"""Visualisation de la réutilisation des têtes de minifigs."""

import csv
from pathlib import Path
from typing import List

import matplotlib.pyplot as plt

from lib.filesystem import ensure_parent_dir


def load_head_reuse(path: Path) -> List[dict]:
    """Charge le CSV head_reuse."""
    rows: List[dict] = []
    with path.open() as csv_file:
        reader = csv.DictReader(csv_file)
        for row in reader:
            rows.append(row)
    return rows


def format_label(row: dict) -> str:
    """Formate le label affiché sur l'axe vertical."""
    character = row["known_character"]
    if character != "":
        return f"{row['part_num']} — {character}"
    return row["part_num"]


def plot_head_reuse(path: Path, destination_path: Path, top: int = 30) -> None:
    """Trace un bar chart horizontal mettant en avant les têtes exclusives ou rares."""
    rows = load_head_reuse(path)
    rows.sort(key=lambda r: (int(r["other_sets"]), -int(r["filtered_sets"]), r["part_num"]))
    selected = rows[:top]
    labels = [format_label(r) for r in selected]
    filtered_counts = [int(r["filtered_sets"]) for r in selected]
    other_counts = [int(r["other_sets"]) for r in selected]
    positions = list(reversed(range(len(selected))))

    fig, ax = plt.subplots(figsize=(12, 0.5 * len(selected) + 1.5))
    ax.barh(positions, filtered_counts, color="#1f78b4", label="Sets filtrés")
    ax.barh(positions, other_counts, left=filtered_counts, color="#b2df8a", label="Autres sets")
    ax.set_yticks(positions)
    ax.set_yticklabels(reversed(labels))
    ax.set_xlabel("Nombre de sets contenant la tête")
    ax.invert_yaxis()
    ax.grid(axis="x", linestyle="--", alpha=0.4)
    ax.legend()
    fig.tight_layout()

    ensure_parent_dir(destination_path)
    fig.savefig(destination_path, dpi=150)
    plt.close(fig)