import os
import boto3
import json
import boto3.exceptions
from pydantic import BaseModel
from typing import Optional

s3_client = None
bucket_config = ''
bucket_data = ''
git_version = ''

class RequestParams(BaseModel):
    id: str
    tag_id: str
    face_id: Optional[str] = None 

class Content(BaseModel):
    type: str
    key: str 
    url: Optional[str] = None

def lambda_handler(event: dict, context):
    global s3_client, bucket_config, bucket_data, git_version
    
    if s3_client is None:
        print("Init Function")
        bucket_config = os.environ.get('BUCKET_CONFIG', 'standout-config')
        bucket_data = os.environ.get('BUCKET_DATA', 'standout-data')
        git_version = os.environ.get('GIT_VERSION', '00000000')

        print(f'      Version: {git_version}')
        print(f'  Bucket Data: {bucket_data}')
        print(f'Bucket Config: {bucket_config}')

        s3_client = boto3.client('s3')

    ## Download redirects file
    try: 
        resp = s3_client.get_object(
            Bucket=bucket_config,
            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
        }
    
    ## Parse request and get content
    try:
        redirects = json.load(resp['Body'])

        params =  RequestParams(**event.get('queryStringParameters', {}))  
        customers = redirects.get('customers', {})                             
        customer = customers.get(params.id, {})
        tags = customer.get('tags', {})
        tag = tags.get(params.tag_id, {})
        content = tag.get('content', None)
        
        # In case of multi face tag select the correct face
        if isinstance(content, dict) and params.face_id:
            content = content.get(params.face_id, None)
        if content is None:
            return {
                    "statusCode": 404
                    }
        
        content = Content(**content)
        match content.type:
            case "s3":
                    file_name = content.key.replace('+',' ') # remove slugify of filename
                    key = f'{customer['name']}/{params.tag_id}{'/'+params.face_id if params.face_id else ''}/{file_name}'
                    final_redirect = s3_client.generate_presigned_url('get_object',
                                                                Params={'Bucket': bucket_data,
                                                                        'Key': key},
                                                                ExpiresIn=120)          
            case "url":
                final_redirect = content.url

    except json.decoder.JSONDecodeError as je:
        print(je)
        return {
                "statusCode": 500
            }
    except KeyError as ke:
        print(ke)
        return {
                "statusCode": 404
            }
    except Exception as e:
        print(e)
        return {
                "statusCode": 500
            }
    
    return {
        "statusCode": 301,
        "headers": {
        "Cache-Control": "no-cache", 
        "Location": str(final_redirect)
        }
    }


if __name__ == "__main__":
    event = {
    "resource": "/",
    "path": "/",
    "httpMethod": "GET",
    "queryStringParameters": {
        "id": "customer1",
        "tag_id": "tag2",
        "face_id": "face2"
        },
    }

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