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

# Title of the App
st.title("Excel Graph Visualizer")

# File Upload Section
uploaded_file = st.file_uploader("Upload your Excel file", type=["xlsx", "xls"])

if uploaded_file:
    # Read Excel file
    try:
        df = pd.read_excel(uploaded_file)
        st.write("Data Preview:")
        st.dataframe(df)

        # Dropdown for selecting graph type
        graph_type = st.selectbox(
            "Select Graph Type",
            ["Clustered Column", "Line Chart", "Single Axis", "Double Axis"]
        )

        # Dropdowns for selecting columns for x and y axes
        x_axis = st.selectbox("Select X-axis column", df.columns)
        y_axis = st.multiselect("Select Y-axis column(s)", df.columns)

        # Generate Graph based on selection
        if graph_type == "Clustered Column" and len(y_axis) > 0:
            fig = px.bar(df, x=x_axis, y=y_axis, barmode="group")
            st.plotly_chart(fig)
        
        elif graph_type == "Line Chart" and len(y_axis) > 0:
            fig = px.line(df, x=x_axis, y=y_axis)
            st.plotly_chart(fig)

        elif graph_type == "Single Axis" and len(y_axis) == 1:
            fig = px.line(df, x=x_axis, y=y_axis[0])
            st.plotly_chart(fig)

        elif graph_type == "Double Axis" and len(y_axis) == 2:
            fig = go.Figure()
            fig.add_trace(go.Scatter(x=df[x_axis], y=df[y_axis[0]], mode='lines', name=y_axis[0]))
            fig.add_trace(go.Scatter(x=df[x_axis], y=df[y_axis[1]], mode='lines', name=y_axis[1], yaxis="y2"))
            
            # Add a secondary y-axis
            fig.update_layout(
                yaxis2=dict(
                    title=y_axis[1],
                    overlaying='y',
                    side='right'
                ),
                title="Double Axis Graph"
            )
            st.plotly_chart(fig)
        else:
            st.warning("Please select appropriate columns and graph type.")
    except Exception as e:
        st.error(f"Error loading file: {e}")
else:
    st.info("Please upload an Excel file to get started.")

# Add Footer
st.write("---")
st.write("Developed using [Streamlit](https://streamlit.io) and [Hugging Face Spaces](https://huggingface.co/spaces).")