#helper/csv_mapper

import csv
import requests
from io import StringIO
#
from typing import List, Dict, Any
import os
from dotenv import load_dotenv
#
import pandas as pd
import math


load_dotenv()


class Settings:
    """configuration"""
    CSV_DOWNLOAD_TIMEOUT = int(os.getenv('CSV_DOWNLOAD_TIMEOUT', 30))
    CSV_MAX_SIZE_MB = int(os.getenv('CSV_MAX_SIZE_MB', 10))

settings = Settings()


def _find_header_row(self, rows, delimiter):
        """ Search row with RFC an name"""

        for idx, row in enumerate(rows):
            #Normalice: Convert to String, clean space, mayus
            clean_row = [str(cell).strip().upper() for cell in row]

            has_rfc = any('RFC' in cell for cell in clean_row)
            has_nombre =any('NOMBRE' in cell for cell in clean_row)

            if has_rfc and has_nombre:
                return idx
        return None


class CSVExtractor:
    """Extract raw data of CSV"""

    @staticmethod
    def download_csv(url: str) -> str:
        """ Download CSV of URL"""
        try: 

            response = requests.get(url, timeout=30)
            response.raise_for_status()

            encoding = response.encoding or 'utf-8'
            content = response.text
            return content, encoding
        except Exception as e:
            raise Exception(f"Error Download CSV: {str(e)}")
        
    
    @staticmethod
    def read_csv(content):
        """ Converts CSV to list of dictionary"""
        for delimiter in[',', ';', '\t']:

            try: 
                lines = content.split('\n')

                header_row_idx = None
                for idx, line in enumerate(lines):
                    if 'RFC' in line.upper():
                        header_row_idx = idx
                        break
                
                if header_row_idx is None:
                    continue

                df = pd.read_csv(
                    StringIO(content),
                    delimiter=delimiter,
                    encoding='utf-8', 
                    skiprows=header_row_idx,
                    dtype=str,
                    keep_default_na=False,
                    na_filter=False)

                df.columns = df.columns.str.strip()

                df = df.dropna(how='all')
                result = df.to_dict('records')
                if result:
                    return result

            except Exception as e:
                print(f"Error with delimiter '{delimiter}': {e}")
                continue
        raise ValueError("Don't read CSV with pandas")