import json
import os

import requests

CONFIG_FILE = "config.json"
OUTPUT_DIR = "downloads"

MODRINTH_API = "https://api.modrinth.com/v2"


def load_config():
    with open(CONFIG_FILE, "r") as f:
        return json.load(f)


def get_mod_project(mod_id):
    """Fetch project info from Modrinth by slug or ID."""
    url = f"{MODRINTH_API}/project/{mod_id}"
    r = requests.get(url)
    if r.status_code != 200:
        print(f"[!] Failed to get project: {mod_id}")
        return None
    return r.json()


def get_latest_version(project_id, mc_version, loader):
    """Fetch latest version compatible with the MC version + loader."""
    url = f"{MODRINTH_API}/project/{project_id}/version"
    params = {"game_versions": f'["{mc_version}"]', "loaders": f'["{loader}"]'}
    r = requests.get(url, params=params)
    if r.status_code != 200 or len(r.json()) == 0:
        print(f"[!] No compatible versions for {project_id}")
        return None

    # First entry is latest
    return r.json()[0]


def download_file(url, dest):
    r = requests.get(url, stream=True)
    if r.status_code != 200:
        print(f"[!] Failed to download: {url}")
        return
    with open(dest, "wb") as f:
        for chunk in r.iter_content(8192):
            f.write(chunk)


def update_server(name, settings):
    mc_version = settings["mc_version"]
    loader = settings["loader"]
    mods = settings["mods"]

    print(f"\n=== Updating {name} ===")
    out_dir = os.path.join(OUTPUT_DIR, name)
    os.makedirs(out_dir, exist_ok=True)

    for mod in mods:
        print(f"\n→ {mod}")

        project = get_mod_project(mod)
        if not project:
            continue

        project_id = project["id"]
        version = get_latest_version(project_id, mc_version, loader)
        if not version:
            continue

        file_info = version["files"][0]
        filename = file_info["filename"]
        url = file_info["url"]

        dest = os.path.join(out_dir, filename)
        print(f"   Downloading {filename}...")
        download_file(url, dest)

    print(f"\n✔ Finished {name}")


def main():
    config = load_config()

    for server_name, settings in config.items():
        update_server(server_name, settings)

    print("\nAll mods updated!")


if __name__ == "__main__":
    main()