from __future__ import annotations

import uuid

import httpx
from sqlalchemy.ext.asyncio import AsyncSession

from cpv3.infrastructure.settings import get_settings
from cpv3.modules.captions.models import CaptionPreset
from cpv3.modules.captions.repository import CaptionPresetRepository
from cpv3.modules.captions.schemas import (
    CaptionPresetCreate,
    CaptionPresetUpdate,
    CaptionStyleConfig,
)
from cpv3.modules.transcription.schemas import Document

ERROR_PRESET_NOT_FOUND = "Пресет субтитров не найден"
ERROR_PRESET_FORBIDDEN = "Нельзя изменять чужой или системный пресет"


# ---------------------------------------------------------------------------
# Caption rendering (calls Remotion service)
# ---------------------------------------------------------------------------


async def generate_captions(
    *,
    video_s3_path: str,
    folder: str,
    transcription: Document,
    style_config: dict | None = None,
    callback_url: str | None = None,
    render_id: str | None = None,
) -> str:
    """Generate captions for a video using the Remotion service.

    Returns render_id (async mode with callback_url) or S3 output path (sync fallback).
    """
    settings = get_settings()

    payload: dict = {
        "folder": folder,
        "videoSrc": video_s3_path,
        "transcription": transcription.model_dump(),
    }
    if style_config is not None:
        payload["styleConfig"] = style_config
    if callback_url is not None:
        payload["callbackUrl"] = callback_url
    if render_id is not None:
        payload["renderId"] = render_id

    timeout = 30.0 if callback_url else 300.0

    async with httpx.AsyncClient(timeout=timeout) as client:
        resp = await client.post(f"{settings.remotion_service_url}/api/render", json=payload)
        resp.raise_for_status()
        data = resp.json()

    # Async mode: Remotion returns { renderId, status: "queued" }
    if callback_url and "renderId" in data:
        return str(data["renderId"])

    # Sync fallback: Remotion returns { output: "s3/path" }
    if isinstance(data, dict) and "output" in data:
        return str(data["output"])

    raise RuntimeError("Unexpected response from remotion service")


# ---------------------------------------------------------------------------
# Preset service
# ---------------------------------------------------------------------------


class CaptionPresetService:
    """Business logic for caption preset CRUD with ownership checks."""

    def __init__(self, session: AsyncSession) -> None:
        self._repo = CaptionPresetRepository(session)

    async def list_presets(self, *, user_id: uuid.UUID) -> list[CaptionPreset]:
        return await self._repo.list_all_for_user(user_id)

    async def get_preset(self, *, preset_id: uuid.UUID) -> CaptionPreset:
        preset = await self._repo.get_by_id(preset_id)
        if preset is None:
            raise ValueError(ERROR_PRESET_NOT_FOUND)
        return preset

    async def create_preset(
        self, *, user_id: uuid.UUID, data: CaptionPresetCreate
    ) -> CaptionPreset:
        return await self._repo.create(user_id=user_id, data=data)

    async def update_preset(
        self,
        *,
        preset_id: uuid.UUID,
        user_id: uuid.UUID,
        data: CaptionPresetUpdate,
    ) -> CaptionPreset:
        preset = await self.get_preset(preset_id=preset_id)
        if preset.is_system or preset.user_id != user_id:
            raise PermissionError(ERROR_PRESET_FORBIDDEN)
        return await self._repo.update(preset, data)

    async def delete_preset(self, *, preset_id: uuid.UUID, user_id: uuid.UUID) -> None:
        preset = await self.get_preset(preset_id=preset_id)
        if preset.is_system or preset.user_id != user_id:
            raise PermissionError(ERROR_PRESET_FORBIDDEN)
        await self._repo.deactivate(preset)

    async def resolve_style_config(
        self,
        *,
        preset_id: uuid.UUID | None = None,
        inline_config: dict | None = None,
    ) -> dict | None:
        """Resolve a style config from preset_id or inline override."""
        if inline_config is not None:
            # Validate by parsing, then return as dict
            cfg = CaptionStyleConfig.model_validate(inline_config)
            return cfg.model_dump(mode="json")
        if preset_id is not None:
            preset = await self.get_preset(preset_id=preset_id)
            return preset.style_config
        return None