import datetime

import boto3
import requests

RETENTION = 'retention'
EXPIRE_FAST = 'expire_fast'
TEMP_MARKER = 'temp'

service = 's3'
region = 'us-east-1'
t = datetime.datetime.utcnow()
algorithm = 'AWS4-HMAC-SHA256'
credential_scope = '/'.join([t.strftime('%Y%m%d'), region, service, 'aws4_request'])

key = 'temp-22e063cd-4ed3-437c-87ac-2bc6e6f328d0/my_file.txt'


def get_tag_xml(key, value):
    return f"<Tagging><TagSet><Tag><Key>{key}</Key><Value>{value}</Value></Tag></TagSet></Tagging>"

def get_tag_xml_real(key, value):
    return f"<Tagging><TagSet><Tag><Key>{key}</Key><Value>never-expire</Value></Tag></TagSet></Tagging>"


conditions = [
    {"x-amz-algorithm": algorithm},
    {"x-amz-credential": credential_scope},
    {"x-amz-date": t.isoformat()},
    {"tagging": get_tag_xml(RETENTION, EXPIRE_FAST)},
    {"success_action_status": "201"},
    {"bucket": 'demo-bucket'},
    ["starts-with", "$key", TEMP_MARKER],
]

fields = {
    "x-amz-algorithm": algorithm,
    "x-amz-credential": credential_scope,
    "x-amz-date": t.isoformat(),
    "tagging": get_tag_xml_real(RETENTION, EXPIRE_FAST),
    "success_action_status": "201",
}

client = boto3.client(
    service_name='s3',
    aws_access_key_id='minioadmin',
    aws_secret_access_key='minioadmin',
    endpoint_url='http://localhost:9000',
)

presigned = client.generate_presigned_post(
    'demo-bucket',
    key,
    Fields=fields,
    Conditions=conditions,
    ExpiresIn=60*60,
)

# Demonstrate how another Python program can use the presigned URL to upload a file
object_name = 'filename.txt'
with open(object_name, 'rb') as f:
    files = {'file': (object_name, f)}
    http_response = requests.post(presigned['url'], data=presigned['fields'], files=files)
print(f'File upload HTTP status code: {http_response.status_code}')
print(http_response.content)