from __future__ import annotations

from fastapi import APIRouter, Depends, HTTPException, Query, Request, Response
from fastapi.responses import HTMLResponse, PlainTextResponse, RedirectResponse
from starlette.concurrency import run_in_threadpool

from ..dependencies import ServiceDep, SettingsDep, StoreDep, authenticate_admin
from ..dns import DnsProviderError
from ..event_statuses import (
    ADMIN_HOSTNAME_DELETED,
    ADMIN_MANAGEMENT_URL_ROTATED,
    ADMIN_UPDATE_URL_ROTATED,
)
from ..security import client_ip, require_admin_csrf
from ..services.ddns import normalize_hostname
from ..web.components import _copy_row
from ..web.forms import first_form_value, request_form
from ..web.templates_admin import _admin_secret_panel, _render_admin_page

ADMIN_TABLE_LIMIT = 100
ADMIN_JSON_OFFSET_CAP = 10_000


def make_router(admin_path: str = "/admin") -> APIRouter:
    router = APIRouter()

    def render_admin(
        service: ServiceDep,
        settings: SettingsDep,
        store: StoreDep,
        table_offsets: dict[str, int] | None = None,
        notice: str | None = None,
    ) -> str:
        table_offsets = table_offsets or {}
        return _render_admin_page(
            service,
            settings,
            store.list_accounts(limit=ADMIN_TABLE_LIMIT, offset=table_offsets.get("accounts", 0)),
            store.list_cleanup_runs(limit=ADMIN_TABLE_LIMIT, offset=table_offsets.get("cleanup_runs", 0)),
            store.list_scheduled_tasks(),
            store.list_update_events(ADMIN_TABLE_LIMIT, offset=table_offsets.get("update_events", 0)),
            store.get_service_metrics(),
            {
                "accounts": store.count_accounts(),
                "cleanup_runs": store.count_cleanup_runs(),
                "update_events": store.count_update_events(),
            },
            table_offsets,
            ADMIN_TABLE_LIMIT,
            notice,
        )

    @router.get(admin_path, response_class=HTMLResponse, include_in_schema=False)
    def admin(
        settings: SettingsDep,
        store: StoreDep,
        service: ServiceDep,
        _: None = Depends(authenticate_admin),
        accounts_offset: int = Query(0, ge=0),
        cleanup_runs_offset: int = Query(0, ge=0),
        update_events_offset: int = Query(0, ge=0),
    ) -> str:
        return render_admin(
            service,
            settings,
            store,
            {
                "accounts": accounts_offset,
                "cleanup_runs": cleanup_runs_offset,
                "update_events": update_events_offset,
            },
        )

    @router.post(f"{admin_path}/hostnames/delete", include_in_schema=False)
    async def admin_delete_account(
        request: Request,
        settings: SettingsDep,
        store: StoreDep,
        service: ServiceDep,
        _: None = Depends(authenticate_admin),
    ) -> Response:
        form = await request_form(request, settings)
        require_admin_csrf(settings, first_form_value(form, "csrf"))
        hostname = normalize_hostname(first_form_value(form, "hostname"), settings, expand_suffix=False)
        if hostname:
            try:
                await run_in_threadpool(service.delete_account, hostname, "admin")
            except DnsProviderError:
                return PlainTextResponse("DNS delete failed; hostname was not deleted", status_code=500)
            await run_in_threadpool(
                store.log_update_event,
                hostname,
                None,
                None,
                ADMIN_HOSTNAME_DELETED,
                "hostname deleted by admin",
                client_ip(request, settings),
            )
        return RedirectResponse(admin_path, status_code=303)

    @router.post(f"{admin_path}/hostnames/rotate", include_in_schema=False)
    async def admin_rotate_account(
        request: Request,
        settings: SettingsDep,
        store: StoreDep,
        service: ServiceDep,
        _: None = Depends(authenticate_admin),
    ) -> Response:
        form = await request_form(request, settings)
        require_admin_csrf(settings, first_form_value(form, "csrf"))
        hostname = normalize_hostname(first_form_value(form, "hostname"), settings, expand_suffix=False)
        action = first_form_value(form, "action")
        account = await run_in_threadpool(store.get_account_by_hostname, hostname)
        if not account:
            raise HTTPException(status_code=404, detail="hostname not found")

        notice = None
        if action == "update":
            rotated = await run_in_threadpool(store.rotate_update_slug, hostname)
            await run_in_threadpool(
                store.log_update_event,
                hostname,
                None,
                None,
                ADMIN_UPDATE_URL_ROTATED,
                "router update URL rotated by admin",
                client_ip(request, settings),
            )
            notice = _admin_secret_panel("Update URL changed", [_copy_row("Update-URL:", service.fritz_update_url(rotated), "Secret")]) if rotated else None
        elif action == "management":
            rotated = await run_in_threadpool(store.rotate_management_slug, hostname)
            await run_in_threadpool(
                store.log_update_event,
                hostname,
                None,
                None,
                ADMIN_MANAGEMENT_URL_ROTATED,
                "dashboard link rotated by admin",
                client_ip(request, settings),
            )
            notice = _admin_secret_panel("Dashboard link changed", [_copy_row("Private dashboard:", service.dashboard_url(rotated), "Secret")]) if rotated else None
        else:
            raise HTTPException(status_code=400, detail="invalid rotation action")
        page = await run_in_threadpool(render_admin, service, settings, store, None, notice)
        return HTMLResponse(page)

    @router.post(f"{admin_path}/cleanup", include_in_schema=False)
    async def admin_run_cleanup(
        request: Request,
        settings: SettingsDep,
        store: StoreDep,
        service: ServiceDep,
        _: None = Depends(authenticate_admin),
    ) -> Response:
        form = await request_form(request, settings)
        require_admin_csrf(settings, first_form_value(form, "csrf"))
        result = await run_in_threadpool(
            store.cleanup,
            settings.cleanup_unused_account_hours,
            settings.cleanup_event_history_hours,
            settings.cleanup_pending_account_hours,
        )
        notice = _admin_secret_panel(
            "Cleanup done",
            [
                _copy_row("Unused hostnames removed", str(result["unused_accounts"])),
                _copy_row("Old update events removed", str(result["update_events"])),
            ],
        )
        page = await run_in_threadpool(render_admin, service, settings, store, None, notice)
        return HTMLResponse(page)

    return router


router = make_router()