"""Download the full scunpacked dataset into a target directory.

Usage:
    python scripts/fetch_data.py [--output-dir DIR]

Default output: backend/data/full (used by the Docker image build).
"""
import argparse
import json
import os
import sys
import urllib.request

BASE_URL = "https://raw.githubusercontent.com/StarCitizenWiki/scunpacked-data/master"
FILES = [
    "ships.json",
    "ship-items.json",
    "fps-items.json",
    "manufacturers.json",
    "items.json",
]
COMMODITY_KEYS = ("className", "name", "type", "subType", "reference")
PLACEHOLDER = "<= PLACEHOLDER =>"


def _commodity_rank(entry):
    class_name = entry.get("className") or ""
    return (0 if "_1SCU_" in class_name else 1, entry.get("size") or 0, class_name)


def build_commodities(items_path, out_path):
    with open(items_path, encoding="utf-8") as f:
        items = json.load(f)

    grouped = {}
    for entry in items:
        class_name = (entry.get("className") or "").lower()
        name = (entry.get("name") or "").strip()
        if entry.get("type") != "Cargo" or "commodity" not in class_name:
            continue
        if not name or name == PLACEHOLDER:
            continue
        grouped.setdefault(name, []).append(entry)

    commodities = [
        {key: best.get(key) for key in COMMODITY_KEYS}
        for best in (min(grouped[name], key=_commodity_rank) for name in sorted(grouped))
    ]
    with open(out_path, "w", encoding="utf-8") as f:
        json.dump(commodities, f, ensure_ascii=False, separators=(",", ":"))
    return len(commodities)


def main():
    default_dir = os.path.abspath(
        os.path.join(os.path.dirname(__file__), "..", "data", "full")
    )
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--output-dir", default=default_dir)
    args = parser.parse_args()

    os.makedirs(args.output_dir, exist_ok=True)
    for name in FILES:
        url = f"{BASE_URL}/{name}"
        dest = os.path.join(args.output_dir, name)
        print(f"Downloading {url} -> {dest}", flush=True)
        urllib.request.urlretrieve(url, dest)
        size = os.path.getsize(dest)
        print(f"  done ({size / 1_000_000:.1f} MB)", flush=True)

    items_path = os.path.join(args.output_dir, "items.json")
    count = build_commodities(
        items_path, os.path.join(args.output_dir, "commodities.json")
    )
    os.remove(items_path)
    print(f"Wrote {count} commodities (items.json discarded)", flush=True)
    return 0


if __name__ == "__main__":
    sys.exit(main())