#!/usr/bin/env python3

from __future__ import annotations

import argparse
import json
from pathlib import Path


def crop_icon(icon: str | None) -> list[int | str] | None:
    if not icon:
        return None

    lines = icon.split("\n")
    xs: list[int] = []
    ys: list[int] = []

    for y, line in enumerate(lines):
        for x, char in enumerate(line):
            if char != " ":
                xs.append(x)
                ys.append(y)

    if not xs:
        return [0, 0, ""]

    min_x = min(xs)
    max_x = max(xs)
    min_y = min(ys)
    max_y = max(ys)
    cropped_lines = [line[min_x : max_x + 1].rstrip() for line in lines[min_y : max_y + 1]]
    return [min_x, min_y, "\n".join(cropped_lines)]


def compact_chains(data: object) -> list[list[object]]:
    if isinstance(data, dict):
        chains = data.get("chains")
    else:
        chains = data

    if not isinstance(chains, list):
        raise ValueError("Input JSON does not contain a valid chains array")

    compact: list[list[object]] = []

    for chain in chains:
        if isinstance(chain, list):
            if len(chain) == 2 and isinstance(chain[1], list):
                compact.append(chain)
                continue
            if len(chain) == 3 and isinstance(chain[1], int) and isinstance(chain[2], list):
                compact.append([chain[0], chain[2]])
                continue
            raise ValueError("Invalid compact chain entry")

        if not isinstance(chain, dict):
            raise ValueError("Expected verbose or compact chain entries as input")

        items = chain.get("items")
        if not isinstance(items, list) or not items:
            continue

        base_id = chain["base_id"]
        compact_items: list[list[object]] = []

        for item in items:
            compact_items.append([
                item["item_id"],
                crop_icon(item.get("icon_nfp_16x16")),
            ])

        compact.append([base_id, compact_items])

    return compact


def main() -> int:
    parser = argparse.ArgumentParser(
        description="Rewrite atc_chains.json into a compact format used by compcount.lua."
    )
    parser.add_argument("source", nargs="?", default="atc_chains_uncompressed.json")
    parser.add_argument("destination", nargs="?", default="atc_chains.json")
    args = parser.parse_args()

    source_path = Path(args.source)
    destination_path = Path(args.destination)
    original_text = source_path.read_text(encoding="utf-8")
    data = json.loads(original_text)
    compact = {"chains": compact_chains(data)}
    compact_text = json.dumps(compact, separators=(",", ":"))
    destination_path.write_text(compact_text, encoding="utf-8")

    print(f"Compacted {source_path} -> {destination_path}")
    print(f"Old size: {len(original_text.encode('utf-8'))} bytes")
    print(f"New size: {len(compact_text.encode('utf-8'))} bytes")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())