import os
import httpx

API_URL = os.getenv("API_URL", "http://api:8000")
_TIMEOUT = httpx.Timeout(15.0, connect=5.0)

# Один клиент на весь процесс — TCP-соединения переиспользуются (keep-alive)
_client: httpx.AsyncClient | None = None


def _get() -> httpx.AsyncClient:
    global _client
    if _client is None or _client.is_closed:
        _client = httpx.AsyncClient(
            base_url=API_URL,
            timeout=_TIMEOUT,
            limits=httpx.Limits(max_keepalive_connections=5, max_connections=10),
        )
    return _client


def _headers(token: str | None = None) -> dict:
    h = {"Content-Type": "application/json"}
    if token:
        h["Authorization"] = f"Bearer {token}"
    return h


# ─── Public ──────────────────────────────────────────────────────────────────

async def get_news(
    offset: int = 0,
    limit: int = 20,
    category: str | None = None,
    tag: str | None = None,
    date_from: str | None = None,
    date_to: str | None = None,
) -> dict | None:
    params: dict = {"offset": offset, "limit": limit}
    if category:
        params["category"] = category
    if tag:
        params["tag"] = tag
    if date_from:
        params["date_from"] = date_from
    if date_to:
        params["date_to"] = date_to
    try:
        r = await _get().get("/news", params=params)
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def get_article(slug: str) -> dict | None:
    try:
        r = await _get().get(f"/news/{slug}")
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def get_categories() -> list:
    try:
        r = await _get().get("/news/categories")
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return []


async def get_tags(limit: int = 30) -> list:
    try:
        r = await _get().get("/news/tags", params={"limit": limit})
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return []


# ─── Admin: Auth ─────────────────────────────────────────────────────────────

async def admin_login(username: str, password: str) -> str | None:
    try:
        r = await _get().post(
            "/admin/login",
            json={"username": username, "password": password},
        )
        if r.status_code == 200:
            return r.json().get("access_token")
        return None
    except httpx.RequestError:
        return None


# ─── Admin: Articles ──────────────────────────────────────────────────────────

async def admin_list_articles(token: str, offset: int = 0, limit: int = 50, status: str | None = None) -> dict | None:
    params: dict = {"offset": offset, "limit": limit}
    if status:
        params["status"] = status
    try:
        r = await _get().get("/admin/articles", params=params, headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_get_article(token: str, article_id: str) -> dict | None:
    try:
        r = await _get().get(f"/admin/articles/{article_id}", headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_create_article(token: str, data: dict) -> dict | None:
    try:
        r = await _get().post("/admin/articles", json=data, headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_update_article(token: str, article_id: str, data: dict) -> dict | None:
    try:
        r = await _get().put(f"/admin/articles/{article_id}", json=data, headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_delete_article(token: str, article_id: str) -> bool:
    try:
        r = await _get().delete(f"/admin/articles/{article_id}", headers=_headers(token))
        return r.status_code == 200
    except httpx.RequestError:
        return False


async def admin_publish_article(token: str, article_id: str) -> bool:
    try:
        r = await _get().post(f"/admin/articles/{article_id}/publish", headers=_headers(token))
        return r.status_code == 200
    except httpx.RequestError:
        return False


# ─── Admin: Categories ────────────────────────────────────────────────────────

async def admin_list_categories(token: str) -> list:
    try:
        r = await _get().get("/admin/categories", headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return []


async def admin_create_category(token: str, name: str, slug: str = "") -> dict | None:
    try:
        r = await _get().post(
            "/admin/categories",
            json={"name": name, "slug": slug or None},
            headers=_headers(token),
        )
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_update_category(token: str, cat_id: str, name: str, slug: str = "") -> dict | None:
    try:
        r = await _get().put(
            f"/admin/categories/{cat_id}",
            json={"name": name, "slug": slug or None},
            headers=_headers(token),
        )
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_delete_category(token: str, cat_id: str) -> bool:
    try:
        r = await _get().delete(f"/admin/categories/{cat_id}", headers=_headers(token))
        return r.status_code == 200
    except httpx.RequestError:
        return False


# ─── Admin: Media ─────────────────────────────────────────────────────────────

async def admin_upload_media(token: str, file_bytes: bytes, filename: str, content_type: str) -> dict | None:
    try:
        r = await _get().post(
            "/admin/media/upload",
            files={"file": (filename, file_bytes, content_type)},
            headers={"Authorization": f"Bearer {token}"},
        )
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_list_media(token: str, offset: int = 0, limit: int = 50, media_type: str | None = None) -> list:
    params: dict = {"offset": offset, "limit": limit}
    if media_type:
        params["media_type"] = media_type
    try:
        r = await _get().get("/admin/media", params=params, headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return []


async def admin_delete_media(token: str, media_id: str) -> bool:
    try:
        r = await _get().delete(f"/admin/media/{media_id}", headers=_headers(token))
        return r.status_code == 200
    except httpx.RequestError:
        return False


# ─── Admin: VK Sources ────────────────────────────────────────────────────────

async def admin_vk_status(token: str) -> dict:
    try:
        r = await _get().get("/admin/vk/status", headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return {"configured": False}


async def admin_vk_list_sources(token: str) -> list:
    try:
        r = await _get().get("/admin/vk/sources", headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return []


async def admin_vk_add_source(token: str, group_id: str, group_name: str, enabled: bool = True) -> dict | None:
    try:
        r = await _get().post(
            "/admin/vk/sources",
            json={"group_id": group_id, "group_name": group_name, "enabled": enabled},
            headers=_headers(token),
        )
        if r.status_code == 201:
            return r.json()
        return {"error": r.json().get("detail", "Ошибка")}
    except httpx.RequestError:
        return None


async def admin_vk_update_source(token: str, source_id: str, group_id: str, group_name: str, enabled: bool) -> dict | None:
    try:
        r = await _get().patch(
            f"/admin/vk/sources/{source_id}",
            json={"group_id": group_id, "group_name": group_name, "enabled": enabled},
            headers=_headers(token),
        )
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_vk_delete_source(token: str, source_id: str) -> bool:
    try:
        r = await _get().delete(f"/admin/vk/sources/{source_id}", headers=_headers(token))
        return r.status_code == 204
    except httpx.RequestError:
        return False


async def admin_vk_import(token: str) -> dict | None:
    try:
        r = await _get().post("/admin/vk/import", headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None


async def admin_vk_import_history(token: str, source_id: str | None = None) -> dict | None:
    url = "/admin/vk/import/history"
    if source_id:
        url += f"/{source_id}"
    try:
        r = await _get().post(url, headers=_headers(token))
        if r.status_code == 200:
            return r.json()
    except httpx.RequestError:
        pass
    return None