"""Cart layout registration and header builders."""
from __future__ import annotations

from typing import Any

from shared.sx.parser import SxExpr


def _register_cart_layouts() -> None:
    from shared.sx.layouts import register_custom_layout
    register_custom_layout("cart-page", _cart_page_full, _cart_page_oob)
    register_custom_layout("cart-admin", _cart_admin_full, _cart_admin_oob)


# ---------------------------------------------------------------------------
# Header helpers
# ---------------------------------------------------------------------------

def _ensure_post_ctx(ctx: dict, page_post: Any) -> dict:
    """Ensure ctx has a 'post' dict from page_post DTO."""
    if ctx.get("post") or not page_post:
        return ctx
    return {**ctx, "post": {
        "id": getattr(page_post, "id", None),
        "slug": getattr(page_post, "slug", ""),
        "title": getattr(page_post, "title", ""),
        "feature_image": getattr(page_post, "feature_image", None),
    }}


async def _ensure_container_nav(ctx: dict) -> dict:
    """Fetch container_nav if not already present."""
    if ctx.get("container_nav"):
        return ctx
    post = ctx.get("post") or {}
    post_id = post.get("id")
    if not post_id:
        return ctx
    slug = post.get("slug", "")
    from shared.infrastructure.fragments import fetch_fragments
    nav_params = {
        "container_type": "page",
        "container_id": str(post_id),
        "post_slug": slug,
    }
    events_nav, market_nav = await fetch_fragments([
        ("events", "container-nav", nav_params),
        ("market", "container-nav", nav_params),
    ], required=False)
    return {**ctx, "container_nav": events_nav + market_nav}


async def _post_header_sx(ctx: dict, page_post: Any, *, oob: bool = False) -> str:
    from shared.sx.helpers import post_header_sx as _shared_post_header_sx
    ctx = _ensure_post_ctx(ctx, page_post)
    ctx = await _ensure_container_nav(ctx)
    return await _shared_post_header_sx(ctx, oob=oob)


def _cart_header_sx(ctx: dict, *, oob: bool = False) -> str:
    from shared.sx.helpers import sx_call, call_url
    return sx_call(
        "menu-row-sx",
        id="cart-row", level=1, colour="sky",
        link_href=call_url(ctx, "cart_url", "/"),
        link_label="cart", icon="fa fa-shopping-cart",
        child_id="cart-header-child", oob=oob,
    )


def _page_cart_header_sx(ctx: dict, page_post: Any, *, oob: bool = False) -> str:
    from shared.sx.helpers import sx_call, call_url
    slug = page_post.slug if page_post else ""
    title = ((page_post.title if page_post else None) or "")[:160]
    label_sx = sx_call("cart-page-label",
        feature_image=page_post.feature_image if page_post else None,
        title=title)
    nav_sx = sx_call("cart-all-carts-link", href=call_url(ctx, "cart_url", "/"))
    return sx_call(
        "menu-row-sx",
        id="page-cart-row", level=2, colour="sky",
        link_href=call_url(ctx, "cart_url", f"/{slug}/"),
        link_label_content=SxExpr(label_sx),
        nav=SxExpr(nav_sx), oob=oob,
    )


async def _cart_page_admin_header_sx(ctx: dict, page_post: Any, *, oob: bool = False,
                                  selected: str = "") -> str:
    from shared.sx.helpers import post_admin_header_sx
    slug = page_post.slug if page_post else ""
    ctx = _ensure_post_ctx(ctx, page_post)
    return await post_admin_header_sx(ctx, slug, oob=oob, selected=selected)


# ---------------------------------------------------------------------------
# Layout functions
# ---------------------------------------------------------------------------

async def _cart_page_full(ctx: dict, **kw: Any) -> str:
    from shared.sx.helpers import render_to_sx_with_env
    page_post = ctx.get("page_post")
    env = {}
    return await render_to_sx_with_env("cart-page-layout-full", env,
        cart_row=SxExpr(_cart_header_sx(ctx)),
        page_cart_row=SxExpr(_page_cart_header_sx(ctx, page_post)),
    )


async def _cart_page_oob(ctx: dict, **kw: Any) -> str:
    from shared.sx.helpers import render_to_sx_with_env, root_header_sx
    page_post = ctx.get("page_post")
    env = {}
    return await render_to_sx_with_env("cart-page-layout-oob", env,
        root_header_oob=SxExpr(await root_header_sx(ctx, oob=True)),
        cart_row_oob=SxExpr(_cart_header_sx(ctx, oob=True)),
        page_cart_row=SxExpr(_page_cart_header_sx(ctx, page_post)),
    )


async def _cart_admin_full(ctx: dict, **kw: Any) -> str:
    from shared.sx.helpers import render_to_sx_with_env
    page_post = ctx.get("page_post")
    selected = kw.get("selected", "")
    env = {}
    return await render_to_sx_with_env("cart-admin-layout-full", env,
        post_header=SxExpr(await _post_header_sx(ctx, page_post)),
        admin_header=SxExpr(await _cart_page_admin_header_sx(ctx, page_post, selected=selected)),
    )


async def _cart_admin_oob(ctx: dict, **kw: Any) -> str:
    page_post = ctx.get("page_post")
    selected = kw.get("selected", "")
    return await _cart_page_admin_header_sx(ctx, page_post, oob=True, selected=selected)