from __future__ import annotations

import logging

from botocore.exceptions import ClientError
from fastapi.testclient import TestClient

from nexus_claude_api.config import Settings
from nexus_claude_api.nexus_client import _map_client_error
from nexus_claude_api.server import create_app


class FakeNexusClient:
    def converse(self, request: dict, *, correlation_id: str | None = None) -> dict:
        assert correlation_id
        assert request["messages"][0]["content"][0]["text"] == "Hello"
        return {
            "ResponseMetadata": {"RequestId": "req-route"},
            "output": {"message": {"content": [{"text": "Hi"}]}},
            "stopReason": "end_turn",
            "usage": {"inputTokens": 3, "outputTokens": 1},
        }

    def converse_stream(self, request: dict, *, correlation_id: str | None = None):
        assert correlation_id
        assert request["messages"][0]["content"][0]["text"] == "Hello"
        return [
            {"contentBlockDelta": {"contentBlockIndex": 0, "delta": {"text": "Hi"}}},
            {"contentBlockStop": {"contentBlockIndex": 0}},
            {"messageStop": {"stopReason": "end_turn"}},
        ]


class AccessDeniedNexusClient:
    def converse(self, request: dict, *, correlation_id: str | None = None) -> dict:
        raise _map_client_error(
            ClientError(
                {
                    "Error": {
                        "Code": "AccessDeniedException",
                        "Message": "not allowed",
                    },
                    "ResponseMetadata": {
                        "HTTPStatusCode": 403,
                        "RequestId": "req-denied",
                    },
                },
                "Converse",
            ),
            operation="converse",
            correlation_id=correlation_id,
        )


def client(nexus_client: object | None = None) -> TestClient:
    settings = Settings.from_values(api_key="test", require_api_key=False)
    return TestClient(
        create_app(settings=settings, nexus_client=nexus_client or FakeNexusClient())
    )


def test_health() -> None:
    response = client().get("/health")
    assert response.status_code == 200
    assert response.json() == {"status": "ok"}


def test_root_head() -> None:
    response = client().head("/")
    assert response.status_code == 200
    assert response.content == b""


def test_models() -> None:
    response = client().get("/v1/models")
    assert response.status_code == 200
    data = response.json()["data"]
    assert [model["id"] for model in data] == ["claude-opus-4.6"]


def test_messages_non_stream() -> None:
    response = client().post(
        "/v1/messages",
        json={
            "model": "claude-opus-4.6",
            "messages": [{"role": "user", "content": "Hello"}],
            "max_tokens": 32,
        },
    )

    assert response.status_code == 200
    body = response.json()
    assert body["id"] == "req-route"
    assert body["content"][0]["text"] == "Hi"


def test_messages_normalizes_legacy_system_role() -> None:
    response = client().post(
        "/v1/messages",
        json={
            "model": "claude-opus-4.6",
            "messages": [
                {"role": "system", "content": "You are helpful."},
                {"role": "user", "content": "Hello"},
            ],
            "max_tokens": 32,
        },
    )

    assert response.status_code == 200
    assert response.json()["content"][0]["text"] == "Hi"


def test_messages_upstream_error_returns_correlation_id() -> None:
    response = client(AccessDeniedNexusClient()).post(
        "/v1/messages",
        json={
            "model": "claude-opus-4.6",
            "messages": [{"role": "user", "content": "Hello"}],
            "max_tokens": 32,
        },
    )

    assert response.status_code == 403
    error = response.json()["error"]
    assert error["type"] == "api_error"
    assert error["correlation_id"]
    assert f"correlation_id={error['correlation_id']}" in error["message"]


def test_client_error_mapping_logs_sanitized_details(caplog) -> None:
    caplog.set_level(logging.WARNING, logger="nexus_claude_api.nexus_client")

    mapped = _map_client_error(
        ClientError(
            {
                "Error": {
                    "Code": "AccessDeniedException",
                    "Message": "model access denied",
                },
                "ResponseMetadata": {
                    "HTTPStatusCode": 400,
                    "RequestId": "req-log",
                },
            },
            "Converse",
        ),
        operation="converse",
        correlation_id="corr-log",
    )

    assert mapped.status_code == 403
    assert mapped.error_type == "api_error"
    record = caplog.records[-1]
    assert record.levelno == logging.WARNING
    assert record.correlation_id == "corr-log"
    assert record.operation == "converse"
    assert record.nexus_error_code == "AccessDeniedException"
    assert record.http_status == 403
    assert record.nexus_request_id == "req-log"
    log_text = caplog.text
    assert "api_key" not in log_text
    assert "Authorization" not in log_text
    assert "aW1hZ2UtYnl0ZXM=" not in log_text


def test_messages_stream() -> None:
    with client().stream(
        "POST",
        "/v1/messages",
        json={
            "model": "claude-opus-4.6",
            "messages": [{"role": "user", "content": "Hello"}],
            "max_tokens": 32,
            "stream": True,
        },
    ) as response:
        body = response.read().decode("utf-8")

    assert response.status_code == 200
    assert "event: message_start" in body
    assert "event: content_block_delta" in body
    assert "event: message_stop" in body


def test_count_tokens() -> None:
    response = client().post(
        "/v1/messages/count_tokens",
        json={
            "model": "claude-opus-4.6",
            "messages": [{"role": "user", "content": "Hello"}],
        },
    )

    assert response.status_code == 200
    assert response.json()["input_tokens"] > 0