from uuid import uuid4

import pytest

from backend.db import get_engine
from backend.models import Folder, User


def initialized_client(client):
    response = client.post(
        "/api/v1/setup/initialize",
        json={"username": "owner", "password": "correct horse battery staple"},
    )
    assert response.status_code == 201
    return client


def create_list(client, name, folder_id=None):
    response = client.post("/api/v1/lists", json={"name": name, "folder_id": folder_id})
    assert response.status_code == 201
    return response.json()


@pytest.mark.asyncio
async def test_move_list_validates_folder_ownership_and_is_atomic(client):
    client = initialized_client(client)
    task_list = create_list(client, "项目")

    from sqlalchemy.ext.asyncio import async_sessionmaker

    session_factory = async_sessionmaker(get_engine(), expire_on_commit=False)
    async with session_factory() as db:
        other = User(username="other", password_hash="not-used")
        db.add(other)
        await db.flush()
        foreign_folder = Folder(user_id=other.id, name="别人的文件夹")
        db.add(foreign_folder)
        await db.commit()
        foreign_folder_id = str(foreign_folder.id)

    response = client.put(
        f"/api/v1/lists/{task_list['id']}/move",
        json={"folder_id": foreign_folder_id, "list_ids": [task_list["id"]]},
    )
    assert response.status_code == 404
    unchanged = next(row for row in client.get("/api/v1/lists").json() if row["id"] == task_list["id"])
    assert unchanged["folder_id"] is None


def test_move_list_between_folder_and_root_applies_target_order_atomically(client):
    client = initialized_client(client)
    folder = client.post("/api/v1/folders", json={"name": "工作"}).json()
    root_a = create_list(client, "根 A")
    root_b = create_list(client, "根 B")
    folder_a = create_list(client, "文件夹 A", folder["id"])

    moved = client.put(
        f"/api/v1/lists/{root_a['id']}/move",
        json={"folder_id": folder["id"], "list_ids": [root_a["id"], folder_a["id"]]},
    )
    assert moved.status_code == 200
    assert moved.json()["folder_id"] == folder["id"]
    folder_rows = [row for row in client.get("/api/v1/lists").json() if row["folder_id"] == folder["id"]]
    assert [row["id"] for row in folder_rows] == [root_a["id"], folder_a["id"]]

    moved_to_root = client.put(
        f"/api/v1/lists/{root_a['id']}/move",
        json={"folder_id": None, "list_ids": [root_b["id"], root_a["id"]]},
    )
    assert moved_to_root.status_code == 200
    assert moved_to_root.json()["folder_id"] is None
    root_rows = [
        row for row in client.get("/api/v1/lists").json()
        if not row["is_inbox"] and row["folder_id"] is None
    ]
    assert [row["id"] for row in root_rows] == [root_b["id"], root_a["id"]]


def test_move_list_rejects_invalid_target_order_without_moving(client):
    client = initialized_client(client)
    folder = client.post("/api/v1/folders", json={"name": "工作"}).json()
    root_a = create_list(client, "根 A")
    folder_a = create_list(client, "文件夹 A", folder["id"])

    response = client.put(
        f"/api/v1/lists/{root_a['id']}/move",
        json={"folder_id": folder["id"], "list_ids": [root_a["id"]]},
    )

    assert response.status_code == 409
    rows = client.get("/api/v1/lists").json()
    unchanged = next(row for row in rows if row["id"] == root_a["id"])
    assert unchanged["folder_id"] is None
    assert [row["id"] for row in rows if row["folder_id"] == folder["id"]] == [folder_a["id"]]


def test_inbox_cannot_be_moved_or_reordered(client):
    client = initialized_client(client)
    inbox = client.get("/api/v1/lists").json()[0]
    folder = client.post("/api/v1/folders", json={"name": "工作"}).json()

    moved = client.put(
        f"/api/v1/lists/{inbox['id']}/move",
        json={"folder_id": folder["id"], "list_ids": [inbox["id"]]},
    )
    assert moved.status_code == 409

    reordered = client.put(
        "/api/v1/lists/reorder", json={"folder_id": None, "list_ids": [inbox["id"]]}
    )
    assert reordered.status_code == 409


def test_reorder_lists_is_scoped_and_persists(client):
    client = initialized_client(client)
    folder = client.post("/api/v1/folders", json={"name": "工作"}).json()
    root_a = create_list(client, "根 A")
    root_b = create_list(client, "根 B")
    folder_a = create_list(client, "文件夹 A", folder["id"])
    folder_b = create_list(client, "文件夹 B", folder["id"])

    assert client.put(
        "/api/v1/lists/reorder",
        json={"folder_id": None, "list_ids": [root_b["id"], root_a["id"]]},
    ).status_code == 204
    assert client.put(
        "/api/v1/lists/reorder",
        json={"folder_id": folder["id"], "list_ids": [folder_b["id"], folder_a["id"]]},
    ).status_code == 204

    rows = client.get("/api/v1/lists").json()
    root_rows = [row for row in rows if not row["is_inbox"] and row["folder_id"] is None]
    folder_rows = [row for row in rows if row["folder_id"] == folder["id"]]
    assert [row["id"] for row in root_rows] == [root_b["id"], root_a["id"]]
    assert [row["id"] for row in folder_rows] == [folder_b["id"], folder_a["id"]]
    assert [row["position"] for row in root_rows] == [0, 1]
    assert [row["position"] for row in folder_rows] == [0, 1]


def test_reorder_rejects_stale_or_mixed_scope_without_partial_write(client):
    client = initialized_client(client)
    folder = client.post("/api/v1/folders", json={"name": "工作"}).json()
    root_a = create_list(client, "根 A")
    root_b = create_list(client, "根 B")
    folder_a = create_list(client, "文件夹 A", folder["id"])

    stale = client.put(
        "/api/v1/lists/reorder", json={"folder_id": None, "list_ids": [root_b["id"]]}
    )
    assert stale.status_code == 409
    mixed = client.put(
        "/api/v1/lists/reorder",
        json={"folder_id": None, "list_ids": [root_b["id"], folder_a["id"]]},
    )
    assert mixed.status_code == 409
    missing = client.put(
        "/api/v1/lists/reorder",
        json={"folder_id": str(uuid4()), "list_ids": [root_a["id"], root_b["id"]]},
    )
    assert missing.status_code == 404

    rows = client.get("/api/v1/lists").json()
    root_rows = [row for row in rows if not row["is_inbox"] and row["folder_id"] is None]
    assert [row["id"] for row in root_rows] == [root_a["id"], root_b["id"]]