"""media.py DTO 单元测试。

覆盖 ``MediaType`` 枚举与 ``MediaUploadResult`` / ``MediaDownloadResult`` /
``MediaMetadata`` / ``AttachmentUploadResult`` 的字段赋值、默认值、不可变
语义与 ``__post_init__`` 校验逻辑。
"""

from __future__ import annotations

import dataclasses
from datetime import datetime

import pytest
from yuxi.channels.contract.dtos.media import (
    AttachmentUploadResult,
    MediaDownloadResult,
    MediaMetadata,
    MediaType,
    MediaUploadResult,
)
from yuxi.channels.contract.errors import ValidationError

pytestmark = pytest.mark.unit


@pytest.mark.unit
class TestMediaType:
    """媒体类型枚举测试。"""

    def test_enum_values_are_correct(self):
        # Arrange
        # Act
        # Assert
        assert MediaType.IMAGE == "image"
        assert MediaType.FILE == "file"
        assert MediaType.AUDIO == "audio"
        assert MediaType.VIDEO == "video"

    def test_enum_inherits_from_str(self):
        # Arrange
        # Act
        # Assert
        assert issubclass(MediaType, str)
        assert isinstance(MediaType.IMAGE, str)

    def test_enum_has_four_members(self):
        # Arrange
        # Act
        members = list(MediaType)
        # Assert
        assert len(members) == 4


@pytest.mark.unit
class TestMediaUploadResult:
    """媒体上传结果 DTO 测试。"""

    def test_required_fields_are_assigned(self):
        # Arrange
        # Act
        result = MediaUploadResult(media_id="img_001")
        # Assert
        assert result.media_id == "img_001"
        assert result.url is None
        assert result.expires_at is None

    def test_with_all_fields(self):
        # Arrange
        now = datetime(2026, 1, 1, 12, 0, 0)
        # Act
        result = MediaUploadResult(
            media_id="img_001",
            url="https://example.com/img.png",
            expires_at=now,
        )
        # Assert
        assert result.url == "https://example.com/img.png"
        assert result.expires_at is now

    def test_is_frozen(self):
        # Arrange
        result = MediaUploadResult(media_id="img_001")
        # Act / Assert
        with pytest.raises(dataclasses.FrozenInstanceError):
            result.media_id = "other"  # type: ignore[misc]

    def test_empty_media_id_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            MediaUploadResult(media_id="")
        assert exc_info.value.field == "media_id"


@pytest.mark.unit
class TestMediaDownloadResult:
    """媒体下载结果 DTO 测试。"""

    def test_fields_are_assigned(self):
        # Arrange
        content = b"\x89PNG"
        # Act
        result = MediaDownloadResult(content=content, size=4)
        # Assert
        assert result.content == content
        assert result.size == 4
        assert result.filename is None
        assert result.mime_type is None

    def test_with_optional_fields(self):
        # Arrange
        # Act
        result = MediaDownloadResult(
            content=b"data",
            size=4,
            filename="test.png",
            mime_type="image/png",
        )
        # Assert
        assert result.filename == "test.png"
        assert result.mime_type == "image/png"

    def test_is_frozen(self):
        # Arrange
        result = MediaDownloadResult(content=b"", size=0)
        # Act / Assert
        with pytest.raises(dataclasses.FrozenInstanceError):
            result.size = 100  # type: ignore[misc]


@pytest.mark.unit
class TestMediaMetadata:
    """媒体元数据 DTO 测试。"""

    def test_required_fields_are_assigned(self):
        # Arrange
        # Act
        meta = MediaMetadata(
            media_id="img_001",
            media_type=MediaType.IMAGE,
            size=1024,
        )
        # Assert
        assert meta.media_id == "img_001"
        assert meta.media_type is MediaType.IMAGE
        assert meta.size == 1024
        assert meta.mime_type is None
        assert meta.created_at is None

    def test_with_optional_fields(self):
        # Arrange
        now = datetime(2026, 1, 1, 12, 0, 0)
        # Act
        meta = MediaMetadata(
            media_id="img_001",
            media_type=MediaType.IMAGE,
            size=1024,
            mime_type="image/png",
            created_at=now,
        )
        # Assert
        assert meta.mime_type == "image/png"
        assert meta.created_at is now

    def test_zero_size_is_valid(self):
        # Arrange
        # Act
        meta = MediaMetadata(media_id="img_001", media_type=MediaType.IMAGE, size=0)
        # Assert - size 为 0 是合法的（非负）
        assert meta.size == 0

    def test_is_frozen(self):
        # Arrange
        meta = MediaMetadata(media_id="img_001", media_type=MediaType.IMAGE, size=1)
        # Act / Assert
        with pytest.raises(dataclasses.FrozenInstanceError):
            meta.media_id = "other"  # type: ignore[misc]

    def test_empty_media_id_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            MediaMetadata(media_id="", media_type=MediaType.IMAGE, size=1)
        assert exc_info.value.field == "media_id"

    def test_negative_size_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            MediaMetadata(media_id="img_001", media_type=MediaType.IMAGE, size=-1)
        assert exc_info.value.field == "size"


@pytest.mark.unit
class TestAttachmentUploadResult:
    """附件上传结果 DTO 测试。"""

    def test_required_fields_are_assigned(self):
        # Arrange
        # Act
        result = AttachmentUploadResult(
            attachment_id="att-1",
            url="https://example.com/att.png",
            mime_type="image/png",
            size_bytes=1024,
        )
        # Assert
        assert result.attachment_id == "att-1"
        assert result.url == "https://example.com/att.png"
        assert result.mime_type == "image/png"
        assert result.size_bytes == 1024
        assert result.expires_at is None

    def test_with_expires_at(self):
        # Arrange
        now = datetime(2026, 1, 1, 12, 0, 0)
        # Act
        result = AttachmentUploadResult(
            attachment_id="att-1",
            url="https://example.com/att.png",
            mime_type="image/png",
            size_bytes=1024,
            expires_at=now,
        )
        # Assert
        assert result.expires_at is now

    def test_is_frozen(self):
        # Arrange
        result = AttachmentUploadResult(
            attachment_id="att-1", url="url", mime_type="mt", size_bytes=1
        )
        # Act / Assert
        with pytest.raises(dataclasses.FrozenInstanceError):
            result.attachment_id = "other"  # type: ignore[misc]

    def test_empty_attachment_id_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            AttachmentUploadResult(attachment_id="", url="url", mime_type="mt", size_bytes=1)
        assert exc_info.value.field == "attachment_id"

    def test_empty_url_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            AttachmentUploadResult(attachment_id="a", url="", mime_type="mt", size_bytes=1)
        assert exc_info.value.field == "url"

    def test_empty_mime_type_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            AttachmentUploadResult(attachment_id="a", url="url", mime_type="", size_bytes=1)
        assert exc_info.value.field == "mime_type"

    def test_non_positive_size_bytes_raises_validation_error(self):
        # Arrange
        # Act / Assert
        with pytest.raises(ValidationError) as exc_info:
            AttachmentUploadResult(attachment_id="a", url="url", mime_type="mt", size_bytes=0)
        assert exc_info.value.field == "size_bytes"