"""T98 (Phase 4): drawer phase-4 bundle.

Five sub-features extending the chat drawer:

* T98.1 — branching UI (create / switch / from-turn).
* T98.2 — significance-review panel (distribution + significance edits).
* T98.3 — hide-from-view toggle (per-turn, via ``manual_edit`` projector
  branch ``turn_hidden``).
* T98.4 — surgical delete with cascade preview (preview modal +
  rewind execution against a target turn).
* T98.5 — remaining v1 edits (chat narrative_anchor + weather).

Tests follow the T59 pattern in ``tests/test_drawer_events_threads_skip.py``
— a TestClient against the real FastAPI app with a per-test temp DB.
"""

from __future__ import annotations

from pathlib import Path

import pytest
from fastapi.testclient import TestClient

from chat.app import app
from chat.db.connection import open_db
from chat.eventlog.log import append_and_apply, append_event
from chat.eventlog.projector import project


@pytest.fixture
def client(tmp_path, monkeypatch):
    cfg = tmp_path / "config.toml"
    cfg.write_text('featherless_api_key = "test"\n')
    monkeypatch.setenv("CHAT_CONFIG_PATH", str(cfg))
    db = tmp_path / "test.db"
    monkeypatch.setenv("CHAT_DB_PATH", str(db))
    with TestClient(app) as c:
        if hasattr(app.state, "background_worker"):
            app.state.background_worker.enabled = False
        yield c


def _bot_payload(bot_id: str, name: str) -> dict:
    return {
        "id": bot_id,
        "name": name,
        "persona": "...",
        "voice_samples": [],
        "traits": [],
        "backstory": "",
        "initial_relationship_to_you": "",
        "kickoff_prose": "",
    }


def _seed_chat(db: Path, *, with_scene: bool = True) -> int:
    """Seed a chat hosted by ``bot_a``; return the latest event id (chat_created)."""
    with open_db(db) as conn:
        append_event(conn, kind="bot_authored", payload=_bot_payload("bot_a", "BotA"))
        append_event(
            conn,
            kind="you_authored",
            payload={"name": "Me", "pronouns": "they/them", "persona": ""},
        )
        chat_event_id = append_event(
            conn,
            kind="chat_created",
            payload={
                "id": "chat_bot_a",
                "host_bot_id": "bot_a",
                "initial_time": "2026-04-26T20:00:00+00:00",
                "narrative_anchor": "Day 1",
                "weather": "",
            },
        )
        if with_scene:
            append_event(
                conn,
                kind="scene_opened",
                payload={
                    "chat_id": "chat_bot_a",
                    "container_id": None,
                    "started_at": "2026-04-26T20:00:00+00:00",
                    "participants": ["you", "bot_a"],
                },
            )
        project(conn)
        return chat_event_id


# ---------------------------------------------------------------------------
# T98.1 — branching UI.
# ---------------------------------------------------------------------------


def test_t98_1_create_branch_emits_branch_created_and_renders(client, tmp_path):
    db = tmp_path / "test.db"
    seed_id = _seed_chat(db)

    response = client.post(
        "/chats/chat_bot_a/drawer/branch/create",
        data={"name": "experiment_a", "origin_event_id": str(seed_id)},
    )
    assert response.status_code == 200

    with open_db(db) as conn:
        rows = conn.execute(
            "SELECT COUNT(*) FROM event_log WHERE kind = 'branch_created'"
        ).fetchone()
        assert rows[0] == 1
        from chat.state.branches import get_branch

        b = get_branch(conn, "experiment_a")
        assert b is not None
        assert b["origin_event_id"] == seed_id
        assert b["chat_id"] == "chat_bot_a"

    # Drawer partial lists the new branch.
    body = response.text
    assert "<h3>Branches</h3>" in body
    assert "experiment_a" in body


def test_t98_1_switch_branch_marks_active_and_unknown_400s(client, tmp_path):
    db = tmp_path / "test.db"
    seed_id = _seed_chat(db)

    # Create branch directly via the service so this test focuses on switch.
    with open_db(db) as conn:
        from chat.services.branching import branch_from_event

        branch_from_event(
            conn, name="experiment_b", origin_event_id=seed_id, chat_id="chat_bot_a"
        )

    response = client.post(
        "/chats/chat_bot_a/drawer/branch/switch",
        data={"name": "experiment_b"},
    )
    assert response.status_code == 200

    with open_db(db) as conn:
        from chat.state.branches import active_branch

        active = active_branch(conn)
        assert active is not None
        assert active["name"] == "experiment_b"

    # Unknown branch -> 400.
    bad = client.post(
        "/chats/chat_bot_a/drawer/branch/switch",
        data={"name": "ghost_branch"},
    )
    assert bad.status_code == 400


def test_t98_1_branch_from_turn_emits_branch_created(client, tmp_path):
    db = tmp_path / "test.db"
    seed_id = _seed_chat(db)

    # Append an extra turn so we can branch from it specifically.
    with open_db(db) as conn:
        turn_id = append_event(
            conn,
            kind="user_turn",
            payload={"chat_id": "chat_bot_a", "prose": "hi", "segments": []},
        )

    response = client.post(
        f"/chats/chat_bot_a/drawer/branch/from-turn/{turn_id}",
        data={"name": "fork_at_turn"},
    )
    assert response.status_code == 200

    with open_db(db) as conn:
        from chat.state.branches import get_branch

        b = get_branch(conn, "fork_at_turn")
        assert b is not None
        assert b["origin_event_id"] == turn_id
        assert b["chat_id"] == "chat_bot_a"

    # Duplicate name -> 400 from service ValueError.
    dup = client.post(
        f"/chats/chat_bot_a/drawer/branch/from-turn/{turn_id}",
        data={"name": "fork_at_turn"},
    )
    assert dup.status_code == 400
    assert seed_id < turn_id  # sanity: turn is after chat_created