import json
from pathlib import Path
import sys
from urllib.request import urlretrieve

API = "https://rustplatform.com/api/"
DOWNLOAD_FILE = "exercises.json"
if not Path(DOWNLOAD_FILE).exists():
    urlretrieve(API, DOWNLOAD_FILE)
    print(f"Saved to {DOWNLOAD_FILE}")

data = json.load(open(DOWNLOAD_FILE))
root = Path(sys.argv[1]) if len(sys.argv) > 1 else Path("rust_bites")


def crate_toml(name: str, libraries: str) -> str:
    libs = libraries.strip()
    deps_block = f"\n[dependencies]\n{libs}\n" if libs else ""
    return f"""[package]
name = "{name}"
version = "0.1.0"
edition = "2021"{deps_block}"""


def root_toml(members) -> str:
    return (
        '[workspace]\nresolver = "2"\nmembers = [\n'
        + "".join(f'  "{m}",\n' for m in members)
        + "]\n"
    )


def lf(s: str) -> str:
    return s.replace("\r\n", "\n").replace("\r", "\n")


new_count = 0
members = []
for ex in data:
    lvl = ex["level"].strip().lower().replace(" ", "-")
    slug = ex["slug"]
    base = root / "exercises" / lvl / slug
    is_new = not base.exists()

    (base / "src").mkdir(parents=True, exist_ok=True)

    if is_new:
        new_count += 1
        (base / "Cargo.toml").write_text(
            crate_toml(slug, ex.get("libraries", "")), encoding="utf-8"
        )
        template = lf(ex["template"]).rstrip() + "\n"
        desc = lf(ex["description"]).rstrip() + "\n"
        (base / "src" / "lib.rs").write_text(template, encoding="utf-8")
        (base / "bite.md").write_text(f"# {ex['name']}\n\n{desc}", encoding="utf-8")

    members.append((Path("exercises") / lvl / slug).as_posix())

(root / "Cargo.toml").write_text(root_toml(members), encoding="utf-8")

print(f"Added {new_count} new exercises. Total now: {len(members)} under {root}")