"""
Visualization functions for ChatSpatial Engine.
Generates publication-quality plots from Phoenix expression predictions.
"""

import numpy as np
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
from matplotlib.colors import LinearSegmentedColormap
from typing import Optional
import io
from PIL import Image as PILImage


# Color palette
COLORS = {
    "immune": "#4ECDC4",
    "tumor": "#FF6B6B",
    "stroma": "#95E1D3",
    "bg": "#0F1419",
    "card_bg": "#1A1F2E",
    "text": "#E8ECF0",
    "accent": "#7C3AED",
    "grid": "#2A3040",
    "border": "#303848",
}

GENE_CATEGORY = {
    "CD8A": "immune", "CD8B": "immune", "CD3D": "immune", "CD3E": "immune",
    "CD4": "immune", "MS4A1": "immune", "CD19": "immune", "CD68": "immune",
    "CD163": "immune", "PTPRC": "immune", "FOXP3": "immune",
    "EPCAM": "tumor", "KRT18": "tumor", "KRT7": "tumor", "MKI67": "tumor", "PCNA": "tumor",
    "COL1A1": "stroma", "VIM": "stroma", "ACTA2": "stroma", "FAP": "stroma",
    "VEGFA": "stroma", "PDCD1": "immune", "CD274": "immune", "CTLA4": "immune",
    "HLA-A": "immune",
}


def gene_expression_bar_chart(top_genes: list, marker_results: dict) -> Optional[plt.Figure]:
    """Horizontal bar chart of top expressed genes, color-coded by category."""
    if not top_genes:
        return None

    genes = [g for g, _ in top_genes[:20]]
    values = [v for _, v in top_genes[:20]]

    fig, ax = plt.subplots(figsize=(8, 6), facecolor=COLORS["bg"])
    ax.set_facecolor(COLORS["bg"])

    bar_colors = []
    for gene in genes:
        cat = GENE_CATEGORY.get(gene, "")
        if cat == "immune":
            bar_colors.append(COLORS["immune"])
        elif cat == "tumor":
            bar_colors.append(COLORS["tumor"])
        elif cat == "stroma":
            bar_colors.append(COLORS["stroma"])
        else:
            bar_colors.append("#6366F1")

    y_pos = np.arange(len(genes))
    bars = ax.barh(y_pos, values, color=bar_colors, edgecolor="none", height=0.7, alpha=0.85)

    ax.set_yticks(y_pos)
    ax.set_yticklabels(genes, fontsize=9, color=COLORS["text"], fontfamily="monospace")
    ax.set_xlabel("Expression (log1p normalized)", fontsize=10, color=COLORS["text"])
    ax.set_title("Top Expressed Genes", fontsize=13, color=COLORS["text"], fontweight="bold", pad=12)

    ax.tick_params(axis="x", colors=COLORS["text"], labelsize=8)
    ax.spines["top"].set_visible(False)
    ax.spines["right"].set_visible(False)
    ax.spines["bottom"].set_color(COLORS["border"])
    ax.spines["left"].set_color(COLORS["border"])
    ax.xaxis.grid(True, color=COLORS["grid"], alpha=0.3, linestyle="--")
    ax.set_axisbelow(True)

    legend_patches = [
        mpatches.Patch(color=COLORS["immune"], label="Immune"),
        mpatches.Patch(color=COLORS["tumor"], label="Tumor"),
        mpatches.Patch(color=COLORS["stroma"], label="Stroma"),
        mpatches.Patch(color="#6366F1", label="Other"),
    ]
    ax.legend(handles=legend_patches, loc="lower right", fontsize=8,
              facecolor=COLORS["card_bg"], edgecolor=COLORS["border"],
              labelcolor=COLORS["text"], framealpha=0.9)

    ax.invert_yaxis()
    plt.tight_layout()
    return fig


def tissue_composition_radar(cell_type_scores: dict) -> Optional[plt.Figure]:
    """Radar/spider plot showing immune vs tumor vs stroma composition."""
    if not cell_type_scores:
        return None

    categories = ["Immune", "Tumor", "Stroma"]
    values = [
        cell_type_scores.get("immune", 0),
        cell_type_scores.get("tumor", 0),
        cell_type_scores.get("stroma", 0),
    ]

    max_val = max(values) if max(values) > 0 else 1
    values_norm = [v / max_val for v in values]
    values_norm += values_norm[:1]

    angles = np.linspace(0, 2 * np.pi, len(categories), endpoint=False).tolist()
    angles += angles[:1]

    fig, ax = plt.subplots(figsize=(5, 5), subplot_kw=dict(polar=True), facecolor=COLORS["bg"])
    ax.set_facecolor(COLORS["bg"])

    ax.fill(angles, values_norm, color=COLORS["accent"], alpha=0.25)
    ax.plot(angles, values_norm, color=COLORS["accent"], linewidth=2.5, marker="o", markersize=8)

    for i, (angle, val, raw) in enumerate(zip(angles[:-1], values_norm[:-1], values)):
        color = [COLORS["immune"], COLORS["tumor"], COLORS["stroma"]][i]
        ax.plot(angle, val, "o", color=color, markersize=12, zorder=5)
        ax.annotate(f"{raw:.1f}", xy=(angle, val), fontsize=9, color=COLORS["text"],
                    ha="center", va="bottom", fontweight="bold",
                    xytext=(0, 10), textcoords="offset points")

    ax.set_xticks(angles[:-1])
    ax.set_xticklabels(categories, fontsize=11, color=COLORS["text"], fontweight="bold")
    ax.set_yticklabels([])
    ax.spines["polar"].set_color(COLORS["border"])
    ax.grid(color=COLORS["grid"], alpha=0.3)
    ax.set_title("Tissue Composition", fontsize=13, color=COLORS["text"],
                 fontweight="bold", pad=20)

    plt.tight_layout()
    return fig


def marker_heatmap(marker_results: dict) -> Optional[plt.Figure]:
    """Compact heatmap of marker gene expression levels."""
    if not marker_results:
        return None

    sorted_markers = sorted(marker_results.items(), key=lambda x: -x[1]["value"])[:16]
    if not sorted_markers:
        return None

    genes = [m[0] for m in sorted_markers]
    values = [m[1]["value"] for m in sorted_markers]
    tiers = [m[1]["tier"] for m in sorted_markers]

    cmap = LinearSegmentedColormap.from_list(
        "expression",
        ["#1A1F2E", "#1E3A5F", "#4ECDC4", "#FFD93D", "#FF6B6B"],
    )

    fig, ax = plt.subplots(figsize=(10, 2.5), facecolor=COLORS["bg"])
    ax.set_facecolor(COLORS["bg"])

    data = np.array(values).reshape(1, -1)
    im = ax.imshow(data, aspect="auto", cmap=cmap, vmin=0, vmax=max(values) * 1.1 if values else 1)

    ax.set_xticks(range(len(genes)))
    ax.set_xticklabels(genes, fontsize=8, color=COLORS["text"], rotation=45, ha="right",
                       fontfamily="monospace")
    ax.set_yticks([])

    for i, (val, tier) in enumerate(zip(values, tiers)):
        ax.text(i, 0, f"{val:.2f}", ha="center", va="center",
                fontsize=7, color="white" if val > max(values) * 0.5 else COLORS["text"],
                fontweight="bold")

    cbar = plt.colorbar(im, ax=ax, orientation="vertical", fraction=0.02, pad=0.02)
    cbar.set_label("Expression", fontsize=8, color=COLORS["text"])
    cbar.ax.tick_params(colors=COLORS["text"], labelsize=7)

    ax.set_title("Marker Gene Expression Heatmap", fontsize=11, color=COLORS["text"],
                 fontweight="bold", pad=8)
    ax.spines[:].set_visible(False)
    plt.tight_layout()
    return fig


def generate_all_plots(phoenix_result: dict) -> dict:
    """Generate all visualization plots from Phoenix output. Returns dict of figures."""
    plots = {}

    if "top_genes" in phoenix_result:
        fig = gene_expression_bar_chart(
            phoenix_result["top_genes"],
            phoenix_result.get("marker_results", {}),
        )
        if fig:
            plots["bar_chart"] = fig

    if "cell_type_scores" in phoenix_result:
        fig = tissue_composition_radar(phoenix_result["cell_type_scores"])
        if fig:
            plots["radar"] = fig

    if "marker_results" in phoenix_result:
        fig = marker_heatmap(phoenix_result["marker_results"])
        if fig:
            plots["heatmap"] = fig

    return plots


def fig_to_pil(fig: plt.Figure) -> PILImage.Image:
    """Convert matplotlib figure to PIL Image."""
    buf = io.BytesIO()
    fig.savefig(buf, format="png", dpi=150, bbox_inches="tight",
                facecolor=fig.get_facecolor(), edgecolor="none")
    buf.seek(0)
    img = PILImage.open(buf).copy()
    buf.close()
    plt.close(fig)
    return img