"""
Base Validator Class

Shared functionality for all validators.
"""

import re
from abc import ABC
from dataclasses import dataclass, field
from enum import Enum
from pathlib import Path
from typing import Any

import yaml


class Severity(str, Enum):
    """Severity levels for validation findings."""
    ERROR = "error"
    WARNING = "warning"
    INFO = "info"


@dataclass
class Violation:
    """A single validation violation."""
    rule_id: str
    message: str
    severity: Severity
    file_path: str = ""
    line: int = 0
    suggestion: str = ""


@dataclass
class ValidationResult:
    """Result of a validation run."""
    violations: list[Violation] = field(default_factory=list)
    files_checked: int = 0

    def has_errors(self) -> bool:
        """Check if there are any error-level violations."""
        return any(v.severity == Severity.ERROR for v in self.violations)

    def error_count(self) -> int:
        """Count error-level violations."""
        return sum(1 for v in self.violations if v.severity == Severity.ERROR)

    def warning_count(self) -> int:
        """Count warning-level violations."""
        return sum(1 for v in self.violations if v.severity == Severity.WARNING)

    def info_count(self) -> int:
        """Count info-level violations."""
        return sum(1 for v in self.violations if v.severity == Severity.INFO)


class BaseValidator(ABC):
    """Base class for architecture, security, and performance validators."""

    # Directories/patterns to ignore by default
    IGNORE_PATTERNS = [
        ".venv", "venv", "node_modules", "__pycache__", ".git",
        ".pytest_cache", ".mypy_cache", "dist", "build", "*.egg-info",
        "migrations", "alembic/versions", ".tox", "htmlcov",
        "site",  # mkdocs build output
    ]

    # Regex for noqa comments: # noqa, # noqa: RULE-001, # noqa: RULE-001, RULE-002
    _NOQA_PATTERN = re.compile(
        r"#\s*noqa(?::\s*([A-Z]+-\d+(?:\s*,\s*[A-Z]+-\d+)*))?",
    )
    # Same for HTML comments: <!-- noqa: RULE-001 -->
    _NOQA_HTML_PATTERN = re.compile(
        r"<!--\s*noqa(?::\s*([A-Z]+-\d+(?:\s*,\s*[A-Z]+-\d+)*))?\s*-->",
    )

    def __init__(
        self,
        rules_dir: str = "",
        project_root: Path | None = None,
        verbose: bool = False,
    ):
        self.rules_dir = rules_dir
        self.project_root = project_root or Path.cwd()
        self.verbose = verbose
        self.rules: list[dict[str, Any]] = []
        self.errors: list[dict[str, Any]] = []
        self.warnings: list[dict[str, Any]] = []
        self.result = ValidationResult()

    def load_rules(self) -> None:
        """Load rules from YAML files."""
        rules_path = self.project_root / self.rules_dir
        if not rules_path.exists():
            print(f"Rules directory not found: {rules_path}")
            return

        for rule_file in rules_path.glob("*.yaml"):
            if rule_file.name.startswith("_"):
                continue  # Skip main config

            with open(rule_file) as f:
                data = yaml.safe_load(f)
                if data and "rules" in data:
                    self.rules.extend(data["rules"])

    def validate(self) -> bool:
        """Run validation. Returns True if passed.

        Subclasses should implement validate_all() instead.
        """
        result = self.validate_all()
        return not result.has_errors() if hasattr(result, "has_errors") else True

    def validate_all(self, target_path: Path | None = None) -> ValidationResult:
        """Run all validations. Override in subclasses."""
        return ValidationResult()

    def add_error(
        self, rule_id: str, message: str, file: str = "", line: int = 0
    ) -> None:
        """Add an error."""
        self.errors.append(
            {
                "rule_id": rule_id,
                "message": message,
                "file": file,
                "line": line,
                "severity": "error",
            }
        )

    def add_warning(
        self, rule_id: str, message: str, file: str = "", line: int = 0
    ) -> None:
        """Add a warning."""
        self.warnings.append(
            {
                "rule_id": rule_id,
                "message": message,
                "file": file,
                "line": line,
                "severity": "warning",
            }
        )

    def add_info(
        self, rule_id: str, message: str, file: str = "", line: int = 0
    ) -> None:
        """Add an informational note."""
        self.warnings.append(
            {
                "rule_id": rule_id,
                "message": message,
                "file": file,
                "line": line,
                "severity": "info",
            }
        )

    def print_results(self) -> None:
        """Print validation results."""
        if not self.errors and not self.warnings:
            print(f"✅ All {self.rules_dir} rules passed!")
            return

        if self.errors:
            print(f"\n❌ {len(self.errors)} errors found:")
            for error in self.errors:
                print(f"  [{error['rule_id']}] {error['message']}")
                if error["file"]:
                    print(f"    File: {error['file']}:{error['line']}")

        if self.warnings:
            print(f"\n⚠️  {len(self.warnings)} warnings:")
            for warning in self.warnings:
                print(f"  [{warning['rule_id']}] {warning['message']}")
                if warning["file"]:
                    print(f"    File: {warning['file']}:{warning['line']}")

    def run(self) -> int:
        """Run validation and return exit code."""
        self.load_rules()
        passed = self.validate()
        self.print_results()
        return 0 if passed else 1

    def _should_ignore_file(self, file_path: Path) -> bool:
        """Check if a file should be ignored based on patterns."""
        path_str = str(file_path)
        return any(pattern in path_str for pattern in self.IGNORE_PATTERNS)

    def _is_noqa_suppressed(self, line: str, rule_id: str) -> bool:
        """Check if a line has a noqa comment suppressing the given rule.

        Supports:
          - ``# noqa`` — suppresses all rules
          - ``# noqa: SEC-001`` — suppresses specific rule
          - ``# noqa: SEC-001, SEC-002`` — suppresses multiple rules
          - ``<!-- noqa: SEC-015 -->`` — HTML comment variant
        """
        for pattern in (self._NOQA_PATTERN, self._NOQA_HTML_PATTERN):
            match = pattern.search(line)
            if match:
                rule_list = match.group(1)
                if not rule_list:
                    return True  # bare # noqa → suppress everything
                suppressed = [r.strip() for r in rule_list.split(",")]
                if rule_id in suppressed:
                    return True
        return False

    def _add_violation(
        self,
        rule_id: str,
        rule_name: str,
        severity: Severity,
        file_path: Path,
        line_number: int,
        message: str,
        context: str = "",
        suggestion: str = "",
    ) -> None:
        """Add a violation to the result."""
        violation = Violation(
            rule_id=rule_id,
            message=f"{rule_name}: {message}",
            severity=severity,
            file_path=str(file_path),
            line=line_number,
            suggestion=suggestion,
        )
        self.result.violations.append(violation)

        if self.verbose and context:
            print(f"  [{rule_id}] {file_path}:{line_number}")
            print(f"    {message}")
            print(f"    Context: {context}")

    def validate_file(self, file_path: Path) -> ValidationResult:
        """Validate a single file."""
        if not file_path.exists():
            print(f"File not found: {file_path}")
            return self.result

        self.result.files_checked = 1
        content = file_path.read_text()
        lines = content.split("\n")
        self._validate_file_content(file_path, content, lines)
        return self.result

    def _validate_file_content(self, file_path: Path, content: str, lines: list[str]):
        """Validate file content. Override in subclasses."""

    def output_results(self, json_output: bool = False, errors_only: bool = False) -> None:
        """Output validation results."""
        if json_output:
            import json
            output = {
                "files_checked": self.result.files_checked,
                "violations": [
                    {
                        "rule_id": v.rule_id,
                        "message": v.message,
                        "severity": v.severity.value,
                        "file": v.file_path,
                        "line": v.line,
                        "suggestion": v.suggestion,
                    }
                    for v in self.result.violations
                    if not errors_only or v.severity == Severity.ERROR
                ],
            }
            print(json.dumps(output, indent=2))
        else:
            self._print_violations(errors_only)

    def _print_violations(self, errors_only: bool = False) -> None:
        """Print violations in human-readable format."""
        violations = self.result.violations
        if errors_only:
            violations = [v for v in violations if v.severity == Severity.ERROR]

        if not violations:
            print(f"\n✅ No issues found! ({self.result.files_checked} files checked)")
            return

        errors = [v for v in violations if v.severity == Severity.ERROR]
        warnings = [v for v in violations if v.severity == Severity.WARNING]
        info = [v for v in violations if v.severity == Severity.INFO]

        if errors:
            print(f"\n❌ {len(errors)} errors:")
            for v in errors:
                print(f"  [{v.rule_id}] {v.file_path}:{v.line}")
                print(f"    {v.message}")
                if v.suggestion:
                    print(f"    💡 {v.suggestion}")

        if warnings and not errors_only:
            print(f"\n⚠️  {len(warnings)} warnings:")
            for v in warnings:
                print(f"  [{v.rule_id}] {v.file_path}:{v.line}")
                print(f"    {v.message}")

        if info and not errors_only:
            print(f"\nℹ️  {len(info)} info:")
            for v in info:
                print(f"  [{v.rule_id}] {v.file_path}:{v.line}")
                print(f"    {v.message}")

        print(f"\n📊 Summary: {len(errors)} errors, {len(warnings)} warnings, {len(info)} info")

    def get_exit_code(self) -> int:
        """Get exit code based on validation results."""
        return 1 if self.result.has_errors() else 0