cobblemon-survival-pack/tools/cobblebase_loot.py

#!/usr/bin/env python3
"""Write the pack's versions of Cobblebase's mining and finder loot tables: a pasture only yields its zone's ores.

Adrian (2026-10-31): Cobblebase's Mining skill should only dig up the ores of the zone its pasture is in. Its tables,
and those of the Ore Finder and the Evolution-item Finder, which hand out the same ores and evolution stones, ignore
the island's zones. This copies them from the Cobblebase jar in build/server/mods and puts the loot condition
`cobblesurvival:in_zone` on every ore and evolution stone, naming the zone of its tier in world/zones.json. The mining
tables also lose the type gems (crafting shortcuts to gate materials such as the Heat Rock; ruins archaeology still
has them) and gain the zone ores Cobblebase leaves out (quartz, the evolution stones). The companion mod takes
Cobblebase's built-in copies of these tables out at server start (ore/BaseLoot.kt), so these files are what is rolled.

Output: datapacks/core/data/cobblebase/loot_table/<table>.json (derived from Cobblebase, MPL-2.0).

Usage: tools/cobblebase_loot.py
"""

import json
import sys
import zipfile
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
OUT = ROOT / "datapacks/core/data/cobblebase/loot_table"
CONDITION = "cobblesurvival:in_zone"

# What an ore tier of world/zones.json drops; evolution-stone tiers drop their stone.
TIER_ITEMS = {
    "coal": ["minecraft:coal"],
    "copper": ["minecraft:raw_copper"],
    "iron": ["minecraft:raw_iron"],
    "gold": ["minecraft:raw_gold"],
    "redstone": ["minecraft:redstone"],
    "lapis": ["minecraft:lapis_lazuli"],
    "emerald": ["minecraft:emerald"],
    "amethyst": ["minecraft:amethyst_shard"],
    "diamond": ["minecraft:diamond"],
    "quartz": ["minecraft:quartz"],
    "netherite": ["minecraft:ancient_debris", "minecraft:netherite_scrap"],
}

# Table families: which items get the zone condition, which are dropped, and where missing zone items are added
# (rarity suffix and weight, like Cobblebase's neighbouring entries).
FAMILIES = {
    "mining_": {"zoned": ("ore", "stone"), "drop_gems": True, "add": {"ore": ("uncommon", 8), "stone": ("rare", 3)}},
    "finder_ore_": {"zoned": ("ore",), "drop_gems": False, "add": {"ore": ("uncommon", 8)}},
    "finder_evo_": {"zoned": ("stone",), "drop_gems": False, "add": {"stone": ("common", 10)}},
}


def cobblebase_jar():
    jars = sorted((ROOT / "build/server/mods").glob("cobblebase-*.jar"))
    if not jars:
        sys.exit("no Cobblebase jar in build/server/mods: run tools/build.py and tools/selftest.py (or the quick check) first")
    return jars[-1]


def zone_items():
    """item id -> (kind, zone) for every ore tier of world/zones.json."""
    ores = json.loads((ROOT / "world/zones.json").read_text())["ores"]
    items = {}
    for tier, ore in ores.items():
        if tier.endswith("_stone"):
            drops, kind = [f"cobblemon:{tier}"], "stone"
        elif tier in TIER_ITEMS:
            drops, kind = TIER_ITEMS[tier], "ore"
        else:
            sys.exit(f"ore tier {tier} has no drop in TIER_ITEMS")
        for item in drops:
            items[item] = (kind, ore["zone"])
    return items


def rewrite(table, family, items):
    spec = FAMILIES[family]
    seen = set()
    for pool in table["pools"]:
        kept = []
        for entry in pool["entries"]:
            name = entry.get("name", "")
            if spec["drop_gems"] and name.endswith("_gem"):
                continue
            kind, zone = items.get(name, (None, None))
            if kind in spec["zoned"]:
                entry = dict(entry, conditions=[{"condition": CONDITION, "zones": [zone]}])
                seen.add(name)
            kept.append(entry)
        pool["entries"] = kept
    return seen


def main():
    items = zone_items()
    jar = zipfile.ZipFile(cobblebase_jar())
    prefix = "data/cobblebase/loot_table/"
    names = sorted(n[len(prefix):-5] for n in jar.namelist() if n.startswith(prefix) and n.endswith(".json"))
    OUT.mkdir(parents=True, exist_ok=True)
    written = []
    for family, spec in FAMILIES.items():
        tables = {name: json.loads(jar.read(f"{prefix}{name}.json")) for name in names if name.startswith(family)}
        if not tables:
            sys.exit(f"Cobblebase has no {family}* loot tables any more")
        seen = set()
        for table in tables.values():
            seen |= rewrite(table, family, items)
        for item, (kind, zone) in sorted(items.items()):
            if kind not in spec["zoned"] or item in seen:
                continue
            rarity, weight = spec["add"][kind]
            target = tables.get(f"{family}{rarity}")
            if target is None:
                sys.exit(f"no table {family}{rarity} to add {item} to")
            target["pools"][0]["entries"].append({
                "type": "minecraft:item", "name": item, "weight": weight,
                "conditions": [{"condition": CONDITION, "zones": [zone]}],
            })
        for name, table in tables.items():
            (OUT / f"{name}.json").write_text(json.dumps(table, indent=2, ensure_ascii=False) + "\n")
            written.append(name)
    print(f"wrote {len(written)} tables to {OUT.relative_to(ROOT)}: {', '.join(written)}")
    by_zone = {}
    for item, (kind, zone) in items.items():
        by_zone.setdefault(zone, []).append(item.split(":")[1])
    for zone, zoned in sorted(by_zone.items()):
        print(f"  {zone}: {', '.join(sorted(zoned))}")


if __name__ == "__main__":
    main()