"""Cart app data endpoints.

Exposes read-only JSON queries at ``/internal/data/<query_name>`` for
cross-app callers via the internal data client.
"""
from __future__ import annotations

from quart import Blueprint, g, jsonify, request

from shared.infrastructure.data_client import DATA_HEADER
from shared.contracts.dtos import dto_to_dict
from shared.services.registry import services


def register() -> Blueprint:
    bp = Blueprint("data", __name__, url_prefix="/internal/data")

    @bp.before_request
    async def _require_data_header():
        if not request.headers.get(DATA_HEADER):
            return jsonify({"error": "forbidden"}), 403
        from shared.infrastructure.internal_auth import validate_internal_request
        if not validate_internal_request():
            return jsonify({"error": "forbidden"}), 403

    _handlers: dict[str, object] = {}

    @bp.get("/<query_name>")
    async def handle_query(query_name: str):
        handler = _handlers.get(query_name)
        if handler is None:
            return jsonify({"error": "unknown query"}), 404
        result = await handler()
        return jsonify(result)

    # --- cart-summary ---
    async def _cart_summary():
        user_id = request.args.get("user_id", type=int)
        session_id = request.args.get("session_id")
        page_slug = request.args.get("page_slug")
        summary = await services.cart.cart_summary(
            g.s, user_id=user_id, session_id=session_id, page_slug=page_slug,
        )
        return dto_to_dict(summary)

    _handlers["cart-summary"] = _cart_summary

    # --- page-config-ensure ---
    async def _page_config_ensure():
        """Get or create a PageConfig for a container_type + container_id."""
        from sqlalchemy import select
        from shared.models.page_config import PageConfig

        container_type = request.args.get("container_type", "page")
        container_id = request.args.get("container_id", type=int)
        if container_id is None:
            return {"error": "container_id required"}, 400

        row = (await g.s.execute(
            select(PageConfig).where(
                PageConfig.container_type == container_type,
                PageConfig.container_id == container_id,
            )
        )).scalar_one_or_none()

        if row is None:
            row = PageConfig(
                container_type=container_type,
                container_id=container_id,
                features={},
            )
            g.s.add(row)
            await g.s.flush()

        return {
            "id": row.id,
            "container_type": row.container_type,
            "container_id": row.container_id,
        }

    _handlers["page-config-ensure"] = _page_config_ensure

    # --- cart-items (product slugs + quantities for template rendering) ---
    async def _cart_items():
        from sqlalchemy import select
        from shared.models.market import CartItem

        user_id = request.args.get("user_id", type=int)
        session_id = request.args.get("session_id")

        filters = [CartItem.deleted_at.is_(None)]
        if user_id is not None:
            filters.append(CartItem.user_id == user_id)
        elif session_id is not None:
            filters.append(CartItem.session_id == session_id)
        else:
            return []

        result = await g.s.execute(
            select(CartItem).where(*filters)
        )
        items = result.scalars().all()
        return [
            {
                "product_id": item.product_id,
                "product_slug": item.product_slug,
                "quantity": item.quantity,
            }
            for item in items
        ]

    _handlers["cart-items"] = _cart_items

    # --- page-config ---
    async def _page_config():
        """Return a single PageConfig by container_type + container_id."""
        from sqlalchemy import select
        from shared.models.page_config import PageConfig

        ct = request.args.get("container_type", "page")
        cid = request.args.get("container_id", type=int)
        if cid is None:
            return None
        pc = (await g.s.execute(
            select(PageConfig).where(
                PageConfig.container_type == ct,
                PageConfig.container_id == cid,
            )
        )).scalar_one_or_none()
        if not pc:
            return None
        return _page_config_dict(pc)

    _handlers["page-config"] = _page_config

    # --- page-config-by-id ---
    async def _page_config_by_id():
        """Return a single PageConfig by its primary key."""
        from shared.models.page_config import PageConfig

        pc_id = request.args.get("id", type=int)
        if pc_id is None:
            return None
        pc = await g.s.get(PageConfig, pc_id)
        if not pc:
            return None
        return _page_config_dict(pc)

    _handlers["page-config-by-id"] = _page_config_by_id

    # --- page-configs-batch ---
    async def _page_configs_batch():
        """Return PageConfigs for multiple container_ids (comma-separated)."""
        from sqlalchemy import select
        from shared.models.page_config import PageConfig

        ct = request.args.get("container_type", "page")
        ids_raw = request.args.get("ids", "")
        if not ids_raw:
            return []
        ids = [int(x.strip()) for x in ids_raw.split(",") if x.strip()]
        if not ids:
            return []
        result = await g.s.execute(
            select(PageConfig).where(
                PageConfig.container_type == ct,
                PageConfig.container_id.in_(ids),
            )
        )
        return [_page_config_dict(pc) for pc in result.scalars().all()]

    _handlers["page-configs-batch"] = _page_configs_batch

    # --- get-children ---
    async def _get_children():
        """Return ContainerRelation children for a parent."""
        from shared.services.relationships import get_children

        parent_type = request.args.get("parent_type", "")
        parent_id = request.args.get("parent_id", type=int)
        child_type = request.args.get("child_type")
        if not parent_type or parent_id is None:
            return []
        rels = await get_children(g.s, parent_type, parent_id, child_type)
        return [
            {
                "id": r.id,
                "parent_type": r.parent_type,
                "parent_id": r.parent_id,
                "child_type": r.child_type,
                "child_id": r.child_id,
                "sort_order": r.sort_order,
                "label": r.label,
            }
            for r in rels
        ]

    _handlers["get-children"] = _get_children

    return bp


def _page_config_dict(pc) -> dict:
    """Serialize PageConfig to a JSON-safe dict."""
    return {
        "id": pc.id,
        "container_type": pc.container_type,
        "container_id": pc.container_id,
        "features": pc.features or {},
        "sumup_merchant_code": pc.sumup_merchant_code,
        "sumup_api_key": pc.sumup_api_key,
        "sumup_checkout_prefix": pc.sumup_checkout_prefix,
    }