import json
import os
from urllib.parse import urlparse
import uuid
import boto3

def lambda_handler(event, context):

    # event.Records[0].s3.
    source_s3_bucket = event["sourceS3Bucket"]
    source_s3_key = event["sourceS3Key"]
    source_s3 = event["sourceS3"]

    video_name = source_s3_key
    invocation_id = str()
    result_list = []
    result_code = "Succeeded"
    result_string = "The input video object was converted successfully."
    asset_obj_arn = []

    # The type of output group determines which media players can play 
    # the files transcoded by MediaConvert.
    # For more information, see Creating outputs with AWS Elemental MediaConvert.
    output_group_type_dict = {
        "HLS_GROUP_SETTINGS": "HlsGroupSettings",
        "FILE_GROUP_SETTINGS": "FileGroupSettings",
        "CMAF_GROUP_SETTINGS": "CmafGroupSettings",
        "DASH_ISO_GROUP_SETTINGS": "DashIsoGroupSettings",
        "MS_SMOOTH_GROUP_SETTINGS": "MsSmoothGroupSettings"
    }

    try:
        job_name = "Default"
        with open("job.json") as file:
            job_settings = json.load(file)

        job_settings["Inputs"][0]["FileInput"] = source_s3

        # The path of each output video is constructed based on the values of 
        # the attributes in each object of OutputGroups in the job.json file. 
        destination_s3 = "s3://{0}/{1}/{2}/" \
            .format(os.environ["DEST_BUCKET"],
                    os.path.splitext(os.path.basename(source_s3_key))[0],
                    os.path.splitext(os.path.basename(job_name))[0])
        for output_group in job_settings["OutputGroups"]:
            output_group_type = output_group["OutputGroupSettings"]["Type"]
            if output_group_type in output_group_type_dict.keys():
                output_group_type = output_group_type_dict[output_group_type]
                output_group["OutputGroupSettings"][output_group_type]["Destination"] = \
                    "{0}{1}".format(destination_s3,str(uuid.uuid4()))
            else:
                raise ValueError("Exception: Unknown Output Group Type {}."
                                 .format(output_group_type))
            

        job_metadata_dict = {
            "assetID": str(uuid.uuid4()),
            # "application": os.environ["Application"],
            "input": source_s3,
            "settings": job_name
        }

        region = os.environ["AWS_DEFAULT_REGION"]
        queue = os.environ["CONVERT_QUEUE"]
        endpoints = boto3.client("mediaconvert", region_name=region) \
            .describe_endpoints()
        client = boto3.client("mediaconvert", region_name=region, 
                               endpoint_url=endpoints["Endpoints"][0]["Url"], 
                               verify=False)

        try:
            response = client.create_job(
                Role=os.environ["MEDIA_CONVERT_ROLE"], 
                Tags=job_metadata_dict, 
                Settings=job_settings,
                Queue=queue)
            invocation_id = response["Job"]["Id"]
            for output_group in job_settings["OutputGroups"]:
                output_group_type = output_group["OutputGroupSettings"]["Type"]
                if output_group_type in output_group_type_dict.keys():
                    output_group_type = output_group_type_dict[output_group_type]
                    asset_obj_name = (output_group["OutputGroupSettings"][output_group_type]["Destination"])
                    asset_obj_arn.append(asset_obj_name.replace("s3://","arn:aws:s3:::")+".m3u8")
        # You can customize error handling based on different error codes that 
        # MediaConvert can return.
        # For more information, see MediaConvert error codes. 
        # When the result_code is TemporaryFailure, S3 Batch Operations retries 
        # the task before the job is completed. If this is the final retry, 
        # the error message is included in the final report.
        except Exception as error:
            result_code = "TemporaryFailure"
            raise
    
    except Exception as error:
        if result_code != "TemporaryFailure":
            result_code = "PermanentFailure"


    finally:
        result_list.append({
            # "taskId": task_id,
            "resultCode": result_code,
            "resultString": result_string,
            "videoName": video_name
        })

    return {
        "invocation_id": invocation_id,
        "results": result_list,
        "asset_obj_arn": asset_obj_arn,
        "source_s3_bucket": source_s3_bucket,
        "source_s3_key": source_s3_key,
        "source_s3":source_s3
    }