#!/usr/bin/env python3
"""Generate crates/horizon-command/src/vanilla_order.rs: the order of
the children of each node of vanilla's command tree where Horizon's tree
registers them in a different order. Brigadier keeps children in
registration order, and /help (smart usage) lists them that way.

  python3 tools/test_command_parse_parity.py         # exports .local/command-parse-parity/tree.json
  command_parse_fixture tree rust_tree.json          # Horizon's tree in its registration order
  generate_command_order.py VANILLA_TREE RUST_TREE
"""
import argparse
import json
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]


def main():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("vanilla", type=Path)
    parser.add_argument("rust", type=Path)
    parser.add_argument("--out", type=Path, default=ROOT / "crates/horizon-command/src/vanilla_order.rs")
    args = parser.parse_args()
    vanilla = json.loads(args.vanilla.read_text())
    rust = json.loads(args.rust.read_text())
    rows = []

    def walk(v, r, path):
        names = list(v.get("children", {}))
        # GameRuleCommand registers the rules in a Reference2ObjectOpenHashMap's
        # (identity hash) order, which changes from run to run.
        if path == ["gamerule"]:
            return
        order = r.get("order", [])
        shared = [n for n in names if n in order]
        if shared != [n for n in order if n in names]:
            rows.append((" ".join(path), shared))
        for n in names:
            if n in r.get("children", {}):
                walk(v["children"][n], r["children"][n], path + [n])

    walk(vanilla, rust, [])
    if not rows or rows[0][0] != "":
        raise SystemExit("expected the root's order to differ")
    lines = [
        "//! The order of node children in vanilla's command tree, for the nodes",
        "//! where Horizon's tree registers them differently (path of node names",
        "//! from the root, children in vanilla's order). Generated by",
        "//! tools/generate_command_order.py; do not edit by hand.",
        "",
        "pub const ORDER: &[(&str, &[&str])] = &[",
    ]
    for path, names in rows:
        joined = ", ".join(f'"{n}"' for n in names)
        lines.append(f'    ("{path}", &[{joined}]),')
    lines += ["];", ""]
    args.out.write_text("\n".join(lines))
    print(f"wrote {len(rows)} nodes to {args.out}")


if __name__ == "__main__":
    main()