interfaces/api/routes/extraction_routes.py

"""Audio extraction API routes."""
from fastapi import APIRouter, BackgroundTasks, UploadFile, Form, HTTPException
from fastapi.responses import JSONResponse
from dataclasses import asdict
from typing import Optional

from ..dependencies import ValidatedVideo, ExtractionParams, UseCases, Services, BearerToken
from ..responses import JobCreatedResponse
from application.dto.extraction_request import ExtractionRequestDTO
from domain.entities.job import Job
from domain.exceptions.domain_exceptions import (
    ValidationError, 
    DuplicateExternalJobIdError, 
    InvalidExternalJobIdFormatError
)

router = APIRouter()

@router.post("/extract", 
            response_model=JobCreatedResponse,
            summary="Extract Audio from Video",
            description="""
            Extract audio from uploaded video file.
            
            All files are processed asynchronously and return a job ID for tracking progress.
            Use the job status endpoint to check processing status and download the result when complete.
            """,
            responses={
                202: {
                    "description": "Job created for async processing",
                    "model": JobCreatedResponse
                },
                400: {
                    "description": "Invalid input", 
                    "content": {
                        "application/json": {
                            "examples": {
                                "invalid_job_id": {
                                    "summary": "Invalid external job ID",
                                    "value": {
                                        "error": "Invalid external job ID format",
                                        "code": "INVALID_EXTERNAL_JOB_ID_FORMAT",
                                        "field": "job_id"
                                    }
                                },
                                "duplicate_job_id": {
                                    "summary": "Duplicate external job ID",
                                    "value": {
                                        "error": "External job ID already exists: my-job-123",
                                        "code": "DUPLICATE_EXTERNAL_JOB_ID"
                                    }
                                }
                            }
                        }
                    }
                },
                401: {
                    "description": "Authentication required", 
                    "content": {
                        "application/json": {
                            "example": {
                                "error": "Authentication required",
                                "code": "AUTHENTICATION_ERROR"
                            }
                        }
                    }
                },
                500: {"description": "Processing error"}
            })
async def extract_audio(
    background_tasks: BackgroundTasks,
    video: ValidatedVideo,
    params: ExtractionParams,
    token: BearerToken,
    use_cases: UseCases,
    services: Services,
    job_id: Optional[str] = Form(None, description="Optional external job identifier")
):
    """
    Extract audio from uploaded video file.
    
    All videos are processed asynchronously regardless of file size.
    Returns a job ID that can be used to:
    - Check processing status: GET /jobs/{job_id}
    - Download result when complete: GET /jobs/{job_id}/download
    """
    # Validate external job ID format if provided
    if job_id:
        try:
            use_cases.validation_service.validate_external_job_id(job_id)
        except InvalidExternalJobIdFormatError as e:
            raise HTTPException(
                status_code=400, 
                detail={
                    "error": "Invalid external job ID format",
                    "details": str(e),
                    "code": "INVALID_EXTERNAL_JOB_ID_FORMAT",
                    "field": "job_id",
                    "value": e.job_id
                }
            )
    
    # Get file size
    file_size = _get_file_size(video)
    
    # Create job with external ID and bearer token
    try:
        job = Job.create_new(
            video_filename=video.filename,
            file_size_bytes=file_size,
            output_format=params.output_format,
            quality=params.quality,
            external_job_id=job_id,
            bearer_token=token
        )
    except Exception as e:
        # This shouldn't happen with Job.create_new, but catch any unexpected errors
        raise HTTPException(status_code=500, detail=f"Failed to create job: {str(e)}")
    
    # Save uploaded file with the job ID
    file_path = await services.file_repository.save_stream(
        video, 
        video.filename,
        job_id=job.id  # Pass the job ID here
    )
    
    # Create DTO
    extraction_dto = ExtractionRequestDTO(
        video_filename=video.filename,
        video_file_path=file_path,
        video_file_size=file_size,
        output_format=params.output_format,
        quality=params.quality,
        content_type=video.content_type
    )
    
    # Execute use case with pre-created job
    try:
        result = await use_cases.extract_audio_async.execute_with_job(
            job,  # Pass the job object
            extraction_dto,
            background_tasks
        )
        
        return JSONResponse(
            content=asdict(result),
            status_code=202
        )
    except DuplicateExternalJobIdError as e:
        # Clean up input file on error
        await services.file_repository.delete_file(file_path)
        raise HTTPException(
            status_code=400, 
            detail={
                "error": str(e),
                "code": "DUPLICATE_EXTERNAL_JOB_ID",
                "external_job_id": e.external_job_id
            }
        )
    except Exception as e:
        # Clean up input file on error
        await services.file_repository.delete_file(file_path)
        raise

def _get_file_size(video: UploadFile) -> int:
    """Get the size of the uploaded file."""
    video.file.seek(0, 2)  # Seek to end
    size = video.file.tell()
    video.file.seek(0)     # Reset pointer to start
    return size