#!/usr/bin/env python3
"""Build the island world template from world/world.json.

  1. Prepare the local test server (build/server) with the pack, plus Chunky
     (a pregeneration tool, added only for this run and removed afterwards).
  2. Create the world (named after the recipe's "name") with its seed, world
     type and gamerules, and pregenerate a circle of `pregen_radius` around
     0,0 (the island plus a strip of sea; the sea corners inside the square
     border generate when someone gets there).
  3. In the same session: load the circle again row by row until Regenerating
     Ore Veins has put its veins and the companion mod its ore nodes into every
     chunk (both only fill a new chunk while it is loaded, a few a tick, and
     Chunky is faster), save, measure where the land ends (tools/world_report.py)
     and set a square world border `border_margin` blocks outside the outermost
     coast.
  4. Copy the world to build/world-template without player data, then run
     the world checks and render the map (build/island-map.png).

The test server's eula.txt must already accept the Minecraft EULA (run
`tools/smoke_test.py --accept-eula` once); this script never writes it.
For a quick check after a change, use tools/quick_check.py instead.

Usage: tools/make_world.py
"""
import argparse
import json
import math
import re
import shutil
import subprocess
import sys
import time
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent))
from mcserver import BUILD, ROOT, SERVER, Server, chunky, eula_accepted, prepare, scan_log  # noqa: E402
import world_report  # noqa: E402
from numpy import hypot as np_hypot  # noqa: E402

TEMPLATE = BUILD / "world-template"
SKIP = shutil.ignore_patterns("playerdata", "advancements", "stats", "session.lock")


def border_for(world, recipe):
    """Square border around the land, `border_margin` past the outermost coast."""
    data = world_report.analyse(world)
    land = world_report.island_mask(data)
    zs, xs = land.nonzero()
    ox, oz = data["origin"]
    x0, x1 = int(xs.min()) + ox, int(xs.max()) + ox + 1
    z0, z1 = int(zs.min()) + oz, int(zs.max()) + oz + 1
    far = float(np_hypot(xs + ox, zs + oz).max())
    if far + recipe["border_margin"] > recipe["pregen_radius"]:
        sys.exit(f"land reaches {far:.0f} blocks from 0,0; raise pregen_radius ({recipe['pregen_radius']}) in "
                 f"world/world.json to at least land + border_margin")
    cx, cz = round((x0 + x1) / 2), round((z0 + z1) / 2)
    size = max(x1 - x0, z1 - z0) + 2 * recipe["border_margin"]
    print(f"land spans x {x0}..{x1}, z {z0}..{z1}, at most {far:.0f} blocks from 0,0; "
          f"border center {cx},{cz} size {size}")
    return cx, cz, size


def fill_veins(server, radius):
    """Keep each chunk row of the pregenerated circle loaded until the vein mod has filled it; returns chunks left."""
    # A forced row also fully loads the two chunks around it (some of them new, past the circle's edge), so the wait
    # counts the loaded, unfilled chunks in the row and two chunks around it.
    started, left, rows = time.time(), 0, radius // 16 + 1
    for cz in range(-rows, rows + 1):
        half = math.isqrt(max(0, rows * rows - cz * cz))
        area = f"{-half * 16} {cz * 16} {half * 16 + 15} {cz * 16 + 15}"
        around = f"{-half * 16 - 32} {cz * 16 - 32} {half * 16 + 47} {cz * 16 + 47}"
        server.command(f"forceload add {area}")
        deadline = time.time() + 60
        while True:
            reply = server.command(f"cobblesurvival veins unfilled {around}")
            match = re.search(r"unfilled chunks: (\d+)", reply)
            if not match:
                raise RuntimeError(f"veins unfilled: unexpected reply {reply!r}")
            unfilled = int(match[1])
            if unfilled == 0 or time.time() > deadline:
                break
            time.sleep(0.5)
        server.command(f"forceload remove {area}")
        left += unfilled
    print(f"veins filled in {time.time() - started:.0f}s" + (f"; {left} chunks left unfilled" if left else ""))
    return left


def main():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.parse_args()
    if not eula_accepted():
        sys.exit("build/server/eula.txt does not accept the Minecraft EULA yet; run "
                 "tools/smoke_test.py --accept-eula first if you accept it.")

    recipe = json.loads((ROOT / "world/world.json").read_text())
    args_file = prepare()
    world = SERVER / recipe["name"]
    shutil.rmtree(world, ignore_errors=True)
    props = {"level-name": recipe["name"], "level-seed": recipe["seed"], "level-type": recipe["level_type"]}
    with chunky(recipe), Server(args_file, props, heap="8G", stdout_name="make-world-stdout.log") as server:
        print(f"server started in {server.wait_ready():.0f}s")
        status = server.command("worldgen_editor status")
        if "cobblesurvival_island" not in status:
            raise RuntimeError(f"world did not get the island world type:\n{status}")
        for rule, value in recipe.get("gamerules", {}).items():
            print(f"  {server.command(f'gamerule {rule} {str(value).lower()}').strip()}")
        seconds = server.pregenerate(0, 0, recipe["pregen_radius"], shape="circle")
        print(f"pregeneration finished in {seconds:.0f}s")
        fill_veins(server, recipe["pregen_radius"])
        server.command("save-all flush")
        cx, cz, size = border_for(world, recipe)
        print(f"  {server.command(f'worldborder center {cx} {cz}').strip()}")
        print(f"  {server.command(f'worldborder set {size}').strip()}")
        server.command("save-all flush")
        server.stop()
    problems = scan_log(server.log)
    if problems:
        print("server log problems:\n" + "\n".join(f"  - {p}" for p in problems))

    shutil.rmtree(TEMPLATE, ignore_errors=True)
    shutil.copytree(world, TEMPLATE, ignore=SKIP)
    size = sum(f.stat().st_size for f in TEMPLATE.rglob("*") if f.is_file())
    print(f"world template: {TEMPLATE.relative_to(ROOT)} ({size / 1e6:.0f} MB)")
    result = subprocess.run([sys.executable, "-I", str(ROOT / "tools/world_report.py"), str(TEMPLATE)])
    sys.exit(result.returncode or (1 if problems else 0))


if __name__ == "__main__":
    main()