"""Thin synchronous HTTP client for the demo console (frozen API contract, `app/api/schemas.py`).

The console never imports backend code: it talks to `API_BASE_URL` only. Responses are kept as plain dicts —
the console reads a handful of fields and must survive a backend that still serves fixtures (#12).
Every failure is raised as `ApiError` with a short Russian message, so pages can show it instead of crashing.
"""

from __future__ import annotations

import os
from typing import Any, Protocol

import httpx

DEFAULT_DOCTOR = "doc-smirnova"
DEFAULT_TOKEN = "tok-andrey"


def api_base_url() -> str:
    return os.environ.get("API_BASE_URL", "http://localhost:8000").rstrip("/")


def doctor_id() -> str:
    return os.environ.get("DEMO_DOCTOR_ID", DEFAULT_DOCTOR)


def fallback_token() -> str:
    return os.environ.get("DEMO_PERSONA_TOKEN", DEFAULT_TOKEN)


class ApiError(RuntimeError):
    """Any API failure (network, HTTP status, bad JSON) with a message fit for the presenter."""


class DemoApi(Protocol):
    """What the playback runner needs; `ConsoleApi` implements it, tests use a fake."""

    def clock(self) -> dict[str, Any]: ...

    def advance(self, days: float = 0, hours: float = 0) -> dict[str, Any]: ...

    def send_event(
        self,
        token: str,
        type_: str,
        *,
        text: str | None = None,
        button: str | None = None,
        params: dict[str, Any] | None = None,
    ) -> list[dict[str, Any]]: ...

    def outbox(self, token: str) -> list[dict[str, Any]]: ...

    def patients(self, doctor: str) -> list[dict[str, Any]]: ...


class ConsoleApi:
    """Client for `/api/v1`. Short timeouts everywhere except clock moves, which replay the scheduler."""

    def __init__(self, base_url: str | None = None, *, timeout: float = 5.0, client: httpx.Client | None = None):
        self.base_url = (base_url or api_base_url()).rstrip("/")
        self._timeout = timeout
        self._client = client or httpx.Client(timeout=timeout)

    # ------------------------------------------------------------------ plumbing
    def _request(self, method: str, path: str, *, timeout: float | None = None, **kwargs: Any) -> Any:
        url = f"{self.base_url}{path}"
        try:
            resp = self._client.request(method, url, timeout=timeout or self._timeout, **kwargs)
        except httpx.TimeoutException as exc:
            raise ApiError(f"{method} {path}: API не ответил вовремя") from exc
        except httpx.HTTPError as exc:
            raise ApiError(f"{method} {path}: API недоступен ({type(exc).__name__})") from exc
        if resp.status_code >= 400:
            raise ApiError(f"{method} {path}: HTTP {resp.status_code}")
        try:
            return resp.json()
        except ValueError as exc:
            raise ApiError(f"{method} {path}: ответ не JSON") from exc

    def close(self) -> None:
        self._client.close()

    # ------------------------------------------------------------------ service
    def health(self) -> bool:
        try:
            return self._request("GET", "/health", timeout=2).get("status") == "ok"
        except (ApiError, AttributeError):
            return False

    # ------------------------------------------------------------------ demo controls (ADR-005)
    def personas(self) -> list[dict[str, Any]]:
        return list(self._request("GET", "/api/v1/demo/personas"))

    def clock(self) -> dict[str, Any]:
        return dict(self._request("GET", "/api/v1/demo/clock"))

    def advance(self, days: float = 0, hours: float = 0) -> dict[str, Any]:
        # The backend replays the scheduler up to the new time inside this call: allow it time.
        body = {"days": days, "hours": hours}
        return dict(self._request("POST", "/api/v1/demo/clock/advance", json=body, timeout=60))

    def reset(self) -> dict[str, Any]:
        return dict(self._request("POST", "/api/v1/demo/reset", timeout=60))

    # ------------------------------------------------------------------ patient dialog
    def send_event(
        self,
        token: str,
        type_: str,
        *,
        text: str | None = None,
        button: str | None = None,
        params: dict[str, Any] | None = None,
    ) -> list[dict[str, Any]]:
        body: dict[str, Any] = {"type": type_, "params": params or {}}
        if text is not None:
            body["text"] = text
        if button is not None:
            body["button"] = button
        data = self._request("POST", f"/api/v1/dialog/{token}/events", json=body, timeout=30)
        return list(data.get("replies", []))

    def outbox(self, token: str) -> list[dict[str, Any]]:
        return list(self._request("GET", f"/api/v1/dialog/{token}/outbox").get("replies", []))

    def history(self, token: str, limit: int = 100) -> list[dict[str, Any]]:
        return list(self._request("GET", f"/api/v1/dialog/{token}/history", params={"limit": limit}))

    # ------------------------------------------------------------------ doctor side
    def patients(self, doctor: str) -> list[dict[str, Any]]:
        return list(self._request("GET", f"/api/v1/doctors/{doctor}/patients"))

    def alerts(self, doctor: str, since_id: int = -1, open_only: bool = False) -> list[dict[str, Any]]:
        params = {"since_id": since_id, "open_only": str(open_only).lower()}
        return list(self._request("GET", f"/api/v1/doctors/{doctor}/alerts", params=params))

    def connect(self, body: dict[str, Any]) -> dict[str, Any]:
        """`POST /patients/connect` (ConnectPatientIn) → {token, code, deep_link}."""
        return dict(self._request("POST", "/api/v1/patients/connect", json=body, timeout=30))

    def ack(self, alert_id: int, doctor: str) -> dict[str, Any]:
        return dict(self._request("POST", f"/api/v1/alerts/{alert_id}/ack", json={"doctor_id": doctor}))


def personas_or_fallback(api: ConsoleApi) -> tuple[list[dict[str, Any]], str | None]:
    """Demo personas for the selector, degrading step by step so the console always has someone to talk as.

    1. `GET /demo/personas` (patients with a scenario file);
    2. the demo doctor's patient list (real tokens; no scenario file yet, e.g. before #18 lands);
    3. a single persona with the token from `DEMO_PERSONA_TOKEN` (fixtures use `tok-andrey`).
    Returns the personas and a note for the presenter when a fallback was used.
    """
    try:
        personas = [p for p in api.personas() if isinstance(p, dict) and p.get("token")]
        if personas:
            return personas, None
        error = "API не вернул персон со сценарием"
    except ApiError as exc:
        error = str(exc)
    try:
        patients = [p for p in api.patients(doctor_id()) if isinstance(p, dict) and p.get("token")]
    except ApiError:
        patients = []
    if patients:
        # The demo hero first: the scenario file is guessed from the name later (`default_scenario_path`).
        patients.sort(key=lambda p: not str(p.get("display_name", "")).startswith("Андрей"))
        personas = [
            {
                "token": p["token"],
                "display_name": p.get("display_name") or p["token"],
                "therapy_day": p.get("therapy_day", 0),
                "scenario": None,
            }
            for p in patients
        ]
        return personas, f"{error}; показаны пациенты врача"
    token = fallback_token()
    fallback = {
        "token": token,
        "display_name": "Андрей С." if token == DEFAULT_TOKEN else token,
        "therapy_day": 0,
        "scenario": None,
    }
    return [fallback], f"{error}; используется токен из окружения"