"""
Video management API endpoints.
"""
import os
import shutil
from uuid import uuid4
from datetime import datetime
from typing import Optional
from urllib.parse import quote

from fastapi import (
    APIRouter,
    Depends,
    HTTPException,
    Request,
    UploadFile,
    File,
    Form,
    Query,
    status,
)
from fastapi.responses import FileResponse

from slowapi import Limiter
from slowapi.util import get_remote_address

from app.config import get_settings
from app.dependencies import get_current_user, get_supabase
from app.models.user import AccountType
from app.models.video import (
    VideoUpload,
    Video,
    VideoStatus,
    AnalysisMode,
    VideoStatusResponse,
    VideoListResponse,
)
from app.services.supabase_client import SupabaseService


router = APIRouter()

def _annotated_video_path(video_id: str) -> str:
    # Produced by analysis pipelines (e.g. analysis/team_analysis.py)
    return os.path.join("output_videos", "annotated", f"{video_id}.mp4")


def _get_limiter(request: Request) -> Limiter:
    return request.app.state.limiter


def get_video_info(file_path: str) -> dict:
    """Extract video metadata using OpenCV."""
    try:
        import cv2
        cap = cv2.VideoCapture(file_path)
    except ImportError:
        print("⚠️ OpenCV not installed, skipping video metadata extraction")
        return {
            "fps": 30.0,
            "frame_count": 0,
            "width": 1920,
            "height": 1080,
            "duration_seconds": 0,
        }
    
    try:
        if not cap.isOpened():
            return {}
        
        fps = cap.get(cv2.CAP_PROP_FPS)
        frame_count = int(cap.get(cv2.CAP_PROP_FRAME_COUNT))
        width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
        height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
        
        duration = frame_count / fps if fps > 0 else 0
        
        cap.release()
        
        return {
            "fps": fps,
            "frame_count": frame_count,
            "width": width,
            "height": height,
            "duration_seconds": duration,
        }
    except Exception:
        return {}
    finally:
        try:
            cap.release()
        except Exception:
            pass


@router.post("/upload", response_model=Video, status_code=status.HTTP_201_CREATED)
async def upload_video(
    request: Request,
    file: UploadFile = File(...),
    title: Optional[str] = Form(None, max_length=200),
    description: Optional[str] = Form(None, max_length=1000),
    analysis_mode: AnalysisMode = Form(...),
    organization_id: Optional[str] = Form(None),
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Upload a video for analysis.
    
    - **file**: Video file (mp4, avi, mov, mkv)
    - **analysis_mode**: 'team' or 'personal'
    - **organization_id**: Required for TEAM analysis
    """
    settings = get_settings()

    # Apply a modest rate limit to uploads to avoid resource exhaustion.
    limiter = _get_limiter(request)
    limiter.limit("10/hour")(lambda request: None)(request)
    
    # Validate file extension
    if not file.filename:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Missing filename"
        )

    _, ext = os.path.splitext(file.filename)
    ext = ext.lstrip(".").lower()
    if ext not in settings.allowed_extensions_list:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"Invalid file type. Allowed: {settings.allowed_video_extensions}"
        )
    
    # Basic content-type validation (defence-in-depth – still rely on OpenCV check later)
    allowed_mime_types = {
        "video/mp4",
        "video/x-msvideo",
        "video/quicktime",
        "video/x-matroska",
    }
    if file.content_type and file.content_type.lower() not in allowed_mime_types:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invalid content type for video upload",
        )

    # Validate file size
    file.file.seek(0, 2)  # Seek to end
    file_size = file.file.tell()
    file.file.seek(0)  # Reset
    
    if file_size > settings.max_upload_size_bytes:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=f"File too large. Maximum: {settings.max_upload_size_mb}MB"
        )
    
    # Validate team analysis requirements
    if analysis_mode == AnalysisMode.TEAM:
        allowed_types = [AccountType.TEAM.value, AccountType.COACH.value]
        if current_user.get("account_type") not in allowed_types:
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="Team analysis requires a TEAM or COACH account"
            )
        
        # Determine the user's organization context
        user_org_id = current_user.get("organization_id")
        if user_org_id in ("null", "undefined", ""):
            user_org_id = None
        
        # If the user is a team manager but organization_id isn't in token (unlikely but safe check)
        if not user_org_id and current_user.get("account_type") == AccountType.TEAM.value:
            orgs = await supabase.select("organizations", filters={"owner_id": current_user["id"]})
            if orgs:
                user_org_id = str(orgs[0]["id"])

        if organization_id in ("null", "undefined", ""):
            organization_id = None

        if not organization_id:
            organization_id = user_org_id

        # Determine if we should allow null organization_id
        # We allow it for individual coaches who aren't linked yet.
        is_coach = current_user.get("account_type") == AccountType.COACH.value
        
        if not organization_id and not is_coach:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="organization_id is required and you are not linked to any organization"
            )
            
        # Verify org access if an organization_id is provided or found
        if organization_id and str(organization_id) != str(user_org_id):
            # For robustness, if it's a team account, double check org ownership if the ID doesn't match token
            if current_user.get("account_type") == AccountType.TEAM.value:
                org = await supabase.select_one("organizations", str(organization_id))
                if not org or org.get("owner_id") != current_user["id"]:
                    raise HTTPException(status_code= status.HTTP_403_FORBIDDEN, detail="Access denied to this organization")
            else:
                 raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You can only upload to your linked organization")
    
    # Generate unique filename and save. We never trust the original name for paths.
    video_id = str(uuid4())
    filename = f"{video_id}.{ext}"
    # Ensure uploader id does not introduce path traversal
    safe_uploader_id = str(current_user["id"]).replace("/", "_").replace("\\", "_")
    storage_path = os.path.join(settings.upload_dir, safe_uploader_id, filename)
    
    os.makedirs(os.path.dirname(storage_path), exist_ok=True)
    
    with open(storage_path, "wb") as buffer:
        shutil.copyfileobj(file.file, buffer)
    
    # Get video metadata
    video_info = get_video_info(storage_path)
    if not video_info or not video_info.get("frame_count"):
        # Reject unreadable / non-video uploads
        try:
            os.remove(storage_path)
        except Exception:
            pass
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Uploaded file is not a readable video"
        )
    
    # Create database record
    video_record = {
        "id": video_id,
        "uploader_id": current_user["id"],
        "title": title or file.filename,
        "description": description,
        "analysis_mode": analysis_mode.value,
        "status": VideoStatus.PENDING.value,
        "storage_path": storage_path,
        "file_size_bytes": file_size,
        "organization_id": organization_id,
        **video_info,
    }
    
    await supabase.insert("videos", video_record)
    
    return Video(
        **video_record,
        created_at=datetime.utcnow(),
        download_url=f"/api/videos/{video_id}/download",
        annotated_download_url=f"/api/videos/{video_id}/annotated",
        has_annotated=os.path.exists(_annotated_video_path(video_id)),
    )


@router.get("", response_model=VideoListResponse)
async def list_videos(
    page: int = Query(1, ge=1),
    page_size: int = Query(20, ge=1, le=100),
    status_filter: Optional[VideoStatus] = Query(None),
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    List videos uploaded by the current user.
    """
    # Determine filtering strategy based on role and organization link
    filters = {}
    user_org_id = current_user.get("organization_id")
    account_type = current_user.get("account_type")

    if user_org_id:
        # Linked users see team videos + their own personal uploads
        # In Supabase, we can use an OR filter or just fetch all team videos
        # For simplicity in this logic, we'll fetch team videos as the primary feed
        filters["organization_id"] = user_org_id
    elif account_type == AccountType.TEAM.value:
        orgs = await supabase.select("organizations", filters={"owner_id": current_user["id"]})
        if orgs:
            filters["organization_id"] = orgs[0]["id"]
        else:
            filters["uploader_id"] = current_user["id"]
    else:
        filters["uploader_id"] = current_user["id"]
        
    if status_filter:
        filters["status"] = status_filter.value
    
    videos = await supabase.select(
        "videos",
        filters=filters,
        order_by="created_at",
        ascending=False,
    )
    
    # Paginate
    total = len(videos)
    start = (page - 1) * page_size
    end = start + page_size
    paginated = videos[start:end]
    
    return VideoListResponse(
        videos=[
            Video(
                **{
                    **v,
                    "download_url": f"/api/videos/{v.get('id')}/download",
                    "annotated_download_url": f"/api/videos/{v.get('id')}/annotated",
                    "has_annotated": bool(v.get("annotated_url")) or os.path.exists(_annotated_video_path(str(v.get('id')))),
                }
            )
            for v in paginated
        ],
        total=total,
        page=page,
        page_size=page_size,
    )


@router.get("/{video_id}", response_model=Video)
async def get_video(
    video_id: str,
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Get video details by ID.
    """
    video = await supabase.select_one("videos", video_id)
    
    if not video:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Video not found"
        )
    
    # Check ownership or organization access
    is_owner = str(video["uploader_id"]) == str(current_user["id"])
    
    is_org_member = False
    if video.get("organization_id") and current_user.get("organization_id"):
        if str(video["organization_id"]) == str(current_user["organization_id"]):
            is_org_member = True
            
    if not is_owner and not is_org_member:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="You don't have access to this video"
        )
    
    return Video(
        **{
            **video,
            "download_url": f"/api/videos/{video_id}/download",
            "annotated_download_url": f"/api/videos/{video_id}/annotated",
            "has_annotated": bool(video.get("annotated_url")) or os.path.exists(_annotated_video_path(video_id)),
        }
    )


@router.get("/{video_id}/download")
async def download_video(
    video_id: str,
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Download a previously uploaded video.
    Authenticated and ownership-checked.
    """
    video = await supabase.select_one("videos", video_id)
    if not video:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Video not found")

    # Check ownership or organization access
    is_owner = str(video.get("uploader_id")) == str(current_user["id"])
    
    is_org_member = False
    if video.get("organization_id") and current_user.get("organization_id"):
        if str(video["organization_id"]) == str(current_user["organization_id"]):
            is_org_member = True
            
    if not is_owner and not is_org_member:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You don't have access to this video")

    storage_path = video.get("storage_path")
    if not storage_path or not os.path.exists(storage_path):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Video file not found on server")

    # Prefer the original filename for download if available
    original_title = (video.get("title") or f"{video_id}").strip()
    safe_name = quote(original_title.replace("/", "_").replace("\\", "_"))
    _, ext = os.path.splitext(storage_path)
    ext = ext if ext else ".mp4"
    
    # Guess media type based on extension
    media_types = {
        ".mp4": "video/mp4",
        ".webm": "video/webm",
        ".avi": "video/x-msvideo",
        ".mov": "video/quicktime",
        ".mkv": "video/x-matroska",
    }
    media_type = media_types.get(ext.lower(), "video/mp4")

    return FileResponse(
        path=storage_path,
        filename=f"{safe_name}{ext}",
        media_type=media_type,
        content_disposition_type="inline"
    )


@router.get("/{video_id}/annotated")
async def download_annotated_video(
    video_id: str,
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Download the annotated output video (if available).
    Redirects to Supabase signed URL when stored in cloud, otherwise streams from disk.
    Ownership-checked via the uploaded video record.
    """
    from fastapi.responses import RedirectResponse

    video = await supabase.select_one("videos", video_id)
    if not video:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Video not found")
    # Check ownership or organization access
    is_owner = str(video.get("uploader_id")) == str(current_user["id"])
    
    is_org_member = False
    if video.get("organization_id") and current_user.get("organization_id"):
        if str(video["organization_id"]) == str(current_user["organization_id"]):
            is_org_member = True
            
    if not is_owner and not is_org_member:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="You don't have access to this video")

    # Prefer Supabase signed URL (cloud storage) — redirect the client directly
    annotated_url = video.get("annotated_url")
    if annotated_url and annotated_url.startswith("https"):
        return RedirectResponse(url=annotated_url, status_code=302)

    # Fallback: serve from local disk
    annotated_path = _annotated_video_path(video_id)
    if not os.path.exists(annotated_path):
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Annotated video not available yet")

    original_title = (video.get("title") or f"{video_id}").strip()
    safe_name = quote(original_title.replace("/", "_").replace("\\", "_"))
    return FileResponse(
        path=annotated_path,
        filename=f"{safe_name}-annotated.mp4",
        media_type="video/mp4",
        content_disposition_type="inline"
    )


@router.get("/{video_id}/status", response_model=VideoStatusResponse)
async def get_video_status(
    video_id: str,
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Get video processing status with robust error handling for network issues.
    """
    try:
        video = await supabase.select_one("videos", video_id)
        
        if not video:
            raise HTTPException(
                status_code=status.HTTP_404_NOT_FOUND,
                detail="Video not found"
            )
        
        # Security: Only owner or team members can see status
        is_owner = str(video["uploader_id"]) == str(current_user["id"])
        
        # Check org access if uploader is different
        is_org_member = False
        if not is_owner and video.get("organization_id") and current_user.get("organization_id"):
            if str(video["organization_id"]) == str(current_user["organization_id"]):
                is_org_member = True
        
        if not is_owner and not is_org_member:
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="You don't have access to this video status"
            )
        
        # HEAL: If status is failed but an analysis result was actually written, 
        # then the process likely finished but the final status update was interrupted.
        if video["status"] == VideoStatus.FAILED.value:
            try:
                results = await supabase.select("analysis_results", filters={"video_id": video_id}, limit=1)
                if results:
                    video["status"] = VideoStatus.COMPLETED.value
                    video["progress_percent"] = 100
                    video["current_step"] = "Complete (Auto-Recovered)"
                    # Apply heal to DB so it doesn't repeat
                    await supabase.update("videos", video_id, {
                        "status": VideoStatus.COMPLETED.value,
                        "progress_percent": 100,
                        "current_step": "Complete (Auto-Recovered)"
                    })
            except Exception as e:
                print(f"⚠️  Auto-heal check failed for video {video_id}: {e}")
        
        return VideoStatusResponse(
            id=video["id"],
            status=VideoStatus(video["status"]),
            progress_percent=video.get("progress_percent") or 0,
            current_step=video.get("current_step") or "Initializing",
            error_message=video.get("error_message"),
        )
    except HTTPException:
        raise
    except Exception as e:
        print(f"❌ Error fetching video status for {video_id}: {e}")
        # Return 503 instead of 500 for network/database connection errors
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Temporary database connection error. Please try again in a few moments."
        )


@router.delete("/{video_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_video(
    video_id: str,
    current_user: dict = Depends(get_current_user),
    supabase: SupabaseService = Depends(get_supabase),
):
    """
    Delete a video and associated data.
    Allows uploader, team owner, or coach (if in same org) to delete.
    """
    video = await supabase.select_one("videos", video_id)
    
    if not video:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Video not found"
        )
    
    # Permission Check: Uploader can always delete
    is_owner = str(video["uploader_id"]) == str(current_user["id"])
    
    # Organization Check: Team Owner or Coach can delete team videos
    is_org_authorized = False
    if video.get("organization_id") and current_user.get("organization_id"):
        if str(video["organization_id"]) == str(current_user["organization_id"]):
            if current_user.get("account_type") in [AccountType.TEAM.value, AccountType.COACH.value]:
                is_org_authorized = True

    if not is_owner and not is_org_authorized:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="You don't have permission to delete this video"
        )
    
    # 1. Delete original file
    if video.get("storage_path") and os.path.exists(video["storage_path"]):
        try:
            os.remove(video["storage_path"])
        except Exception as e:
            print(f"Error removing original video: {e}")

    # 2. Delete annotated video (if any)
    annotated_path = _annotated_video_path(video_id)
    if os.path.exists(annotated_path):
        try:
            os.remove(annotated_path)
        except Exception as e:
            print(f"Error removing annotated video: {e}")

    # 3. Clean up personal analysis outputs (if any)
    # Personal analysis uses a different naming convention: {video_id}_output.mp4 etc.
    from app.api.personal_analysis import PERSONAL_OUTPUT_DIR
    for suffix in ["_output.mp4", "_output.avi", "_report.txt", "_input.mp4", "_input.avi"]:
        personal_path = os.path.join(PERSONAL_OUTPUT_DIR, f"{video_id}{suffix}")
        if os.path.exists(personal_path):
            try:
                os.remove(personal_path)
            except Exception:
                pass

    # 4. Best-effort cascade delete related rows
    for table in ["analysis_results", "detections", "analytics", "personal_analyses", "clips"]:
        try:
            await supabase.delete_where(table, {"video_id": video_id})
        except Exception:
            # Fallback for tables that might use different columns or not exist
            try:
                if table == "personal_analyses":
                    await supabase.delete_where(table, {"job_id": video_id})
                elif table == "clips":
                    # Advanced analytics clips usually linked via video_id
                    await supabase.delete_where(table, {"video_id": video_id})
            except Exception:
                pass
    
    # 5. Delete database record
    await supabase.delete("videos", video_id)
    
    return None