import pytest
from unittest.mock import MagicMock, patch

from pr_agent.git_providers.gitlab_provider import GitLabProvider
from gitlab import Gitlab
from gitlab.v4.objects import Project, ProjectFile
from gitlab.exceptions import GitlabGetError


class TestGitLabProvider:
    """Test suite for GitLab provider functionality."""
    
    @pytest.fixture
    def mock_gitlab_client(self):
        client = MagicMock()
        return client
    
    @pytest.fixture
    def mock_project(self):
        project = MagicMock()
        return project
    
    @pytest.fixture
    def gitlab_provider(self, mock_gitlab_client, mock_project):
        with patch('pr_agent.git_providers.gitlab_provider.gitlab.Gitlab', return_value=mock_gitlab_client), \
             patch('pr_agent.git_providers.gitlab_provider.get_settings') as mock_settings:
            
            mock_settings.return_value.get.side_effect = lambda key, default=None: {
                "GITLAB.URL": "https://gitlab.com",
                "GITLAB.PERSONAL_ACCESS_TOKEN": "fake_token"
            }.get(key, default)
            
            mock_gitlab_client.projects.get.return_value = mock_project
            provider = GitLabProvider("https://gitlab.com/test/repo/-/merge_requests/1")
            provider.gl = mock_gitlab_client
            provider.id_project = "test/repo"
            return provider

    def test_get_pr_file_content_success(self, gitlab_provider, mock_project):
        mock_file = MagicMock(ProjectFile)
        mock_file.decode.return_value = "# Changelog\n\n## v1.0.0\n- Initial release"
        mock_project.files.get.return_value = mock_file
        
        content = gitlab_provider.get_pr_file_content("CHANGELOG.md", "main")
        
        assert content == "# Changelog\n\n## v1.0.0\n- Initial release"
        mock_project.files.get.assert_called_once_with("CHANGELOG.md", "main")
        mock_file.decode.assert_called_once()

    def test_get_pr_file_content_with_bytes(self, gitlab_provider, mock_project):
        mock_file = MagicMock(ProjectFile)
        mock_file.decode.return_value = b"# Changelog\n\n## v1.0.0\n- Initial release"
        mock_project.files.get.return_value = mock_file
        
        content = gitlab_provider.get_pr_file_content("CHANGELOG.md", "main")
        
        assert content == "# Changelog\n\n## v1.0.0\n- Initial release"
        mock_project.files.get.assert_called_once_with("CHANGELOG.md", "main")

    def test_get_pr_file_content_file_not_found(self, gitlab_provider, mock_project):
        mock_project.files.get.side_effect = GitlabGetError("404 Not Found")
        
        content = gitlab_provider.get_pr_file_content("CHANGELOG.md", "main")
        
        assert content == ""
        mock_project.files.get.assert_called_once_with("CHANGELOG.md", "main")

    def test_get_pr_file_content_other_exception(self, gitlab_provider, mock_project):
        mock_project.files.get.side_effect = Exception("Network error")
        
        content = gitlab_provider.get_pr_file_content("CHANGELOG.md", "main")
        
        assert content == ""

    def test_create_or_update_pr_file_create_new(self, gitlab_provider, mock_project):
        mock_project.files.get.side_effect = GitlabGetError("404 Not Found")
        mock_file = MagicMock()
        mock_project.files.create.return_value = mock_file
        
        new_content = "# Changelog\n\n## v1.1.0\n- New feature"
        commit_message = "Add CHANGELOG.md"
        
        gitlab_provider.create_or_update_pr_file(
            "CHANGELOG.md", "feature-branch", new_content, commit_message
        )
        
        mock_project.files.get.assert_called_once_with("CHANGELOG.md", "feature-branch")
        mock_project.files.create.assert_called_once_with({
            'file_path': 'CHANGELOG.md',
            'branch': 'feature-branch',
            'content': new_content,
            'commit_message': commit_message,
        })

    def test_create_or_update_pr_file_update_existing(self, gitlab_provider, mock_project):
        mock_file = MagicMock(ProjectFile)
        mock_file.decode.return_value = "# Old changelog content"
        mock_project.files.get.return_value = mock_file
        
        new_content = "# New changelog content"
        commit_message = "Update CHANGELOG.md"
        
        gitlab_provider.create_or_update_pr_file(
            "CHANGELOG.md", "feature-branch", new_content, commit_message
        )
        
        mock_project.files.get.assert_called_once_with("CHANGELOG.md", "feature-branch")
        mock_file.content = new_content
        mock_file.save.assert_called_once_with(branch="feature-branch", commit_message=commit_message)

    def test_create_or_update_pr_file_update_exception(self, gitlab_provider, mock_project):
        mock_project.files.get.side_effect = Exception("Network error")
        
        with pytest.raises(Exception):
            gitlab_provider.create_or_update_pr_file(
                "CHANGELOG.md", "feature-branch", "content", "message"
            )

    def test_has_create_or_update_pr_file_method(self, gitlab_provider):
        assert hasattr(gitlab_provider, "create_or_update_pr_file")
        assert callable(getattr(gitlab_provider, "create_or_update_pr_file"))

    def test_method_signature_compatibility(self, gitlab_provider):
        import inspect
        
        sig = inspect.signature(gitlab_provider.create_or_update_pr_file)
        params = list(sig.parameters.keys())
        
        expected_params = ['file_path', 'branch', 'contents', 'message']
        assert params == expected_params

    @pytest.mark.parametrize("content,expected", [
        ("simple text", "simple text"),
        (b"bytes content", "bytes content"),
        ("", ""),
        (b"", ""),
        ("unicode: café", "unicode: café"),
        (b"unicode: caf\xc3\xa9", "unicode: café"),
    ])
    def test_content_encoding_handling(self, gitlab_provider, mock_project, content, expected):
        mock_file = MagicMock(ProjectFile)
        mock_file.decode.return_value = content
        mock_project.files.get.return_value = mock_file
        
        result = gitlab_provider.get_pr_file_content("test.md", "main")
        
        assert result == expected