#!/usr/bin/env python3
"""Write Regenerating Ore Veins' config from the zone plan, so every ore tier only has veins in its zone.

world/zones.json → "ores" lists the tiers. This tool writes pack/config/regenerating_ore_veins/:

  * areas.json: each surface zone that has a tier, as boxes from the zone grid (build/zone-layout.json,
    24-block cells; rows of cells merged into rectangles), named <zone>_<n>, reaching from bedrock to
    the build limit. The mod's boxes are centre plus half-size, so a box covers its cells except their
    last row and column of blocks: no box reaches into a neighbouring zone.
  * veins.json: one vein per tier, or two when the tier has "stone" and "deepslate" blocks (an upper vein
    from y 0 up, "<tier>_deep" below). A surface tier's veins are limited to its zone's boxes and kept out
    of the cave biomes, which are zones of their own; a cave tier's veins to its cave biome. The mod checks
    the area for every block and the biome at a vein's centre. One vein only for the self-tests comes
    last ("selftest", a single coal block); its area lies far outside the world border, so it never
    generates, and the tests place it by command. Each tier with "showcase" also gets "<tier>_showcase", a full
    radius-2 vein in the same place-only area, which tools/make_world.py places by hand near the zone's sample point.
  * global.json: regenerators can't be broken by players (allow_breaking false), so nobody can remove a
    vein for good; explosions don't destroy veins.
  * vein_locator.json: the Vein Locator from a compass and a copper ingot (mid-game) instead of netherite.

It also writes world/vein-sources.json, the veins as item sources for the field guide (tools/fieldguide/build.py
reads it by default): what each tier's blocks drop and in which zone.

Re-run after changing the zone plan or the grid (tools/zone_layout.py) and commit the result.

Usage: tools/zone_ores.py
"""
import json
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent
OUT = ROOT / "pack/config/regenerating_ore_veins"
LAYOUT = ROOT / "build/zone-layout.json"
BOTTOM, TOP = -64, 320
SELFTEST_AREA = "selftest_nowhere"
SOURCES = ROOT / "world/vein-sources.json"
# What an ore block drops, where it isn't the block itself or "<name>_ore" → "<name>".
DROPS = {"iron": "raw_iron", "copper": "raw_copper", "gold": "raw_gold", "lapis": "lapis_lazuli",
         "nether_quartz": "quartz", "amethyst_block": "amethyst_block", "budding_amethyst": "amethyst_shard"}


def drop_of(block):
    namespace, name = block.split(":")
    base = name.removeprefix("deepslate_").removeprefix("dripstone_").removeprefix("terracotta_")
    base = base.removesuffix("_ore") if base.endswith("_ore") else base
    return f"{namespace}:{DROPS.get(base, base)}"


def rectangles(mask, size):
    """Cover the True cells of a size×size row-major mask with rectangles (col0, row0, col1, row1)."""
    open_runs, done = {}, []
    for row in range(size + 1):
        runs = set()
        col = 0
        while row < size and col < size:
            if mask[row * size + col]:
                start = col
                while col < size and mask[row * size + col]:
                    col += 1
                runs.add((start, col - 1))
            col += 1
        for run in list(open_runs):
            if run not in runs:
                done.append((run[0], open_runs.pop(run), run[1], row - 1))
        for run in runs:
            open_runs.setdefault(run, row)
    return sorted(done, key=lambda r: (r[1], r[0]))


def zone_areas(layout, zone_id):
    size, step, radius = layout["size"], layout["step"], layout["radius"]
    index = layout["zones"].index(zone_id)
    mask = [value == index for value in layout["grid"]]
    areas = []
    for n, (c0, r0, c1, r1) in enumerate(rectangles(mask, size)):
        # Cell i covers -radius - step/2 + i*step ... +step-1 (as in zone/Zones.kt).
        x0, z0 = c0 * step - radius - step // 2, r0 * step - radius - step // 2
        w, h = (c1 - c0 + 1) * step, (r1 - r0 + 1) * step
        areas.append({"dimension": "minecraft:overworld", "name": f"{zone_id}_{n}", "type": "box",
                      "x": x0 + w // 2 - 1, "y": (BOTTOM + TOP) // 2, "z": z0 + h // 2 - 1,
                      "dimx": w // 2 - 1, "dimy": (TOP - BOTTOM) // 2, "dimz": h // 2 - 1})
    return areas


def vein(vein_id, blocks, spec, defaults, y_range, where):
    seconds = spec["regen_minutes"] * 60
    jitter = round(seconds * spec.get("jitter", defaults["jitter"]))
    return {
        "id": vein_id,
        "blocks": [b for b, _ in blocks],
        "weights": [w for _, w in blocks],
        "dimension_whitelist": ["minecraft:overworld"],
        **where,
        "shape": "sphere",
        "min_radius": spec["radius"][0],
        "max_radius": spec["radius"][1],
        "attempts": spec.get("attempts", defaults["attempts"]),
        "min_y": y_range[0],
        "max_y": y_range[1],
        "chunk_minimum_generation_separation": spec["spacing"],
        "fill_factor": spec.get("fill", defaults["fill"]),
        "regeneration_interval_seconds": seconds,
        "regeneration_interval_jitter": {"range_min": -jitter, "range_max": jitter},
    }


def selftest_vein():
    return {"id": "selftest", "blocks": ["minecraft:coal_ore"], "dimension_whitelist": ["minecraft:overworld"],
            "area_whitelist": [SELFTEST_AREA], "shape": "sphere", "min_radius": 0, "max_radius": 0,
            "attempts": 1, "min_y": 0, "max_y": 0, "chunk_minimum_generation_separation": 64,
            "fill_factor": 1.0, "regeneration_interval_seconds": 3600,
            "regeneration_interval_jitter": {"range_min": 0, "range_max": 0}}


def main():
    if not LAYOUT.exists():
        sys.exit(f"{LAYOUT.relative_to(ROOT)} is missing: run tools/zone_layout.py first.")
    layout = json.loads(LAYOUT.read_text())
    plan = json.loads((ROOT / "world/zones.json").read_text())
    defaults = plan["ore_defaults"]
    caves = {c["id"]: c["biome"] for c in plan["caves"]}
    surface = {z["id"] for z in plan["zones"]}

    areas, area_names, veins = [], {}, []
    for tier, spec in plan["ores"].items():
        zone = spec["zone"]
        if zone in caves:
            where = {"biome_whitelist": [caves[zone]]}
        elif zone in surface:
            if zone not in area_names:
                boxes = zone_areas(layout, zone)
                if not boxes:
                    sys.exit(f"zone {zone} (ore tier {tier}) has no cells in the grid")
                areas += boxes
                area_names[zone] = [a["name"] for a in boxes]
            where = {"area_whitelist": area_names[zone], "biome_blacklist": sorted(caves.values())}
        else:
            sys.exit(f"ore tier {tier}: unknown zone {zone}")
        low, high = spec["y"]
        if spec.get("showcase"):
            blocks = [(spec["stone"], 1)] if spec.get("stone") else [tuple(b) for b in spec["blocks"]]
            showcase = vein(f"{tier}_showcase", blocks, spec, defaults, (0, 0), {"area_whitelist": [SELFTEST_AREA]})
            veins.append({**showcase, "min_radius": 2, "max_radius": 2, "fill_factor": 0.8})
        if "blocks" in spec:
            veins.append(vein(tier, spec["blocks"], spec, defaults, (low, high), where))
            continue
        if spec.get("stone") and high >= 0:
            veins.append(vein(tier, [(spec["stone"], 1)], spec, defaults, (max(low, 0), high), where))
        if spec.get("deepslate") and low < 0:
            deep_id = f"{tier}_deep" if spec.get("stone") and high >= 0 else tier
            veins.append(vein(deep_id, [(spec["deepslate"], 1)], spec, defaults, (low, min(high, -1)), where))

    areas.append({"dimension": "minecraft:overworld", "name": SELFTEST_AREA, "type": "box",
                  "x": 29_000_000, "y": 0, "z": 29_000_000, "dimx": 0, "dimy": 0, "dimz": 0})
    veins.append(selftest_vein())

    OUT.mkdir(parents=True, exist_ok=True)
    (OUT / "areas.json").write_text(json.dumps(areas, indent=1) + "\n")
    (OUT / "veins.json").write_text(json.dumps(veins, indent=1) + "\n")
    (OUT / "global.json").write_text(json.dumps({
        "allow_breaking": False,
        "break_hardness": 5.0,
        "default_regeneration_seconds": 3600,
        "default_jitter_interval": {"range_min": 0, "range_max": 0},
        "regeneration_smoke_particles": True,
        "destroyed_by_explosives": False,
        "default_fill_factor": defaults["fill"],
    }, indent=2) + "\n")
    (OUT / "vein_locator.json").write_text(json.dumps({
        "allow_crafting": True,
        "allow_use": True,
        "crafting_recipe": ["minecraft:compass", "minecraft:copper_ingot"],
        "craft_any_order": True,
        "chance_to_break": 0.75,
        "use_durability": False,
        "durability": 2,
        "stack_size": 64,
    }, indent=2) + "\n")
    names = {z["id"]: z["name"] for z in plan["zones"] + plan["caves"]}
    sources = []
    for tier, spec in plan["ores"].items():
        blocks = [b for b, _ in spec.get("blocks", [])] + [spec[k] for k in ("stone", "deepslate") if spec.get(k)]
        for item in dict.fromkeys(drop_of(b) for b in blocks):
            sources.append({"item": item, "how": f"Regenerating {tier.replace('_', ' ')} vein in {names[spec['zone']]}",
                            "kind": "ore vein", "needs": []})
    SOURCES.write_text(json.dumps({
        "_comment": "Generated by tools/zone_ores.py from world/zones.json; extra item sources for the field guide.",
        "sources": sources}, indent=1) + "\n")
    per_zone = {}
    for tier, spec in plan["ores"].items():
        per_zone.setdefault(spec["zone"], []).append(tier)
    print(f"wrote {len(veins)} veins ({len(plan['ores'])} tiers) and {len(areas)} areas to {OUT.relative_to(ROOT)}")
    for zone, tiers in per_zone.items():
        boxes = len(area_names.get(zone, []))
        print(f"  {zone}: {', '.join(tiers)}" + (f" ({boxes} boxes)" if boxes else " (cave biome)"))


if __name__ == "__main__":
    main()