"""TikTok media upload manager for handling video uploads.

This module provides functionality for uploading videos to TikTok's API,
focusing on a chunked upload process suitable for large video files.
"""

import asyncio
import logging
import os
from collections.abc import Callable
from dataclasses import dataclass
from enum import Enum
from typing import Any, Literal

import httpx

from src.marqetive.platforms.exceptions import (
    InvalidFileTypeError,
    MediaUploadError,
)
from src.marqetive.utils.file_handlers import download_file
from src.marqetive.utils.media import (
    detect_mime_type,
    format_file_size,
    get_chunk_count,
)
from src.marqetive.utils.retry import STANDARD_BACKOFF, retry_async

logger = logging.getLogger(__name__)

# Constants for TikTok Media Upload
DEFAULT_CHUNK_SIZE = 5 * 1024 * 1024  # 5MB chunks
MAX_VIDEO_SIZE = 10 * 1024 * 1024 * 1024  # 10GB, hypothetical
MIN_VIDEO_DURATION_SECS = 3
MAX_VIDEO_DURATION_SECS = 600  # 10 minutes
DEFAULT_REQUEST_TIMEOUT = 300.0

# Hypothetical TikTok API endpoints for media
MEDIA_API_BASE_URL = "https://open.tiktokapis.com/v2/video"

# Supported MIME types for TikTok
SUPPORTED_VIDEO_TYPES = ["video/mp4", "video/quicktime"]  # MOV


class ProcessingState(str, Enum):
    """States for async media processing."""

    PENDING = "pending"
    PROCESSING = "processing"
    READY = "ready"
    FAILED = "failed"


@dataclass
class UploadProgress:
    """Progress information for a media upload."""

    upload_id: str | None
    file_path: str
    bytes_uploaded: int
    total_bytes: int
    status: Literal["init", "uploading", "processing", "completed", "failed"]

    @property
    def percentage(self) -> float:
        if self.total_bytes == 0:
            return 0.0
        return (self.bytes_uploaded / self.total_bytes) * 100

    def __str__(self) -> str:
        return (
            f"Upload Progress: {self.percentage:.1f}% "
            f"({format_file_size(self.bytes_uploaded)} / "
            f"{format_file_size(self.total_bytes)}) - {self.status}"
        )


@dataclass
class MediaUploadResult:
    """Result of a successful media upload."""

    upload_id: str
    media_id: str | None = None  # Available after processing
    size: int | None = None
    processing_info: dict[str, Any] | None = None


class TikTokMediaManager:
    """Manages video uploads to the TikTok API.

    This class handles the complexities of chunked uploads for large video files
    and monitors the processing status of the uploaded media.
    """

    def __init__(
        self,
        access_token: str,
        open_id: str,
        *,
        progress_callback: Callable[[UploadProgress], None] | None = None,
        timeout: float = DEFAULT_REQUEST_TIMEOUT,
    ) -> None:
        """Initialize the TikTok media manager."""
        self.access_token = access_token
        self.open_id = open_id
        self.progress_callback = progress_callback
        self.timeout = timeout
        self.base_url = MEDIA_API_BASE_URL
        self.client = httpx.AsyncClient(
            timeout=httpx.Timeout(timeout),
            headers={"Authorization": f"Bearer {access_token}"},
        )

    async def __aenter__(self) -> "TikTokMediaManager":
        return self

    async def __aexit__(self, *args: Any) -> None:
        await self.client.aclose()

    async def upload_media(
        self,
        file_path: str,
        *,
        chunk_size: int = DEFAULT_CHUNK_SIZE,
        wait_for_processing: bool = True,
    ) -> MediaUploadResult:
        """Upload a video file to TikTok.

        Args:
            file_path: The local path or URL of the video to upload.
            chunk_size: The size of each chunk to upload in bytes.
            wait_for_processing: If True, wait until the video is processed and ready.

        Returns:
            A MediaUploadResult containing the upload and media IDs.

        Raises:
            FileNotFoundError: If the local file does not exist.
            InvalidFileTypeError: If the file is not a supported video format.
            MediaUploadError: If the upload or processing fails.
        """
        if file_path.startswith(("http://", "https://")):
            logger.info(f"Downloading media from URL: {file_path}")
            file_path = await download_file(file_path)

        if not os.path.exists(file_path):
            raise FileNotFoundError(f"Media file not found: {file_path}")

        mime_type = detect_mime_type(file_path)
        file_size = os.path.getsize(file_path)
        self._validate_media(mime_type, file_size)

        # TikTok uses a one-step chunked upload
        result = await self.chunked_upload(
            file_path,
            chunk_size=chunk_size,
        )

        # Note: TikTok's real API might have a different flow for processing.
        # This is a hypothetical implementation.
        if wait_for_processing:
            await self._wait_for_processing(result, file_path)

        return result

    async def chunked_upload(
        self, file_path: str, *, chunk_size: int = DEFAULT_CHUNK_SIZE
    ) -> MediaUploadResult:
        """Upload a video using the chunked upload method.

        This is a simplified model of how a chunked upload to TikTok might work.
        The actual API may differ.

        Args:
            file_path: Path to the video file.
            chunk_size: Size of each upload chunk.

        Returns:
            MediaUploadResult with upload ID.
        """
        file_size = os.path.getsize(file_path)
        chunk_count = get_chunk_count(file_path, chunk_size)
        upload_id = None  # Hypothetically obtained from an INIT step if needed

        if self.progress_callback:
            self.progress_callback(
                UploadProgress(
                    upload_id=upload_id,
                    file_path=file_path,
                    bytes_uploaded=0,
                    total_bytes=file_size,
                    status="init",
                )
            )

        @retry_async(config=STANDARD_BACKOFF)
        async def _do_upload() -> MediaUploadResult:
            bytes_uploaded = 0

            # Hypothetical: The real API may require separate INIT/APPEND/FINALIZE steps.
            # This implementation models a single POST with all chunks.
            async def file_iterator():
                nonlocal bytes_uploaded
                with open(file_path, "rb") as f:
                    for i, chunk in enumerate(iter(lambda: f.read(chunk_size), b"")):
                        bytes_uploaded += len(chunk)
                        if self.progress_callback:
                            self.progress_callback(
                                UploadProgress(
                                    upload_id=upload_id,
                                    file_path=file_path,
                                    bytes_uploaded=bytes_uploaded,
                                    total_bytes=file_size,
                                    status="uploading",
                                )
                            )
                        logger.debug(f"Uploading chunk {i + 1}/{chunk_count}")
                        yield chunk

            # In a real scenario, you'd likely get an upload URL first.
            upload_url = f"{self.base_url}/upload/"
            response = await self.client.post(
                upload_url,
                params={"open_id": self.open_id},
                content=file_iterator(),
                headers={"Content-Type": "video/mp4"},
            )
            response.raise_for_status()
            result_data = response.json()
            upload_id = result_data.get("data", {}).get("video", {}).get("video_id")

            if not upload_id:
                raise MediaUploadError(
                    "Upload succeeded but did not return a video ID.", platform="tiktok"
                )

            result = MediaUploadResult(
                upload_id=upload_id,
                media_id=upload_id,  # Assume upload_id is the media_id
                size=file_size,
            )

            if self.progress_callback:
                self.progress_callback(
                    UploadProgress(
                        upload_id=upload_id,
                        file_path=file_path,
                        bytes_uploaded=file_size,
                        total_bytes=file_size,
                        status="completed",
                    )
                )

            logger.info(f"Chunked upload completed for TikTok: {upload_id}")
            return result

        try:
            return await _do_upload()
        except httpx.HTTPError as e:
            raise MediaUploadError(
                f"TikTok video upload failed: {e}",
                platform="tiktok",
                media_type=detect_mime_type(file_path),
            ) from e

    async def _wait_for_processing(
        self, result: MediaUploadResult, file_path: str
    ) -> None:
        """Wait for async video processing to complete.

        This is a hypothetical implementation.
        """
        logger.info(f"Waiting for TikTok video processing: {result.upload_id}")
        # In a real implementation, you would poll a status endpoint.
        # Here, we'll just simulate a delay.
        await asyncio.sleep(5)  # Simulate processing time
        if self.progress_callback:
            self.progress_callback(
                UploadProgress(
                    upload_id=result.upload_id,
                    file_path=file_path,
                    bytes_uploaded=os.path.getsize(file_path),
                    total_bytes=os.path.getsize(file_path),
                    status="processing",
                )
            )
        logger.info(f"TikTok video processing assumed complete: {result.upload_id}")

    def _validate_media(self, mime_type: str, file_size: int) -> None:
        """Validate media type and size against TikTok's requirements."""
        if mime_type not in SUPPORTED_VIDEO_TYPES:
            raise InvalidFileTypeError(
                f"Unsupported video type for TikTok: {mime_type}. "
                f"Supported types are: {', '.join(SUPPORTED_VIDEO_TYPES)}",
                platform="tiktok",
            )

        if file_size > MAX_VIDEO_SIZE:
            raise MediaUploadError(
                f"Video file size ({format_file_size(file_size)}) exceeds the "
                f"TikTok limit of {format_file_size(MAX_VIDEO_SIZE)}",
                platform="tiktok",
                media_type=mime_type,
            )
        # Add duration validation logic here if possible to check before upload
