"""Render the hero gallery: 4 sample images x (raw | cluster masks | berry keypoints)."""
import json
import sys
from pathlib import Path

import matplotlib

matplotlib.use("Agg")
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
from matplotlib.patches import Polygon
from PIL import Image

sys.path.insert(0, str(Path(__file__).resolve().parent))
from vivid_utils import STYLE

ROOT = Path(__file__).resolve().parents[1]
DATA = ROOT / "data"
GRAPE_CATEGORY_ID = 1
MASK_COLORS = ["#6366F1", "#F59E0B", "#10B981", "#EF4444", "#8B5CF6", "#06B6D4"]

# Override with specific file_names after eyeballing candidates; None = auto-pick
GALLERY_FILES = None


def pick_samples(meta):
    if GALLERY_FILES:
        return list(GALLERY_FILES)
    picks = []
    pool = meta[meta.cluster_count.between(2, 8)].sort_values("berry_count")
    for q in (0.15, 0.45, 0.7, 0.95):
        row = pool.iloc[min(int(q * len(pool)), len(pool) - 1)]
        if row.file_name not in picks:
            picks.append(row.file_name)
    return picks


def main():
    meta = pd.read_csv(DATA / "metadata.csv")
    samples = pick_samples(meta)
    print("gallery samples:", samples)

    print("Loading COCO json...")
    coco = json.loads((DATA / "anns" / "instances_updated.json").read_text())
    ids = {im["file_name"]: im["id"] for im in coco["images"] if im["file_name"] in samples}
    polys = {name: [] for name in samples}
    id_to_name = {v: k for k, v in ids.items()}
    for ann in coco["annotations"]:
        if ann["category_id"] != GRAPE_CATEGORY_ID or ann["image_id"] not in id_to_name:
            continue
        for seg in ann["segmentation"]:
            pts = np.asarray(seg, dtype=float).reshape(-1, 2)
            polys[id_to_name[ann["image_id"]]].append(pts)

    fig, axes = plt.subplots(len(samples), 3, figsize=(9, 3.9 * len(samples)),
                             dpi=STYLE["dpi"], facecolor="white")
    col_titles = ["image", "cluster masks", "berry keypoints"]
    for r, name in enumerate(samples):
        img = Image.open(DATA / "imgs" / name).convert("RGB")
        img.thumbnail((900, 900))
        scale = img.width / meta.set_index("file_name").loc[name, "width"]
        pts = np.load(DATA / "anns" / "points" / (Path(name).stem + ".npy")) * scale
        for c in range(3):
            ax = axes[r, c]
            ax.imshow(img)
            ax.set_xticks([]), ax.set_yticks([])
            for spine in ax.spines.values():
                spine.set_visible(False)
            if r == 0:
                ax.set_title(col_titles[c], fontsize=12, color=STYLE["text"])
        for i, poly in enumerate(polys[name]):
            axes[r, 1].add_patch(Polygon(poly * scale, closed=True, alpha=0.45,
                                         facecolor=MASK_COLORS[i % len(MASK_COLORS)],
                                         edgecolor="white", linewidth=1.0))
        axes[r, 2].scatter(pts[:, 0], pts[:, 1], s=4, color="#FDE047",
                           edgecolors="#B45309", linewidths=0.3)
        axes[r, 2].text(0.02, 0.02, f"{len(pts)} berries", transform=axes[r, 2].transAxes,
                        fontsize=11, fontweight="bold", color="white",
                        bbox=dict(facecolor="black", alpha=0.6, pad=3))
    fig.tight_layout()
    out = ROOT / "assets" / "hero_gallery.png"
    fig.savefig(out, dpi=STYLE["dpi"], facecolor="white", bbox_inches="tight")
    print("wrote", out)


if __name__ == "__main__":
    main()