"""Extraction des têtes de minifigs présentes dans chaque set filtré."""

import csv
from pathlib import Path
from typing import Dict, Iterable, List, Sequence, Set, Tuple

from lib.filesystem import ensure_parent_dir
from lib.rebrickable.minifig_heads import HEAD_CATEGORIES
from lib.rebrickable.stats import read_rows


def load_parts_filtered(path: Path) -> List[dict]:
    """Charge parts_filtered.csv en mémoire."""
    return read_rows(path)


def load_parts_catalog(path: Path) -> Dict[str, dict]:
    """Construit un index des pièces avec leur catégorie et leur nom."""
    catalog: Dict[str, dict] = {}
    with path.open() as catalog_file:
        reader = csv.DictReader(catalog_file)
        for row in reader:
            catalog[row["part_num"]] = row
    return catalog


def select_head_parts(catalog: Dict[str, dict]) -> Set[str]:
    """Sélectionne les références de têtes via leur catégorie."""
    return {part_num for part_num, row in catalog.items() if row["part_cat_id"] in HEAD_CATEGORIES}


def aggregate_heads_by_set(
    parts_rows: Iterable[dict],
    catalog: Dict[str, dict],
    head_parts: Set[str],
) -> List[dict]:
    """Agrège les têtes de minifigs par set en éliminant les rechanges et doublons."""
    seen: Set[Tuple[str, str]] = set()
    heads: List[dict] = []
    for row in parts_rows:
        if row["part_num"] not in head_parts:
            continue
        if row["is_spare"] == "true":
            continue
        key = (row["set_num"], row["part_num"])
        if key in seen:
            continue
        part = catalog[row["part_num"]]
        heads.append(
            {
                "set_num": row["set_num"],
                "part_num": row["part_num"],
                "part_name": part["name"],
            }
        )
        seen.add(key)
    heads.sort(key=lambda row: (row["set_num"], row["part_num"]))
    return heads


def write_heads_by_set(destination_path: Path, rows: Sequence[dict]) -> None:
    """Écrit le CSV intermédiaire listant les têtes de minifigs par set."""
    ensure_parent_dir(destination_path)
    fieldnames = ["set_num", "part_num", "part_name"]
    with destination_path.open("w", newline="") as csv_file:
        writer = csv.DictWriter(csv_file, fieldnames=fieldnames)
        writer.writeheader()
        for row in rows:
            writer.writerow(row)


def build_minifigs_by_set(
    parts_filtered_path: Path,
    parts_catalog_path: Path,
    destination_path: Path,
) -> None:
    """Construit le CSV listant les têtes de minifigs présentes par set."""
    parts_rows = load_parts_filtered(parts_filtered_path)
    parts_catalog = load_parts_catalog(parts_catalog_path)
    head_parts = select_head_parts(parts_catalog)
    heads = aggregate_heads_by_set(parts_rows, parts_catalog, head_parts)
    write_heads_by_set(destination_path, heads)