"""The canvas panel: tabs, sources, saving, and what a model may move."""

from __future__ import annotations

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

from lembas.db.models import (
    KIND_AGENT,
    Attachment,
    Chat,
    Connection,
    Model,
    ScratchDoc,
    User,
)
from lembas.services import canvas as canvas_service
from lembas.services import scratch as scratch_service
from lembas.services import settings_store
from lembas.services.crypto import encrypt
from lembas.services.library import documents as documents_service
from lembas.services.library import notes as notes_service


def _page(db, user, base, text: str):
    """A knowledge document, without going near the network."""
    from lembas.services.fetch import Fetched

    return documents_service.store_page(
        db,
        owner=user,
        base=base,
        page=Fetched(url="http://example.test/terms", title="Terms", text=text),
    )


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


# --- Tab bookkeeping, with no HTTP in the way ---------------------------------
def test_a_key_with_a_colon_in_the_path_survives():
    """`split`, not `str.split`: a key that lost half its path would silently
    open a different file."""
    assert canvas_service.split("agent:/srv/a:b.py") == ("agent", "/srv/a:b.py")


def test_one_file_has_one_key():
    """A tab a model opened and a tab a person opened must be one tab, or the
    panel shows the same file twice and only one is the one being saved."""
    assert (
        canvas_service.path_key("/srv/app", "./main.py")
        == canvas_service.path_key("/srv/app", "main.py")
        == canvas_service.path_key("/srv/app", "/srv/app/main.py")
    )


def test_opening_the_same_key_twice_is_one_tab():
    state: dict = {}
    canvas_service.open_tab(state, {"key": "note:1", "title": "A"})
    canvas_service.open_tab(state, {"key": "note:1", "title": "A"})
    assert len(state["tabs"]) == 1
    assert state["active"] == "note:1"


def test_a_model_opening_a_tab_does_not_take_the_screen():
    """An agent reads forty files in a long reply. If each one took the panel,
    somebody reading the third would be dragged through the other
    thirty-seven -- and anybody halfway through an edit would lose it."""
    state: dict = {}
    canvas_service.open_tab(state, {"key": "note:1", "title": "Mine"})
    canvas_service.open_tab(state, {"key": "agent:/a.py", "title": "Theirs"}, activate=False)

    assert state["active"] == "note:1"
    assert [t["key"] for t in state["tabs"]] == ["note:1", "agent:/a.py"]


def test_the_first_tab_is_activated_even_by_a_model():
    """Otherwise a panel full of tabs would have nothing in front, which reads
    as a panel that failed to load."""
    state: dict = {}
    canvas_service.open_tab(state, {"key": "agent:/a.py"}, activate=False)
    assert state["active"] == "agent:/a.py"


def test_eviction_never_closes_the_tab_in_front():
    state: dict = {}
    canvas_service.open_tab(state, {"key": "note:keep"})
    for index in range(canvas_service.MAX_TABS + 4):
        canvas_service.open_tab(state, {"key": f"agent:/f{index}.py"}, activate=False)

    keys = [t["key"] for t in state["tabs"]]
    assert len(keys) == canvas_service.MAX_TABS
    assert "note:keep" in keys
    assert state["active"] == "note:keep"


def test_closing_the_active_tab_moves_to_another():
    state: dict = {}
    canvas_service.open_tab(state, {"key": "note:1"})
    canvas_service.open_tab(state, {"key": "note:2"})
    canvas_service.close_tab(state, "note:2")
    assert state["active"] == "note:1"


def test_closing_the_last_tab_leaves_nothing_active():
    state: dict = {}
    canvas_service.open_tab(state, {"key": "note:1"})
    canvas_service.close_tab(state, "note:1")
    assert state["active"] == ""
    assert state["tabs"] == []


def test_merge_keeps_a_tab_opened_during_the_reply():
    """`_persist` is the single writer and its snapshot was seeded when the
    reply began, so overwriting would drop what somebody opened since."""
    stored = {"tabs": [{"key": "note:mine", "title": "Mine"}], "active": "note:mine"}
    live = {"tabs": [{"key": "agent:/a.py", "title": "Theirs"}], "active": "agent:/a.py"}

    merged = canvas_service.merge(stored, live)
    assert {t["key"] for t in merged["tabs"]} == {"note:mine", "agent:/a.py"}
    # And a reply finishing ten minutes later must not move what is in front.
    assert merged["active"] == "note:mine"


# --- Through the routes --------------------------------------------------------
def test_the_panel_opens_empty(client: TestClient, db, registered, make_chat):
    _add_connection(db)
    chat_id = make_chat()
    response = client.get(f"/api/chats/{chat_id}/canvas")
    assert response.status_code == 200
    assert "Nothing open" in response.text


def test_someone_elses_chat_is_a_404(client: TestClient, db, registered, make_chat):
    _add_connection(db)
    other = User(name="Sam", email="sam@shire.test", password_hash="x")
    db.add(other)
    db.commit()
    chat = Chat(user_id=other.id, model_id="test-model")
    db.add(chat)
    db.commit()

    assert client.get(f"/api/chats/{chat.id}/canvas").status_code == 404
    assert (
        client.post(f"/api/chats/{chat.id}/canvas/tabs", data={"key": "note:1"}).status_code
        == 404
    )


def test_a_get_never_opens_a_tab(client: TestClient, db, registered, make_chat):
    """There is no CSRF token here and the cookie is SameSite Lax, so a
    state-changing GET is a link somebody can be made to follow."""
    _add_connection(db)
    chat_id = make_chat()
    client.get(f"/api/chats/{chat_id}/canvas?key=scratch:{chat_id}")
    assert not (db.get(Chat, chat_id).canvas_json or {}).get("tabs")


def test_opening_and_closing_the_scratch_document(client: TestClient, db, registered, make_chat):
    _add_connection(db)
    chat_id = make_chat()

    opened = client.post(
        f"/api/chats/{chat_id}/canvas/tabs", data={"key": f"scratch:{chat_id}"}
    )
    assert opened.status_code == 200
    db.expire_all()
    assert (db.get(Chat, chat_id).canvas_json or {})["active"] == f"scratch:{chat_id}"

    client.post(f"/api/chats/{chat_id}/canvas/tabs/close", data={"key": f"scratch:{chat_id}"})
    db.expire_all()
    assert (db.get(Chat, chat_id).canvas_json or {})["tabs"] == []


def test_a_scratch_key_naming_another_chat_is_refused(
    client: TestClient, db, registered, make_chat
):
    """A forged key must not reach another conversation's pad."""
    _add_connection(db)
    mine = make_chat()
    theirs = make_chat()

    response = client.post(f"/api/chats/{mine}/canvas/tabs", data={"key": f"scratch:{theirs}"})
    assert "another chat" in response.text
    db.expire_all()
    assert not (db.get(Chat, mine).canvas_json or {}).get("tabs")


def test_an_unknown_source_says_so_rather_than_500ing(
    client: TestClient, db, registered, make_chat
):
    """An exception page swapped into a side panel is a blank side panel."""
    _add_connection(db)
    chat_id = make_chat()
    response = client.post(f"/api/chats/{chat_id}/canvas/tabs", data={"key": "wizard:1"})
    assert response.status_code == 200
    assert "nothing to open" in response.text.lower()


def test_a_tab_whose_row_was_deleted_renders_an_error(
    client: TestClient, db, registered, make_chat
):
    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    note = notes_service.create(db, owner=user, title="Gone", body="soon")
    client.post(f"/api/chats/{chat_id}/canvas/tabs", data={"key": f"note:{note.id}"})
    notes_service.delete(db, note)

    response = client.get(f"/api/chats/{chat_id}/canvas")
    assert response.status_code == 200
    assert "not there any more" in response.text


# --- Saving --------------------------------------------------------------------
def test_a_note_is_saved_through_the_canvas(client: TestClient, db, registered, make_chat):
    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    note = notes_service.create(db, owner=user, title="Errands", body="alpha")

    doc = canvas_service._stamp(note, note.body)
    response = client.post(
        f"/api/chats/{chat_id}/canvas/save",
        data={"key": f"note:{note.id}", "text": "beta", "revision": doc},
    )
    assert response.status_code == 200
    db.expire_all()
    assert db.get(type(note), note.id).body == "beta"


def test_a_stale_revision_writes_nothing(client: TestClient, db, registered, make_chat):
    """Never save silently over somebody else's change, and never discard what
    was typed here either -- the card carries both."""
    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    note = notes_service.create(db, owner=user, title="Errands", body="alpha")

    response = client.post(
        f"/api/chats/{chat_id}/canvas/save",
        data={"key": f"note:{note.id}", "text": "beta", "revision": "0:999"},
    )
    assert response.status_code == 200
    assert "changed after you opened it" in response.text
    # What was typed comes back in the box, so Overwrite is one click.
    assert "beta" in response.text
    db.expire_all()
    assert db.get(type(note), note.id).body == "alpha"


def test_an_empty_revision_overwrites(client: TestClient, db, registered, make_chat):
    """Which is exactly what Overwrite on the conflict card sends: somebody has
    been shown both versions and chosen."""
    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    note = notes_service.create(db, owner=user, title="Errands", body="alpha")

    client.post(
        f"/api/chats/{chat_id}/canvas/save",
        data={"key": f"note:{note.id}", "text": "beta", "revision": ""},
    )
    db.expire_all()
    assert db.get(type(note), note.id).body == "beta"


def test_someone_elses_note_cannot_be_saved(client: TestClient, db, registered, make_chat):
    """Sharing grants reading only."""
    _add_connection(db)
    chat_id = make_chat()
    other = User(name="Sam", email="sam@shire.test", password_hash="x")
    db.add(other)
    db.commit()
    note = notes_service.create(db, owner=other, title="Theirs", body="alpha")

    response = client.post(
        f"/api/chats/{chat_id}/canvas/save",
        data={"key": f"note:{note.id}", "text": "beta", "revision": ""},
    )
    db.expire_all()
    assert db.get(type(note), note.id).body == "alpha"
    assert "not there any more" in response.text or "not yours" in response.text


def test_an_attachment_has_no_save_path(client: TestClient, db, registered, make_chat):
    """`DELETE /api/files/{id}` already refuses once an attachment has been sent
    because it would rewrite a message somebody read. Editing is the same act
    with a quieter failure."""
    _add_connection(db)
    chat_id = make_chat()
    attachment = Attachment(
        user_id=db.get(Chat, chat_id).user_id,
        chat_id=chat_id,
        filename="notes.txt",
        stored_name="x.txt",
        media_type="text/plain",
        kind="text",
        extracted_text="alpha",
    )
    db.add(attachment)
    db.commit()

    response = client.post(
        f"/api/chats/{chat_id}/canvas/save",
        data={"key": f"file:{attachment.id}", "text": "beta", "revision": ""},
    )
    assert "only be read" in response.text
    db.expire_all()
    assert db.get(Attachment, attachment.id).extracted_text == "alpha"


def test_an_attachment_from_another_chat_is_refused(
    client: TestClient, db, registered, make_chat
):
    """A canvas must not browse another conversation's files by id."""
    _add_connection(db)
    mine = make_chat()
    theirs = make_chat()
    attachment = Attachment(
        user_id=db.get(Chat, theirs).user_id,
        chat_id=theirs,
        filename="notes.txt",
        stored_name="x.txt",
        media_type="text/plain",
        kind="text",
        extracted_text="alpha",
    )
    db.add(attachment)
    db.commit()

    response = client.post(
        f"/api/chats/{mine}/canvas/tabs", data={"key": f"file:{attachment.id}"}
    )
    assert "another chat" in response.text


# --- The agent source, without a machine ------------------------------------------
def test_an_ordinary_chat_cannot_open_a_project_file(
    client: TestClient, db, registered, make_chat
):
    _add_connection(db)
    chat_id = make_chat()
    response = client.post(
        f"/api/chats/{chat_id}/canvas/tabs", data={"key": "agent:/etc/passwd"}
    )
    assert "no connection" in response.text
    db.expire_all()
    assert not (db.get(Chat, chat_id).canvas_json or {}).get("tabs")


def test_an_agent_chat_without_the_permission_cannot_either(
    client: TestClient, db, registered, make_chat
):
    """Re-derived server-side on every request; the template flag is decoration."""
    _add_connection(db)
    chat_id = make_chat()
    chat = db.get(Chat, chat_id)
    chat.kind = KIND_AGENT
    chat.ssh_profile_id = "nothing"
    db.commit()
    settings_store.update(db, {"enabled": True}, key=settings_store.AGENTS)
    user = db.get(User, chat.user_id)
    user.role = "user"
    settings_store.update(db, {"default_permissions": {"tools.agent": False}})
    db.commit()

    assert canvas_service.agent_ready(db, user, chat) is None


# --- The document source ------------------------------------------------------------
def test_a_documents_text_can_be_replaced(client: TestClient, db, registered, make_chat):
    """Replacing a failed extraction by hand is the main reason to want this."""
    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    base = documents_service.create_base(db, owner=user, name="Contracts")
    document = _page(db, user, base, "alpha")
    document.extraction_error = "Could not read this."
    db.commit()

    documents_service.set_text(db, document, "beta")
    db.expire_all()
    refreshed = documents_service.get(db, document.id, user)
    assert refreshed.extracted_text == "beta"
    # The old apology beside the new text would be the page contradicting itself.
    assert refreshed.extraction_error == ""


def test_editing_a_document_does_not_change_a_transcript(db, registered, make_chat):
    """`files.copy_document` copies the text when a document is attached, so an
    edit only changes what future searches find."""
    from lembas.services import files as files_service

    _add_connection(db)
    chat_id = make_chat()
    user = db.get(User, db.get(Chat, chat_id).user_id)
    base = documents_service.create_base(db, owner=user, name="Contracts")
    document = _page(db, user, base, "alpha")
    attachment = files_service.copy_document(
        db, user_id=user.id, chat_id=chat_id, document=document
    )

    documents_service.set_text(db, document, "beta")
    db.expire_all()
    assert db.get(Attachment, attachment.id).extracted_text == "alpha"


# --- The scratch document -----------------------------------------------------------
def test_the_pad_is_made_once_per_chat(db, registered, make_chat):
    _add_connection(db)
    chat = db.get(Chat, make_chat())

    first = scratch_service.for_chat(db, chat)
    second = scratch_service.for_chat(db, chat)
    assert first.id == second.id
    assert db.scalars(select(ScratchDoc)).all() == [first]


def test_asking_whether_there_is_one_does_not_make_one(db, registered, make_chat):
    """Otherwise every chat ever opened acquires an empty row."""
    _add_connection(db)
    chat = db.get(Chat, make_chat())
    assert scratch_service.get(db, chat) is None
    assert db.scalars(select(ScratchDoc)).all() == []


def test_appending_twice_keeps_both(db, registered, make_chat):
    """A read-and-concatenate at the call site would let two calls in one round
    each read the same body, and the second would drop the first."""
    _add_connection(db)
    chat = db.get(Chat, make_chat())
    doc = scratch_service.for_chat(db, chat)

    scratch_service.append(db, doc, "first", author="model")
    scratch_service.append(db, doc, "second", author="model")
    assert "first" in doc.body
    assert "second" in doc.body


def test_the_pad_keeps_trailing_whitespace(db, registered, make_chat):
    """A save that silently trims the line you are standing on is the kind of
    thing that makes an editor feel broken."""
    _add_connection(db)
    chat = db.get(Chat, make_chat())
    doc = scratch_service.for_chat(db, chat)
    scratch_service.update(db, doc, body="a line   \n")
    assert doc.body == "a line   \n"


def test_attaching_the_pad_copies_it(client: TestClient, db, registered, make_chat):
    """The pad goes on being written after the message is sent, by both sides."""
    _add_connection(db)
    chat_id = make_chat()
    chat = db.get(Chat, chat_id)
    doc = scratch_service.for_chat(db, chat)
    scratch_service.update(db, doc, body="the draft")

    response = client.post("/api/files/from-scratch", data={"chat_id": chat_id})
    assert response.status_code == 200

    scratch_service.update(db, doc, body="changed since")
    db.expire_all()
    attachment = db.scalar(select(Attachment))
    assert attachment.extracted_text == "the draft"


def test_an_empty_pad_is_not_worth_attaching(client: TestClient, db, registered, make_chat):
    _add_connection(db)
    chat_id = make_chat()
    response = client.post("/api/files/from-scratch", data={"chat_id": chat_id})
    assert "not available" in response.text
    assert db.scalar(select(Attachment)) is None


def test_the_pad_of_another_chat_cannot_be_attached(
    client: TestClient, db, registered, make_chat
):
    _add_connection(db)
    other = User(name="Sam", email="sam@shire.test", password_hash="x")
    db.add(other)
    db.commit()
    chat = Chat(user_id=other.id, model_id="test-model")
    db.add(chat)
    db.commit()
    scratch_service.update(db, scratch_service.for_chat(db, chat), body="theirs")

    response = client.post("/api/files/from-scratch", data={"chat_id": chat.id})
    assert "not available" in response.text
    assert db.scalar(select(Attachment)) is None


# --- Where the panel appears ---------------------------------------------------------
def test_the_panel_is_on_a_chat_and_not_on_the_new_chat_screen(
    client: TestClient, db, registered, make_chat
):
    """Absent before there is a row, for the reason the scope menu is: there is
    nothing to hang a tab on yet."""
    _add_connection(db)
    assert 'id="canvas"' not in client.get("/chat").text
    assert 'id="canvas"' in client.get(f"/chat/{make_chat()}").text


def test_the_panel_shares_one_slot_with_the_others(
    client: TestClient, db, registered, make_chat
):
    """At 1280px the sidebar plus two panels leaves about seventy pixels of
    conversation, so only one of the three is ever open."""
    _add_connection(db)
    page = client.get(f"/chat/{make_chat()}").text
    assert 'data-toggle="#canvas" data-toggle-group="side"' in page


@pytest.mark.parametrize("verb", ["get"])
def test_the_tab_routes_refuse_the_wrong_method(
    client: TestClient, db, registered, make_chat, verb
):
    """A control wired to a method its route does not serve fails silently."""
    _add_connection(db)
    chat_id = make_chat()
    assert getattr(client, verb)(f"/api/chats/{chat_id}/canvas/tabs").status_code == 405
    assert getattr(client, verb)(f"/api/chats/{chat_id}/canvas/save").status_code == 405


# --- Opening a file by looking rather than by spelling --------------------------
def _agent_chat(db, make_chat) -> Chat:
    """An agent chat with a usable connection, so `agent_ready` says yes.

    No SSH server is needed: the panel's head, tab strip and open row render
    without reading anything off the far side, which is exactly the part under
    test here.
    """
    from lembas.db.models import SshProfile

    _add_connection(db)
    chat = db.get(Chat, make_chat())
    profile = SshProfile(
        owner_id=chat.user_id,
        name="box",
        host="127.0.0.1",
        port=22,
        username="tester",
        auth="password",
        password_encrypted=encrypt(""),
        host_key="ssh-ed25519 AAAA",
        default_dir="/srv/app",
        enabled=True,
    )
    db.add(profile)
    db.commit()
    chat.kind = KIND_AGENT
    chat.ssh_profile_id = profile.id
    chat.project_dir = "/srv/app"
    db.commit()
    settings_store.update(db, {"enabled": True}, key=settings_store.AGENTS)
    return chat


def test_the_panel_offers_a_dialog_rather_than_a_path_box(
    client: TestClient, db, registered, make_chat
):
    """This was the one control left that asked somebody to remember an
    absolute path on another machine -- the same complaint the folder page's
    directory field answered with a picker.

    The button cannot carry an `hx-post`: the path is not known until the dialog
    closes, so ui.js posts it afterwards. What it must carry is the profile the
    browse endpoint is hung off and the directory to open at, or the dialog
    starts at the account's home and every path is a walk from there.
    """
    chat = _agent_chat(db, make_chat)

    body = client.get(f"/api/chats/{chat.id}/canvas").text

    assert "data-canvas-open" in body
    assert 'data-profile="' + chat.ssh_profile_id + '"' in body
    assert 'data-dir="/srv/app"' in body
    # The typed path box is gone, and with it the only field named `key` that a
    # person was expected to fill in by hand.
    assert 'name="key"' not in body


def test_a_chat_with_no_machine_is_offered_no_file_dialog(
    client: TestClient, db, registered, make_chat
):
    """`canvas_agent` gates it, and it is re-derived server-side on every
    request -- a button that opened an empty browser would be worse than none."""
    _add_connection(db)
    chat_id = make_chat()

    body = client.get(f"/api/chats/{chat_id}/canvas").text

    assert "data-canvas-open" not in body
    # Scratch is still there: it needs no machine.
    assert "scratch:" in body