import io
import os
from base64 import b64encode

import frappe
from frappe import _
from frappe.utils.data import add_to_date, get_time, getdate
from pyqrcode import create as qr_create

from erpnext import get_region


def create_qr_code(doc, method):
	"""Create QR Code after inserting Sales Inv
	"""

	region = get_region(doc.company)
	if region not in ['Saudi Arabia']:
		return

	# if QR Code field not present, do nothing
	if not hasattr(doc, 'qr_code'):
		return

	# Don't create QR Code if it already exists
	qr_code = doc.get("qr_code")
	if qr_code and frappe.db.exists({"doctype": "File", "file_url": qr_code}):
		return

	meta = frappe.get_meta('Sales Invoice')

	for field in meta.get_image_fields():
		if field.fieldname == 'qr_code':
			''' TLV conversion for
			1. Seller's Name
			2. VAT Number
			3. Time Stamp
			4. Invoice Amount
			5. VAT Amount
			'''
			tlv_array = []
			# Sellers Name

			'''TODO: Fix arabic conversion'''
			# seller_name = frappe.db.get_value(
			# 	'Company',
			# 	doc.company,
			# 	'company_name_in_arabic')

			# if not seller_name:
			# 	frappe.throw(_('Arabic name missing for {} in the company document'.format(doc.company)))

			seller_name = doc.company
			tag = bytes([1]).hex()
			length = bytes([len(seller_name)]).hex()
			value = seller_name.encode('utf-8').hex()
			tlv_array.append(''.join([tag, length, value]))

			# VAT Number
			tax_id = frappe.db.get_value('Company', doc.company, 'tax_id')
			if not tax_id:
				frappe.throw(_('Tax ID missing for {} in the company document'.format(doc.company)))

			tag = bytes([2]).hex()
			length = bytes([len(tax_id)]).hex()
			value = tax_id.encode('utf-8').hex()
			tlv_array.append(''.join([tag, length, value]))

			# Time Stamp
			posting_date = getdate(doc.posting_date)
			time = get_time(doc.posting_time)
			seconds = time.hour * 60 * 60 + time.minute * 60 + time.second
			time_stamp = add_to_date(posting_date, seconds=seconds)
			time_stamp = time_stamp.strftime('%Y-%m-%dT%H:%M:%SZ')

			tag = bytes([3]).hex()
			length = bytes([len(time_stamp)]).hex()
			value = time_stamp.encode('utf-8').hex()
			tlv_array.append(''.join([tag, length, value]))

			# Invoice Amount
			invoice_amount = str(doc.total)
			tag = bytes([4]).hex()
			length = bytes([len(invoice_amount)]).hex()
			value = invoice_amount.encode('utf-8').hex()
			tlv_array.append(''.join([tag, length, value]))

			# VAT Amount
			vat_amount = str(doc.total_taxes_and_charges)

			tag = bytes([5]).hex()
			length = bytes([len(vat_amount)]).hex()
			value = vat_amount.encode('utf-8').hex()
			tlv_array.append(''.join([tag, length, value]))

			# Joining bytes into one
			tlv_buff = ''.join(tlv_array)

			# base64 conversion for QR Code
			base64_string = b64encode(bytes.fromhex(tlv_buff)).decode()

			qr_image = io.BytesIO()
			url = qr_create(base64_string, error='L')
			url.png(qr_image, scale=2, quiet_zone=1)

			# making file
			filename = f"QR-CODE-{doc.name}.png".replace(os.path.sep, "__")
			_file = frappe.get_doc({
				"doctype": "File",
				"file_name": filename,
				"is_private": 0,
				"content": qr_image.getvalue(),
				"attached_to_doctype": doc.get("doctype"),
				"attached_to_name": doc.get("name"),
				"attached_to_field": "qr_code"
			})

			_file.save()

			# assigning to document
			doc.db_set('qr_code', _file.file_url)
			doc.notify_update()

			break


def delete_qr_code_file(doc, method):
	"""Delete QR Code on deleted sales invoice"""

	region = get_region(doc.company)
	if region not in ['Saudi Arabia']:
		return

	if hasattr(doc, 'qr_code'):
		if doc.get('qr_code'):
			file_doc = frappe.get_list('File', {
				'file_url': doc.get('qr_code')
			})
			if len(file_doc):
				frappe.delete_doc('File', file_doc[0].name)

def delete_vat_settings_for_company(doc, method):
	if doc.country != 'Saudi Arabia':
		return

	settings_doc = frappe.get_doc('KSA VAT Setting', {'company': doc.name})
	settings_doc.delete()