"""How full the context is, what a reply cost, and how fast it arrived."""

from __future__ import annotations

from fastapi.testclient import TestClient
from sqlalchemy import select

from lembas.db.models import Connection, Model
from lembas.services.crypto import encrypt
from lembas.services.llm.openai_client import context_from


def _model(db, **kwargs) -> Model:
    connection = Connection(
        name="Test", base_url="http://127.0.0.1:1", api_key_encrypted=encrypt("")
    )
    db.add(connection)
    db.commit()
    model = Model(connection_id=connection.id, model_id="test-model", **kwargs)
    db.add(model)
    db.commit()
    return model


# --- Reading a context length off /v1/models ---------------------------------
def test_context_length_is_read_from_any_of_the_spellings():
    assert context_from({"id": "m", "context_length": 8192}) == 8192
    assert context_from({"id": "m", "max_model_len": 32768}) == 32768
    assert context_from({"id": "m", "context_window": 4096}) == 4096
    assert context_from({"id": "m", "meta": {"n_ctx": 2048}}) == 2048


def test_a_quoted_number_is_accepted_but_a_label_is_not():
    """Some servers quote it. "8192 tokens" is a label, not a measurement."""
    assert context_from({"id": "m", "context_length": "8192"}) == 8192
    assert context_from({"id": "m", "context_length": "8192 tokens"}) == 0


def test_an_absent_or_implausible_context_length_is_zero():
    assert context_from({"id": "m"}) == 0
    assert context_from({"id": "m", "context_length": 0}) == 0
    assert context_from({"id": "m", "context_length": 64}) == 0
    assert context_from({"id": "m", "context_length": 10**9}) == 0
    # True is an int in Python, and it is not a context length.
    assert context_from({"id": "m", "context_length": True}) == 0


# --- Discovery ---------------------------------------------------------------
async def test_discovery_fills_in_a_context_length(client: TestClient, db, registered, mock_http):
    import httpx

    mock_http(
        lambda _r: httpx.Response(
            200, json={"data": [{"id": "big-model", "context_length": 16384}]}
        )
    )
    client.post(
        "/admin/connections",
        data={"name": "Local", "base_url": "http://x.test", "api_key": ""},
        follow_redirects=False,
    )
    model = db.scalar(select(Model).where(Model.model_id == "big-model"))
    assert model.context_length == 16384


async def test_discovery_never_overwrites_a_number_an_admin_typed(
    client: TestClient, db, registered, mock_http
):
    """A refresh must not undo a correction. Administrators set this precisely
    because the endpoint was wrong or silent."""
    import httpx

    mock_http(
        lambda _r: httpx.Response(200, json={"data": [{"id": "m", "context_length": 4096}]})
    )
    client.post(
        "/admin/connections",
        data={"name": "Local", "base_url": "http://x.test", "api_key": ""},
        follow_redirects=False,
    )
    model = db.scalar(select(Model).where(Model.model_id == "m"))
    model.context_length = 131072
    db.commit()

    connection = db.scalar(select(Connection))
    client.post(f"/admin/connections/{connection.id}/refresh", follow_redirects=False)

    db.refresh(model)
    assert model.context_length == 131072


# --- The admin field ---------------------------------------------------------
def test_an_admin_can_set_and_clear_the_context_length(client: TestClient, db, registered):
    model = _model(db)
    client.post(
        f"/admin/models/{model.id}",
        data={"context_length": "8192", "position": ""},
        follow_redirects=False,
    )
    db.refresh(model)
    assert model.context_length == 8192

    client.post(
        f"/admin/models/{model.id}", data={"context_length": "", "position": ""},
        follow_redirects=False,
    )
    db.refresh(model)
    assert model.context_length == 0


def test_junk_in_the_context_length_field_is_ignored_not_a_500(
    client: TestClient, db, registered
):
    model = _model(db, context_length=4096)
    response = client.post(
        f"/admin/models/{model.id}",
        data={"context_length": "eight thousand", "position": ""},
        follow_redirects=False,
    )
    assert response.status_code == 303
    db.refresh(model)
    assert model.context_length == 4096