import re
import shutil

from fastapi import APIRouter, HTTPException, Request

import db
import worker
from config import OUTPUTS

router = APIRouter()


def slugify(name: str) -> str:
    return re.sub(r"[^a-z0-9]+", "_", name.lower().strip()).strip("_")


def valid_slug(slug: str) -> str:
    if not re.match(r"^[a-z0-9_]+$", slug):
        raise HTTPException(400, "invalid slug")
    return slug


@router.get("/decks")
async def list_decks():
    return [dict(d) for d in db.get_decks()]


@router.get("/decks/{slug}")
async def get_deck(slug: str):
    slug = valid_slug(slug)
    d = db.get_deck(slug)
    if not d:
        raise HTTPException(404)
    return {**dict(d), "log": db.get_logs(slug)}


@router.post("/decks", status_code=201)
async def create_deck(request: Request):
    body = await request.json()
    name = body.get("deck_name", "").strip()
    card_text = body.get("cards", "").strip()
    commander = body.get("commander", "").strip()
    if not name or not card_text:
        raise HTTPException(400, "deck_name and cards required")

    slug = slugify(name)
    card_names = [l.strip() for l in card_text.splitlines() if l.strip()]
    if not card_names:
        raise HTTPException(400, "no cards")
    if not commander:
        commander = card_names[0]

    # Commander always at position 0; remove any existing occurrence first
    card_names = [n for n in card_names if n != commander]
    card_names.insert(0, commander)

    existing = db.get_deck(slug)
    if existing and existing["status"] in ("queued", "running"):
        raise HTTPException(409, "deck already processing")

    with db.conn() as c:
        c.execute(
            "INSERT OR REPLACE INTO decks (slug, deck_name, status, commander, price_usd, done, total) VALUES (?,?,?,?,0,0,?)",
            (slug, name, "queued", commander, len(card_names))
        )
        c.execute("DELETE FROM cards WHERE deck_slug=?", (slug,))
        c.execute("DELETE FROM logs WHERE deck_slug=?", (slug,))
        for i, card_name in enumerate(card_names):
            c.execute(
                "INSERT INTO cards (deck_slug, name, position, fetch_status) VALUES (?,?,?,'pending')",
                (slug, card_name, i + 1)
            )

    await worker.queue.put(slug)
    return {"slug": slug}


@router.patch("/decks/{slug}")
async def edit_deck(slug: str, request: Request):
    slug = valid_slug(slug)
    deck = db.get_deck(slug)
    if not deck:
        raise HTTPException(404)
    if deck["status"] in ("queued", "running"):
        raise HTTPException(409, "deck is processing")

    body = await request.json()
    remove_ids: list[int] = body.get("remove", [])
    add_names: list[str] = [n.strip() for n in body.get("add", []) if n.strip()]
    new_name: str = body.get("deck_name", deck["deck_name"]).strip() or deck["deck_name"]
    new_commander: str = body.get("commander", deck["commander"]).strip() or deck["commander"]

    with db.conn() as c:
        for cid in remove_ids:
            row = c.execute(
                "SELECT filename FROM cards WHERE id=? AND deck_slug=?", (cid, slug)
            ).fetchone()
            if row and row["filename"]:
                p = OUTPUTS / slug / row["filename"]
                if p.exists():
                    p.unlink()
            c.execute("DELETE FROM cards WHERE id=? AND deck_slug=?", (cid, slug))

        max_pos = c.execute(
            "SELECT COALESCE(MAX(position), 0) FROM cards WHERE deck_slug=?", (slug,)
        ).fetchone()[0]

        for i, card_name in enumerate(add_names):
            c.execute(
                "INSERT INTO cards (deck_slug, name, position, fetch_status) VALUES (?,?,?,'pending')",
                (slug, card_name, max_pos + i + 1)
            )

        # Ensure commander has a card row; if not, insert at position 0 so it sorts first
        existing_commander = c.execute(
            "SELECT id FROM cards WHERE deck_slug=? AND name=? LIMIT 1",
            (slug, new_commander)
        ).fetchone()
        if not existing_commander:
            c.execute(
                "INSERT INTO cards (deck_slug, name, position, fetch_status) VALUES (?,?,0,'pending')",
                (slug, new_commander)
            )

        c.execute(
            "UPDATE decks SET deck_name=?, commander=?, status='queued' WHERE slug=?",
            (new_name, new_commander, slug)
        )
        c.execute("INSERT INTO logs (deck_slug, line) VALUES (?,?)", (slug, "Deck edited — re-queued."))

    db.recalc_done(slug)
    await worker.queue.put(slug)
    return {"slug": slug}


@router.delete("/decks/{slug}", status_code=204)
async def delete_deck(slug: str):
    slug = valid_slug(slug)
    deck = db.get_deck(slug)
    if not deck:
        raise HTTPException(404)
    if deck["status"] in ("queued", "running"):
        raise HTTPException(409, "can't delete while processing")

    deck_dir = OUTPUTS / slug
    if deck_dir.exists():
        shutil.rmtree(deck_dir)
    with db.conn() as c:
        c.execute("DELETE FROM decks WHERE slug=?", (slug,))
    return None