feat: Add DeepSeek Model component (#5443)

* feat: Add DeepSeek component

* Adiciona DeepseekModelComponent ao __init__.py

* [autofix.ci] apply automated fixes

* Add DeepSeek icon and update component files

* Add DeepSeek icon and update all related files

* [autofix.ci] apply automated fixes

* Change DeepSeek icon color to blue (#080c34)

* [autofix.ci] apply automated fixes

* Revert DeepSeek icon color to black

* [autofix.ci] apply automated fixes

* remove: name parameter from DeepSeekModel to avoid backwards compatibility issues

* test: add unit tests for DeepSeek model component with mocks

* fix: correct formatting issues in DeepSeek model tests

* feat: update DeepSeek icon color to #4c6cfc

* fix: make DeepSeek API key field required

* fix: format SecretStrInput to comply with line length limit in DeepSeekModelComponent

* feat: add dark mode support for component icon

* [autofix.ci] apply automated fixes

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Edwin Jose <edwin.jose@datastax.com>

src/backend/tests/unit/components/models/test_deepseek.py

@@ -0,0 +1,112 @@
+from unittest.mock import MagicMock
+
+import pytest
+from langflow.components.models import DeepSeekModelComponent
+from langflow.custom import Component
+from langflow.custom.utils import build_custom_component_template
+
+
+def test_deepseek_initialization():
+    component = DeepSeekModelComponent()
+    assert component.display_name == "DeepSeek"
+    assert component.description == "Generate text using DeepSeek LLMs."
+    assert component.icon == "DeepSeek"
+
+
+def test_deepseek_template():
+    deepseek = DeepSeekModelComponent()
+    component = Component(_code=deepseek._code)
+    frontend_node, _ = build_custom_component_template(component)
+
+    # Verify basic structure
+    assert isinstance(frontend_node, dict)
+
+    # Verify inputs
+    assert "template" in frontend_node
+    input_names = [input_["name"] for input_ in frontend_node["template"].values() if isinstance(input_, dict)]
+
+    expected_inputs = [
+        "max_tokens",
+        "model_kwargs",
+        "json_mode",
+        "model_name",
+        "api_base",
+        "api_key",
+        "temperature",
+        "seed",
+    ]
+
+    for input_name in expected_inputs:
+        assert input_name in input_names
+
+
+@pytest.mark.parametrize(
+    ("temperature", "max_tokens"),
+    [
+        (0.5, 100),
+        (1.0, 500),
+        (1.5, 1000),
+    ],
+)
+@pytest.fixture
+def mock_chat_openai(mocker):
+    return mocker.patch("langchain_openai.ChatOpenAI")
+
+
+def test_deepseek_build_model(mock_chat_openai):
+    component = DeepSeekModelComponent()
+    component.temperature = 0.7
+    component.max_tokens = 100
+    component.api_key = "test-key"
+
+    # Mock the ChatOpenAI instance
+    mock_instance = MagicMock()
+    mock_chat_openai.return_value = mock_instance
+
+    model = component.build_model()
+
+    # Verify ChatOpenAI was called with correct params
+    mock_chat_openai.assert_called_once_with(
+        max_tokens=100,
+        model_kwargs={},
+        model="deepseek-chat",
+        base_url="https://api.deepseek.com",
+        api_key="test-key",
+        temperature=0.7,
+        seed=1,
+        streaming=False,
+    )
+    assert model == mock_instance
+
+
+def test_deepseek_get_models(mocker):
+    component = DeepSeekModelComponent()
+
+    # Mock requests.get
+    mock_get = mocker.patch("requests.get")
+    mock_response = MagicMock()
+    mock_response.json.return_value = {"data": [{"id": "deepseek-chat"}, {"id": "deepseek-coder"}]}
+    mock_get.return_value = mock_response
+
+    # Test with API key
+    component.api_key = "test-key"
+    models = component.get_models()
+    assert models == ["deepseek-chat", "deepseek-coder"]
+
+    # Verify API call
+    mock_get.assert_called_once_with(
+        "https://api.deepseek.com/models",
+        headers={"Authorization": "Bearer test-key", "Accept": "application/json"},
+        timeout=10,
+    )
+
+
+def test_deepseek_error_handling(mock_chat_openai):
+    component = DeepSeekModelComponent()
+    component.api_key = "invalid-key"
+
+    # Mock ChatOpenAI to raise exception
+    mock_chat_openai.side_effect = Exception("Invalid API key")
+
+    with pytest.raises(Exception, match="Invalid API key"):
+        component.build_model()