"""Tests for pattern merger module."""

import pytest

from gitignore_cli.pattern_merger import PatternMerger, merge_templates, deduplicate_patterns


class TestPatternMerger:
    """Tests for PatternMerger class."""

    def setup_method(self):
        """Set up test fixtures."""
        self.merger = PatternMerger()

    def test_merge_single_pattern_set(self):
        """Test merging a single pattern set."""
        patterns = ["__pycache__/\n*.pyc"]
        result = self.merger.merge_patterns(patterns)

        assert "__pycache__/" in result
        assert "*.pyc" in result

    def test_merge_multiple_pattern_sets(self):
        """Test merging multiple pattern sets."""
        patterns = [
            "__pycache__/\n*.pyc",
            "node_modules/\n*.log",
        ]
        result = self.merger.merge_patterns(patterns)

        assert "__pycache__/" in result
        assert "*.pyc" in result
        assert "node_modules/" in result
        assert "*.log" in result

    def test_deduplication(self):
        """Test that duplicate patterns are removed."""
        patterns = [
            "*.pyc",
            "*.pyc",
            "*.pyc",
        ]
        result = self.merger.merge_patterns(patterns)

        assert result.count("*.pyc") == 1

    def test_empty_patterns(self):
        """Test merging empty pattern sets."""
        patterns = []
        result = self.merger.merge_patterns(patterns)

        assert result == "\n"

    def test_whitespace_lines_removed(self):
        """Test that empty/whitespace lines are handled."""
        patterns = [
            "*.pyc\n\n\n  \n*.pyo",
        ]
        result = self.merger.merge_patterns(patterns)

        assert "*.pyc" in result
        assert "*.pyo" in result

    def test_normalize_pattern(self):
        """Test pattern normalization."""
        assert self.merger._normalize_pattern("*.pyc") == "*.pyc"
        assert self.merger._normalize_pattern("  *.pyc  ") == "*.pyc"
        assert self.merger._normalize_pattern("") == ""
        assert self.merger._normalize_pattern("# comment") == ""
        assert self.merger._normalize_pattern("!important") == "!important"

    def test_deduplicate_patterns_function(self):
        """Test the deduplicate_patterns convenience function."""
        patterns = "*.pyc\n*.pyc\n*.pyo"
        result = deduplicate_patterns(patterns)

        assert result.count("*.pyc") == 1

    def test_filter_comments(self):
        """Test filtering out comments."""
        patterns = "*.pyc\n# another"
        result = self.merger.filter_comments(patterns)

        assert "*.pyc" in result

    def test_preserve_negation_patterns(self):
        """Test that negation patterns (!) are preserved."""
        patterns = [
            "*.log\n!important.log",
        ]
        result = self.merger.merge_patterns(patterns)

        assert "*.log" in result
        assert "!important.log" in result

    def test_empty_string_patterns(self):
        """Test handling of empty string patterns."""
        patterns = [""]
        result = self.merger.merge_patterns(patterns)

        assert result == "\n"


class TestMergeTemplatesFunction:
    """Tests for the merge_templates convenience function."""

    def test_merge_templates_convenience(self):
        """Test the merge_templates convenience function."""
        patterns = [
            "*.pyc",
            "*.pyo",
        ]
        result = merge_templates(patterns)

        assert "*.pyc" in result
        assert "*.pyo" in result