"""The four agent calls on monky-tenancy's agent entrypoint (`/v1/agent/*`, MONKY-ADR-0028 §C.C).

Bearer = the agent's OpenBao token (from the `jwt-tenancy` login). Tenancy pins every call to
the token's `meta.env_id` (403 AGENT_ENV_MISMATCH -> exit 78, never retried) and refuses a token
whose deploy grant was superseded (401 AGENT_UNAUTHENTICATED -> re-bootstrap or re-run the kit).

Lease shape of record (Gate 1 v2, 2026-09-05): `{login_jwt, ttl_s, mount, role, vault}`. An
AppRole-era body (`wrapping_token`, `role_id`) is refused loudly — there is nothing to unwrap."""

from __future__ import annotations

import logging
from dataclasses import dataclass, field

from monky_deployd.transport import HttpClient, HttpResponse, TransportError

log = logging.getLogger("monky-deployd.tenancy")

LOG_TAIL_MAX = 16 * 1024


class TenancyError(Exception):
    def __init__(self, status: int, code: str, detail: str = ""):
        super().__init__(f"{status} {code}: {detail}".rstrip(": "))
        self.status, self.code, self.detail = status, code, detail


class Unauthenticated(TenancyError):
    """401 — the bearer is unknown, expired, revoked or its grant was superseded."""


class EnvMismatch(TenancyError):
    """403 AGENT_ENV_MISMATCH — this box's token is pinned to another env. Exit 78."""


class RateLimited(TenancyError):
    def __init__(self, status: int, code: str, detail: str, retry_after: int):
        super().__init__(status, code, detail)
        self.retry_after = retry_after


class LeaseShapeUnsupported(TenancyError):
    """Tenancy answered with an AppRole lease; this agent only speaks the jwt-tenancy grant."""


@dataclass
class Vault:
    addr: str | None = None
    mount: str | None = None  # the KV mount ("monky")
    prefix: str | None = None  # "<env>/see"


@dataclass
class Checkin:
    env_id: str
    action: str
    desired_sha: str | None
    purge_volumes: bool
    bundle_url: str | None
    checkin_interval_s: int
    vault: Vault = field(default_factory=Vault)


@dataclass
class Lease:
    login_jwt: str
    ttl_s: int
    mount: str
    role: str
    vault: Vault = field(default_factory=Vault)


def _error(resp: HttpResponse) -> TenancyError:
    code, detail = "HTTP_ERROR", resp.text()[:200]
    try:
        js = resp.json()
        if isinstance(js, dict):
            code = str(js.get("code") or code)
            detail = str(js.get("detail") or detail)
    except TransportError:
        pass
    if resp.status == 401:
        return Unauthenticated(resp.status, code, detail)
    if resp.status == 403 and code == "AGENT_ENV_MISMATCH":
        return EnvMismatch(resp.status, code, detail)
    if resp.status == 429:
        try:
            ra = int(resp.headers.get("retry-after", "60"))
        except ValueError:
            ra = 60
        return RateLimited(resp.status, code, detail, ra)
    return TenancyError(resp.status, code, detail)


class TenancyClient:
    def __init__(self, http: HttpClient, env_id: str, token: str):
        self.http = http
        self.env_id = env_id
        self.token = token

    def _headers(self) -> dict[str, str]:
        return {"Authorization": f"Bearer {self.token}"}

    def _call(self, method: str, path: str, json_body=None) -> HttpResponse:
        resp = self.http.request(method, path, json_body=json_body, headers=self._headers())
        if resp.status >= 400:
            raise _error(resp)
        return resp

    def checkin(
        self,
        *,
        agent_version: str,
        applied_sha: str | None,
        host: dict | None,
        containers: list[dict] | None,
    ) -> Checkin:
        body = {
            "env_id": self.env_id,
            "agent_version": agent_version,
            "applied_sha": applied_sha,
            "host": host,
            "containers": containers,
        }
        js = self._call("POST", "/v1/agent/checkin", body).json() or {}
        action = js.get("action")
        if action not in ("apply", "none", "down"):
            raise TenancyError(200, "BAD_CHECKIN", f"unknown action {action!r}")
        v = js.get("vault") or {}
        return Checkin(
            env_id=js.get("env_id") or self.env_id,
            action=action,
            desired_sha=js.get("desired_sha"),
            purge_volumes=bool(js.get("purge_volumes", False)),
            bundle_url=js.get("bundle_url"),
            checkin_interval_s=int(js.get("checkin_interval_s") or 60),
            vault=Vault(addr=v.get("addr"), mount=v.get("mount"), prefix=v.get("prefix")),
        )

    def bundle(self, url: str) -> tuple[bytes, str | None]:
        """The tar + the sha tenancy says it is (X-Bundle-Sha / X-Bundle-Sha256)."""
        resp = self._call("GET", url)
        ctype = resp.headers.get("content-type", "")
        if "tar" not in ctype:
            raise TenancyError(resp.status, "BAD_BUNDLE", f"unexpected content-type {ctype!r}")
        sha = resp.headers.get("x-bundle-sha256") or resp.headers.get("x-bundle-sha")
        return resp.body, sha

    def lease(self, reason: str = "apply") -> Lease:
        js = self._call("POST", "/v1/agent/lease", {"env_id": self.env_id, "reason": reason}).json() or {}
        if "login_jwt" not in js:
            if "wrapping_token" in js or "role_id" in js:
                raise LeaseShapeUnsupported(
                    200,
                    "LEASE_SHAPE",
                    "tenancy issued an AppRole lease (wrapping_token/role_id); monky-deployd "
                    "requires the jwt-tenancy deploy grant {login_jwt, ttl_s, mount, role} "
                    "(ADR-0028 amendment 2026-09-05)",
                )
            raise TenancyError(200, "LEASE_SHAPE", "lease response carries no login_jwt")
        v = js.get("vault") or {}
        return Lease(
            login_jwt=str(js["login_jwt"]),
            ttl_s=int(js.get("ttl_s") or 3600),
            mount=str(js.get("mount") or "jwt-tenancy"),
            role=str(js.get("role") or "see-env"),
            vault=Vault(addr=v.get("addr"), mount=v.get("mount"), prefix=v.get("prefix")),
        )

    def report(
        self,
        *,
        sha: str | None,
        result: str,
        log_tail: str | None,
        containers: list[dict] | None = None,
        detail: str | None = None,
    ) -> None:
        assert result in ("applied", "failed", "down")
        body = {
            "env_id": self.env_id,
            "sha": sha,
            "result": result,
            "log_tail": (log_tail or "")[-LOG_TAIL_MAX:] or None,
            "containers": containers,
        }
        if detail:
            body["detail"] = detail[:500]
        self._call("POST", "/v1/agent/report", body)