import base64
import hashlib
import hmac
import json

from edge.events import Event


def sign(secret: str, nonce: str, ts: str, body: bytes) -> str:
    msg = nonce.encode() + ts.encode() + body
    return hmac.new(secret.encode(), msg, hashlib.sha256).hexdigest()


class PostClient:
    def __init__(self, url: str, device_id: str, secret: str,
                 nonce_fn, now_fn, http_post=None, timeout: float = 5.0):
        self.url = url
        self.device_id = device_id
        self.secret = secret
        self.nonce_fn = nonce_fn
        self.now_fn = now_fn
        self.timeout = timeout
        if http_post is None:
            import requests
            http_post = requests.post
        self._post = http_post

    def send(self, event: Event, snapshots: list[bytes]) -> bool:
        payload = event.to_payload(self.device_id)
        payload["snapshots"] = [base64.b64encode(s).decode() for s in snapshots]
        body = json.dumps(payload, sort_keys=True)
        nonce = self.nonce_fn()
        ts = str(self.now_fn())
        headers = {
            "Content-Type": "application/json",
            "X-Nonce": nonce,
            "X-Timestamp": ts,
            "X-Signature": sign(self.secret, nonce, ts, body.encode()),
        }
        try:
            resp = self._post(self.url, data=body, headers=headers, timeout=self.timeout)
        except Exception:
            return False
        return 200 <= resp.status_code < 300