main.py

from pydantic import BaseModel
from fastapi import FastAPI, UploadFile, HTTPException
from ffmpeg import input, output, run
from botocore.exceptions import ClientError
import ffmpeg
import boto3
import os

app = FastAPI()

# Define your AWS S3 credentials and bucket name
aws_access_key_id = os.environ['AWS_ACCESS_KEY_ID']
aws_secret_access_key = os.environ['AWS_SECRET_ACCESS_KEY']
s3_bucket_name = os.environ['S3_BUCKET_NAME']
aws_env = os.environ['AWS_ENV']
aws_region = 'eu-central-1'
temp_dir = '/tmp/'
# Initialize an S3 client
s3_client = boto3.client('s3', aws_access_key_id=aws_access_key_id, aws_secret_access_key=aws_secret_access_key, region_name=aws_region)

class CutRequest(BaseModel):
    quote_filename: str
    segments: list[tuple[float, float]]
    news_name: str
    news_id: int

async def json_stripper(request: CutRequest):
    raw_body = await request.body()
    try:
        # Decode the raw body
        body_str = raw_body.decode('utf-8')
    
        # Remove any surrounding quotes if present
        body_str = body_str.strip('"')
        
        # Unescape the JSON string
        body_str = body_str.replace('\\"', '"')
        
        # Parse the JSON
        body = json.loads(body_str)
        
        return body
    except json.JSONDecodeError as e:
        print(f"JSON Decode Error: {e}")
        raise HTTPException(status_code=400, detail=f"Invalid JSON: {str(e)}")
    except Exception as e:
        print(f"Error: {e}")
        raise HTTPException(status_code=400, detail=str(e))

def download_file(news_name: str, quote_filename: str, new_filename: str = "source.mp3"):
    s3_directory = f'{aws_env}/{news_name}'
    s3_object_key = f'{s3_directory}/{quote_filename}'
    local_file = os.path.join(temp_dir, new_filename)

    try:
        # Ensure the download directory exists
        os.makedirs(temp_dir, exist_ok=True)

        s3_client.download_file(s3_bucket_name, s3_object_key, local_file)
        print(f"File downloaded and saved as: {local_file}")
        
        # Return the local_file path
        return local_file

    except ClientError as e:
        if e.response['Error']['Code'] == "404":
            raise HTTPException(status_code=404, detail=f"The file {quote_filename} does not exist in S3.")
        else:
            raise HTTPException(status_code=500, detail=f"Failed to download file from S3: {str(e)}")
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"An unexpected error occurred: {str(e)}")


@app.post("/cut-audio")
async def cut_audio(request: CutRequest):
    # Use json_stripper to parse the request body
    body = await json_stripper(request)
    
    # Validate the body against CutRequest model
    try:
        cut_request = CutRequest(**body)
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))

    # Now you can use cut_request in your function
    download_file(cut_request.news_name, cut_request.quote_filename)
    for i, (start, end) in enumerate(cut_request.segments):
        output_file = f"/tmp/cut_quote_{i}.mp3"
        try:
            (
                ffmpeg
                .input('/tmp/source.mp3', ss=start, to=end)
                .output(output_file)
                .run()
            )
        except ffmpeg.Error as e:
            raise HTTPException(status_code=500, detail=str(e))
        try:
            s3_output_key = f'{aws_env}/{cut_request.news_id}/genBase_segment_{i}.mp3' 
            s3_client.upload_file(output_file, s3_bucket_name, s3_output_key)
        except Exception as e:
            raise HTTPException(status_code=500, detail=f"Failed to upload file to S3: {e}")

    return {"message": "Audio cut successfully"}

@app.post("/merge_audio/{output_key}")
async def merge_audio(output_key: str):
    s3_directory = output_key
    # Output file name
    output_file = temp_dir + 'output.mp3'

    # Use python-ffmpeg to merge audio clips
    # input_file_paths = [temp_dir + input_file for input_file in input_files]
    # input_args = [input(file_path) for file_path in input_file_paths]
    input_file = 'list.txt'

    try:
        intermediate_output = temp_dir + 'intermediate_output.mp3'
        ffmpeg.input(input_file, format='concat', safe=0).output(intermediate_output, c='copy').run()
        ffmpeg.input(intermediate_output).audio.filter('loudnorm').output(output_file, audio_bitrate='256k', ar='44100').run()
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"FFmpeg Error: {e}")

    # Upload the merged file back to S3
    s3_output_key = f'{s3_directory}/final.mp3'
    try:
        s3_client.upload_file(output_file, s3_bucket_name, s3_output_key)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Failed to upload file to S3: {e}")

    return {"message": "Audio clips successfully merged and saved in S3"}

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7680)