#!/usr/bin/env python3
"""
Architecture Validator
======================
Validates code against architectural rules defined in .architecture-rules.yaml

This script checks that the codebase follows key architectural decisions:
- Separation of concerns (routes vs services)
- Proper exception handling (domain exceptions vs HTTPException)
- Correct use of Pydantic vs SQLAlchemy models
- Service layer patterns
- API endpoint patterns

Usage:
    python scripts/validate_architecture.py              # Check all files
    python scripts/validate_architecture.py --fix        # Auto-fix where possible
    python scripts/validate_architecture.py --verbose    # Detailed output
    python scripts/validate_architecture.py app/api/     # Check specific directory
"""

import argparse
import ast
import re
import sys
from dataclasses import dataclass, field
from enum import Enum
from pathlib import Path
from typing import Any

import yaml


class Severity(Enum):
    """Validation severity levels"""

    ERROR = "error"
    WARNING = "warning"
    INFO = "info"


@dataclass
class Violation:
    """Represents an architectural rule violation"""

    rule_id: str
    rule_name: str
    severity: Severity
    file_path: Path
    line_number: int
    message: str
    context: str = ""
    suggestion: str = ""


@dataclass
class ValidationResult:
    """Results of architecture validation"""

    violations: list[Violation] = field(default_factory=list)
    files_checked: int = 0
    rules_applied: 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 has_warnings(self) -> bool:
        """Check if there are any warning-level violations"""
        return any(v.severity == Severity.WARNING for v in self.violations)


class ArchitectureValidator:
    """Main validator class"""

    def __init__(self, config_path: Path, verbose: bool = False):
        """Initialize validator with configuration"""
        self.config_path = config_path
        self.verbose = verbose
        self.config = self._load_config()
        self.result = ValidationResult()
        self.project_root = Path.cwd()

    def _load_config(self) -> dict[str, Any]:
        """Load validation rules from YAML config"""
        if not self.config_path.exists():
            print(f"❌ Configuration file not found: {self.config_path}")
            sys.exit(1)

        with open(self.config_path) as f:
            config = yaml.safe_load(f)

        print(f"📋 Loaded architecture rules: {config.get('project', 'unknown')}")
        return config

    def validate_all(self, target_path: Path = None) -> ValidationResult:
        """Validate all files or specific path"""
        print("\n🔍 Starting architecture validation...\n")

        target = target_path or self.project_root

        # Validate API endpoints
        self._validate_api_endpoints(target)

        # Validate service layer
        self._validate_service_layer(target)

        # Validate models
        self._validate_models(target)

        # Validate exception handling
        self._validate_exceptions(target)

        # Validate JavaScript
        self._validate_javascript(target)

        # Validate templates
        self._validate_templates(target)

        return self.result

    def _validate_api_endpoints(self, target_path: Path):
        """Validate API endpoint rules (API-001, API-002, API-003, API-004)"""
        print("📡 Validating API endpoints...")

        api_files = list(target_path.glob("app/api/v1/**/*.py"))
        self.result.files_checked += len(api_files)

        for file_path in api_files:
            if self._should_ignore_file(file_path):
                continue

            content = file_path.read_text()
            lines = content.split("\n")

            # API-001: Check for Pydantic model usage
            self._check_pydantic_usage(file_path, content, lines)

            # API-002: Check for business logic in endpoints
            self._check_no_business_logic_in_endpoints(file_path, content, lines)

            # API-003: Check exception handling
            self._check_endpoint_exception_handling(file_path, content, lines)

            # API-004: Check authentication
            self._check_endpoint_authentication(file_path, content, lines)

    def _check_pydantic_usage(self, file_path: Path, content: str, lines: list[str]):
        """API-001: Ensure endpoints use Pydantic models"""
        rule = self._get_rule("API-001")
        if not rule:
            return

        # Check for response_model in route decorators
        route_pattern = r"@router\.(get|post|put|delete|patch)"
        dict_return_pattern = r"return\s+\{.*\}"

        for i, line in enumerate(lines, 1):
            # Check for dict returns in endpoints
            if re.search(route_pattern, line):
                # Look ahead for function body
                func_start = i
                indent = len(line) - len(line.lstrip())

                # Find function body
                for j in range(func_start, min(func_start + 20, len(lines))):
                    if j >= len(lines):
                        break

                    func_line = lines[j]
                    if re.search(dict_return_pattern, func_line):
                        self._add_violation(
                            rule_id="API-001",
                            rule_name=rule["name"],
                            severity=Severity.ERROR,
                            file_path=file_path,
                            line_number=j + 1,
                            message="Endpoint returns raw dict instead of Pydantic model",
                            context=func_line.strip(),
                            suggestion="Define a Pydantic response model and use response_model parameter",
                        )

    def _check_no_business_logic_in_endpoints(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """API-002: Ensure no business logic in endpoints"""
        rule = self._get_rule("API-002")
        if not rule:
            return

        anti_patterns = [
            (r"db\.add\(", "Database operations should be in service layer"),
            (r"db\.commit\(\)", "Database commits should be in service layer"),
            (r"db\.query\(", "Database queries should be in service layer"),
            (r"db\.execute\(", "Database operations should be in service layer"),
        ]

        for i, line in enumerate(lines, 1):
            # Skip service method calls (allowed)
            if "_service." in line or "service." in line:
                continue

            for pattern, message in anti_patterns:
                if re.search(pattern, line):
                    self._add_violation(
                        rule_id="API-002",
                        rule_name=rule["name"],
                        severity=Severity.ERROR,
                        file_path=file_path,
                        line_number=i,
                        message=message,
                        context=line.strip(),
                        suggestion="Move database operations to service layer",
                    )

    def _check_endpoint_exception_handling(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """API-003: Check proper exception handling in endpoints"""
        rule = self._get_rule("API-003")
        if not rule:
            return

        # Parse file to check for try/except in route handlers
        try:
            tree = ast.parse(content)
        except SyntaxError:
            return

        for node in ast.walk(tree):
            if isinstance(node, ast.FunctionDef):
                # Check if it's a route handler
                has_router_decorator = any(
                    isinstance(d, ast.Call)
                    and isinstance(d.func, ast.Attribute)
                    and getattr(d.func.value, "id", None) == "router"
                    for d in node.decorator_list
                )

                if has_router_decorator:
                    # Check if function body has try/except
                    has_try_except = any(
                        isinstance(child, ast.Try) for child in ast.walk(node)
                    )

                    # Check if function calls service methods
                    has_service_call = any(
                        isinstance(child, ast.Call)
                        and isinstance(child.func, ast.Attribute)
                        and "service" in getattr(child.func.value, "id", "").lower()
                        for child in ast.walk(node)
                    )

                    if has_service_call and not has_try_except:
                        self._add_violation(
                            rule_id="API-003",
                            rule_name=rule["name"],
                            severity=Severity.WARNING,
                            file_path=file_path,
                            line_number=node.lineno,
                            message=f"Endpoint '{node.name}' calls service but lacks exception handling",
                            context=f"def {node.name}(...)",
                            suggestion="Wrap service calls in try/except and convert to HTTPException",
                        )

    def _check_endpoint_authentication(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """API-004: Check authentication on endpoints"""
        rule = self._get_rule("API-004")
        if not rule:
            return

        # This is a warning-level check
        # Look for endpoints without Depends(get_current_*)
        for i, line in enumerate(lines, 1):
            if "@router." in line and (
                "post" in line or "put" in line or "delete" in line
            ):
                # Check next 5 lines for auth
                has_auth = False
                for j in range(i, min(i + 5, len(lines))):
                    if "Depends(get_current_" in lines[j]:
                        has_auth = True
                        break

                if not has_auth and "include_in_schema=False" not in " ".join(
                    lines[i : i + 5]
                ):
                    self._add_violation(
                        rule_id="API-004",
                        rule_name=rule["name"],
                        severity=Severity.WARNING,
                        file_path=file_path,
                        line_number=i,
                        message="Endpoint may be missing authentication",
                        context=line.strip(),
                        suggestion="Add Depends(get_current_user) or similar if endpoint should be protected",
                    )

    def _validate_service_layer(self, target_path: Path):
        """Validate service layer rules (SVC-001, SVC-002, SVC-003, SVC-004)"""
        print("🔧 Validating service layer...")

        service_files = list(target_path.glob("app/services/**/*.py"))
        self.result.files_checked += len(service_files)

        for file_path in service_files:
            if self._should_ignore_file(file_path):
                continue

            content = file_path.read_text()
            lines = content.split("\n")

            # SVC-001: No HTTPException in services
            self._check_no_http_exception_in_services(file_path, content, lines)

            # SVC-002: Proper exception handling
            self._check_service_exceptions(file_path, content, lines)

            # SVC-003: DB session as parameter
            self._check_db_session_parameter(file_path, content, lines)

    def _check_no_http_exception_in_services(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """SVC-001: Services must not raise HTTPException"""
        rule = self._get_rule("SVC-001")
        if not rule:
            return

        for i, line in enumerate(lines, 1):
            if "raise HTTPException" in line:
                self._add_violation(
                    rule_id="SVC-001",
                    rule_name=rule["name"],
                    severity=Severity.ERROR,
                    file_path=file_path,
                    line_number=i,
                    message="Service raises HTTPException - use domain exceptions instead",
                    context=line.strip(),
                    suggestion="Create custom exception class (e.g., VendorNotFoundError) and raise that",
                )

            if (
                "from fastapi import HTTPException" in line
                or "from fastapi.exceptions import HTTPException" in line
            ):
                self._add_violation(
                    rule_id="SVC-001",
                    rule_name=rule["name"],
                    severity=Severity.ERROR,
                    file_path=file_path,
                    line_number=i,
                    message="Service imports HTTPException - services should not know about HTTP",
                    context=line.strip(),
                    suggestion="Remove HTTPException import and use domain exceptions",
                )

    def _check_service_exceptions(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """SVC-002: Check for proper exception handling"""
        rule = self._get_rule("SVC-002")
        if not rule:
            return

        for i, line in enumerate(lines, 1):
            # Check for generic Exception raises
            if re.match(r"\s*raise Exception\(", line):
                self._add_violation(
                    rule_id="SVC-002",
                    rule_name=rule["name"],
                    severity=Severity.WARNING,
                    file_path=file_path,
                    line_number=i,
                    message="Service raises generic Exception - use specific domain exception",
                    context=line.strip(),
                    suggestion="Create custom exception class for this error case",
                )

    def _check_db_session_parameter(
        self, file_path: Path, content: str, lines: list[str]
    ):
        """SVC-003: Service methods should accept db session as parameter"""
        rule = self._get_rule("SVC-003")
        if not rule:
            return

        # Check for SessionLocal() creation in service files
        for i, line in enumerate(lines, 1):
            if "SessionLocal()" in line and "class" not in line:
                self._add_violation(
                    rule_id="SVC-003",
                    rule_name=rule["name"],
                    severity=Severity.ERROR,
                    file_path=file_path,
                    line_number=i,
                    message="Service creates database session internally",
                    context=line.strip(),
                    suggestion="Accept db: Session as method parameter instead",
                )

    def _validate_models(self, target_path: Path):
        """Validate model rules"""
        print("📦 Validating models...")

        model_files = list(target_path.glob("app/models/**/*.py"))
        self.result.files_checked += len(model_files)

        # Basic validation - can be extended
        for file_path in model_files:
            if self._should_ignore_file(file_path):
                continue

            content = file_path.read_text()
            lines = content.split("\n")

            # Check for mixing SQLAlchemy and Pydantic
            for i, line in enumerate(lines, 1):
                if re.search(r"class.*\(Base.*,.*BaseModel.*\)", line):
                    self._add_violation(
                        rule_id="MDL-002",
                        rule_name="Separate SQLAlchemy and Pydantic models",
                        severity=Severity.ERROR,
                        file_path=file_path,
                        line_number=i,
                        message="Model mixes SQLAlchemy Base and Pydantic BaseModel",
                        context=line.strip(),
                        suggestion="Keep SQLAlchemy models and Pydantic models separate",
                    )

    def _validate_exceptions(self, target_path: Path):
        """Validate exception handling patterns"""
        print("⚠️  Validating exception handling...")

        py_files = list(target_path.glob("**/*.py"))

        for file_path in py_files:
            if self._should_ignore_file(file_path):
                continue

            content = file_path.read_text()
            lines = content.split("\n")

            # EXC-002: Check for bare except
            for i, line in enumerate(lines, 1):
                if re.match(r"\s*except\s*:", line):
                    self._add_violation(
                        rule_id="EXC-002",
                        rule_name="No bare except clauses",
                        severity=Severity.ERROR,
                        file_path=file_path,
                        line_number=i,
                        message="Bare except clause catches all exceptions including system exits",
                        context=line.strip(),
                        suggestion="Specify exception type: except ValueError: or except Exception:",
                    )

    def _validate_javascript(self, target_path: Path):
        """Validate JavaScript patterns"""
        print("🟨 Validating JavaScript...")

        js_files = list(target_path.glob("static/admin/js/**/*.js"))
        self.result.files_checked += len(js_files)

        for file_path in js_files:
            content = file_path.read_text()
            lines = content.split("\n")

            # JS-001: Check for window.apiClient
            for i, line in enumerate(lines, 1):
                if (
                    "window.apiClient" in line
                    and "//" not in line[: line.find("window.apiClient")]
                    if "window.apiClient" in line
                    else True
                ):
                    self._add_violation(
                        rule_id="JS-001",
                        rule_name="Use apiClient directly",
                        severity=Severity.WARNING,
                        file_path=file_path,
                        line_number=i,
                        message="Use apiClient directly instead of window.apiClient",
                        context=line.strip(),
                        suggestion="Replace window.apiClient with apiClient",
                    )

            # JS-002: Check for console usage
            for i, line in enumerate(lines, 1):
                if re.search(r"console\.(log|warn|error)", line):
                    # Skip if it's a comment or bootstrap message
                    if "//" in line or "✅" in line or "eslint-disable" in line:
                        continue

                    self._add_violation(
                        rule_id="JS-002",
                        rule_name="Use centralized logger",
                        severity=Severity.WARNING,
                        file_path=file_path,
                        line_number=i,
                        message="Use centralized logger instead of console",
                        context=line.strip()[:80],
                        suggestion="Use window.LogConfig.createLogger('moduleName')",
                    )

    def _validate_templates(self, target_path: Path):
        """Validate template patterns"""
        print("📄 Validating templates...")

        template_files = list(target_path.glob("app/templates/admin/**/*.html"))
        self.result.files_checked += len(template_files)

        for file_path in template_files:
            # Skip base template and partials
            if "base.html" in file_path.name or "partials" in str(file_path):
                continue

            content = file_path.read_text()
            lines = content.split("\n")

            # TPL-001: Check for extends
            has_extends = any(
                "{% extends" in line and "admin/base.html" in line for line in lines
            )

            if not has_extends:
                self._add_violation(
                    rule_id="TPL-001",
                    rule_name="Templates must extend base",
                    severity=Severity.ERROR,
                    file_path=file_path,
                    line_number=1,
                    message="Admin template does not extend admin/base.html",
                    context=file_path.name,
                    suggestion="Add {% extends 'admin/base.html' %} at the top",
                )

    def _get_rule(self, rule_id: str) -> dict[str, Any]:
        """Get rule configuration by ID"""
        # Look in different rule categories
        for category in [
            "api_endpoint_rules",
            "service_layer_rules",
            "model_rules",
            "exception_rules",
            "javascript_rules",
            "template_rules",
        ]:
            rules = self.config.get(category, [])
            for rule in rules:
                if rule.get("id") == rule_id:
                    return rule
        return None

    def _should_ignore_file(self, file_path: Path) -> bool:
        """Check if file should be ignored"""
        ignore_patterns = self.config.get("ignore", {}).get("files", [])

        for pattern in ignore_patterns:
            if file_path.match(pattern):
                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 = "",
    ):
        """Add a violation to results"""
        violation = Violation(
            rule_id=rule_id,
            rule_name=rule_name,
            severity=severity,
            file_path=file_path,
            line_number=line_number,
            message=message,
            context=context,
            suggestion=suggestion,
        )
        self.result.violations.append(violation)

    def print_report(self):
        """Print validation report"""
        print("\n" + "=" * 80)
        print("📊 ARCHITECTURE VALIDATION REPORT")
        print("=" * 80 + "\n")

        print(f"Files checked: {self.result.files_checked}")
        print(f"Total violations: {len(self.result.violations)}\n")

        # Group by severity
        errors = [v for v in self.result.violations if v.severity == Severity.ERROR]
        warnings = [v for v in self.result.violations if v.severity == Severity.WARNING]

        if errors:
            print(f"\n❌ ERRORS ({len(errors)}):")
            print("-" * 80)
            for violation in errors:
                self._print_violation(violation)

        if warnings:
            print(f"\n⚠️  WARNINGS ({len(warnings)}):")
            print("-" * 80)
            for violation in warnings:
                self._print_violation(violation)

        # Summary
        print("\n" + "=" * 80)
        if self.result.has_errors():
            print("❌ VALIDATION FAILED - Fix errors before committing")
            print("=" * 80)
            return 1
        if self.result.has_warnings():
            print("⚠️  VALIDATION PASSED WITH WARNINGS")
            print("=" * 80)
            return 0
        print("✅ VALIDATION PASSED - No violations found")
        print("=" * 80)
        return 0

    def print_json(self) -> int:
        """Print validation results as JSON"""
        import json

        violations_json = []
        for v in self.result.violations:
            rel_path = (
                str(v.file_path.relative_to(self.project_root))
                if self.project_root in v.file_path.parents
                else str(v.file_path)
            )
            violations_json.append(
                {
                    "rule_id": v.rule_id,
                    "rule_name": v.rule_name,
                    "severity": v.severity.value,
                    "file_path": rel_path,
                    "line_number": v.line_number,
                    "message": v.message,
                    "context": v.context or "",
                    "suggestion": v.suggestion or "",
                }
            )

        output = {
            "files_checked": self.result.files_checked,
            "total_violations": len(self.result.violations),
            "errors": len(
                [v for v in self.result.violations if v.severity == Severity.ERROR]
            ),
            "warnings": len(
                [v for v in self.result.violations if v.severity == Severity.WARNING]
            ),
            "violations": violations_json,
        }

        print(json.dumps(output, indent=2))

        return 1 if self.result.has_errors() else 0

    def _print_violation(self, v: Violation):
        """Print a single violation"""
        rel_path = (
            v.file_path.relative_to(self.project_root)
            if self.project_root in v.file_path.parents
            else v.file_path
        )

        print(f"\n  [{v.rule_id}] {v.rule_name}")
        print(f"  File: {rel_path}:{v.line_number}")
        print(f"  Issue: {v.message}")

        if v.context and self.verbose:
            print(f"  Context: {v.context}")

        if v.suggestion:
            print(f"  💡 Suggestion: {v.suggestion}")


def main():
    """Main entry point"""
    parser = argparse.ArgumentParser(
        description="Validate architecture patterns in codebase",
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog=__doc__,
    )

    parser.add_argument(
        "path",
        nargs="?",
        type=Path,
        default=Path.cwd(),
        help="Path to validate (default: current directory)",
    )

    parser.add_argument(
        "-c",
        "--config",
        type=Path,
        default=Path.cwd() / ".architecture-rules.yaml",
        help="Path to architecture rules config (default: .architecture-rules.yaml)",
    )

    parser.add_argument(
        "-v",
        "--verbose",
        action="store_true",
        help="Show detailed output including context",
    )

    parser.add_argument(
        "--errors-only", action="store_true", help="Only show errors, suppress warnings"
    )

    parser.add_argument(
        "--json",
        action="store_true",
        help="Output results as JSON (for programmatic use)",
    )

    args = parser.parse_args()

    # Create validator
    validator = ArchitectureValidator(args.config, verbose=args.verbose)

    # Run validation
    result = validator.validate_all(args.path)

    # Output results
    if args.json:
        exit_code = validator.print_json()
    else:
        exit_code = validator.print_report()

    sys.exit(exit_code)


if __name__ == "__main__":
    main()