#!/usr/bin/env python3
"""Generate crates/horizon-client/src/lan/tracking.rs: every entity type's
tracking settings (EntityType.Builder clientTrackingRange, updateInterval and
trackDeltas, which ChunkMap.TrackedEntity and ServerEntity use to decide who
sees an entity and how often its movement is sent), read from the decompiled
EntityTypes.java.

  generate_entity_tracking.py [--sources .local/minecraft/<pinned version>/sources/client]
"""
import argparse
import re
from pathlib import Path

try:
    from . import lab
except ImportError:
    import lab

ROOT = Path(__file__).resolve().parents[1]
INT_MAX = 2147483647


def parse(sources):
    text = (sources / "net/minecraft/world/entity/EntityTypes.java").read_text()
    out = []
    for m in re.finditer(r"public static final EntityType<[\w.]+> (\w+) = register\((.*?)\n   \);", text, re.S):
        name, body = m.group(1).lower(), m.group(2)
        range_ = re.findall(r"\.clientTrackingRange\((\d+)\)", body)
        interval = re.findall(r"\.updateInterval\((\w+(?:\.\w+)?)\)", body)
        track = ".dontTrackDeltas()" not in body
        r = int(range_[-1]) if range_ else 5
        if ".noUpdateInterval()" in body or (interval and interval[-1] == "Integer.MAX_VALUE"):
            i = 0
        else:
            i = int(interval[-1]) if interval else 3
        out.append((f"minecraft:{name}", r, i, track))
    return sorted(out)


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--sources", type=Path, default=lab.GAME / "sources/client")
    parser.add_argument("--out", type=Path, default=ROOT / "crates/horizon-client/src/lan/tracking.rs")
    args = parser.parse_args()
    rows = parse(args.sources)
    if len(rows) < 100:
        raise SystemExit(f"only {len(rows)} entity types found")
    lines = [
        "//! Entity tracking settings per entity type (EntityType.Builder",
        "//! clientTrackingRange in chunks, updateInterval in ticks with 0 for never,",
        "//! trackDeltas). Generated by tools/generate_entity_tracking.py from the",
        "//! decompiled EntityTypes.java; do not edit by hand.",
        "",
        "/// (entity type, tracking range in chunks, update interval, track deltas), sorted.",
        "pub const TRACKING: &[(&str, u8, u32, bool)] = &[",
    ]
    lines += [f'    ("{n}", {r}, {i}, {str(t).lower()}),' for n, r, i, t in rows]
    lines += [
        "];",
        "",
        "/// The settings of one entity type; unknown types get the builder defaults.",
        "pub fn settings(kind: &str) -> (u8, u32, bool) {",
        "    TRACKING",
        "        .binary_search_by(|row| row.0.cmp(kind))",
        "        .map_or((5, 3, true), |i| (TRACKING[i].1, TRACKING[i].2, TRACKING[i].3))",
        "}",
        "",
    ]
    args.out.write_text("\n".join(lines))
    print(f"wrote {len(rows)} entity types to {args.out}")


if __name__ == "__main__":
    main()