"""Unit tests for data-resource path derivation and helpers.

These tests do not need a database because they exercise pure helpers.
"""

from __future__ import annotations

import datetime
from types import SimpleNamespace
from unittest.mock import MagicMock

import pytest
from backend.resources import (
    compute_jupyter_relative_path,
    resource_directory,
    resource_payload,
)
from backend.services.storage import (
    _object_key_tail,
    _safe_file_name,
    _safe_path_segment,
    _strip_uniqueness_suffix,
)


_BIND_WS = "01WS0000000000000000000A"
_BIND_USER = "01USR0000000000000000000A"


class _ExecuteResult:
    def __init__(self, rows):
        self._rows = rows

    def all(self):
        return self._rows


class _BindSessionMock:
    """Mocked session for bind_resource.

    ``new_object_key`` is the StorageObjects row of the upload being bound;
    ``same_name_rows`` are (DataResources, StorageObjects) candidates already
    in the workspace with the same resource_name.
    """

    def __init__(
        self,
        new_object_key: str,
        same_name_rows=(),
        reused_resource=None,
        usage_type: str = "data_resource",
    ):
        self._new_object_key = new_object_key
        self._same_name_rows = list(same_name_rows)
        self._reused_resource = reused_resource
        self._usage_type = usage_type
        self._scalar_calls = 0

    async def scalar(self, _stmt):
        from sqlalchemy import TextClause

        if isinstance(_stmt, TextClause):
            return 1  # GET_LOCK 成功
        self._scalar_calls += 1
        # 1st scalar: UploadSessions lookup; 2nd: active 绑定行复用检查。
        if self._scalar_calls == 1:
            return SimpleNamespace(
                upload_id="01UPL0000000000000000000B",
                storage_object_id="01OBJ0000000000000000000B",
                workspace_id=_BIND_WS,
                user_id=_BIND_USER,
                usage_type=self._usage_type,
            )
        if self._scalar_calls == 2 and self._reused_resource is not None:
            return self._reused_resource
        return None

    async def get(self, _model, _pk):
        return _make_storage_object(self._new_object_key)

    async def execute(self, _stmt):
        from sqlalchemy import TextClause

        if isinstance(_stmt, TextClause):
            return _ExecuteResult([])  # RELEASE_LOCK
        # 模拟 SQL 的 owner 过滤与 self-exclusion:只返回属于当前用户且
        # 不是当前 upload 已绑定对象的同名候选。
        rows = [
            (resource, storage_object)
            for resource, storage_object in self._same_name_rows
            if resource.owner_user_id == _BIND_USER
            and resource.storage_object_id != "01OBJ0000000000000000000B"
        ]
        return _ExecuteResult(rows)

    def add(self, _obj):
        pass

    async def flush(self):
        pass

    async def refresh(self, _obj, attribute_names=None):
        _obj.created_at = datetime.datetime.now(datetime.UTC).replace(tzinfo=None)
        _obj.updated_at = datetime.datetime.now(datetime.UTC).replace(tzinfo=None)


def _bind_context():
    return SimpleNamespace(
        request_id="01REQ0000000000000000000A",
        user=SimpleNamespace(user_id=_BIND_USER),
        workspace=SimpleNamespace(workspace_id=_BIND_WS),
    )


def _bind_payload():
    return SimpleNamespace(
        resource_name="data.csv", description=None, visibility="private"
    )


@pytest.mark.asyncio
async def test_bind_resource_rejects_duplicate_name_in_same_directory() -> None:
    """Same resource_name in the same directory raises 409."""
    from backend.resources import bind_resource

    existing_rows = [
        (
            _make_resource(_BIND_WS, _BIND_USER),
            _make_storage_object(f"{_BIND_WS}/{_BIND_USER}/data.csv"),
        )
    ]
    session = _BindSessionMock(
        new_object_key=f"{_BIND_WS}/{_BIND_USER}/data.csv",
        same_name_rows=existing_rows,
    )
    with pytest.raises(Exception) as exc_info:
        await bind_resource(
            upload_id="01UPL0000000000000000000B",
            payload=_bind_payload(),
            request=MagicMock(),
            context=_bind_context(),
            session=session,
        )
    assert exc_info.value.status_code == 409
    assert "already exists" in exc_info.value.detail


@pytest.mark.asyncio
async def test_bind_resource_allows_same_name_in_different_directory() -> None:
    """Same resource_name in a different directory binds successfully."""
    from backend.resources import bind_resource

    existing_rows = [
        (
            _make_resource(_BIND_WS, _BIND_USER),
            _make_storage_object(f"{_BIND_WS}/{_BIND_USER}/data.csv"),
        )
    ]
    session = _BindSessionMock(
        new_object_key=f"{_BIND_WS}/{_BIND_USER}/subdir/data.csv",
        same_name_rows=existing_rows,
    )
    result = await bind_resource(
        upload_id="01UPL0000000000000000000B",
        payload=_bind_payload(),
        request=MagicMock(),
        context=_bind_context(),
        session=session,
    )
    assert result["data"]["resource_name"] == "data.csv"
    assert result["data"]["jupyter_accessible_path"] == "subdir/data.csv"


@pytest.mark.asyncio
async def test_bind_resource_allows_same_name_when_workspace_empty() -> None:
    """No same-name rows at all: bind succeeds (root directory)."""
    from backend.resources import bind_resource

    session = _BindSessionMock(
        new_object_key=f"{_BIND_WS}/{_BIND_USER}/data.csv",
    )
    result = await bind_resource(
        upload_id="01UPL0000000000000000000A",
        payload=_bind_payload(),
        request=MagicMock(),
        context=_bind_context(),
        session=session,
    )
    assert result["data"]["resource_name"] == "data.csv"


@pytest.mark.asyncio
async def test_bind_resource_allows_same_name_for_different_owner() -> None:
    """其他用户在同目录下的同名资源不阻塞当前用户的绑定。"""
    from backend.resources import bind_resource

    other_user = "01USR0000000000000000000B"
    existing_rows = [
        (
            _make_resource(_BIND_WS, other_user),
            _make_storage_object(f"{_BIND_WS}/{other_user}/data.csv"),
        )
    ]
    session = _BindSessionMock(
        new_object_key=f"{_BIND_WS}/{_BIND_USER}/data.csv",
        same_name_rows=existing_rows,
    )
    result = await bind_resource(
        upload_id="01UPL0000000000000000000C",
        payload=_bind_payload(),
        request=MagicMock(),
        context=_bind_context(),
        session=session,
    )
    assert result["data"]["resource_name"] == "data.csv"


@pytest.mark.asyncio
async def test_bind_resource_allows_rebinding_same_storage_object() -> None:
    """重新绑定同一 upload_id 应走 idempotent 复用路径,不触发 409。"""
    from backend.resources import bind_resource

    new_object_key = f"{_BIND_WS}/{_BIND_USER}/data.csv"
    existing_resource = _make_resource(_BIND_WS, _BIND_USER)
    existing_resource.resource_name = "data.csv"
    existing_resource.storage_object_id = "01OBJ0000000000000000000B"
    existing_object = _make_storage_object(new_object_key)
    existing_object.storage_object_id = "01OBJ0000000000000000000B"
    same_name_rows = [(existing_resource, existing_object)]
    session = _BindSessionMock(
        new_object_key=new_object_key,
        same_name_rows=same_name_rows,
        reused_resource=existing_resource,
    )
    result = await bind_resource(
        upload_id="01UPL0000000000000000000B",
        payload=_bind_payload(),
        request=MagicMock(),
        context=_bind_context(),
        session=session,
    )
    assert result["meta"]["reused"] is True
    assert result["data"]["resource_name"] == "data.csv"


@pytest.mark.asyncio
async def test_bind_resource_rejects_non_data_resource_upload() -> None:
    """其他用途(如 working_copy)的 upload session 不能 bind 成数据资源。"""
    from backend.resources import bind_resource

    session = _BindSessionMock(
        new_object_key=f"{_BIND_WS}/{_BIND_USER}/data.csv",
        usage_type="working_copy",
    )
    with pytest.raises(Exception) as exc_info:
        await bind_resource(
            upload_id="01UPL0000000000000000000B",
            payload=_bind_payload(),
            request=MagicMock(),
            context=_bind_context(),
            session=session,
        )
    assert exc_info.value.status_code == 409
    assert "not created for a data resource" in exc_info.value.detail


def test_safe_path_segment_cleans_special_characters():
    assert _safe_path_segment("train") == "train"
    assert _safe_path_segment("train v1") == "train_v1"
    assert _safe_path_segment("../foo") == "foo"
    assert _safe_path_segment("a/b") == "a_b"
    assert _safe_path_segment("...") == "untitled"


def test_safe_file_name_rejects_traversal_and_hidden():
    assert _safe_file_name("data.csv") == "data.csv"
    with pytest.raises(Exception):
        _safe_file_name("../data.csv")
    with pytest.raises(Exception):
        _safe_file_name(".hidden.csv")


def _make_resource(workspace_id: str, owner_user_id: str):
    return SimpleNamespace(
        resource_id="01RES0000000000000000000A",
        workspace_id=workspace_id,
        storage_object_id="01OBJ0000000000000000000A",
        owner_user_id=owner_user_id,
        resource_name="sample",
        description=None,
        visibility="workspace",
        status="active",
        created_at=datetime.datetime.now(datetime.UTC).replace(tzinfo=None),
        updated_at=datetime.datetime.now(datetime.UTC).replace(tzinfo=None),
    )


def _make_storage_object(object_key: str):
    return SimpleNamespace(
        storage_object_id="01OBJ0000000000000000000A",
        object_key=object_key,
        file_name="data.csv",
        file_extension=".csv",
        mime_type="text/csv",
        size_bytes=42,
        content_hash="a" * 64,
        object_status="available",
    )


def test_resource_payload_legacy_dot_resources():
    ws = "01WS00000000000000000000A"
    user = "01USR000000000000000000A"
    payload = resource_payload(
        _make_resource(ws, user),
        _make_storage_object(f"{ws}/{user}/.resources/data.csv"),
    )
    assert payload["jupyter_accessible_path"] == ".resources/data.csv"
    assert payload["absolute_path"].endswith(f"{ws}/{user}/.resources/data.csv")


def test_resource_payload_new_flat_path():
    ws = "01WS00000000000000000000A"
    user = "01USR000000000000000000A"
    payload = resource_payload(
        _make_resource(ws, user),
        _make_storage_object(f"{ws}/{user}/data.csv"),
    )
    assert payload["jupyter_accessible_path"] == "data.csv"
    assert payload["absolute_path"].endswith(f"{ws}/{user}/data.csv")


def test_resource_payload_new_nested_path():
    ws = "01WS00000000000000000000A"
    user = "01USR000000000000000000A"
    payload = resource_payload(
        _make_resource(ws, user),
        _make_storage_object(f"{ws}/{user}/train/v1/data.csv"),
    )
    assert payload["jupyter_accessible_path"] == "train/v1/data.csv"
    assert payload["absolute_path"].endswith(f"{ws}/{user}/train/v1/data.csv")


def test_compute_jupyter_relative_path_for_legacy_and_new_paths():
    # Legacy .resources path still resolves correctly.
    assert compute_jupyter_relative_path("notebooks/exp.ipynb", ".resources/data.csv") == "../.resources/data.csv"
    # New nested path resolves relative to the script directory.
    assert compute_jupyter_relative_path("notebooks/exp.ipynb", "train/v1/data.csv") == "../train/v1/data.csv"
    # Same-directory script.
    assert compute_jupyter_relative_path("exp.ipynb", "data.csv") == "data.csv"


def test_resource_directory_parses_object_key():
    ws = "01WS00000000000000000000A"
    user = "01USR000000000000000000A"
    # 根目录文件:目录为 ""。
    assert resource_directory(f"{ws}/{user}/data.csv", ws, user) == ""
    # 子目录 / 多级目录。
    assert resource_directory(f"{ws}/{user}/sub/data.csv", ws, user) == "sub"
    assert (
        resource_directory(f"{ws}/{user}/train/v1/data.csv", ws, user)
        == "train/v1"
    )
    # 旧版 .resources 布局:目录为 ".resources"。
    assert (
        resource_directory(f"{ws}/{user}/.resources/data.csv", ws, user)
        == ".resources"
    )
    # 不匹配 ws/user 前缀的键按根目录处理。
    assert resource_directory("other-bucket-key.csv", ws, user) == ""


def test_object_key_tail_and_strip_uniqueness_suffix():
    ws = "01WS00000000000000000000A"
    user = "01USR000000000000000000A"
    # 前缀剥离。
    assert _object_key_tail(f"{ws}/{user}/sub/data.csv", ws, user) == "sub/data.csv"
    assert _object_key_tail("no-prefix.csv", ws, user) == "no-prefix.csv"
    # 带唯一化后缀的 key 恢复为原始路径(26 位 ULID 后缀)。
    suffix = "01arz3ndektsv4rrffq69g5fav"  # 26 chars
    assert (
        _strip_uniqueness_suffix(f"sub/data-{suffix}.csv") == "sub/data.csv"
    )
    assert _strip_uniqueness_suffix(f"data-{suffix}.csv") == "data.csv"
    assert _strip_uniqueness_suffix(f"data-{suffix}") == "data"
    # 普通文件名不受影响(短后缀、无连字符、目录含连字符)。
    assert _strip_uniqueness_suffix("sub/data.csv") == "sub/data.csv"
    assert _strip_uniqueness_suffix("data-v1.csv") == "data-v1.csv"
    assert _strip_uniqueness_suffix("my-dir/data.csv") == "my-dir/data.csv"
    assert _strip_uniqueness_suffix("data") == "data"


def test_data_resources_model_allows_duplicate_storage_object_reference() -> None:
    """With uk_data_resources_object dropped, no unique index covers
    storage_object_id, so multiple DataResources rows may reference the
    same storage object.
    """
    from common.db.models import DataResources

    index_names = {idx.name for idx in DataResources.__table__.indexes}
    assert "uk_data_resources_object" not in index_names
    for idx in DataResources.__table__.indexes:
        if idx.unique:
            cols = {c.name for c in idx.columns}
            assert "storage_object_id" not in cols, (
                f"unexpected unique index {idx.name} on storage_object_id"
            )