import asyncio
import re
from urllib.parse import urlparse

import httpx

API_BASE = "https://api2.moxfield.com/v3/decks/all"

# A plain "python-httpx/…" UA gets blocked by Moxfield's edge; a normal
# browser UA does not. There's no server-rendered deck data in the page
# HTML to fall back to (it's a client-rendered SPA), so this API call is
# the only viable path — verified by hand against api2.moxfield.com.
HEADERS = {
    "User-Agent": (
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 "
        "(KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36"
    ),
    "Accept": "application/json",
}

# Boards that represent physical cards belonging to the deck. Sideboard and
# maybeboard are staging areas, not part of the actual decklist.
DECK_BOARDS = [
    "mainboard", "commanders", "companions", "signatureSpells",
    "attractions", "contraptions", "planes", "schemes", "stickers",
]

_ID_RE = re.compile(r"^[A-Za-z0-9_-]{6,}$")


def parse_deck_id(text: str) -> str:
    text = text.strip()
    if not text:
        raise ValueError("empty Moxfield URL")
    if "moxfield.com" not in text.lower() and _ID_RE.match(text):
        return text
    parts = [p for p in urlparse(text).path.split("/") if p]
    if len(parts) >= 2 and parts[0] == "decks":
        return parts[1]
    raise ValueError("could not parse a deck id from that Moxfield URL")


async def fetch_deck(client: httpx.AsyncClient, deck_id: str) -> dict:
    url = f"{API_BASE}/{deck_id}"
    r = None
    for attempt in range(4):
        r = await client.get(url, headers=HEADERS)
        if r.status_code == 200:
            return r.json()
        if r.status_code == 404:
            raise ValueError("deck not found on Moxfield (private, deleted, or wrong id?)")
        if r.status_code == 403:
            raise ValueError("Moxfield blocked the request (403) — try again in a bit")
        if r.status_code in (429, 500, 502, 503, 504):
            wait = float(r.headers.get("Retry-After", 2 ** attempt))
            await asyncio.sleep(wait)
            continue
        r.raise_for_status()
    r.raise_for_status()
    raise ValueError("failed to fetch deck from Moxfield")


def _is_token(card: dict) -> bool:
    return card.get("layout") == "token" or (card.get("type_line") or "").startswith("Token")


def extract(deck_json: dict, include_tokens: bool) -> dict:
    """Flatten a Moxfield deck payload into (name, commanders, entries).

    Each entry carries a scryfall_id when Moxfield has one on file, which lets
    the fetch pipeline pull the exact printing (and both faces of a DFC/MDFC)
    straight from Scryfall's /cards/{id} instead of a fuzzy name search.
    """
    boards = deck_json.get("boards", {})
    commanders: list[str] = []
    entries: list[dict] = []

    for board_name in DECK_BOARDS:
        board = boards.get(board_name) or {}
        for row in board.get("cards", {}).values():
            card = row.get("card") or {}
            name = card.get("name") or ""
            scry_id = card.get("scryfall_id")
            qty = max(1, int(row.get("quantity") or 1))
            if board_name == "commanders" and name:
                commanders.append(name)
            for _ in range(qty):
                entries.append({"name": name, "scry_id": scry_id, "is_token": False})

    if include_tokens:
        seen_ids = {e["scry_id"] for e in entries if e["scry_id"]}
        token_cards: dict[str, dict] = {}

        for row in (boards.get("tokens") or {}).get("cards", {}).values():
            c = row.get("card") or {}
            if c.get("scryfall_id"):
                token_cards[c["scryfall_id"]] = c

        for c in (deck_json.get("tokenMappings") or {}).values():
            if c.get("scryfall_id") and _is_token(c):
                token_cards[c["scryfall_id"]] = c

        for scry_id, c in token_cards.items():
            if scry_id in seen_ids:
                continue
            entries.append({"name": c.get("name") or "", "scry_id": scry_id, "is_token": True})

    return {
        "name": deck_json.get("name") or "Moxfield Deck",
        "commanders": commanders,
        "entries": entries,
    }