#   DrCr: Web-based double-entry bookkeeping framework
#   Copyright (C) 2022  Lee Yingtong Li (RunasSudo)
#
#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU Affero General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU Affero General Public License for more details.
#
#   You should have received a copy of the GNU Affero General Public License
#   along with this program.  If not, see <https://www.gnu.org/licenses/>.

from flask import abort, redirect, render_template, request

from .. import AMOUNT_DPS
from ..database import db_session
from ..models import TrialBalancer
from ..webapp import all_transactions, app
from .models import BalanceAssertion, GeneralJournalPosting, GeneralJournalTransaction

from datetime import datetime

@app.route('/general-journal')
def general_journal():
	return render_template('general_journal/general_journal.html', transactions=sorted(GeneralJournalTransaction.query.all(), key=lambda t: t.dt))

@app.route('/general-journal/new', methods=['GET', 'POST'])
def general_journal_new():
	if request.method == 'GET':
		return render_template('general_journal/general_journal_edit.html', transaction=None)
	
	# New transaction
	transaction = GeneralJournalTransaction(
		dt=datetime.strptime(request.form['dt'], '%Y-%m-%d'),
		description=request.form['description'],
		postings=[]
	)
	
	for account, sign, amount in zip(request.form.getlist('account'), request.form.getlist('sign'), request.form.getlist('amount')):
		quantity = round(float(amount) * (10**AMOUNT_DPS))
		if sign == 'cr':
			quantity = -quantity
		
		posting = GeneralJournalPosting(
			account=account,
			quantity=quantity,
			commodity='$'  # TODO: Commodities
		)
		transaction.postings.append(posting)
	
	transaction.assert_valid()
	
	db_session.add(transaction)
	db_session.commit()
	
	return redirect('/general-journal')

@app.route('/balance-assertions')
def balance_assertions():
	assertions = BalanceAssertion.query.all()
	
	# Check assertion status
	transactions = all_transactions()
	assertion_status = {}
	for assertion in assertions:
		# FIXME: This is very inefficient
		balancer = TrialBalancer()
		balancer.apply_transactions([t for t in transactions if t.dt <= assertion.dt])
		
		# TODO: Commodities
		if balancer.accounts[assertion.account].quantity == assertion.quantity:
			assertion_status[assertion] = True
		else:
			assertion_status[assertion] = False
	
	return render_template('general_journal/balance_assertions.html', assertions=assertions, assertion_status=assertion_status)

@app.route('/balance-assertions/new', methods=['GET', 'POST'])
def balance_assertions_new():
	if request.method == 'GET':
		return render_template('general_journal/balance_assertions_edit.html', assertion=None)
	
	quantity = round(float(request.form['amount']) * (10**AMOUNT_DPS))
	if request.form['sign'] == 'cr':
		quantity = -quantity
	
	# New balance assertion
	assertion = BalanceAssertion(
		dt=datetime.strptime(request.form['dt'], '%Y-%m-%d'),
		description=request.form['description'],
		account=request.form['account'],
		quantity=quantity,
		commodity='$'
	)
	db_session.add(assertion)
	db_session.commit()
	
	return redirect('/balance-assertions')

@app.route('/balance-assertions/edit', methods=['GET', 'POST'])
def balance_assertions_edit():
	assertion = db_session.get(BalanceAssertion, request.args['id'])
	if not assertion:
		abort(404)
	
	if request.method == 'GET':
		return render_template('general_journal/balance_assertions_edit.html', assertion=assertion)
	
	quantity = round(float(request.form['amount']) * (10**AMOUNT_DPS))
	if request.form['sign'] == 'cr':
		quantity = -quantity
	
	# Edit balance assertion
	assertion.dt = datetime.strptime(request.form['dt'], '%Y-%m-%d')
	assertion.description = request.form['description']
	assertion.account = request.form['account']
	assertion.quantity = quantity
	
	db_session.commit()
	
	return redirect('/balance-assertions')