"""Video person identification endpoints."""

from __future__ import annotations

from datetime import date
from typing import Annotated, Optional

from fastapi import APIRouter, Depends, HTTPException, Query, Request, status
from fastapi.responses import FileResponse, Response, StreamingResponse
from sqlalchemy.orm import Session

from backend.db.session import get_db
from backend.db.models import Photo, User
from backend.api.auth import get_current_user_with_id
from backend.schemas.videos import (
    ListVideosResponse,
    VideoListItem,
    PersonInfo,
    VideoPeopleResponse,
    VideoPersonInfo,
    IdentifyVideoRequest,
    IdentifyVideoResponse,
    RemoveVideoPersonResponse,
)
from backend.services.video_service import (
    list_videos_for_identification,
    get_video_people,
    identify_person_in_video,
    remove_person_from_video,
    get_video_people_count,
)
from backend.services.thumbnail_service import get_video_thumbnail_path

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


@router.get("", response_model=ListVideosResponse)
def list_videos(
    current_user: Annotated[dict, Depends(get_current_user_with_id)],
    folder_path: Optional[str] = Query(None, description="Filter by folder path"),
    date_from: Optional[str] = Query(None, description="Filter by date taken (from, YYYY-MM-DD)"),
    date_to: Optional[str] = Query(None, description="Filter by date taken (to, YYYY-MM-DD)"),
    has_people: Optional[bool] = Query(None, description="Filter videos with/without identified people"),
    person_name: Optional[str] = Query(None, description="Filter videos containing person with this name"),
    sort_by: str = Query("filename", description="Sort field: filename, date_taken, date_added"),
    sort_dir: str = Query("asc", description="Sort direction: asc or desc"),
    page: int = Query(1, ge=1),
    page_size: int = Query(50, ge=1, le=200),
    db: Session = Depends(get_db),
) -> ListVideosResponse:
    """List videos for person identification."""
    # Parse date filters
    date_from_parsed = None
    date_to_parsed = None
    if date_from:
        try:
            date_from_parsed = date.fromisoformat(date_from)
        except ValueError:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Invalid date_from format: {date_from}. Use YYYY-MM-DD",
            )
    if date_to:
        try:
            date_to_parsed = date.fromisoformat(date_to)
        except ValueError:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=f"Invalid date_to format: {date_to}. Use YYYY-MM-DD",
            )
    
    # Validate sort parameters
    if sort_by not in ["filename", "date_taken", "date_added"]:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Invalid sort_by: {sort_by}. Must be filename, date_taken, or date_added",
        )
    if sort_dir not in ["asc", "desc"]:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Invalid sort_dir: {sort_dir}. Must be asc or desc",
        )
    
    # Get videos
    videos, total = list_videos_for_identification(
        db=db,
        folder_path=folder_path,
        date_from=date_from_parsed,
        date_to=date_to_parsed,
        has_people=has_people,
        person_name=person_name,
        sort_by=sort_by,
        sort_dir=sort_dir,
        page=page,
        page_size=page_size,
    )
    
    # Build response items
    items = []
    for video in videos:
        # Get people for this video
        people_data = get_video_people(db, video.id)
        identified_people = []
        for person, linkage in people_data:
            identified_people.append(
                PersonInfo(
                    id=person.id,
                    first_name=person.first_name,
                    last_name=person.last_name,
                    middle_name=person.middle_name,
                    maiden_name=person.maiden_name,
                    date_of_birth=person.date_of_birth,
                )
            )
        
        # Convert date_added to date if it's datetime
        date_added = video.date_added
        if hasattr(date_added, "date"):
            date_added = date_added.date()
        
        items.append(
            VideoListItem(
                id=video.id,
                filename=video.filename,
                path=video.path,
                date_taken=video.date_taken,
                date_added=date_added,
                identified_people=identified_people,
                identified_people_count=len(identified_people),
            )
        )
    
    return ListVideosResponse(items=items, page=page, page_size=page_size, total=total)


@router.get("/{video_id}/people", response_model=VideoPeopleResponse)
def get_video_people_endpoint(
    video_id: int,
    db: Session = Depends(get_db),
) -> VideoPeopleResponse:
    """Get all people identified in a video."""
    # Verify video exists
    video = db.query(Photo).filter(
        Photo.id == video_id,
        Photo.media_type == "video"
    ).first()
    
    if not video:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Video {video_id} not found",
        )
    
    # Get people
    people_data = get_video_people(db, video_id)
    
    people = []
    for person, linkage in people_data:
        # Get username if identified_by_user_id exists
        username = None
        if linkage.identified_by_user_id:
            user = db.query(User).filter(User.id == linkage.identified_by_user_id).first()
            if user:
                username = user.username
        
        people.append(
            VideoPersonInfo(
                person_id=person.id,
                first_name=person.first_name,
                last_name=person.last_name,
                middle_name=person.middle_name,
                maiden_name=person.maiden_name,
                date_of_birth=person.date_of_birth,
                identified_by=username,
                identified_date=linkage.created_date,
            )
        )
    
    return VideoPeopleResponse(video_id=video_id, people=people)


@router.post("/{video_id}/identify", response_model=IdentifyVideoResponse)
def identify_person_in_video_endpoint(
    video_id: int,
    request: IdentifyVideoRequest,
    current_user: Annotated[dict, Depends(get_current_user_with_id)],
    db: Session = Depends(get_db),
) -> IdentifyVideoResponse:
    """Identify a person in a video."""
    user_id = current_user.get("id")
    
    try:
        person, created_person = identify_person_in_video(
            db=db,
            video_id=video_id,
            person_id=request.person_id,
            first_name=request.first_name,
            last_name=request.last_name,
            middle_name=request.middle_name,
            maiden_name=request.maiden_name,
            date_of_birth=request.date_of_birth,
            user_id=user_id,
        )
        
        message = (
            f"Person '{person.first_name} {person.last_name}' identified in video"
            if not created_person
            else f"Created new person '{person.first_name} {person.last_name}' and identified in video"
        )
        
        return IdentifyVideoResponse(
            video_id=video_id,
            person_id=person.id,
            created_person=created_person,
            message=message,
        )
    except ValueError as e:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(e),
        )


@router.delete("/{video_id}/people/{person_id}", response_model=RemoveVideoPersonResponse)
def remove_person_from_video_endpoint(
    video_id: int,
    person_id: int,
    current_user: Annotated[dict, Depends(get_current_user_with_id)],
    db: Session = Depends(get_db),
) -> RemoveVideoPersonResponse:
    """Remove person identification from video."""
    try:
        removed = remove_person_from_video(
            db=db,
            video_id=video_id,
            person_id=person_id,
        )
        
        if removed:
            return RemoveVideoPersonResponse(
                video_id=video_id,
                person_id=person_id,
                removed=True,
                message=f"Person {person_id} removed from video {video_id}",
            )
        else:
            return RemoveVideoPersonResponse(
                video_id=video_id,
                person_id=person_id,
                removed=False,
                message=f"Person {person_id} not found in video {video_id}",
            )
    except ValueError as e:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=str(e),
        )


@router.get("/{video_id}/thumbnail")
def get_video_thumbnail(
    video_id: int,
    db: Session = Depends(get_db),
) -> FileResponse:
    """Get video thumbnail (generated on-demand and cached)."""
    # Verify video exists
    video = db.query(Photo).filter(
        Photo.id == video_id,
        Photo.media_type == "video"
    ).first()
    
    if not video:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Video {video_id} not found",
        )
    
    # Generate or get cached thumbnail
    thumbnail_path = get_video_thumbnail_path(video.path)
    
    if not thumbnail_path or not thumbnail_path.exists():
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail="Failed to generate video thumbnail",
        )
    
    # Return thumbnail with caching headers
    response = FileResponse(
        str(thumbnail_path),
        media_type="image/jpeg",
    )
    response.headers["Cache-Control"] = "public, max-age=86400"  # Cache for 1 day
    return response


@router.get("/{video_id}/video")
def get_video_file(
    video_id: int,
    request: Request,
    db: Session = Depends(get_db),
):
    """Serve video file for playback with range request support."""
    import os
    import mimetypes
    from starlette.responses import FileResponse
    
    # Verify video exists
    video = db.query(Photo).filter(
        Photo.id == video_id,
        Photo.media_type == "video"
    ).first()
    
    if not video:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Video {video_id} not found",
        )
    
    if not os.path.exists(video.path):
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail=f"Video file not found: {video.path}",
        )
    
    # Determine media type from file extension
    media_type, _ = mimetypes.guess_type(video.path)
    if not media_type or not media_type.startswith('video/'):
        media_type = "video/mp4"
    
    file_size = os.path.getsize(video.path)
    # Get range header - Starlette normalizes headers to lowercase
    range_header = request.headers.get("range")
    
    # Debug: Write to file to verify code execution
    try:
        with open("/tmp/video_debug.log", "a") as f:
            all_headers = {k: v for k, v in request.headers.items()}
            f.write(f"Video {video_id}: range_header={range_header}, all_headers={all_headers}\n")
            if hasattr(request, 'scope'):
                scope_headers = request.scope.get("headers", [])
                f.write(f"  scope headers: {scope_headers}\n")
            f.flush()
    except Exception as e:
        with open("/tmp/video_debug.log", "a") as f:
            f.write(f"Debug write error: {e}\n")
            f.flush()
    
    # Also check request scope directly as fallback
    if not range_header and hasattr(request, 'scope'):
        scope_headers = request.scope.get("headers", [])
        for header_name, header_value in scope_headers:
            if header_name.lower() == b"range":
                range_header = header_value.decode() if isinstance(header_value, bytes) else header_value
                with open("/tmp/video_debug.log", "a") as f:
                    f.write(f"  Found range in scope: {range_header}\n")
                    f.flush()
                break
    
    if range_header:
        try:
            # Parse range header: "bytes=start-end"
            range_match = range_header.replace("bytes=", "").split("-")
            start_str = range_match[0].strip()
            end_str = range_match[1].strip() if len(range_match) > 1 and range_match[1] else ""
            
            start = int(start_str) if start_str else 0
            end = int(end_str) if end_str else file_size - 1
            
            # Validate range
            if start < 0:
                start = 0
            if end >= file_size:
                end = file_size - 1
            if start > end:
                return Response(
                    status_code=416,
                    headers={"Content-Range": f"bytes */{file_size}"}
                )
            
            # Read the requested chunk
            chunk_size = end - start + 1
            
            def generate_chunk():
                with open(video.path, "rb") as f:
                    f.seek(start)
                    remaining = chunk_size
                    while remaining > 0:
                        chunk = f.read(min(8192, remaining))
                        if not chunk:
                            break
                        yield chunk
                        remaining -= len(chunk)
            
            from fastapi.responses import StreamingResponse
            return StreamingResponse(
                generate_chunk(),
                status_code=206,
                headers={
                    "Content-Range": f"bytes {start}-{end}/{file_size}",
                    "Accept-Ranges": "bytes",
                    "Content-Length": str(chunk_size),
                    "Content-Type": media_type,
                    "Content-Disposition": "inline",
                    "Cache-Control": "public, max-age=3600",
                },
                media_type=media_type,
            )
        except (ValueError, IndexError):
            # If range parsing fails, fall through to serve full file
            pass
    
    # No range request or parsing failed - serve full file with range support headers
    response = FileResponse(
        video.path,
        media_type=media_type,
    )
    response.headers["Content-Disposition"] = "inline"
    response.headers["Accept-Ranges"] = "bytes"
    response.headers["Cache-Control"] = "public, max-age=3600"
    return response