#!/usr/bin/env python3
"""Create or update a Prism Launcher instance from build/stage/full.

Writes instance.cfg and mmc-pack.json (Minecraft + NeoForge from pack.toml),
then syncs the client-side files with packwiz-installer. Run tools/build.py
first. Run it again after changing the pack; options and saves in the
instance are left alone. Close the instance in Prism before syncing.

When build/world-template exists (tools/make_world.py), it is copied into the
instance as the save "Cobblemon Survival Island" unless that save already
exists; --replace-world overwrites it, --save-name puts it into another save
folder instead (e.g. next to a save someone has played).

Usage: tools/prism_instance.py [--name NAME] [--prism-dir DIR] [--memory MB] [--replace-world] [--save-name NAME]
"""
import argparse
import json
import shutil
import sys
import tomllib
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parent))
from packwiz_sync import sync  # noqa: E402

ROOT = Path(__file__).resolve().parent.parent
PRISM_DIRS = (Path.home() / ".var/app/org.prismlauncher.PrismLauncher/data/PrismLauncher",
              Path.home() / ".local/share/PrismLauncher")


def write_cfg(path, name, memory):
    settings = {}
    if path.exists():
        for line in path.read_text().splitlines():
            if "=" in line:
                key, value = line.split("=", 1)
                settings[key] = value
    settings.update({
        "InstanceType": "OneSix",
        "name": name,
        "iconKey": settings.get("iconKey", "default"),
        "notes": "Dev instance of the Cobblemon Survival Pack, synced by tools/prism_instance.py",
        "OverrideMemory": "true",
        "MinMemAlloc": "1024",
        "MaxMemAlloc": str(memory),
        "AutomaticJava": "true",
    })
    body = "[General]\n" + "".join(f"{k}={v}\n" for k, v in sorted(settings.items()) if k != "[General]")
    path.write_text(body)


def write_components(path, versions):
    path.write_text(json.dumps({
        "components": [
            {"uid": "net.minecraft", "version": versions["minecraft"], "important": True},
            {"uid": "net.neoforged", "version": versions["neoforge"]},
        ],
        "formatVersion": 1,
    }, indent=4) + "\n")


def main():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("--name", default="Cobblemon Survival Pack (dev)")
    parser.add_argument("--prism-dir", type=Path, help="Prism data folder (auto-detected)")
    parser.add_argument("--memory", type=int, default=6144, help="max heap in MB")
    parser.add_argument("--replace-world", action="store_true", help="overwrite the island save in the instance")
    parser.add_argument("--save-name", default="Cobblemon Survival Island", help="save folder for the world template")
    args = parser.parse_args()

    prism = args.prism_dir or next((d for d in PRISM_DIRS if (d / "instances").is_dir()), None)
    if not prism:
        sys.exit("Prism Launcher data folder not found; pass --prism-dir")
    stage = ROOT / "build/stage/full"
    if not (stage / "pack.toml").exists():
        sys.exit("build/stage/full is missing; run tools/build.py first")

    instance = prism / "instances" / args.name
    game = instance / "minecraft"
    game.mkdir(parents=True, exist_ok=True)
    pack = tomllib.loads((stage / "pack.toml").read_text())
    write_cfg(instance / "instance.cfg", args.name, args.memory)
    write_components(instance / "mmc-pack.json", pack["versions"])
    sync("client", game, stage)

    template, save = ROOT / "build/world-template", game / "saves" / args.save_name
    if (template / "level.dat").exists():
        if save.exists() and not args.replace_world:
            print(f"kept existing save {save.name} (use --replace-world to overwrite it)")
        else:
            shutil.rmtree(save, ignore_errors=True)
            shutil.copytree(template, save)
            print(f"installed world template as save {save.name}")
    print(f"Prism instance ready: {instance}")


if __name__ == "__main__":
    main()