import pytest
import json
import tempfile
import os
from errorfix.rules.rule import Rule, Severity
from errorfix.rules.loader import RuleLoader


class TestRule:
    def test_rule_creation(self):
        rule = Rule(
            id="py001",
            name="Undefined Variable",
            pattern=r"NameError: name '(\w+)' is not defined",
            fix="Declare '{name}' before using it or check for typos",
            description="NameError occurs when trying to use an undefined variable",
            severity="error",
            language="python"
        )
        assert rule.id == "py001"
        assert rule.name == "Undefined Variable"
        assert rule.pattern == r"NameError: name '(\w+)' is not defined"
        assert "name" in rule.fix
        assert rule.language == "python"
        assert rule.severity == Severity.ERROR

    def test_rule_with_capture_groups(self):
        rule = Rule(
            id="py002",
            name="Unexpected Indent",
            pattern=r"SyntaxError: unexpected indent around line (?P<line>\d+)",
            fix="Remove the extra indentation on line {line}",
            description="Unexpected indentation error",
            severity="error",
            language="python"
        )
        assert "{line}" in rule.fix

    def test_rule_to_dict(self):
        rule = Rule(
            id="test001",
            name="Test Rule",
            pattern="Test pattern",
            fix="Test fix",
            description="Test description"
        )
        data = rule.to_dict()
        assert data["id"] == "test001"
        assert data["name"] == "Test Rule"
        assert data["severity"] == "error"

    def test_rule_from_dict(self):
        data = {
            "id": "from_dict_test",
            "name": "From Dict",
            "pattern": ".*",
            "fix": "fix",
            "description": "desc"
        }
        rule = Rule.from_dict(data)
        assert rule.id == "from_dict_test"


class TestRuleLoader:
    def test_load_yaml_rules(self, tmp_path):
        rules_file = tmp_path / "python_errors.yaml"
        rules_file.write_text("""[
  {
    "id": "py001",
    "name": "Undefined Variable",
    "pattern": "NameError: name '([\\\\w]+)' is not defined",
    "fix": "Declare before using",
    "description": "Undefined variable error",
    "severity": "error",
    "language": "python"
  }
]
""")
        loader = RuleLoader()
        rules = loader.load_yaml(str(rules_file))
        assert len(rules) == 1
        assert rules[0].language == "python"

    def test_load_json_rules(self, tmp_path):
        rules_file = tmp_path / "js_errors.json"
        rules_file.write_text('''[
  {
    "id": "js001",
    "name": "Reference Error",
    "pattern": "ReferenceError: ([\\\\w]+) is not defined",
    "fix": "Ensure declared before use",
    "description": "Reference to undefined variable",
    "severity": "error",
    "language": "javascript"
  }
]
''')
        loader = RuleLoader()
        rules = loader.load_json(str(rules_file))
        assert len(rules) == 1
        assert rules[0].language == "javascript"

    def test_load_directory(self, tmp_path):
        subdir = tmp_path / "python"
        subdir.mkdir()
        rules_file = subdir / "errors.yaml"
        rules_file.write_text("""
- id: py_test
  name: Test Rule
  pattern: "TestError"
  fix: "Fix the test"
  description: "Test rule"
  severity: "info"
  language: "python"
""")
        loader = RuleLoader()
        rules = loader.load_directory(str(tmp_path))
        assert len(rules) >= 1

    def test_filter_rules_by_language(self):
        loader = RuleLoader()
        from errorfix.rules.rule import Rule
        rules = [
            Rule(id="p1", name="P1", pattern=".*", fix="f", description="d", language="python"),
            Rule(id="p2", name="P2", pattern=".*", fix="f", description="d", language="javascript"),
            Rule(id="p3", name="P3", pattern=".*", fix="f", description="d", language="python"),
        ]
        filtered = loader.filter_rules(rules, language="python")
        assert len(filtered) == 2

    def test_load_nonexistent_file(self):
        loader = RuleLoader()
        with pytest.raises(FileNotFoundError):
            loader.load_yaml("/nonexistent/path.yaml")