from flask import (request, render_template, redirect,
                   url_for, send_from_directory, send_file, g)
from .models import ModelForm, BondDeal, Counterparties
from sqlalchemy.exc import IntegrityError
from wtforms.fields import BooleanField
import pandas as pd
from pandas.tseries.offsets import BDay
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
import socket

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:
        hostname = socket.gethostname()
        if hostname == 'debian':
            q = g.queue = redis.Redis(unix_socket_path='/var/run/redis/redis.sock')
        elif hostname =='gomez':
            q = g.queue = redis.Redis(host='debian')
    return q

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

class BondForm(ModelForm):
    upload_globeop = BooleanField(label="Upload to globeop?")
    class Meta:
        model = BondDeal
        include_foreign_keys = True
        exclude = ['dealid', 'lastupdate', #we generate it with a trigger at the server level
                   'principal_payment', 'accrued_payment']

@app.route('/trades/<int:tradeid>', methods=['GET', 'POST'])
@app.route('/trades/', defaults={'tradeid': None}, methods=['GET', 'POST'])
def trade_manage(tradeid):
    trade = BondDeal.query.get(tradeid) if tradeid else BondDeal()
    if tradeid:
        bond_form = BondForm(obj = trade)
        old_ticket_name = trade.ticket
    else:
        bond_form = BondForm(trade_date =  pd.datetime.today().date(),
                             settle_date = pd.datetime.today().date() + 3 * BDay())
        #add extra empty fields
        bond_form.folder.choices = [(None, '')] + bond_form.folder.choices
        bond_form.buysell.choices = [(None, '')] + bond_form.buysell.choices
        bond_form.asset_class.choices = [(None, '')] + bond_form.asset_class.choices
    bond_form.cp_code.choices = bond_form.cp_code.choices + list(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 tradeid and 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 as e:
                app.logger.error(e)
            finally:
                if bond_form.upload_globeop.data:
                    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.desc(), BondDeal.id.desc())
    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)