#   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 ..database import db_session
from ..webapp import app
from .models import StatementLine, StatementLinePosting, StatementLineTransaction

@app.route('/statement-lines')
def statement_lines():
	return render_template('statement_lines.html', statement_lines=StatementLine.query.all())

@app.route('/statement-lines/charge', methods=['POST'])
def statement_line_charge():
	statement_line = db_session.get(StatementLine, request.form['line-id'])
	if not statement_line:
		abort(404)
	
	# Delete existing postings
	if len(statement_line.postings) > 0:
		for posting in statement_line.postings:
			if len(posting.transaction.postings) > 2:
				# Complex posting
				raise Exception('Cannot automatically delete a StatementLineTransaction with >2 postings')
			
			# Queue for deletion
			db_session.delete(posting.transaction)
	
	transaction = StatementLineTransaction(
		dt=statement_line.dt,
		description=statement_line.description,
		postings=[
			StatementLinePosting(statement_line=statement_line, account=statement_line.source_account, quantity=statement_line.quantity, commodity=statement_line.commodity),
			StatementLinePosting(account=request.form['charge-account'], quantity=-statement_line.quantity, commodity=statement_line.commodity)
		]
	)
	
	db_session.add(transaction)
	db_session.commit()
	
	return 'OK'

@app.route('/statement-lines/edit-transaction', methods=['GET', 'POST'])
def statement_line_edit_transaction():
	statement_line = db_session.get(StatementLine, request.args['line-id'])
	if not statement_line:
		abort(404)
	
	if request.method == 'GET':
		# FIXME: Show existing transaction details
		return render_template('statement_line_edit_transaction.html', statement_line=statement_line)
	
	# Delete existing postings
	if len(statement_line.postings) > 0:
		for posting in statement_line.postings:
			if len(posting.transaction.postings) > 2:
				# Complex posting
				raise Exception('Cannot automatically delete a StatementLineTransaction with >2 postings')
			
			# Queue for deletion
			db_session.delete(posting.transaction)
	
	transaction = StatementLineTransaction(
		dt=statement_line.dt,
		description=request.form['description'],
		postings=[
			StatementLinePosting(statement_line=statement_line, account=statement_line.source_account, quantity=statement_line.quantity, commodity=statement_line.commodity),
			StatementLinePosting(account=request.form['charge-account'], quantity=-statement_line.quantity, commodity=statement_line.commodity)
		]
	)
	
	db_session.add(transaction)
	db_session.commit()
	
	return redirect('/statement-lines')