#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from __future__ import annotations
from typing import Iterator, Dict, Any, Tuple, TextIO, List
import re
import datetime
import csv

RE_INT = re.compile(r'-?[0-9]+')
RE_FLOAT = re.compile(r'-?[0-9]+\.[0-9]+')
RE_STR_START = re.compile(r'.*,"[^"]*$')
RE_STR_END = re.compile(r'^[^"]*",.*')


def cast_value(value: str) -> Any:
    if value == '':
        return None
    elif value[0] == '"' and value[-1] == '"':
        return value[1:-1]
    elif value == 'T':
        return True
    elif value == 'F':
        return False
    elif RE_INT.fullmatch(value):
        return int(value)
    elif RE_FLOAT.fullmatch(value):
        return float(value)
    elif len(value) == 10 and value[4] == '-' and value[7] == '-':
        return datetime.datetime.strptime(value, '%Y-%m-%d').date()
    elif len(value) == 8 and value[2] == ':' and value[5] == ':':
        return datetime.time.fromisoformat(value)
    else:
        raise RuntimeError(f'unable to infer type of value "{value}"')


def convert_value(value: Any, table: str = None, column: str = None) -> str:
    if value is None:
        return ''
    if type(value) == str:
        return '"' + value.replace('"', '""') + '"'
    elif type(value) == bool:
        return 'T' if value else 'F'
    elif type(value) == datetime.datetime and table is not None and column is not None:
        if value.year == 1899 and value.month == 12 and value.day == 30:
            return value.strftime('%H:%M:%S')
        elif value.hour == 0 and value.minute == 0 and value.second == 0:
            return value.strftime('%Y-%m-%d')
    return str(value)


class CsvFile:
    file: TextIO
    reader: csv.reader
    writer: csv.writer

    def __init__(self, file: TextIO):
        self.file = file
        self.writer = csv.writer(self.file, doublequote=False, quoting=csv.QUOTE_NONE, escapechar='\\', quotechar=None)
        self.reader = csv.reader(self.file, doublequote=False, quoting=csv.QUOTE_NONE, escapechar='\\', quotechar=None)

    def __enter__(self) -> CsvFile:
        return self

    def __exit__(self, exc_type, exc_val, exc_tb) -> None:
        return self.file.__exit__(exc_type, exc_val, exc_tb)

    def __iter__(self) -> Iterator[List[str]]:
        return self.reader.__iter__()

    def row(self, *fields, raw: bool = False):
        if not raw:
            fields = (convert_value(field) for field in fields)
        self.writer.writerow(fields)

    def header(self, *headers):
        self.writer.writerow(str(h) for h in headers)


def csv_open(filename: str, mode: str = 'w+') -> CsvFile:
    return CsvFile(open(filename, mode, encoding='utf-8', newline=''))


def csv_parse(filename: str) -> Iterator[Tuple]:
    with csv_open(filename, 'r') as f:
        rows = f.__iter__()
        yield tuple([field.strip() for field in next(rows)])
        yield from (tuple(cast_value(field) for field in row) for row in rows)


def csv_parse_dict(filename: str) -> Iterator[Dict[str, Any]]:
    rows = csv_parse(filename)
    header = next(rows)
    return ({header[i]: part for i, part in enumerate(row)} for row in rows)