import pandas as pd
import numpy as np
from fuson_plm.utils.logging import log_update

def clean_rows_and_cols(df: pd.Series) -> pd.Series:
    """
    Deletes empty rows and columns
    
    Args:
        df (pd.Series): input DatFrame to be cleaned 
        
    Returns:
        pd.Series: cleaned DataFrame
    """
    # Delete rows with no data
    log_update(f"\trow cleaning...\n\t\toriginal # rows: {len(df)}")
    log_update("\t\tdropping rows where all entries are np.nan...")
    df = df.dropna(how='all')
    log_update(f"\t\tnew # rows: {len(df)}")

    # Delete columns with no data
    log_update(f"\tcolumn cleaning...\n\t\toriginal # columns: {len(df.columns)}")
    log_update("\t\tdropping columns where all entries are np.nan...")
    df = df.dropna(axis=1,how='all')
    log_update(f"\t\tnew # columns: {len(df.columns)}")
    log_update(f"\t\tcolumn names: {','.join(list(df.columns))}")

    return df

def check_columns_for_listlike(df: pd.DataFrame, cols_of_interest: list, delimiters: set):
    """
    Checks if a column contains any listlike items
    
    Args:
        df (pd.DataFrame): DataFrame to be investigated
        cols_of_interest (list): columns in df to be investigated for list-containing potential
        delimiters (set): set of potential delimiting strings to search for. A column with any of these strings is considered listlike.
    
    Returns:
        dict: dictionary containing a set {} of all delimiters found in each column
            e.g., { 'col1': {',',';'},
                    'col2': {'|'}   }
    """
    # return the delimiters/listlike things found for each column
    return_dict = {}

    log_update("\tchecking if any of our columns of interest look listlike (contain list objects or delimiters)...")
    for col in cols_of_interest:
        unique_col = list(df[col].value_counts().index)
        listlike = any([check_item_for_listlike(x, delimiters) for x in unique_col])

        if listlike:
            found_delims = df[col].apply(lambda x: check_item_for_listlike(x, delimiters)).value_counts().reset_index()['index'].to_list()
            unique_found_delims = set()
            for x in found_delims:
                unique_found_delims = unique_found_delims.union(x)

            return_dict[col] = unique_found_delims
        else:
            return_dict[col] = False
        
        # display the return dict
        log_update(f"\t\tcolumn name: {col}\tlistlike: {return_dict[col]}")
    
    return return_dict

def check_item_for_listlike(x, delimiters: set):
    """
    Checks if a column looks like it contains a list of items, rather than an inidvidual item, based on string delimiters.

    Args:
        x: the item to check. Any dtype. 
        delimiters: a set of delimiters to check for. e.g., {',', ';', '|', '\t', ' ', ':', '-', '/', '\\', '\n'}

    Returns:
        If x is a string: the set (may be empty) of delimiters contained in the string
        If x is not a string: the dtype of x 
    """
    if isinstance(x, str):
        return find_delimiters(x, delimiters)
    else:
        if x is None:
            # if it's None, it's not listlike, it's just empty. return {} because it has no delimiters. 
            return {}
        if type(x)==float:
            # if it's nan, it's not listlike, it's just empty. return {} because it has no delimiters. 
            if np.isnan(x):
                return {}
        return type(x)

def find_delimiters(seq: str, delimiters: set) -> set:
    """
    Find and return a set of delimiters in a sequence. Helper mtehod for check_item_for_listlike.

    Args:
        seq (str): The sequence you wish to search for invalid characters.
        delimiters (set): a set of delimiters to check for. e.g., {',', ';', '|', '\t', ' ', ':', '-', '/', '\\', '\n'}

    Returns:
        set: A set of characters in the sequence that are not in the set of valid characters.
    """
    unique_chars = set(seq) # set of all characters in the sequence; unique_chars = {A, C} for protein="AAACCC"
    overlap = delimiters.intersection(unique_chars)

    if len(overlap)==0:
        return {}
    else:
        return overlap

def find_invalid_chars(seq: str, valid_chars: set) -> set:
    """
    Find and return a set of invalid characters in a sequence.

    Args:
        seq (str): The sequence you wish to search for invalid characters.
        valid_chars (set): A set of valid characters.

    Returns:
        set: A set of characters in the sequence that are not in the set of valid characters.
    """
    unique_chars = set(seq) # set of all characters in the sequence; unique_chars = {A, C} for protein="AAACCC"

    if unique_chars.issubset(valid_chars):  # e.g. unique_chars = {A,C}, and {A,C} is a subset of valid_chars
        return ''
    else: # e.g. unique_chars = {A,X}. {A,X} is not a subset of valid_chars because X is not in valid_chars
        return unique_chars.difference(valid_chars) # e.g. {A,X} - valid_chars = {X}