import boto3
import json
import boto3.exceptions
from botocore.exceptions import ClientError

s3_client = None

def lambda_handler(event: dict, context):
    global s3_client

    if s3_client is None:
        s3_client = boto3.client('s3')
        for x in s3_client.list_buckets()['Buckets']:
            print(f"{x['Name']}: {x['CreationDate'].isoformat()}")

    try: 
        resp = s3_client.get_object(
            Bucket='standout-data',
            Key='redirects.json'
        )
    except s3_client.exceptions.NoSuchKey as e:
        print(e)
        # Oppure pagina "siamo spiacenti ma il contenuto non e' disponibile"
        return {
            "statusCode": 404
        }
    try:
        redirects = json.load(resp["Body"])
        params =  event.get('queryStringParameters', {})
        customer = redirects.get(params['cust_id'], {})
        gadget = customer.get(params['gadget_id'], {})

        content = gadget.get('content', None)
        dest = None
        if content and isinstance(content, dict):
            dest = content[params['face_id']]
        else:
            dest = content

        if dest and isinstance(dest, dict):
            match dest.get('type', 's3'):
                case "s3":
                    try:
                        response = s3_client.generate_presigned_url('get_object',
                                                                    Params={'Bucket': 'standout-data',
                                                                            'Key': dest['key']},
                                                                    ExpiresIn=120)
                    except ClientError as e:
                        print(e)
                    finally:
                        dest = response


    except json.decoder.JSONDecodeError as je:
        print(je)
        return {
                "statusCode": 500
            }
    except KeyError as ke:
        print(ke)
        return {
                "statusCode": 500
            }
    
    return {
        "statusCode": 301,
        "headers": {
        "Cache-Control": "no-cache", 
        "Location": str(dest)
        }
    }


if __name__ == "__main__":
    event = {
    "resource": "/",
    "path": "/",
    "httpMethod": "GET",
    "queryStringParameters": {
        "cust_id": "cust_id1",
        "gadget_id": "gadget_id1",
        "face_id": "face_id3"
        },
    }

    print(json.dumps(lambda_handler(
        event,
        None
    ), indent=2))