import streamlit as st
import pandas as pd
import plotly.express as px

# Set the page layout for Streamlit
st.set_page_config(layout="wide")

# Title and Introduction
st.title("Data Visualization App")
st.markdown(""" 
    This app allows you to upload a table (CSV or Excel) and ask for graphs to visualize the data.
    Based on your question, the app will generate interactive graphs using **Plotly**.

    ### Available Features:
    - **Graph of a column**: Visualize a column as a graph.
    - **Scatter plot**: Visualize relationships between two columns.
    
    Upload your data and ask questions to generate visualizations.
""")

# File uploader in the sidebar
file_name = st.sidebar.file_uploader("Upload file:", type=['csv', 'xlsx'])

# File processing and question answering
if file_name is None:
    st.markdown('<p class="font">Please upload an excel or csv file </p>', unsafe_allow_html=True)
else:
    try:
        # Check file type and handle reading accordingly
        if file_name.name.endswith('.csv'):
            df = pd.read_csv(file_name, sep=';', encoding='ISO-8859-1')  # Adjust encoding if needed
        elif file_name.name.endswith('.xlsx'):
            df = pd.read_excel(file_name, engine='openpyxl')  # Use openpyxl to read .xlsx files
        else:
            st.error("Unsupported file type")
            df = None

        if df is not None:
            numeric_columns = df.select_dtypes(include=['object']).columns
            for col in numeric_columns:
                df[col] = pd.to_numeric(df[col], errors='ignore')

            st.write("Original Data:")
            st.write(df)

            df_numeric = df.copy()
            df = df.astype(str)

            # Display the first 5 rows of the dataframe in an editable grid
            st.write("Sample data for graph generation:")
            st.write(df.head())

    except Exception as e:
        st.error(f"Error reading file: {str(e)}")

    # User input for the graph query
    question = st.text_input('Ask your graph-related question')

    with st.spinner():
        if st.button('Generate Graph'):
            try:
                if 'between' in question.lower() and 'and' in question.lower():
                    # Handle scatter plot (graph between two columns)
                    columns = question.split('between')[-1].split('and')
                    columns = [col.strip() for col in columns]
                    if len(columns) == 2 and all(col in df.columns for col in columns):
                        fig = px.scatter(df, x=columns[0], y=columns[1], title=f"Scatter Plot between {columns[0]} and {columns[1]}")
                        st.plotly_chart(fig, use_container_width=True)
                        st.success(f"Here is the scatter plot between '{columns[0]}' and '{columns[1]}'.")
                    else:
                        st.warning("Columns not found in the dataset.")
                elif 'column' in question.lower():
                    # Handle graph of a single column
                    column = question.split('of')[-1].strip()
                    if column in df.columns:
                        fig = px.line(df, x=df.index, y=column, title=f"Graph of column '{column}'")
                        st.plotly_chart(fig, use_container_width=True)
                        st.success(f"Here is the graph of column '{column}'.")
                    else:
                        st.warning(f"Column '{column}' not found in the data.")
                else:
                    st.warning("Please ask a valid graph-related question (e.g., 'make a graph between column1 and column2').")

            except Exception as e:
                st.warning(f"Error processing question or generating graph: {str(e)}")