#!/usr/bin/env python3
"""
Code Validation Script
Automatisierte Validierung nach Änderungen an steps/ und services/

Features:
- Syntax-Check (compile)
- Import-Check (importlib)
- Type-Hint Validation (mypy optional)
- Async/Await Pattern Check
- Logger Usage Check
- Quick execution (~1-2 seconds)

Usage:
    python scripts/validate_code.py                 # Check all
    python scripts/validate_code.py services/       # Check services only
    python scripts/validate_code.py --changed       # Check only git changed files
    python scripts/validate_code.py --mypy          # Include mypy checks
"""

import sys
import os
import ast
import importlib.util
import traceback
from pathlib import Path
from typing import List, Tuple, Optional
import subprocess
import argparse

# ANSI Colors
GREEN = '\033[92m'
RED = '\033[91m'
YELLOW = '\033[93m'
BLUE = '\033[94m'
RESET = '\033[0m'
BOLD = '\033[1m'

class ValidationError:
    def __init__(self, file: str, error_type: str, message: str, line: Optional[int] = None):
        self.file = file
        self.error_type = error_type
        self.message = message
        self.line = line
    
    def __str__(self):
        loc = f":{self.line}" if self.line else ""
        return f"{RED}✗{RESET} {self.file}{loc}\n  {YELLOW}[{self.error_type}]{RESET} {self.message}"


class CodeValidator:
    def __init__(self, root_dir: Path):
        self.root_dir = root_dir
        self.errors: List[ValidationError] = []
        self.warnings: List[ValidationError] = []
        self.checked_files = 0
    
    def add_error(self, file: str, error_type: str, message: str, line: Optional[int] = None):
        self.errors.append(ValidationError(file, error_type, message, line))
    
    def add_warning(self, file: str, error_type: str, message: str, line: Optional[int] = None):
        self.warnings.append(ValidationError(file, error_type, message, line))
    
    def check_syntax(self, file_path: Path) -> bool:
        """Check Python syntax by compiling"""
        try:
            with open(file_path, 'r', encoding='utf-8') as f:
                source = f.read()
            compile(source, str(file_path), 'exec')
            return True
        except SyntaxError as e:
            self.add_error(
                str(file_path.relative_to(self.root_dir)),
                "SYNTAX",
                f"{e.msg}",
                e.lineno
            )
            return False
        except Exception as e:
            self.add_error(
                str(file_path.relative_to(self.root_dir)),
                "SYNTAX",
                f"Unexpected error: {e}"
            )
            return False
    
    def check_imports(self, file_path: Path) -> bool:
        """Check if imports are valid"""
        try:
            # Add project root to path
            sys.path.insert(0, str(self.root_dir))
            
            spec = importlib.util.spec_from_file_location("module", file_path)
            if spec and spec.loader:
                module = importlib.util.module_from_spec(spec)
                spec.loader.exec_module(module)
            return True
        except ImportError as e:
            self.add_error(
                str(file_path.relative_to(self.root_dir)),
                "IMPORT",
                f"{e}"
            )
            return False
        except Exception as e:
            # Ignore runtime errors, we only care about imports
            if "ImportError" in str(type(e)) or "ModuleNotFoundError" in str(type(e)):
                self.add_error(
                    str(file_path.relative_to(self.root_dir)),
                    "IMPORT",
                    f"{e}"
                )
                return False
            return True
        finally:
            # Remove from path
            if str(self.root_dir) in sys.path:
                sys.path.remove(str(self.root_dir))
    
    def check_patterns(self, file_path: Path) -> bool:
        """Check common patterns and anti-patterns"""
        try:
            with open(file_path, 'r', encoding='utf-8') as f:
                source = f.read()
            
            tree = ast.parse(source, str(file_path))
            
            # Check 1: Async functions should use await, not asyncio.run()
            for node in ast.walk(tree):
                if isinstance(node, ast.FunctionDef):
                    is_async = isinstance(node, ast.AsyncFunctionDef)
                    
                    # Check for asyncio.run() in async function
                    if is_async:
                        for child in ast.walk(node):
                            if isinstance(child, ast.Call):
                                if isinstance(child.func, ast.Attribute):
                                    if (isinstance(child.func.value, ast.Name) and 
                                        child.func.value.id == 'asyncio' and 
                                        child.func.attr == 'run'):
                                        self.add_warning(
                                            str(file_path.relative_to(self.root_dir)),
                                            "ASYNC",
                                            f"asyncio.run() in async function '{node.name}' - use await instead",
                                            node.lineno
                                        )
                    
                    # Check for logger.warn (should be logger.warning)
                    for child in ast.walk(node):
                        if isinstance(child, ast.Call):
                            if isinstance(child.func, ast.Attribute):
                                # MOTIA-SPECIFIC: warn() is correct, warning() is NOT supported
                                if child.func.attr == 'warning':
                                    self.add_warning(
                                        str(file_path.relative_to(self.root_dir)),
                                        "LOGGER",
                                        f"logger.warning() not supported by Motia - use logger.warn()",
                                        child.lineno
                                    )
            
            # Check 2: Services should use self.logger if context available
            if 'services/' in str(file_path):
                # Check if class has context parameter but uses logger instead of self.logger
                for node in ast.walk(tree):
                    if isinstance(node, ast.ClassDef):
                        has_context = False
                        uses_module_logger = False
                        
                        # Check __init__ for context parameter
                        for child in node.body:
                            if isinstance(child, ast.FunctionDef) and child.name == '__init__':
                                for arg in child.args.args:
                                    if arg.arg == 'context':
                                        has_context = True
                        
                        # Check for logger.info/error/etc calls
                        for child in ast.walk(node):
                            if isinstance(child, ast.Call):
                                if isinstance(child.func, ast.Attribute):
                                    if (isinstance(child.func.value, ast.Name) and 
                                        child.func.value.id == 'logger'):
                                        uses_module_logger = True
                        
                        if has_context and uses_module_logger:
                            self.add_warning(
                                str(file_path.relative_to(self.root_dir)),
                                "LOGGER",
                                f"Class '{node.name}' has context but uses 'logger' - use 'self.logger' for Workbench visibility",
                                node.lineno
                            )
            
            return True
        except Exception as e:
            # Don't fail validation for pattern checks
            return True
    
    def check_file(self, file_path: Path) -> bool:
        """Run all checks on a file"""
        self.checked_files += 1
        
        # 1. Syntax check (must pass)
        if not self.check_syntax(file_path):
            return False
        
        # 2. Import check (must pass)
        if not self.check_imports(file_path):
            return False
        
        # 3. Pattern checks (warnings only)
        self.check_patterns(file_path)
        
        return True
    
    def find_python_files(self, paths: List[str]) -> List[Path]:
        """Find all Python files in given paths"""
        files = []
        for path_str in paths:
            path = self.root_dir / path_str
            if path.is_file() and path.suffix == '.py':
                files.append(path)
            elif path.is_dir():
                files.extend(path.rglob('*.py'))
        return files
    
    def get_changed_files(self) -> List[Path]:
        """Get git changed files"""
        try:
            result = subprocess.run(
                ['git', 'diff', '--name-only', 'HEAD'],
                cwd=self.root_dir,
                capture_output=True,
                text=True
            )
            
            # Also get staged files
            result2 = subprocess.run(
                ['git', 'diff', '--cached', '--name-only'],
                cwd=self.root_dir,
                capture_output=True,
                text=True
            )
            
            all_files = result.stdout.strip().split('\n') + result2.stdout.strip().split('\n')
            
            python_files = []
            for f in all_files:
                if f and f.endswith('.py'):
                    file_path = self.root_dir / f
                    if file_path.exists():
                        # Only include services/ and steps/
                        if 'services/' in f or 'steps/' in f:
                            python_files.append(file_path)
            
            return python_files
        except Exception as e:
            print(f"{YELLOW}⚠ Could not get git changed files: {e}{RESET}")
            return []
    
    def validate(self, paths: List[str], only_changed: bool = False) -> bool:
        """Run validation on all files"""
        print(f"{BOLD}🔍 Code Validation{RESET}\n")
        
        if only_changed:
            files = self.get_changed_files()
            if not files:
                print(f"{GREEN}✓{RESET} No changed Python files in services/ or steps/")
                return True
            print(f"Checking {len(files)} changed files...\n")
        else:
            files = self.find_python_files(paths)
            print(f"Checking {len(files)} files in {', '.join(paths)}...\n")
        
        # Check each file
        for file_path in sorted(files):
            rel_path = str(file_path.relative_to(self.root_dir))
            print(f"  {BLUE}→{RESET} {rel_path}...", end='')
            
            if self.check_file(file_path):
                print(f" {GREEN}✓{RESET}")
            else:
                print(f" {RED}✗{RESET}")
        
        # Print results
        print(f"\n{BOLD}Results:{RESET}")
        print(f"  Files checked: {self.checked_files}")
        print(f"  Errors: {len(self.errors)}")
        print(f"  Warnings: {len(self.warnings)}")
        
        # Print errors
        if self.errors:
            print(f"\n{BOLD}{RED}Errors:{RESET}")
            for error in self.errors:
                print(f"  {error}")
        
        # Print warnings
        if self.warnings:
            print(f"\n{BOLD}{YELLOW}Warnings:{RESET}")
            for warning in self.warnings:
                print(f"  {warning}")
        
        # Summary
        print()
        if self.errors:
            print(f"{RED}✗ Validation failed with {len(self.errors)} error(s){RESET}")
            return False
        elif self.warnings:
            print(f"{YELLOW}⚠ Validation passed with {len(self.warnings)} warning(s){RESET}")
            return True
        else:
            print(f"{GREEN}✓ All checks passed!{RESET}")
            return True


def run_mypy(root_dir: Path, paths: List[str]) -> bool:
    """Run mypy type checker"""
    print(f"\n{BOLD}🔍 Running mypy type checker...{RESET}\n")
    
    try:
        result = subprocess.run(
            ['mypy'] + paths + ['--ignore-missing-imports', '--no-error-summary'],
            cwd=root_dir,
            capture_output=True,
            text=True
        )
        
        if result.stdout:
            print(result.stdout)
        
        if result.returncode == 0:
            print(f"{GREEN}✓ mypy: No type errors{RESET}")
            return True
        else:
            print(f"{RED}✗ mypy found type errors{RESET}")
            return False
    except FileNotFoundError:
        print(f"{YELLOW}⚠ mypy not installed - skipping type checks{RESET}")
        print(f"  Install with: pip install mypy")
        return True


def main():
    parser = argparse.ArgumentParser(description='Validate Python code in services/ and steps/')
    parser.add_argument('paths', nargs='*', default=['services/', 'steps/'],
                       help='Paths to check (default: services/ steps/)')
    parser.add_argument('--changed', '-c', action='store_true',
                       help='Only check git changed files')
    parser.add_argument('--mypy', '-m', action='store_true',
                       help='Run mypy type checker')
    parser.add_argument('--verbose', '-v', action='store_true',
                       help='Verbose output')
    
    args = parser.parse_args()
    
    root_dir = Path(__file__).parent.parent
    validator = CodeValidator(root_dir)
    
    # Run validation
    success = validator.validate(args.paths, only_changed=args.changed)
    
    # Run mypy if requested
    if args.mypy and success:
        mypy_success = run_mypy(root_dir, args.paths)
        success = success and mypy_success
    
    # Exit with appropriate code
    sys.exit(0 if success else 1)


if __name__ == '__main__':
    main()