"""Choosing the approval mode: after a chat exists, and before one does.

The regression test at the top is the one that was missing. The mode select in
the topbar posted with `hx-post` against a route that only answers `PATCH`, so
every change returned 405 and the mode never moved -- and htmx surfaces nothing
on a failed request, so the control looked like it had worked. A control wired
to a method the route does not serve fails exactly this quietly, which is why
the assertion below reads the row rather than the response.
"""

from __future__ import annotations

import pytest
from fastapi.testclient import TestClient
from sqlalchemy import select

from lembas.db.models import KIND_AGENT, Chat, Connection, Model, SshProfile, User
from lembas.services import settings_store
from lembas.services.agent import policy


def _agent_chat(db, *, mode: str = policy.MODE_MANUAL) -> Chat:
    """An agent chat pointed at a profile that is never actually connected to.

    Nothing here opens a connection: changing the mode is a database write, and
    a real sshd would only make the test slower and flakier.

    A model is needed even though nothing generates: with none, `index.html`
    renders the "no models available" screen *instead of* the thread and the
    composer, so a test asserting on composer markup would pass against a page
    that does not contain a composer at all. That is not hypothetical -- it is
    how the first version of the assertion below came to be vacuous.
    """
    settings_store.update(db, {"enabled": True}, key=settings_store.AGENTS)
    user = db.scalars(select(User)).first()
    assert user is not None

    connection = Connection(name="c", base_url="http://127.0.0.1:1", api_key_encrypted="")
    db.add(connection)
    db.commit()
    db.add(Model(connection_id=connection.id, model_id="m"))
    db.commit()

    profile = SshProfile(
        owner_id=user.id,
        name="Test box",
        host="127.0.0.1",
        port=22,
        username="tester",
        host_key="host key",
        host_fingerprint="SHA256:x",
        default_dir="/project",
    )
    db.add(profile)
    db.commit()

    chat = Chat(
        user_id=user.id,
        model_id="m",
        connection_id=connection.id,
        kind=KIND_AGENT,
        ssh_profile_id=profile.id,
        project_dir="/project",
        agent_mode=mode,
    )
    db.add(chat)
    db.commit()
    return chat


def test_patching_the_mode_changes_it(client: TestClient, db, registered):
    chat = _agent_chat(db)

    response = client.patch(f"/api/chats/{chat.id}", data={"agent_mode": policy.MODE_PLAN})
    assert response.status_code == 204, response.text

    db.refresh(chat)
    assert chat.agent_mode == policy.MODE_PLAN


def test_the_mode_form_uses_a_method_the_route_serves(client: TestClient, db, registered):
    """The bug itself, stated as a test rather than as a comment.

    POST is not merely unhandled here, it is *silently* unhandled: htmx swallows
    the 405 and the select keeps showing whatever was clicked. Asserting the
    method is refused is what stops somebody reintroducing `hx-post` and finding
    the mode unchangeable again with nothing in the logs.
    """
    chat = _agent_chat(db)
    refused = client.post(f"/api/chats/{chat.id}", data={"agent_mode": policy.MODE_AUTO})
    assert refused.status_code == 405
    db.refresh(chat)
    assert chat.agent_mode == policy.MODE_MANUAL


def test_the_rendered_form_patches(client: TestClient, db, registered):
    """And that the template actually carries it, since that is where it broke.

    Pinned to the mode form by its id rather than to any `hx-patch` on the
    page: the model picker and the system-prompt box patch the same URL, so a
    looser assertion would have passed throughout the entire life of the bug.
    """
    chat = _agent_chat(db)
    body = client.get(f"/chat/{chat.id}").text

    assert 'id="agent-mode-form"' in body
    form = body[body.index('id="agent-mode-form"') :][:200]
    assert f'hx-patch="/api/chats/{chat.id}"' in form
    assert "hx-post" not in form
    # And that the select outside it is actually submitted by it.
    assert 'form="agent-mode-form"' in body


def test_the_mode_is_offered_beside_the_composer_not_in_the_topbar(
    client: TestClient, db, registered
):
    """Where it is matters: it belongs where the message is written.

    Asserted on order rather than on a class name so it survives a restyle --
    what is being pinned is that the control comes after the thread, not what
    it looks like.
    """
    chat = _agent_chat(db)
    body = client.get(f"/chat/{chat.id}").text

    assert body.index('id="thread"') < body.index('id="agent-mode-form"')


# --- Chosen before the first word --------------------------------------------
def _profile_for(db) -> SshProfile:
    """A usable connection, and the feature switched on, with no chat yet."""
    settings_store.update(db, {"enabled": True}, key=settings_store.AGENTS)
    user = db.scalars(select(User)).first()
    assert user is not None
    connection = Connection(name="c", base_url="http://127.0.0.1:1", api_key_encrypted="")
    db.add(connection)
    db.commit()
    db.add(Model(connection_id=connection.id, model_id="m"))
    profile = SshProfile(
        owner_id=user.id,
        name="Test box",
        host="127.0.0.1",
        port=22,
        username="tester",
        host_key="host key",
        host_fingerprint="SHA256:x",
        default_dir="/project",
    )
    db.add(profile)
    db.commit()
    return profile


def test_a_chat_can_start_in_plan_mode(client: TestClient, db, registered):
    """The whole point: reaching Plan without first sending something in Manual."""
    profile = _profile_for(db)

    client.post(
        "/api/chats/start",
        data={
            "content": "have a look around",
            "kind": "agent",
            "ssh_profile_id": profile.id,
            "project_dir": "/project",
            "agent_mode": policy.MODE_PLAN,
        },
    )

    chat = db.scalars(select(Chat)).one()
    assert chat.kind == KIND_AGENT
    assert chat.agent_mode == policy.MODE_PLAN


def test_a_chat_started_with_no_mode_is_manual(client: TestClient, db, registered):
    """The column default still governs, so nobody's habits change."""
    profile = _profile_for(db)

    client.post(
        "/api/chats/start",
        data={"content": "hello", "kind": "agent", "ssh_profile_id": profile.id},
    )

    assert db.scalars(select(Chat)).one().agent_mode == policy.MODE_MANUAL


def test_an_unrecognised_mode_at_creation_is_ignored(client: TestClient, db, registered):
    profile = _profile_for(db)

    client.post(
        "/api/chats/start",
        data={
            "content": "hello",
            "kind": "agent",
            "ssh_profile_id": profile.id,
            "agent_mode": "root",
        },
    )

    assert db.scalars(select(Chat)).one().agent_mode == policy.MODE_MANUAL


def test_a_mode_on_a_plain_chat_is_ignored(client: TestClient, db, registered):
    """A plain chat has no approval loop, so a mode on one means nothing.

    It must not silently become an agent chat either: the connection is what
    decides that, and there is none here.
    """
    _profile_for(db)

    client.post("/api/chats/start", data={"content": "hello", "agent_mode": policy.MODE_AUTO})

    chat = db.scalars(select(Chat)).one()
    assert chat.kind != KIND_AGENT
    assert chat.agent_mode == policy.MODE_MANUAL


@pytest.mark.parametrize("wanted", ["", "sudo", "PLAN", "edit;auto"])
def test_an_unrecognised_mode_is_ignored(client: TestClient, db, registered, wanted):
    """Ignored rather than refused: an unknown mode is a bug in the sender, and
    failing the whole request would leave the reader with a chat they cannot
    change. The safe outcome is that nothing moves."""
    chat = _agent_chat(db, mode=policy.MODE_EDIT)

    client.patch(f"/api/chats/{chat.id}", data={"agent_mode": wanted})

    db.refresh(chat)
    assert chat.agent_mode == policy.MODE_EDIT