#!/bin/env python3

from typing import List, Tuple
import argparse
import requests
import re
import xlrd
import tempfile


URL = 'https://www.post.at/g/c/postlexikon'
BUTTON = re.compile(r'title="PLZ Bestimmungsort" href="(.*?)"')


def get_excel_url() -> str:
    r = requests.get(URL, headers={'User-Agent': 'Mozilla/5.0'})
    if r.status_code != 200:
        raise RuntimeError(f'Unexpected response: {r.status_code} {r.reason}')

    matches = BUTTON.findall(r.text)
    if len(matches) == 0:
        raise RuntimeError('Unable to find url of file')

    return matches[0]


def download_excel() -> List[Tuple[int, str, int, str, int, str]]:
    with tempfile.NamedTemporaryFile() as f:
        with requests.get(get_excel_url(), stream=True) as r:
            if r.status_code != 200:
                raise RuntimeError(f'Unexpected response: {r.status_code} {r.reason}')
            for chunk in r.iter_content(chunk_size=8192):
                f.write(chunk)

        rows = []
        wb = xlrd.open_workbook(f.name)
        sheet = wb.sheet_by_index(0)
        for r in range(1, sheet.nrows):
            row = sheet.row_values(r)
            rows.append((int(row[0]), row[1], int(row[2]), row[3], int(row[4]), row[5]))
        return rows


def write_sql(data: List[Tuple[int, str, int, str, int, str]]) -> None:
    gemeinden = {gkz: name for _, _, _, _, gkz, name in data}
    orte = {okz: (name, gkz) for _, _, okz, name, gkz, _ in data}

    with open('plz.sql', 'wb') as f:
        f.write(b'\n')

        f.write(b"INSERT INTO AT_gemeinde VALUES\n")
        for gem_nr, gem_name in gemeinden.items():
            f.write(f"({gem_nr}, {gem_nr // 10000}, '{gem_name}'),\n".encode('utf8'))
        f.seek(-2, 1)
        f.write(b';\n\n')

        f.write(b"INSERT INTO AT_ort VALUES\n")
        for okz, (name, gkz) in orte.items():
            f.write(f"({okz:5}, {gkz}, '{name}'),\n".encode('utf8'))
        f.seek(-2, 1)
        f.write(b';\n\n')

        f.write(b"INSERT INTO AT_plz VALUES\n")
        for plz, dest, okz, _, _, _ in data:
            f.write(f"({plz}, {okz:5}, {100000 * plz + okz}, '{dest}'),\n".encode('utf8'))
        f.seek(-2, 1)
        f.write(b';\n\n')


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    args = parser.parse_args()
    write_sql(download_excel())