmethod
    def from_log(cls, info):
        resource = normalize_path(info['resource'])

        referrer = urlparse(info['referer'])
        if referrer.netloc in DOMAINS:
            ref = normalize_path(referrer.path)
        else:
            ref = referrer.netloc

        return cls(
            info['address'], info['useragent'], ref,
            datetime.strptime(info['date'], DATE_FMT), resource
        )


def interesting(resource):
    return resource.endswith('.html') or resource == '/'


def parse(logs_paths):
    logs = []
    for lp in logs_paths:
        with open(lp) as logs_file:
            logs += logs_file.read().splitlines()

    matches = (ACCESS_RE.match(l) for l in logs)
    return tuple(
        Access.from_log(m) for m in matches
        if (m is not None and interesting(m['resource']))
    )


Visit = List[Access]


@dataclass
class Visitor:
    address: str
    useragent: str
    referrers: List[str]
    visits: List[Visit]


def useragent_kind(ua_string):
    ua = user_agents.parse(ua_string)
    if ua.is_pc:
        return 'pc'
    if ua.is_mobile:
        return 'mobile'
    if ua.is_tablet:
        return 'tablet'
    if ua.is_bot:
        return 'bot'
    warn(f'Unknown user agent kind: {ua_string}')
    return 'n/a'


def sort_visits(accesses):
    visitors: Dict[Tuple(str, str), Visitor] = {}

    for a in accesses:
        key = (a.address, a.useragent)

        visitor = visitors.get(key)
        if visitor is None:
            visitor = Visitor(
                a.address,
                useragent_kind(a.useragent),
                a.referrer,
                [[a]]
            )
            visitors[key] = visitor
            continue

        last_visit = visitor.visits[-1]
        last_access = last_visit[-1].time
        if a.time - last_access < VISIT_MAX_DURATION:
            last_visit.append(a)
            continue

        visitor.visits.append([a])

    return visitors


def find_days(visits):
    return {
        v[0].time.replace(hour=0, minute=0, second=0)
        for v in visits
    }


def daily_visitors(visitors, output_path):
    days: Dict[datetime, Counter] = defaultdict(Counter)
    columns = ('mobile', 'tablet', 'pc', 'bot', 'n/a')

    print('Visitors:')

    for v in visitors.values():
        for day in find_days(v.visits):
            days[day][v.useragent] += 1

    with open(output_path, 'w') as f:
        out = csv.writer(f)
        out.writerow(('day', 'total', *columns))
        print('day', 'total', *columns, sep='\t')

        for day in sorted(days):
            counter = days[day]
            counters = tuple(counter[c] for c in columns)
            values = (day.strftime('%F'), sum(counters), *counters)

            out.writerow(values)
            print(*values, sep='\t')


def daily_stats(visitors, output_dir):
    output_dir = Path(output_dir)
    daily_visitors(visitors, output_dir.joinpath('dailyvisitors.csv'))
    # daily_visits(visitors, output_dir.joinpath('dailyvisits.csv'))
    # daily_pages_per_visit(visitors, output_dir.joinpath('dailypagespervisit.csv'))
    # daily_page_hits(visitors, output_dir.joinpath('dailypagehits.csv'))
    # daily_referrers(visitors, output_dir.joinpath('dailyreferrers.csv'))


def global_stats(visitors, output_dir):
    pass


def main(logs_paths, output_dir):
    accesses = parse(logs_paths)
    visitors = sort_visits(accesses)
    daily_stats(visitors, output_dir)
    global_stats(visitors, output_dir)


if __name__ == '__main__':
    main(argv[1:-1], argv[-1])