import streamlit as st
import plotly.graph_objects as go
import plotly.express as px
import numpy as np
import pandas as pd
from PIL import Image

import io
from datetime import datetime
import matplotlib.pyplot as plt
import scanpy as sc
from itertools import combinations
from typing import Optional
from scipy.sparse import issparse
from scipy.stats import mannwhitneyu
from src.backend.flux_distribution import adata_to_long_df, p_to_star

# Standard color map for metabolic interaction types
INTERACTION_COLORS = {
    "Competition": "#d32f2f",   # Red
    "Release": "#1976d2",       # Blue
    "Cooperation": "#388e3c",   # Green
    "Amensalism": "#fbc02d",    # Amber
    "Neutralism": "#7b1fa2",    # Purple
    "Interaction": "#607d8b"    # Grey (fallback)
}



try:
    from statsmodels.stats.multitest import multipletests
    _HAS_STATSMODELS = True
except ImportError:
    _HAS_STATSMODELS = False

def display_help_button(help_text, plot_name):
    """
    Shows a help popover with insights for the plot.
    """
    if help_text:
        with st.popover("", icon=":material/help:", help="Click for insights", use_container_width=True):
            st.markdown(f"#### <i class='fas fa-lightbulb'></i> Plot Insights", unsafe_allow_html=True)
            st.markdown(help_text)

def display_plot_with_download(fig, plot_name: str = "plot", help_text: str = None):
    """
    Display a matplotlib figure with aligned help and download buttons on top right.
    Reuses same figure object to prevent flickering.
    """
    # Use consistent column ratios: Spacer, Help, Download.
    cols = st.columns([0.7, 0.2, 0.1], gap="small")
    
    with cols[1]:
        display_help_button(help_text, plot_name)

    with cols[2]:
        # Generate PDF file
        pdf_buffer = io.BytesIO()
        fig.savefig(pdf_buffer, format='pdf', dpi=300, bbox_inches='tight')
        file_data = pdf_buffer.getvalue()
        
        st.download_button(
            label="",
            data=file_data,
            file_name=f"{plot_name}_{datetime.now().strftime('%Y%m%d_%H%M%S')}.pdf",
            mime="application/pdf",
            key=f"download_{plot_name}_{id(fig)}",
            help="Download as PDF",
            icon=":material/download:",
            use_container_width=True
        )
    
    # Display the plot
    st.pyplot(fig, use_container_width=False)

def display_plotly_with_download(fig, plot_name: str = "plot", help_text: str = None):
    """
    Display a Plotly figure with aligned help button on top right.
    Optimized to prevent flickering on reruns.
    """
    cols = st.columns([0.7, 0.2, 0.1], gap="small")
    with cols[1]:
        display_help_button(help_text, plot_name)
    
    with cols[2]:
        st.empty() 
    
    # Use a unique key to prevent redraws and add config to disable animations for faster rendering
    st.plotly_chart(
        fig, 
        use_container_width=False,
        key=f"plotly_{plot_name}_{id(fig)}",
        config={"displayModeBar": False, "responsive": True, "staticPlot": False}
    )

def display_interactive_spatial_plot(adata, color_key="domain", spot_size = 6, plot_name="spatial_plot", title: Optional[str] = None, help_text: Optional[str] = None):
    # spot_size = spot_size
    try:
        # Create columns for help/download above the plot if help_text is provided
        if help_text:
            col_space, col_help, col_download = st.columns([5.0, 0.5, 0.5], gap="small")
            with col_help:
                display_help_button(help_text, plot_name)

        library_id = list(adata.uns["spatial"].keys())[0]
        img_key = "hires" if "hires" in adata.uns["spatial"][library_id]["images"] else "downscaled_fullres"
        img = adata.uns["spatial"][library_id]["images"][img_key]
        sf_key = f"tissue_{img_key}_scalef"
        sf = adata.uns["spatial"][library_id]["scalefactors"][sf_key]
        coords = adata.obsm["spatial"] * sf

        if color_key in adata.var_names:
            var_idx = adata.var_names.get_loc(color_key)
            raw = adata.X[:, var_idx]
            color_values = raw.toarray().flatten() if hasattr(raw, "toarray") else np.asarray(raw).flatten()
            is_categorical = False
        elif color_key in adata.obs.columns:
            color_values = adata.obs[color_key].values
            is_categorical = not pd.api.types.is_numeric_dtype(adata.obs[color_key])
        else:
            color_values = np.full(len(coords), "N/A")
            is_categorical = True

        df = pd.DataFrame({
            "x": coords[:, 0],
            "y": coords[:, 1],
            "color": color_values.astype(str) if is_categorical else color_values,
            "domain": adata.obs["domain"].values if "domain" in adata.obs.columns else "N/A",
            "spot_id": adata.obs_names.tolist()
        })

        last_key = st.session_state.get(f"{plot_name}_last_key")
        if last_key != color_key:
            st.session_state.pop(f"{plot_name}_relayout", None)
            st.session_state[f"{plot_name}_last_key"] = color_key

        plot_state = st.session_state.get(plot_name, {})
        relayout = None
        
        if isinstance(plot_state, dict):
            relayout = plot_state.get("relayout_data") or plot_state.get("relayout")
        elif hasattr(plot_state, "selection"):
             relayout = getattr(plot_state, "relayout_data", None)

        zoom_ratio = 1.0 
        has_zoom = relayout and isinstance(relayout, dict) and "xaxis.range[0]" in relayout
        
        if has_zoom:
            try:
                xr = [relayout["xaxis.range[0]"], relayout["xaxis.range[1]"]]
                zoom_ratio = abs(xr[1] - xr[0]) / img.shape[1]
            except (IndexError, KeyError, ZeroDivisionError):
                zoom_ratio = 1.0

        fig = go.Figure()
        fig.add_layout_image(
            dict(
                source=Image.fromarray((img * 255).astype(np.uint8)),
                xref="x", yref="y",
                x=0, y=0,
                sizex=img.shape[1], sizey=img.shape[0],
                sizing="stretch", layer="below"
            )
        )

        if is_categorical:
            palette = px.colors.qualitative.T10
            unique_vals = sorted(df["color"].astype(str).unique())

            for i, val in enumerate(unique_vals):
                sub = df[df["color"].astype(str) == val]
                fig.add_trace(go.Scattergl(
                    x=sub["x"], 
                    y=sub["y"],
                    customdata=np.stack((sub["spot_id"], sub["domain"]), axis=-1),
                    mode="markers", 
                    name=str(val),
                    marker=dict(
                        size=spot_size,
                        color=palette[i % len(palette)],
                        line=dict(width=0.5, color='white')
                    ),
                    hovertemplate=(
                        "<b>Domain: %{customdata[1]}</b><br>"
                        "<span style='font-size:0.8rem;'>ID: %{customdata[0]}</span>"
                        "<extra></extra>"
                    )
                ))
        else:
            fig.add_trace(go.Scattergl(
                x=df["x"], y=df["y"],
                customdata=np.stack((df["spot_id"], df["domain"]), axis=-1),
                mode="markers",
                marker=dict(
                    size=spot_size, 
                    color=df["color"],
                    colorscale="Jet", 
                    showscale=True,
                    colorbar=dict(
                        thickness=8,
                        len=0.75,
                        xref="paper",
                        yref="paper",
                        tickfont=dict(size=10),
                        outlinewidth=0,
                    ),
                    line=dict(width=0.3, color='white')
                ),
                hovertemplate=(
                    "<b>Domain: %{customdata[1]}</b><br>"
                    f"<b>Flux:</b> %{{marker.color:.3e}}<br>"
                    "<span style='font-size:0.8rem;'>ID: %{customdata[0]}</span>"
                    "<extra></extra>"
                )
            ))

        # Enforce square axes aligned to tissue image
        fig.update_xaxes(
            visible=False, 
            range=[0, img.shape[1]], 
            scaleanchor="y",
            scaleratio=1,
        )

        fig.update_yaxes(
            visible=False,
            range=[img.shape[0], 0],
            scaleanchor="x",
            scaleratio=1,
            constrain="domain",
        )

        fig.update_layout(
            title=dict(
                text=title if title else "",
                x=0.5,
                y=0.98,
                xanchor="center",
                yanchor="top",
                font=dict(size=16)
            ) if title else None,
            margin=dict(l=0, r=0, t=40 if title else 0, b=0),
            legend=dict(
                orientation="v",
                yanchor="top",
                y=0.99,
                xanchor="left",
                x=0.01,
                bgcolor="rgba(255,255,255,0.6)"
            ),
            paper_bgcolor='rgba(0,0,0,0)',
            plot_bgcolor='rgba(0,0,0,0)',
            dragmode="pan",
            uirevision="constant"
        )

        plot_event = st.plotly_chart(
            fig, 
            use_container_width=False, 
            config={'scrollZoom': True}, 
            key=plot_name, 
            on_select="rerun"
        )
        if plot_event and hasattr(plot_event, "get"):
             relayout = plot_event.get("relayout_data") or plot_event.get("selection", {}).get("relayout_data")
             if relayout:
                 st.session_state[f"{plot_name}_relayout"] = relayout

        return True

    except Exception as e:
        st.error(f"Error rendering interactive plot: {e}")
        return False

def display_formatted_table(df: pd.DataFrame, title: Optional[str] = None):
    """Display a dataframe with scientific notation for small float values."""
    if title:
        st.markdown(f"##### <i class='fas fa-table'></i> {title}", unsafe_allow_html=True)
    
    config = {}
    if not df.empty:
        for col in df.select_dtypes(include=['float']).columns:
            if 'p_val' in col.lower() or 'pvalue' in col.lower() or df[col].abs().max() < 1e-2:
                config[col] = st.column_config.NumberColumn(format="%.2e")
            else:
                config[col] = st.column_config.NumberColumn(format="%.4f")
            
    st.dataframe(df, width='stretch', column_config=config)



def add_significance_brackets(ax, df, domain_order, y_col="flux"):
    """
    Add pairwise significance brackets above a boxen/box plot.
    Uses Mann-Whitney U test with FDR-BH correction across all pairs.
    Only significant pairs (p_adj < 0.05) are annotated.
    """
    pairs = list(combinations(domain_order, 2))
    pvalues = []
    valid_pairs = []

    for d1, d2 in pairs:
        g1 = df.loc[df["domain"] == d1, y_col].dropna()
        g2 = df.loc[df["domain"] == d2, y_col].dropna()
        if len(g1) < 3 or len(g2) < 3:
            continue
        _, p = mannwhitneyu(g1, g2, alternative="two-sided")
        pvalues.append(p)
        valid_pairs.append((d1, d2))

    if not valid_pairs:
        return

    if _HAS_STATSMODELS:
        _, p_adj, _, _ = multipletests(pvalues, method="fdr_bh")
    else:
        p_adj = np.array(pvalues)

    y_max = df[y_col].max()
    y_range = df[y_col].max() - df[y_col].min()
    step = y_range * 0.08

    bracket_y = y_max + step
    for (d1, d2), p in zip(valid_pairs, p_adj):
        star = p_to_star(p)
        if star == "ns":
            continue
        x1 = domain_order.index(d1)
        x2 = domain_order.index(d2)
        mid = (x1 + x2) / 2
        ax.plot([x1, x1, x2, x2], [bracket_y, bracket_y + step * 0.3, bracket_y + step * 0.3, bracket_y],
                lw=1.2, c="black")
        ax.text(mid, bracket_y + step * 0.35, star, ha="center", va="bottom", fontsize=9)
        bracket_y += step * 0.9   # stack brackets upward

def create_plotly_tme_plot(adata, interaction_type_df, interaction_score_df, selected_rxn_id, selected_display_name, percentile_threshold=95):

    coords_df = pd.DataFrame(adata.obsm["spatial"], index=adata.obs.index, columns=['x', 'y'])
    y_max = coords_df['y'].max()
    coords_df['y_plot'] = y_max - coords_df['y']
    coords_df['domain'] = adata.obs['domain'] if 'domain' in adata.obs.columns else "N/A"
    
    if percentile_threshold > 0:
        thresh = interaction_score_df['Interaction score'].quantile(percentile_threshold / 100)
        scores = interaction_score_df[interaction_score_df['Interaction score'] >= thresh]
    else:
        scores = interaction_score_df

    rxn_mask = interaction_type_df['Reaction'].str.replace(r'_(b|f)$', '', regex=True) == selected_rxn_id
    rxn_data = interaction_type_df[rxn_mask]

    merged = pd.merge(rxn_data, scores, on=['Source', 'Target'])
    
    if merged.empty:
        return None

    fig = go.Figure()

    fig.add_trace(go.Scattergl(
        x=coords_df['x'], y=coords_df['y_plot'],
        mode='markers',
        marker=dict(size=4, color='#bdbdbd', opacity=0.5), # All spots in background
        name='Tissue Background',
        customdata=np.stack((coords_df.index, coords_df['domain']), axis=-1),
        hovertemplate="<b>Spot ID: %{customdata[0]}</b><br>Domain: %{customdata[1]}<extra></extra>",
        showlegend=False
    ))

    types = merged['Interaction type'].unique()
    colors = px.colors.qualitative.T10
    
    for i, t in enumerate(types):
        sub = merged[merged['Interaction type'] == t]
        
        s_coords = coords_df.loc[sub['Source'], ['x', 'y_plot']].values
        t_coords = coords_df.loc[sub['Target'], ['x', 'y_plot']].values
        
        n = len(sub)
        edge_x = np.full(n * 3, np.nan)
        edge_y = np.full(n * 3, np.nan)
        edge_x[0::3] = s_coords[:, 0]; edge_x[1::3] = t_coords[:, 0]
        edge_y[0::3] = s_coords[:, 1]; edge_y[1::3] = t_coords[:, 1]

        fig.add_trace(go.Scattergl(
            x=edge_x, y=edge_y,
            mode='lines',
            line=dict(width=3, color=INTERACTION_COLORS.get(t, "#607d8b")),
            name=str(t),
            hoverinfo='none', # Hover is handled by midpoints
            connectgaps=False
        ))

        # Midpoints for robust hover in the middle of lines
        mid_x = (s_coords[:, 0] + t_coords[:, 0]) / 2
        mid_y = (s_coords[:, 1] + t_coords[:, 1]) / 2
        
        fig.add_trace(go.Scattergl(
            x=mid_x, y=mid_y,
            mode='markers',
            marker=dict(size=12, opacity=0), # Large invisible target
            name=str(t),
            hovertemplate=f"<b>Interaction: {t}</b><br>Score: %{{customdata:.4f}}<extra></extra>",
            customdata=sub['Interaction score'].values,
            showlegend=False
        ))

    active_spots = sorted(list(set(merged['Source']).union(set(merged['Target']))))
    active_df = coords_df.loc[active_spots]
    
    fig.add_trace(go.Scattergl(
        x=active_df['x'], y=active_df['y_plot'],
        mode='markers',
        marker=dict(size=5, color='#424242', opacity=0.9, line=dict(width=1, color='white')),
        name='Interacting Spots',
        customdata=np.stack((active_df.index, active_df['domain']), axis=-1),
        hovertemplate="<b>Spot ID: %{customdata[0]}</b><br>Domain: %{customdata[1]}<extra></extra>",
        showlegend=True
    ))

    fig.update_layout(
        title=dict(
            text=f"Metabolic Interactions: {selected_display_name}",
        ),
        xaxis=dict(visible=False), yaxis=dict(visible=False, scaleanchor="x"),
        plot_bgcolor='#fcfcfc', paper_bgcolor='white',
        width=850, height=850, margin=dict(l=10, r=10, t=60, b=10),
        legend=dict(orientation="h", y=1.02, x=0, xanchor="left", title="Interaction Type:"),
        hovermode='closest',
        hoverdistance=30  # Makes it easier to hover on lines
    )
    return fig

def create_plotly_comm_plot(interaction_scores, adata, percentile_threshold=80):
    """
    Optimized Communication Strength plot using WebGL and vectorized coordinates.
    """
    coords_df = pd.DataFrame(adata.obsm["spatial"], index=adata.obs.index, columns=['x', 'y'])
    y_max = coords_df['y'].max()
    coords_df['y_plot'] = y_max - coords_df['y']
    coords_df['domain'] = adata.obs['domain'] if 'domain' in adata.obs.columns else "N/A"

    if percentile_threshold > 0:
        thresh = interaction_scores['Interaction score'].quantile(percentile_threshold / 100)
        interaction_scores = interaction_scores[interaction_scores['Interaction score'] >= thresh]

    valid = interaction_scores[
        (interaction_scores['Source'].isin(coords_df.index)) & 
        (interaction_scores['Target'].isin(coords_df.index))
    ]

    if valid.empty: return None

    fig = go.Figure()
    # Background
    fig.add_trace(go.Scattergl(
        x=coords_df['x'], y=coords_df['y_plot'],
        mode='markers', 
        marker=dict(size=4, color='#bdbdbd', opacity=0.3), # All spots in background
        name='Tissue Background',
        customdata=np.stack((coords_df.index, coords_df['domain']), axis=-1),
        hovertemplate="<b>Spot ID: %{customdata[0]}</b><br>Domain: %{customdata[1]}<extra></extra>",
        showlegend=False
    ))

    # Binned Edges (Vectorized)
    n_bins = 5
    valid = valid.copy()
    valid['bin'] = pd.qcut(valid['Interaction score'], n_bins, labels=False, duplicates='drop')
    
    for b in range(n_bins):
        sub = valid[valid['bin'] == b]
        if sub.empty: continue
        
        s_coords = coords_df.loc[sub['Source'], ['x', 'y_plot']].values
        t_coords = coords_df.loc[sub['Target'], ['x', 'y_plot']].values
        
        n = len(sub)
        edge_x = np.full(n * 3, np.nan)
        edge_y = np.full(n * 3, np.nan)
        edge_x[0::3] = s_coords[:, 0]; edge_x[1::3] = t_coords[:, 0]
        edge_y[0::3] = s_coords[:, 1]; edge_y[1::3] = t_coords[:, 1]

        fig.add_trace(go.Scattergl(
            x=edge_x, y=edge_y,
            mode='lines',
            line=dict(width=0.5 + b*1.5, color=px.colors.sample_colorscale("Viridis", b/(n_bins-1))[0]),
            name=f"Level {b+1}", hoverinfo='none'
        ))

    fig.update_layout(
        title="Cell-Cell Metabolic Communication Strengths",
        xaxis=dict(visible=False), yaxis=dict(visible=False, scaleanchor="x"),
        plot_bgcolor='#fcfcfc', width=850, height=850,
        legend=dict(title="Score Bin:", orientation="v", x=1.02, y=1)
    )
    return fig