#!/usr/bin/env python

# This is free and unencumbered software released into the public domain.

'''extract and process donation data from Whiteleaf logs.

This only accounts for donation done through the WL system.
'''

import sys
if sys.version_info < (3, 7):
    sys.exit("Python 3.7 or higher is required")

from typing import *

import argparse
from collections import defaultdict
from decimal import Decimal
from datetime import datetime as DateTime
from dataclasses import dataclass
import os
from pathlib import Path
import re
import shelve

# a sum in US dollars
Amount = Decimal

@dataclass(frozen=True)
class Donation:
    paypig: str
    date: DateTime

@dataclass(frozen=True)
class SimpleDonation(Donation):
    amount: Amount

@dataclass(frozen=True)
class Subscription(Donation):
    tier: int

    # reference: http://xanderhal.com/subscribe
    TIERS = {
            1: 5,
            2: 10,
            3: 20,
            4: 40,
    } 

    @property
    def amount(self) -> Amount:
        return Subscription.TIERS[self.tier]

@dataclass(frozen=True)
class GiftedSubscription(Subscription):
    victim: str


PATTERNS = [re.compile(r) for r in (
    r'\[(?P<date>.*?)\] Broadcast: (?P<paypig>\w+) has donated \$(?P<amount>.+?)!',
    r'\[(?P<date>.*?)\] Broadcast: (?P<paypig>\w+) got a Tier (?P<tier>\d)',
    r'\[(?P<date>.*?)\] Broadcast: (?P<paypig>\w+) gave (?P<victim>\w+) a Tier (?P<tier>\d)',
    )]

def parse_donations(lines: Iterable[str]) -> Iterable[Donation]:
    for line in lines:
        for pattern in PATTERNS:
            m = pattern.match(line)
            if m:
                break
        else:
            continue
        x = m.groupdict()
        date = DateTime.strptime(x['date'], '%Y-%m-%d %H:%M:%S %Z')
        if 'victim' in x:
            yield GiftedSubscription(
                    date=date,
                    paypig=x['paypig'],
                    tier=int(x['tier']),
                    victim=x['victim'],
                )
        elif 'tier' in x:
            yield Subscription(
                    date=date,
                    paypig=x['paypig'],
                    tier=int(x['tier']),
                )
        else:
            yield SimpleDonation(
                    date=date,
                    paypig=x['paypig'],
                    amount=Decimal(x['amount'].replace(',', '')),
                )

def all_source_files():
    return Path().glob('*.txt')

CACHE_FILE = Path('.cache.db')
def load_data() -> Dict[str, List[Donation]]:
    '''load all the parsed data, using the cache if possible'''
    with shelve.open(os.fspath(CACHE_FILE), protocol=4) as cache:
        fresh_time = CACHE_FILE.stat().st_mtime
        for f in all_source_files():
            if f.name not in cache or f.stat().st_mtime >= fresh_time:
                cache[f.name] = list(parse_donations(f.open()))
        data = {f.name: cache[f.name] for f in all_source_files()}
    return data

def grand(args):
    '''print grand total'''
    data = load_data()
    print(sum(d.amount for (f, ds) in data.items() for d in ds))

def files(args):
    '''print total per file'''
    data = load_data()
    for (f, ds) in sorted(data.items()):
        print(f, sum(d.amount for d in ds))

def paypigs(args):
    '''print total per paypig'''
    sums = defaultdict(Amount)
    data = load_data()
    for (f, ds) in data.items():
        for d in ds:
            sums[d.paypig] += d.amount
    for paypig, amount in sorted(sums.items(), key=lambda i: i[1]):
        print(paypig, amount)


top = argparse.ArgumentParser()
commands = top.add_subparsers()
argparser_grand = commands.add_parser("grand", help="compute grand total of donations")
argparser_grand.set_defaults(func=grand)
argparser_files = commands.add_parser("files", help="tabulate sum for each logfile")
argparser_files.set_defaults(func=files)
argparser_paypigs = commands.add_parser("paypigs", help="tabulate sum for each paypig")
argparser_paypigs.set_defaults(func=paypigs)

args = top.parse_args()
try:
    func = args.func
except AttributeError:
    top.print_help()
    sys.exit(2)
else:
    func(args)