import matplotlib.pyplot as plt 
import seaborn as sns
import pandas as pd 
import geopandas as gp
import numpy as np

def get_residual_plot(country_name, gdf): 
    fig, ax = plt.subplots(1,1,figsize=(10,6))
    if country_name is None:
        ax.text(0.5, 0.5, "Click on the map to see the IWI time-series here.",
                horizontalalignment='center', verticalalignment='center',
                transform=ax.transAxes, fontsize=14)
        
    elif gdf['country'].str.contains(country_name).any():
        gdf = gdf[gdf['country'] == country_name]
        gdf['date'] = pd.to_datetime(gdf['date'])
        modified_xticks = gdf['date'].dt.to_period('M')
        ticks_unique = np.unique(modified_xticks)
        sns.boxplot(x=modified_xticks, y=gdf['residual'], ax=ax)
        ax.set_xlabel('date')
        ax.set_xticks(range(len(ticks_unique)))
        ax.set_xticklabels(labels = ticks_unique, rotation=45)
        ax.set_ylabel('iwi_value')
        ax.set_title(f'IWI Residual Plot For {country_name}')
        ax.grid(True, linestyle='--', alpha=0.7)
        plt.tight_layout()
        return fig

    else:
        ax.text(0.5, 0.5, "No country data available. Please select another country.",
                    horizontalalignment='center', verticalalignment='center',
                    transform=ax.transAxes, fontsize=14)