from flask import (request, render_template, redirect,
                   url_for, send_from_directory, send_file, g)
from .models import ModelForm, BondDeal, Counterparties
from sqlalchemy import create_engine
from sqlalchemy.exc import IntegrityError
import pandas as pd
import os
import datetime
import redis
from .utils import load_counterparties, load_trades, add_triggers, bump_rev, simple_serialize
from PyPDF2 import PdfFileMerger
from io import BytesIO
from Dawn import app

def cp_choices():
    return Counterparties.query.order_by('name').\
        with_entities(Counterparties.code, Counterparties.name)

def get_queue():
    q = getattr(g, 'queue', None)
    if q is None:
        q = g.queue = redis.Redis(host='debian')
    return q

class CounterpartyForm(ModelForm):
    class Meta:
        model = Counterparties

class BondForm(ModelForm):
    class Meta:
        model = BondDeal
        include_foreign_keys = True
        exclude = ['dealid', 'lastupdate'] #we generate it with a trigger at the server level

@app.route('/trades/<int:tradeid>', methods=['GET', 'POST'])
@app.route('/trades/', defaults={'tradeid': None}, methods=['GET', 'POST'])
def trade_manage(tradeid):
    if tradeid:
        trade = BondDeal.query.get(tradeid)
        bond_form = BondForm(obj = BondDeal.query.get(tradeid))
        #we change the default to update
        bond_form.action.choices = [('UPDATE', 'UPDATE'), ('CANCEL', 'CANCEL')]
        old_ticket_name = trade.ticket
    else:
        trade = BondDeal()
        bond_form = BondForm()
    bond_form.cp_code.choices = cp_choices()
    if bond_form.is_submitted():
        if bond_form.validate():
            bond_form.populate_obj(trade)
            session = bond_form.get_session()
            ticket_file = trade.ticket
            trade.ticket = None
            if not tradeid:
                session.add(trade)
            if ticket_file.filename == '':
                if tradeid:
                    trade.ticket = old_ticket_name
            else:
                if old_ticket_name:
                    trade.ticket = bump_rev(old_ticket_name)
                else:
                    trade.ticket = "{0} {1}.pdf".format(str(trade.trade_date),
                                                        trade.description)
                ticket_file.save(os.path.join(app.config['TICKETS_FOLDER'],
                                              trade.ticket))
            try:
                session.commit()
            except IntegrityError:
                print("TODO: fix this")
            finally:
                q = get_queue()
                q.rpush('trades', simple_serialize(trade))
            return redirect(url_for('list_trades'))
        else:
            return str(bond_form.errors)
    return render_template('trade_entry.html', form=bond_form, trade_id=tradeid)

@app.route('/blotter/')
def list_trades():
    trade_list = BondDeal.query.order_by(BondDeal.trade_date, BondDeal.id)
    return render_template('blotter.html', trades=trade_list.all())

@app.route('/tickets/<int:tradeid>')
def download_ticket(tradeid):
    trade = BondDeal.query.get(tradeid)
    pdf = PdfFileMerger()
    pdf.append(os.path.join(app.config['TICKETS_FOLDER'], trade.ticket))
    pdf.append(os.path.join(app.config['CP_FOLDER'], trade.counterparty.instructions))
    fh = BytesIO()
    pdf.write(fh)
    pdf.close()
    fh.seek(0)
    return send_file(fh, mimetype='application/pdf')

@app.route('/counterparties/<path:instr>', methods=['GET'])
@app.route('/counterparties/', defaults={'instr': None}, methods=['GET'])
def list_counterparties(instr):
    if instr:
        return send_from_directory(filename = instr,
                                   directory = app.config['CP_FOLDER'],
                                   mimetype='application/pdf')
    else:
        cp_list = Counterparties.query.order_by(Counterparties.name)
        return render_template('counterparties.html', counterparties = cp_list.all())

@app.route('/edit_cp/<cpcode>', methods=['GET', 'POST'])
def edit_counterparty(cpcode):
    cp = Counterparties.query.get(cpcode)
    cp_form = CounterpartyForm(obj = cp)
    old_instructions = cp.instructions
    if cp_form.is_submitted():
        if cp_form.validate():
            cp_form.populate_obj(cp)
            session = cp_form.get_session()
            instructions = cp.instructions
            if instructions.filename == '':
                cp.instructions = old_instructions
            else:
                cp.instructions = cp.name + '.pdf'
                instructions.save(os.path.join(app.config['CP_FOLDER'],
                                               cp.instructions))
            session.commit()
            return redirect(url_for('list_counterparties'))
    return render_template('edit_cp.html', form=cp_form, code=cpcode)