import base64
import datetime
import hashlib
import json
import requests
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives import hashes


DEBUG = True
SANDBOX = True

# Endpoint/Host
ENDPOINT = "https://staging.authservices.satispay.com" if SANDBOX else "https://authservices.satispay.com"
HOST = ENDPOINT.replace("https://", "")
# Key 1 got from server for token 1
TOKEN_1 = "STJ2P2"
KEY_ID_1 = "9v77oksdn6d1pktlgmt6a4eg8j8r6ue1rvfd9nu6pnmmtnev57ckuuer9n25edq4k59f1r4smn84k103s9ndevei07bf43la0du967qqu2uu298shvf1916n85i2925kigu847arg9tf5ukr345gbkt4oppij03rqtovvs6jqoq9grhc0g7jhrldpr2hhjkv211bl3ef"
# Key 2 got from server for token 2
TOKEN_2 = "U5C3RN"
KEY_ID_2 = "ldr6m73p4kiitg5ftr2v2abugud6qi6thq8k62lmu7425n52c0c4gvqa0fl6hn118qpfj4oon9gka8jn1orskd4lp16ksrrnv6lj1alrn93pvpnq8ctj380fnm5ef2al126598npec1cckitjm682l9ukjqpt9qilddlbo1b1jhne9gvjplko2cuq4qn29nlacet2kf6"

# To be used
TOKEN = TOKEN_2
KEY_ID = KEY_ID_2


def debug(msg, *args):
    if DEBUG:
        print(msg, *args)


def load_pub_key():
    with open("public.pem", "r") as fin:
        return fin.read()


def load_priv_key():
    with open("private.pem", "rb") as fin:
        return serialization.load_pem_private_key(
            fin.read(),
            password=None,
            backend=default_backend()
        )


def get_key_id():
    print("*** GET KEY ID ***")

    target = "/g_business/v1/authentication_keys"
    headers = {
        "content-type": "application/json",
    }
    data = {
        "public_key": load_pub_key(),
        "token": TOKEN,
    }

    debug("Headers:\n" + json.dumps(headers, indent=4))
    debug("Data:\n" + json.dumps(data, indent=4))

    response = requests.post(
        ENDPOINT + target,
        json=data,
        headers=headers
    )

    print("Response:\n:", response.json())


def get_authorization_header(body_json, target):
    # Digest
    body = json.dumps(body_json)
    digest = "SHA-256=" + base64.b64encode(hashlib.sha256(body.encode()).digest()).decode()
    debug("Digest:\n", digest)

    # Date
    date = datetime.datetime.now(datetime.timezone.utc).strftime('%a, %d %b %Y %H:%M:%S GMT')
    debug("Date:\n", date)

    # Message
    message = "(request-target): post " + target + "\n\
    host: " + HOST + "\n\
    date: " + date + "\n\
    digest: " + digest
    debug("Message:\n", message)

    # Signature
    signature = load_priv_key().sign(
        message.encode(),
        padding.PKCS1v15(),
        hashes.SHA256()
    )
    signature = base64.b64encode(signature).decode()
    debug("Signature:\n", signature)

    # Authorization
    auth = f'Signature keyId="{KEY_ID}", algorithm="rsa-sha256", headers="(request-target) host date digest", signature="{signature}"'
    debug("Authorization:\n", auth)
    debug ("")

    return {
        "date": date,
        "digest": digest,
        "Authorization": auth,
    }


def test_authentication(body_json):
    print("*** TEST AUTHENTICATION ***")

    target = "/wally-services/protocol/tests/signature"
    headers = {
        "content-type": "application/json",
        "host": HOST,
        **get_authorization_header(body_json, target),
    }
    data = body_json

    debug("Headers:\n" + json.dumps(headers, indent=4))
    debug("Data:\n" + json.dumps(data, indent=4))

    response = requests.post(
        ENDPOINT + target,
        json=data,
        headers=headers
    )

    print("Response:\n", response.json())


if __name__ == "__main__":
    body_json = {
        "flow": "MATCH_CODE",
        "amount_unit": 100,
        "currency": "EUR"
    }

    print("Insert function:")
    print("  1. Get key ID")
    print("  2. Test authorization")
    fct = int(input())

    print("")

    if fct == 1:
        get_key_id()
    elif fct == 2:
        test_authentication(body_json)
    else:
        print("Unsupported function")