import streamlit as st
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
import matplotlib.dates as mdates
import plotly.express as px
import plotly.graph_objects as go
import re
from datetime import datetime, timedelta
import warnings
import time
import dask.dataframe as dd

@st.cache_data
def date_from_week(year, week):
    # Assuming the fiscal year starts in August and the week starts from August 1st
    base_date = pd.to_datetime((year - 1).astype(str) + '-08-01')
    dates = base_date + pd.to_timedelta((week - 1) * 7, unit='days')
    return dates

@st.cache_data
def load_data(active_card):
    # st.write(f"{active_card}")
    # Define columns common to multiple cards if there are any
    common_cols = ['FyWeek', 'Itemtype', 'Chaincode', 'State', 'SalesVolume', 'UnitPrice', 'Sales']

    # Columns specific to cards
    card_specific_cols = {
        'card1': ['FyWeek', 'State', 'Itemtype', 'Chaincode', 'SalesVolume'],
        'card2': ['FyWeek', 'Fy', 'State','Store','Address','Zipcode','City','Itemtype', 'Chaincode', 'Containercode', 'SalesVolume', 'UnitPrice', 'Sales'],
    }

    # Choose columns based on the active card
    required_columns = card_specific_cols.get(active_card, common_cols)

    # Define the data types for efficient memory usage
    dtype_spec = {
        'FyWeek': 'string',
        'Fy': 'category',  # Add data type for 'Fy' if it's used
        'Itemtype': 'category',
        'Chaincode': 'category',
        'State': 'category',
        "Store": "category", 
        'Containercode': 'category',
        "Address": "string",
        "Zipcode": "float",
        "City": "category", 
        'SalesVolume': 'float',
        'UnitPrice': 'float',
        'Sales': 'float'
    }

    # Read only the necessary columns
    # st.write(required_columns)
    ddf = dd.read_csv("fy21-24.csv", usecols=required_columns, dtype=dtype_spec)
    df = ddf.compute()


    if active_card in ['card2']:
        df = df.groupby(['FyWeek', 'Fy', 'Chaincode', 'Store', 'Address', 'Zipcode', 'City', 'State', 'Containercode', 'Itemtype'], observed=True).agg({
        'SalesVolume': 'sum',
        'UnitPrice': 'mean',
        'Sales': 'sum'
        }).reset_index()
        df[['FY', 'Week']] = df['FyWeek'].str.split(' Week ', expand=True)
        df['Week'] = df['Week'].astype(int)  # Convert 'Week' to int
        df['Year'] = df['FY'].str[2:].astype(int)  # Extract year part and convert to int
        df['Dt'] = date_from_week(df['Year'], df['Week'])

    # st.write(df.columns)
    return df

# Display logo
st.image("bonnie.png", width=150)  # Adjust width as needed

# Display title
st.title("Bonnie Plants Pricing & Sales Analytics Dashboard")

# Close the div for logo and title
st.markdown('</div>', unsafe_allow_html=True)

#  Initialize session state for storing which card was clicked and item type
if 'active_card' not in st.session_state:
    st.session_state['active_card'] = None
if 'selected_item_type' not in st.session_state:
    st.session_state['selected_item_type'] = 'CORE'  # Set default to 'CORE'

if 'selected_feature' not in st.session_state:
    st.session_state['selected_feature'] = 'Chaincode'  # Default to 'Chain Code'

# Card selection buttons
col1, col2 = st.columns(2)
# Define buttons for plot categories, update session state when clicked
with col1:
    if st.button("Sales Volume Trend for Item Category"):
        st.session_state['active_card'] = 'card1'

with col2:
    if st.button("Sales Volume & Unit Price Correlation for Item Category and Container Code"):
        st.session_state['active_card'] = 'card2'

start_time=time.time()
# st.write(st.session_state['active_card'])
df = load_data(st.session_state['active_card'])
time_taken = time.time() - start_time
st.write(f"Data loaded in {time_taken:.2f} seconds")


# Initialize session state for storing the selected state and feature
if 'selected_state' not in st.session_state:
    st.session_state['selected_state'] = df['State'].unique()[0]  # Default to the first state

############################################ CARD #1 ####################################################
if st.session_state['active_card'] == 'card1':
    # st.write("Processing card1...")
    # Dropdown for selecting the state
    selected_state = st.selectbox('Select State', df['State'].unique())
    # Dropdown for selecting the feature for grouping
    selected_feature = st.selectbox('Select Feature for Grouping', ['Chaincode', 'Itemtype',])
    
    # Filter the dataframe based on selected state
    filtered_df = df[df['State'] == selected_state]
    
    # Time the grouping operation
    start_time = time.time()
    group_data = filtered_df.groupby(['FyWeek', selected_feature],observed=True)['SalesVolume'].sum().reset_index()
    time_taken = time.time() - start_time

    # Plotting
    fig = px.bar(group_data, x='FyWeek', y='SalesVolume', color=selected_feature,
                 title=f'Sales Volume over Fiscal Week in {selected_state} by {selected_feature}',
                 labels={'SalesVolume': 'Sales Volume', 'Fiscal Week Short': 'Fiscal Week'})
    st.plotly_chart(fig)

##########################################################################################################


########################################### CARD #2 ####################################################





if st.session_state['active_card'] == 'card2':
    # Dropdown to select item type (using session_state)
    st.session_state['selected_item_type'] = st.selectbox(
        'Select Item Type', df['Itemtype'].unique(),
        index=list(df['Itemtype'].unique()).index(st.session_state['selected_item_type']))

    # Dropdown to select the grouping category (container code, chain code, or state)
    group_by_option = st.selectbox('Group by', ['Containercode', 'Chaincode', 'State'])

    # Multi-select checkbox to select multiple years
    selected_years = st.multiselect('Select Year(s)', [2021, 2022, 2023, 2024], default=[2021])

    st.subheader(f"Sales Volume & Unit Price Correlation for {group_by_option} in {', '.join(map(str, selected_years))}")

    # Convert 'Dt' column to datetime
    df['Dt'] = pd.to_datetime(df['Dt'], errors='coerce')
    df['Promo'] = np.where(df['Dt'].dt.month.astype(str).isin(['3', '4', '5', '6']), 'Promo', 'NoPromo')
    df["Promo"] = df["Promo"].astype("category")

    # Filter the dataframe based on the selected item type and selected years
    filtered_df = df[(df['Itemtype'] == st.session_state['selected_item_type']) & (df['Dt'].dt.year.isin(selected_years))]

    # Find the top 3 values based on total SalesVolume in the selected grouping category
    top_3_values = filtered_df.groupby(group_by_option, observed=True)['SalesVolume'].sum().nlargest(3).index

    # Filter the data for only the top 3 values
    top_group_data = filtered_df[filtered_df[group_by_option].isin(top_3_values)]

    # Aggregate data
    agg_df = top_group_data.groupby([group_by_option, 'Year', 'Week', 'Dt'], observed=True).agg({
        'SalesVolume': 'sum',
        'UnitPrice': 'mean'
    }).reset_index()

    # Create a new column 'week-year' for X-axis labels
    agg_df['week-year'] = agg_df['Dt'].dt.strftime('%U-%Y')

    # Loop through the top 3 values and create separate plots using Plotly
    for value in top_3_values:
        value_data = agg_df[agg_df[group_by_option] == value]
        # Assuming you have 'value_data' from your previous code
        mean_sales_volume = value_data['SalesVolume'].mean()
        mean_unit_price = value_data['UnitPrice'].mean()

        # Create a Plotly figure
        fig = go.Figure()

        # Add SalesVolume trace
        fig.add_trace(go.Scatter(
            x=value_data['week-year'],
            y=value_data['SalesVolume'],
            mode='lines+markers',
            name='SalesVolume',
            line=dict(color='blue'),
            hovertemplate='SalesVolume: %{y}<br>Week-Year: %{x}'
        ))

        # Add UnitPrice trace on a secondary Y-axis
        fig.add_trace(go.Scatter(
            x=value_data['week-year'],
            y=value_data['UnitPrice'],
            mode='lines+markers',
            name='UnitPrice',
            line=dict(color='green'),
            yaxis='y2',
            hovertemplate='UnitPrice: %{y}<br>Week-Year: %{x}'
        ))
        # Add mean line for SalesVolume
        fig.add_shape(type="line",
                    x0=value_data['week-year'].min(), x1=value_data['week-year'].max(),
                    y0=mean_sales_volume, y1=mean_sales_volume,
                    line=dict(color="blue", width=2, dash="dash"),
                    xref='x', yref='y')

        # Add mean line for UnitPrice (on secondary Y-axis)
        fig.add_shape(type="line",
                    x0=value_data['week-year'].min(), x1=value_data['week-year'].max(),
                    y0=mean_unit_price, y1=mean_unit_price,
                    line=dict(color="green", width=2, dash="dash"),
                    xref='x', yref='y2')

        # Update layout for dual axes
        fig.update_layout(
            template='plotly_white',
            title=f"SalesVolume and UnitPrice - {value} ({group_by_option})",
            xaxis_title='Week-Year',
            yaxis_title='Sales Volume',
            yaxis2=dict(title='UnitPrice', overlaying='y', side='right'),
            legend=dict(x=0.9, y=1.15),
            hovermode="x unified",  # Show both values in a tooltip
            height=600,
            margin=dict(l=50, r=50, t=50, b=50)
        )

        # Rotate X-axis labels
        fig.update_xaxes(tickangle=90)

        # Display the Plotly figure in Streamlit
        st.plotly_chart(fig, use_container_width=True)



##########################################################################################################