from decimal import Decimal

from aspen import Response, log
from aspen.utils import to_age
from gittip import db, AMOUNTS
from gittip.utils import get_participant


class Paydays(object):

    def __init__(self, username, balance):
        self._username = username
        self._paydays = list(db.fetchall("SELECT ts_start, ts_end FROM paydays "
                                         "ORDER BY ts_end DESC"))
        self._npaydays = len(self._paydays)
        self._exchanges = list(db.fetchall( "SELECT * FROM exchanges "
                                            "WHERE participant=%s "
                                            "ORDER BY timestamp ASC"
                                          , (username,)
                                           ))
        self._transfers = list(db.fetchall( "SELECT * FROM transfers "
                                            "WHERE tipper=%s OR tippee=%s "
                                            "ORDER BY timestamp ASC"
                                          , (username, username)
                                          ))
        self._balance = balance


    def __iter__(self):
        """Yield iterators of events.

        Each payday is expected to encompass 0 or 1 exchanges and 0 or more
        transfers per participant. Here we knit them together along with start
        and end events for each payday. If we have exchanges or transfers that
        fall outside of a payday, then we have a logic bug. I am 50% confident
        that this will manifest some day.

        """
        _i = 1
        for payday in self._paydays:

            if not (self._exchanges or self._transfers):
                # Show all paydays since the user started really participating.
                break

            payday_start = { 'event': 'payday-start'
                           , 'timestamp': payday['ts_start']
                           , 'number': self._npaydays - _i
                           , 'balance': Decimal('0.00')
                            }
            payday_end = { 'event': 'payday-end'
                         , 'timestamp': payday['ts_end']
                         , 'number': self._npaydays - _i
                          }
            received = { 'event': 'received'
                       , 'amount': Decimal('0.00')
                       , 'n': 0
                        }
            _i += 1


            events = []
            while (self._exchanges or self._transfers):

                # Take the next event, either an exchange or transfer.
                # ====================================================
                # We do this by peeking at both lists, and popping the list
                # that has the next event.

                exchange = self._exchanges[-1] if self._exchanges else None
                transfer = self._transfers[-1] if self._transfers else None

                if exchange is None:
                    event = self._transfers.pop()
                elif transfer is None:
                    event = self._exchanges.pop()
                elif transfer['timestamp'] > exchange['timestamp']:
                    event = self._transfers.pop()
                else:
                    event = self._exchanges.pop()

                if 'fee' in event:
                    if event['amount'] > 0:
                        event['event'] = 'charge'
                    else:
                        event['event'] = 'credit'
                else:
                    event['event'] = 'transfer'


                # Record the next event.
                # ======================

                if event['timestamp'] < payday_start['timestamp']:
                    if event['event'] == 'exchange':
                        back_on = self._exchanges
                    else:
                        back_on = self._transfers
                    back_on.append(event)
                    break

                if event['event'] == 'transfer':
                    if event['tippee'] == self._username:

                        # Don't leak details about who tipped you. Only show
                        # aggregates for that.

                        received['amount'] += event['amount']
                        received['n'] += 1

                        #continue  # Don't leak!

                events.append(event)

            if not events:
                continue


            # Calculate balance.
            # ==================

            prev = events[0]
            prev['balance'] = self._balance
            for event in events[1:] + [payday_start]:
                if prev['event'] == 'charge':
                    balance = prev['balance'] - prev['amount']
                elif prev['event'] == 'credit':
                    balance = prev['balance'] - prev['amount'] + prev['fee']
                elif prev['event'] == 'transfer':
                    if prev['tippee'] == self._username:
                        balance = prev['balance'] - prev['amount']
                    else:
                        balance = prev['balance'] + prev['amount']
                event['balance'] = balance
                prev = event
            self._balance = payday_start['balance']

            yield payday_start
            for event in reversed(events):
                yield event
            yield payday_end

        # This should catch that logic bug.
        if self._exchanges or self._transfers:
            log("These should be empty:", self._exchanges, self._transfers)
            raise "Logic bug in payday timestamping."

# ========================================================================== ^L

participant = get_participant(request, restrict=True)
paydays = Paydays(participant.username, participant.balance)
hero = "History"
title = "%s - %s" % (participant.username, hero)
locked = False

# ========================================================================== ^L
{% extends templates/profile.html %}
{% block page %}

<table id="history" class="centered">
    <tr><td colspan="7">
        <h2>{{ participant.username == user.username and "You" or participant.username }} joined
        {{ to_age(participant.claimed_time) }}.</h2>
    </td></tr>
    <tr><td colspan="7">

        <h2>{{ participant.username == user.username and "Your" or "Their" }} balance is
            ${{ participant.balance }}.</h2>
        {% if user.ADMIN %}
        <h2>Record an Exchange.</h2>
        <form style="text-align: left;" action="record-an-exchange"
            method="POST">
            <input name="csrf_token" type="hidden" value="{{ csrf_token }}" />
            <input name="amount" placeholder="amount" />
            <input name="fee" placeholder="fee" />
            <br />
            <input name="note" placeholder="note" style="width: 230px" />
            <button type="submit">Submit</button>
        </form>
        {% end %}
    </td></tr>
    {% for event in paydays %}
    {% if event['event'] == 'payday-start' %}
    <tr>
        <th colspan="7"><h2>Gittip #{{ event['number'] }}
            &mdash;{{ event['timestamp'].strftime("%B %d, %Y").replace(' 0', ' ') }}
                ({{ to_age(event['timestamp']) }})</h2></th>
    </tr>
    <tr class="head">
        <td colspan="3" class="outside">&larr; Outside</td>
        <td colspan="4" class="inside">Inside Gittip &rarr;</td>
    </tr>
    <tr class="head">
        <td class="bank">Bank</td>
        <td class="card">Card</td>
        <td class="fees">Fees</td>
        <td class="credits">Credits</td>
        <td class="debits">Debits</td>
        <td class="balance">Balance</td>
        <td class="notes">Notes</td>
    </tr>
    <tr>
        <td class="bank"></td>
        <td class="card"></td>
        <td class="fees"></td>
        <td class="credits"></td>
        <td class="debits"></td>
        <td class="balance">{{ event['balance'] }}</td>
        <td class="notes"></td>
    </tr>
    {% elif event['event'] == 'balance' %}
    <tr>
        <td class="bank"></td>
        <td class="card"></td>
        <td class="fees"></td>
        <td class="credits"></td>
        <td class="debits"></td>
        <td class="balance">{{ event['balance'] }}</td>
        <td class="notes"></td>
    </tr>
    {% elif event['event'] == 'credit' %}
    <tr>
        <td class="bank">{{ -event['amount'] }}</td>
        <td class="card"></td>
        <td class="fees">{{ event['fee'] }}</td>
        <td class="credits"></td>
        <td class="debits">{{ -event['amount'] + event['fee'] }}</td>
        <td class="balance">{{ event['balance'] }}</td>
        {% if event['recorder'] is None %}
        <td class="notes">automatic withdrawal</td>
        {% else %}
        <td class="notes">
            &ldquo;{{ escape(event['note']) }}&rdquo;&mdash;<a
            href="/{{ event['recorder'] }}/">{{ event['recorder'] }}</a>
        </td>
        {% end %}
    </tr>
    {% elif event['event'] == 'charge' %}
    <tr>
        <td class="bank"></td>
        <td class="card">{{ event['amount'] + event['fee'] }}</td>
        <td class="fees">{{ event['fee'] }}</td>
        <td class="credits">{{ event['amount'] }}</td>
        <td class="debits"></td>
        <td class="balance">{{ event['balance'] }}</td>
        {% if event['recorder'] is None %}
        <td class="notes">automatic charge</td>
        {% else %}
        <td class="notes">
            &ldquo;{{ escape(event['note']) }}&rdquo;&mdash;<a
            href="/{{ event['recorder'] }}/">{{ event['recorder'] }}</a>
        </td>
        {% end %}
    </tr>
    {% elif event['event'] == 'transfer' %}
    <tr>
        <td class="bank"></td>
        <td class="card"></td>
        <td class="fees"></td>

        {% if event['tippee'] == participant.username %}
        <td class="credits">{{ event['amount'] }}</td>
        <td class="debits"></td>
        {% else %}
        <td class="credits"></td>
        <td class="debits">{{ event['amount'] }}</td>
        {% end %}

        <td class="balance">{{ event['balance'] }}</td>

        {% if event['tippee'] == participant.username %}
            {% if user.ADMIN and (participant.username != user.username or 'override' in qs) %}
            <td class="notes">from <a href="/{{ event['tipper'] }}/history/">{{ event['tipper'] }}</a></td>
            {% else %}
            <td class="notes">from someone</td>
            {% end %}
        {% else %}
            {% if user.ADMIN %}
            <td class="notes">to
                <a href="/{{ event['tippee'] }}/history/">{{ event['tippee'] }}</a></td>
            {% else %}
            <td class="notes">to
                <a href="/{{ event['tippee'] }}/">{{ event['tippee'] }}</a></td>
            {% end %}
        {% end %}

    </tr>
    {% end %}
{% end %}
</table>

{% end %}