"""Pay With Prompt client. Credits are not money and are not refundable.

One line, after this module is loaded:

    print(Pwp.register("mon-agent").claim_sandbox().redeem("sandbox"))
"""

import json
from urllib import error, request

DEFAULT_BASE = "https://paywithprompt.com"


class PwpError(Exception):
    def __init__(self, status: int, body: object):
        super().__init__(f"HTTP {status}: {body}")
        self.status = status
        self.body = body


def _http(method, url, body, headers, timeout=30):
    data = None if body is None else json.dumps(body).encode()
    req = request.Request(url, data=data, headers=headers, method=method)
    try:
        with request.urlopen(req, timeout=timeout) as res:
            raw = res.read().decode()
            return res.status, json.loads(raw) if raw else {}
    except error.HTTPError as exc:
        raw = exc.read().decode()
        try:
            parsed = json.loads(raw) if raw else {}
        except json.JSONDecodeError:
            parsed = {"message": raw}
        raise PwpError(exc.code, parsed) from None


class Pwp:
    def __init__(self, base=DEFAULT_BASE, key=None, human_key=None):
        self.base = base.rstrip("/")
        self.key = key
        self.human_key = human_key
        self.agent_id = None
        self.last = None

    def _headers(self, key):
        headers = {"content-type": "application/json", "accept": "application/json"}
        if key:
            headers["authorization"] = f"Bearer {key}"
        return headers

    def _call(self, method, path, body=None, key=None):
        status, payload = _http(method, self.base + path, body, self._headers(key))
        self.last = payload
        if status >= 400:
            raise PwpError(status, payload)
        return payload

    @classmethod
    def register(cls, label="agent", base=DEFAULT_BASE, daily_cap=None, voucher_cap=None):
        client = cls(base=base)
        body = {"label": label}
        if daily_cap is not None:
            body["daily_cap"] = daily_cap
        if voucher_cap is not None:
            body["voucher_cap"] = voucher_cap
        data = client._call("POST", "/api/v1/agents/register", body)
        client.key = data.get("api_key")
        client.human_key = data.get("human_key")
        client.agent_id = data.get("agent_id")
        return client

    def claim_sandbox(self):
        self._call("POST", "/api/v1/sandbox/claim", {}, self.key)
        return self

    def me(self):
        return self._call("GET", "/api/v1/me", None, self.key)

    def prompts(self):
        return self._call("GET", "/api/v1/prompts")

    def submit(self, prompt_id, answer):
        self._call("POST", f"/api/v1/prompts/{prompt_id}/submit", {"answer": answer}, self.key)
        return self

    def redeem(self, merchant="sandbox", units=1):
        self._call("POST", "/api/v1/redeem", {"merchant": merchant, "units": units}, self.key)
        return self

    def verify(self, token):
        return self._call("POST", "/api/v1/vouchers/verify", {"token": token})

    def set_caps(self, daily_cap=None, voucher_cap=None, human_key=None):
        body = {}
        if daily_cap is not None:
            body["daily_cap"] = daily_cap
        if voucher_cap is not None:
            body["voucher_cap"] = voucher_cap
        self._call("POST", "/api/v1/caps", body, human_key or self.human_key)
        return self

    def __repr__(self):
        return json.dumps(self.last, ensure_ascii=False)