import base64
from urllib.parse import quote

from fastapi import APIRouter, HTTPException, status
from PIL import Image, UnidentifiedImageError
from pydantic import BaseModel, SecretStr
from starlette.concurrency import run_in_threadpool

from app import f95
from app.blobs import read_bytes
from app.deps import DB, CurrentUser, has_perm
from app.f95_session import open_session, seal
from app.routers.games import make_cover

router = APIRouter(prefix="/api/metadata", tags=["metadata"])


class F95In(BaseModel):
    url: str


class F95SessionIn(BaseModel):
    cookie: SecretStr = SecretStr("")  # Compatibility with previously saved clients.
    xf_user: SecretStr = SecretStr("")
    xf_session: SecretStr = SecretStr("")
    cf_clearance: SecretStr = SecretStr("")
    user_agent: str = ""


class MetaOut(BaseModel):
    url: str
    title: str = ""
    description: str = ""
    tags: list[str] = []
    cover_hash: str | None = None
    cover_preview: str | None = None
    cover_warning: str | None = None
    auth_required: bool = False
    metadata_available: bool = True


def load_metadata(url: str, cookie: str = "", user_agent: str = "") -> dict:
    url = f95.validate_url(url)
    try:
        metadata = f95.load(url, cookie, user_agent)
    except f95.F95AuthError as e:
        return {"url": url, "auth_required": True, "metadata_available": False, "cover_warning": str(e)}
    logged_in = metadata.pop("logged_in", None)
    metadata["cover_hash"] = None
    if image := metadata.pop("image_url", None):
        try:
            metadata["cover_hash"] = make_cover(f95.fetch_image(image, metadata["url"], cookie, user_agent))
            # Unsaved covers cannot be read through the protected /blobs route yet.
            metadata["cover_preview"] = "data:image/webp;base64," + base64.b64encode(
                read_bytes(metadata["cover_hash"])).decode("ascii")
        except f95.F95AuthError as e:
            metadata["auth_required"] = True
            metadata["cover_warning"] = f"{e}. Остальные данные загружены."
        except f95.F95Error as e:
            metadata["cover_warning"] = f"{e}. Остальные данные загружены."
        except (UnidentifiedImageError, OSError, ValueError, Image.DecompressionBombError):
            metadata["cover_warning"] = "Не удалось загрузить превью F95zone. Остальные данные загружены."
    else:
        metadata["auth_required"] = not cookie or logged_in in ("false", "0")
        metadata["cover_warning"] = "В теме не найдено доступное превью. Остальные данные загружены."
    return metadata


def require_import(user: CurrentUser) -> None:
    if not (has_perm(user, "games.upload") or has_perm(user, "games.edit")):
        raise HTTPException(status.HTTP_403_FORBIDDEN, "Нет прав")


@router.put("/f95/session", status_code=204)
async def save_f95_session(body: F95SessionIn, user: CurrentUser, db: DB) -> None:
    require_import(user)
    values = {key: getattr(body, key).get_secret_value().strip()
              for key in ("xf_user", "xf_session", "cf_clearance")}
    if any(values.values()):
        if not (values["xf_user"] or values["xf_session"]):
            raise HTTPException(422, "Добавьте значение xf_user или xf_session для входа в F95zone")
        if any(len(value) > 8192 or any(ord(c) < 33 or ord(c) > 126 or c == ";" for c in value)
               for value in values.values()):
            raise HTTPException(422, "Скопируйте только значение cookie, без имени и дополнительных строк")
        # DevTools can display decoded values. Preserve existing escapes and encode delimiters.
        cookie = "; ".join(f"{key}={quote(value, safe='%') if key.startswith('xf_') else value}"
                           for key, value in values.items() if value)
    else:
        cookie = body.cookie.get_secret_value().strip()
    if cookie.lower().startswith("cookie:"):
        cookie = cookie[7:].strip()
    agent = body.user_agent.strip()
    if (not cookie or len(cookie) > 16384 or len(agent) > 2048
            or any(ord(c) < 32 or ord(c) > 126 for c in cookie + agent)
            or not all("=" in part and part.strip().split("=", 1)[0] for part in cookie.split(";"))):
        raise HTTPException(422, "Вставьте значение заголовка Cookie из запроса F95zone одной строкой")
    user.f95_session = seal(user.id, cookie, agent)
    await db.commit()


@router.delete("/f95/session", status_code=204)
async def delete_f95_session(user: CurrentUser, db: DB) -> None:
    user.f95_session = None
    await db.commit()


@router.post("/f95", response_model=MetaOut)
async def from_f95(body: F95In, user: CurrentUser, db: DB) -> dict:
    require_import(user)
    cookie, agent = open_session(user.id, user.f95_session)
    try:
        result = await run_in_threadpool(load_metadata, body.url, cookie, agent)
        if result.get("auth_required") and user.f95_session:
            user.f95_session = None
            await db.commit()
        return result
    except f95.F95Error as e:
        raise HTTPException(status.HTTP_422_UNPROCESSABLE_ENTITY, str(e))