"""Events app fragment endpoints.

Exposes HTML fragments at ``/internal/fragments/<type>`` for consumption
by other coop apps via the fragment client.
"""

from __future__ import annotations

from quart import Blueprint, Response, g, render_template, request

from shared.infrastructure.fragments import FRAGMENT_HEADER
from shared.infrastructure.data_client import fetch_data
from shared.contracts.dtos import PostDTO, dto_from_dict
from shared.services.registry import services


def register():
    bp = Blueprint("fragments", __name__, url_prefix="/internal/fragments")

    _handlers: dict[str, object] = {}

    @bp.before_request
    async def _require_fragment_header():
        if not request.headers.get(FRAGMENT_HEADER):
            return Response("", status=403)

    @bp.get("/<fragment_type>")
    async def get_fragment(fragment_type: str):
        handler = _handlers.get(fragment_type)
        if handler is None:
            return Response("", status=200, content_type="text/html")
        html = await handler()
        return Response(html, status=200, content_type="text/html")

    # --- container-nav fragment: calendar entries + calendar links -----------

    async def _container_nav_handler():
        container_type = request.args.get("container_type", "page")
        container_id = int(request.args.get("container_id", 0))
        post_slug = request.args.get("post_slug", "")
        paginate_url_base = request.args.get("paginate_url", "")
        page = int(request.args.get("page", 1))
        exclude = request.args.get("exclude", "")
        excludes = [e.strip() for e in exclude.split(",") if e.strip()]

        html_parts = []

        # Calendar entries nav
        if not any(e.startswith("calendar") for e in excludes):
            entries, has_more = await services.calendar.associated_entries(
                g.s, container_type, container_id, page,
            )
            if entries:
                html_parts.append(await render_template(
                    "fragments/container_nav_entries.html",
                    entries=entries, has_more=has_more,
                    page=page, post_slug=post_slug,
                    paginate_url_base=paginate_url_base,
                ))

        # Calendar links nav
        if not any(e.startswith("calendar") for e in excludes):
            calendars = await services.calendar.calendars_for_container(
                g.s, container_type, container_id,
            )
            if calendars:
                html_parts.append(await render_template(
                    "fragments/container_nav_calendars.html",
                    calendars=calendars, post_slug=post_slug,
                ))

        return "\n".join(html_parts)

    _handlers["container-nav"] = _container_nav_handler

    # --- container-cards fragment: entries for blog listing cards ------------

    async def _container_cards_handler():
        post_ids_raw = request.args.get("post_ids", "")
        post_slugs_raw = request.args.get("post_slugs", "")
        post_ids = [int(x) for x in post_ids_raw.split(",") if x.strip()]
        post_slugs = [x.strip() for x in post_slugs_raw.split(",") if x.strip()]
        if not post_ids:
            return ""

        # Build post_id -> slug mapping
        slug_map = {}
        for i, pid in enumerate(post_ids):
            slug_map[pid] = post_slugs[i] if i < len(post_slugs) else ""

        batch = await services.calendar.confirmed_entries_for_posts(g.s, post_ids)
        return await render_template(
            "fragments/container_cards_entries.html",
            batch=batch, post_ids=post_ids, slug_map=slug_map,
        )

    _handlers["container-cards"] = _container_cards_handler

    # --- account-nav-item fragment: tickets + bookings links for account nav -

    async def _account_nav_item_handler():
        return await render_template("fragments/account_nav_items.html")

    _handlers["account-nav-item"] = _account_nav_item_handler

    # --- account-page fragment: tickets or bookings panel --------------------

    async def _account_page_handler():
        slug = request.args.get("slug", "")
        user_id = request.args.get("user_id", type=int)
        if not user_id:
            return ""

        if slug == "tickets":
            tickets = await services.calendar.user_tickets(g.s, user_id=user_id)
            return await render_template(
                "fragments/account_page_tickets.html",
                tickets=tickets,
            )
        elif slug == "bookings":
            bookings = await services.calendar.user_bookings(g.s, user_id=user_id)
            return await render_template(
                "fragments/account_page_bookings.html",
                bookings=bookings,
            )
        return ""

    _handlers["account-page"] = _account_page_handler

    # --- link-card fragment: event page preview card ----------------------------

    async def _link_card_handler():
        from shared.infrastructure.urls import events_url

        slug = request.args.get("slug", "")
        keys_raw = request.args.get("keys", "")

        # Batch mode
        if keys_raw:
            slugs = [k.strip() for k in keys_raw.split(",") if k.strip()]
            parts = []
            for s in slugs:
                parts.append(f"<!-- fragment:{s} -->")
                raw = await fetch_data("blog", "post-by-slug", params={"slug": s}, required=False)
                post = dto_from_dict(PostDTO, raw) if raw else None
                if post:
                    calendars = await services.calendar.calendars_for_container(
                        g.s, "page", post.id,
                    )
                    cal_names = ", ".join(c.name for c in calendars) if calendars else ""
                    parts.append(await render_template(
                        "fragments/link_card.html",
                        title=post.title,
                        feature_image=post.feature_image,
                        calendar_names=cal_names,
                        link=events_url(f"/{post.slug}"),
                    ))
            return "\n".join(parts)

        # Single mode
        if not slug:
            return ""
        raw = await fetch_data("blog", "post-by-slug", params={"slug": slug}, required=False)
        post = dto_from_dict(PostDTO, raw) if raw else None
        if not post:
            return ""
        calendars = await services.calendar.calendars_for_container(
            g.s, "page", post.id,
        )
        cal_names = ", ".join(c.name for c in calendars) if calendars else ""
        return await render_template(
            "fragments/link_card.html",
            title=post.title,
            feature_image=post.feature_image,
            calendar_names=cal_names,
            link=events_url(f"/{post.slug}"),
        )

    _handlers["link-card"] = _link_card_handler

    bp._fragment_handlers = _handlers

    return bp