from __future__ import annotations

import httpx
import pytest

from iti.service_client import (
    ServiceClient,
    ServiceConfig,
    ServiceHTTPError,
    ServiceUnavailableError,
)
from iti.service_client.config import CircuitBreakerConfig, RetryConfig


def _json_response(status_code: int, payload: dict) -> httpx.Response:
    return httpx.Response(status_code, json=payload)


def test_service_client_sends_json_headers_token_trace_and_path():
    seen: dict[str, object] = {}

    def handler(request: httpx.Request) -> httpx.Response:
        seen["url"] = str(request.url)
        seen["authorization"] = request.headers.get("Authorization")
        seen["trace_id"] = request.headers.get("X-Trace-Id")
        return _json_response(200, {"ok": True})

    client = ServiceClient(
        ServiceConfig(name="erp", base_url="http://erp.local", token="token-a"),
        transport=httpx.MockTransport(handler),
    )

    result = client.get("/users/{id}", path={"id": 12}, params={"active": "1"})

    assert result == {"ok": True}
    assert seen["url"] == "http://erp.local/users/12?active=1"
    assert seen["authorization"] == "Bearer token-a"
    assert isinstance(seen["trace_id"], str)
    assert seen["trace_id"]


def test_service_client_retries_idempotent_statuses():
    calls = {"count": 0}

    def handler(request: httpx.Request) -> httpx.Response:
        calls["count"] += 1
        if calls["count"] == 1:
            return _json_response(503, {"error": "busy"})
        return _json_response(200, {"ok": True})

    client = ServiceClient(
        ServiceConfig(
            name="erp",
            base_url="http://erp.local",
            retry=RetryConfig(attempts=2, backoff=0),
        ),
        transport=httpx.MockTransport(handler),
    )

    assert client.get("/health") == {"ok": True}
    assert calls["count"] == 2


def test_service_client_does_not_retry_post_by_default():
    calls = {"count": 0}

    def handler(request: httpx.Request) -> httpx.Response:
        calls["count"] += 1
        return _json_response(503, {"error": "busy"})

    client = ServiceClient(
        ServiceConfig(
            name="erp",
            base_url="http://erp.local",
            retry=RetryConfig(attempts=3, backoff=0),
        ),
        transport=httpx.MockTransport(handler),
    )

    with pytest.raises(ServiceHTTPError) as exc_info:
        client.post("/jobs", json={"kind": "users"})

    assert exc_info.value.status_code == 503
    assert calls["count"] == 1


def test_service_client_opens_circuit_breaker_after_failures():
    def handler(request: httpx.Request) -> httpx.Response:
        return _json_response(500, {"error": "failed"})

    client = ServiceClient(
        ServiceConfig(
            name="erp",
            base_url="http://erp.local",
            circuit_breaker=CircuitBreakerConfig(
                enabled=True,
                fail_max=1,
                reset_timeout=30,
            ),
        ),
        transport=httpx.MockTransport(handler),
    )

    with pytest.raises(ServiceHTTPError):
        client.get("/health")

    with pytest.raises(ServiceUnavailableError, match="circuit breaker is open"):
        client.get("/health")