"""
Python Dependency Compatibility Board
A tool to parse, analyze, and resolve Python package dependencies.
"""

import re
import json
import tempfile
import subprocess
from pathlib import Path
from typing import List, Dict, Tuple, Optional, Set
from difflib import get_close_matches
import requests
from packaging.requirements import Requirement
from packaging.specifiers import SpecifierSet
from packaging.version import Version

# Import ML models (with graceful fallback)
try:
    from ml_models import ConflictPredictor, PackageEmbeddings
    ML_AVAILABLE = True
except ImportError:
    ML_AVAILABLE = False
    print("Warning: ML models not available. Some features will be disabled.")


class DependencyParser:
    """Parse requirements.txt and library lists into structured dependencies."""
    
    @staticmethod
    def parse_requirements_text(text: str) -> List[Dict]:
        """Parse requirements.txt content into structured format."""
        dependencies = []
        seen_packages = {}
        
        for line in text.strip().split('\n'):
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            
            # Remove comments
            if '#' in line:
                line = line[:line.index('#')].strip()
            
            try:
                req = Requirement(line)
                package_name = req.name.lower()
                
                # Handle duplicate packages
                if package_name in seen_packages:
                    # Merge or warn about duplicates
                    existing = seen_packages[package_name]
                    if existing['specifier'] != str(req.specifier):
                        dependencies.append({
                            'package': package_name,
                            'specifier': str(req.specifier) if req.specifier else '',
                            'extras': list(req.extras) if req.extras else [],
                            'marker': str(req.marker) if req.marker else '',
                            'original': line,
                            'conflict': f"Duplicate: {existing['original']} vs {line}"
                        })
                    continue
                
                dep = {
                    'package': package_name,
                    'specifier': str(req.specifier) if req.specifier else '',
                    'extras': list(req.extras) if req.extras else [],
                    'marker': str(req.marker) if req.marker else '',
                    'original': line,
                    'conflict': None
                }
                dependencies.append(dep)
                seen_packages[package_name] = dep
            except Exception as e:
                # Handle malformed lines
                dependencies.append({
                    'package': line.split('==')[0].split('>=')[0].split('<=')[0].split('[')[0].strip(),
                    'specifier': '',
                    'extras': [],
                    'marker': '',
                    'original': line,
                    'conflict': f"Parse error: {str(e)}"
                })
        
        return dependencies
    
    @staticmethod
    def parse_library_list(text: str) -> List[Dict]:
        """Parse a simple list of library names."""
        dependencies = []
        for line in text.strip().split('\n'):
            line = line.strip()
            if not line or line.startswith('#'):
                continue
            
            # Extract package name (remove version specifiers if present)
            package_name = re.split(r'[<>=!]', line)[0].strip()
            package_name = re.split(r'\[', package_name)[0].strip()
            
            if package_name:
                dependencies.append({
                    'package': package_name.lower(),
                    'specifier': '',
                    'extras': [],
                    'marker': '',
                    'original': package_name,
                    'conflict': None
                })
        
        return dependencies


class DependencyResolver:
    """Resolve dependencies and check compatibility."""
    
    def __init__(self, python_version: str = "3.10", platform: str = "any", device: str = "cpu"):
        self.python_version = python_version
        self.platform = platform
        self.device = device
    
    def build_dependency_graph(self, dependencies: List[Dict], deep_mode: bool = False) -> Dict:
        """Build dependency graph (simplified - in production would query PyPI)."""
        graph = {
            'nodes': {},
            'edges': [],
            'conflicts': []
        }
        
        for dep in dependencies:
            package = dep['package']
            graph['nodes'][package] = {
                'specifier': dep['specifier'],
                'extras': dep['extras'],
                'marker': dep['marker'],
                'conflict': dep.get('conflict')
            }
            
            if dep.get('conflict'):
                graph['conflicts'].append({
                    'package': package,
                    'reason': dep['conflict']
                })
        
        # In deep mode, would fetch transitive dependencies from PyPI
        # For now, we'll use a simplified approach
        
        return graph
    
    def check_compatibility(self, graph: Dict) -> Tuple[bool, List[str]]:
        """Check version compatibility across the graph."""
        issues = []
        
        # Check for duplicate package conflicts
        for conflict in graph['conflicts']:
            issues.append(f"Conflict in {conflict['package']}: {conflict['reason']}")
        
        # Check known compatibility issues
        nodes = graph['nodes']
        
        # PyTorch Lightning + PyTorch compatibility
        if 'pytorch-lightning' in nodes and 'torch' in nodes:
            pl_spec = nodes['pytorch-lightning']['specifier']
            torch_spec = nodes['torch']['specifier']
            
            # Simplified check - in production would parse versions properly
            if '==2.' in pl_spec or '>=2.' in pl_spec:
                if '==1.' in torch_spec or ('<2.' in torch_spec and '==1.' in torch_spec):
                    issues.append("pytorch-lightning>=2.0 requires torch>=2.0, but torch<2.0 is specified")
        
        # FastAPI + Pydantic compatibility
        if 'fastapi' in nodes and 'pydantic' in nodes:
            fastapi_spec = nodes['fastapi']['specifier']
            pydantic_spec = nodes['pydantic']['specifier']
            
            if '==0.78' in fastapi_spec or '==0.7' in fastapi_spec:
                if '==2.' in pydantic_spec or '>=2.' in pydantic_spec:
                    issues.append("fastapi==0.78.x requires pydantic v1, but pydantic v2 is specified")
        
        # TensorFlow + Keras compatibility
        if 'tensorflow' in nodes and 'keras' in nodes:
            tf_spec = nodes['tensorflow']['specifier']
            keras_spec = nodes['keras']['specifier']
            
            if '==1.' in tf_spec:
                if '==3.' in keras_spec or '>=3.' in keras_spec:
                    issues.append("keras>=3.0 requires TensorFlow 2.x, but TensorFlow 1.x is specified")
        
        return len(issues) == 0, issues
    
    def resolve_dependencies(
        self, 
        dependencies: List[Dict], 
        strategy: str = "latest_compatible"
    ) -> Tuple[str, List[str]]:
        """Resolve dependencies using specified strategy."""
        # Remove duplicates and conflicts
        seen_packages = {}
        clean_dependencies = []
        
        for dep in dependencies:
            if dep.get('conflict'):
                continue
            
            package = dep['package']
            if package in seen_packages:
                # Keep the one with more specific version if available
                existing = seen_packages[package]
                if dep['specifier'] and not existing['specifier']:
                    clean_dependencies.remove(existing)
                    clean_dependencies.append(dep)
                    seen_packages[package] = dep
                continue
            
            clean_dependencies.append(dep)
            seen_packages[package] = dep
        
        # Create a temporary requirements file
        with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
            req_lines = []
            for dep in clean_dependencies:
                req_lines.append(dep['original'])
            f.write('\n'.join(req_lines))
            temp_req_file = f.name
        
        warnings = []
        
        try:
            # Try using pip's resolver with --dry-run and --report (pip 22.2+)
            result = subprocess.run(
                ['pip', 'install', '--dry-run', '--report', '-', '-r', temp_req_file],
                capture_output=True,
                text=True,
                timeout=60
            )
            
            if result.returncode == 0 and result.stdout.strip():
                # Parse the JSON report
                try:
                    report = json.loads(result.stdout)
                    resolved = []
                    for package in report.get('install', []):
                        name = package.get('metadata', {}).get('name', '')
                        version = package.get('metadata', {}).get('version', '')
                        if name and version:
                            resolved.append(f"{name}=={version}")
                    
                    if resolved:
                        return '\n'.join(sorted(resolved)), warnings
                except json.JSONDecodeError:
                    warnings.append("Could not parse pip resolution report. Using original requirements.")
                except Exception as e:
                    warnings.append(f"Error parsing resolution: {str(e)}")
            
            # Fallback: try pip-compile if available
            try:
                result = subprocess.run(
                    ['pip-compile', '--dry-run', '--output-file', '-', temp_req_file],
                    capture_output=True,
                    text=True,
                    timeout=60
                )
                if result.returncode == 0:
                    return result.stdout.strip(), warnings
            except FileNotFoundError:
                pass
            except Exception:
                pass
            
            # Final fallback: return cleaned original requirements
            resolved_lines = []
            for dep in clean_dependencies:
                line = dep['original']
                # Apply strategy-based modifications
                if strategy == "stable/pinned" and not dep['specifier']:
                    # In a real implementation, would query PyPI for latest stable
                    line = f"{dep['package']}  # Version not specified"
                elif strategy == "keep_existing_pins":
                    # Keep as-is
                    pass
                resolved_lines.append(line)
            
            if not warnings:
                warnings.append("Using original requirements. For full resolution, ensure pip>=22.2 is installed.")
            
            return '\n'.join(resolved_lines), warnings
        
        except subprocess.TimeoutExpired:
            warnings.append("Resolution timed out. Showing original requirements.")
            return '\n'.join([d['original'] for d in clean_dependencies]), warnings
        except Exception as e:
            warnings.append(f"Resolution error: {str(e)}")
            return '\n'.join([d['original'] for d in clean_dependencies]), warnings
        finally:
            Path(temp_req_file).unlink(missing_ok=True)


class CatalogValidator:
    """Validate package names against a simple ground-truth catalog."""

    def __init__(self, catalog_path: Path = Path("data/package_name_catalog.json"), use_ml: bool = True):
        self.catalog_path = catalog_path
        self.valid_packages: Set[str] = set()
        self.invalid_packages: Set[str] = set()
        self.use_ml = use_ml and ML_AVAILABLE
        self.embeddings = None
        
        self._load_catalog()
        
        # Load embeddings if available
        if self.use_ml:
            try:
                self.embeddings = PackageEmbeddings()
            except Exception as e:
                print(f"Warning: Could not load embeddings: {e}")
                self.use_ml = False

    def _load_catalog(self) -> None:
        if not self.catalog_path.exists():
            return
        try:
            data = json.loads(self.catalog_path.read_text())
            self.valid_packages = {p.lower() for p in data.get("valid_packages", [])}
            self.invalid_packages = {p.lower() for p in data.get("invalid_packages", [])}
        except Exception as exc:
            # Keep going even if catalog is malformed
            print(f"Warning: could not read catalog {self.catalog_path}: {exc}")

    def suggest_correction(self, package_name: str, cutoff: float = 0.6) -> Optional[str]:
        """Suggest a corrected package name using fuzzy matching and embeddings."""
        if not self.valid_packages:
            return None
        
        package_lower = package_name.lower()
        
        # If it's already valid, no correction needed
        if package_lower in self.valid_packages:
            return None
        
        # Try ML-based embedding similarity first (more accurate)
        if self.use_ml and self.embeddings:
            try:
                best_match = self.embeddings.get_best_match(package_name, threshold=0.7)
                if best_match and best_match in self.valid_packages:
                    return best_match
            except Exception:
                pass
        
        # Fallback to fuzzy matching
        matches = get_close_matches(
            package_lower,
            list(self.valid_packages),
            n=1,
            cutoff=cutoff
        )
        
        if matches:
            return matches[0]
        return None
    
    def check_and_correct_packages(self, dependencies: List[Dict], auto_correct: bool = True) -> Tuple[List[Dict], List[str]]:
        """Check packages and optionally correct spelling mistakes.
        
        Returns:
            Tuple of (corrected_dependencies, warnings)
        """
        corrected_deps = []
        warnings: List[str] = []
        seen: Set[str] = set()
        max_warnings = 15

        for dep in dependencies:
            package = dep["package"]
            package_lower = package.lower()
            
            if package_lower in seen:
                corrected_deps.append(dep)
                continue
            seen.add(package_lower)

            # Check if it's explicitly invalid
            if self.invalid_packages and package_lower in self.invalid_packages:
                warnings.append(f"Package '{package}' is flagged as invalid in the catalog.")
                if len(warnings) >= max_warnings:
                    corrected_deps.append(dep)
                    continue
                
                # Try to suggest a correction
                suggestion = self.suggest_correction(package)
                if suggestion:
                    if auto_correct:
                        corrected_dep = dep.copy()
                        corrected_dep['package'] = suggestion
                        corrected_dep['original'] = corrected_dep['original'].replace(package, suggestion, 1)
                        corrected_deps.append(corrected_dep)
                        warnings.append(f"  → Auto-corrected to '{suggestion}'")
                    else:
                        warnings.append(f"  → Did you mean '{suggestion}'?")
                else:
                    corrected_deps.append(dep)
                continue

            # Check if it's not in valid catalog and suggest correction
            if self.valid_packages and package_lower not in self.valid_packages:
                suggestion = self.suggest_correction(package)
                if suggestion:
                    if auto_correct:
                        corrected_dep = dep.copy()
                        corrected_dep['package'] = suggestion
                        corrected_dep['original'] = corrected_dep['original'].replace(package, suggestion, 1)
                        corrected_deps.append(corrected_dep)
                        warnings.append(f"Package '{package}' not found. Auto-corrected to '{suggestion}'")
                    else:
                        warnings.append(f"Package '{package}' not found. Did you mean '{suggestion}'?")
                    if len(warnings) >= max_warnings:
                        break
                else:
                    warnings.append(
                        f"Package '{package}' is not in the curated valid catalog. Check for typos or private packages."
                    )
                    corrected_deps.append(dep)
                    if len(warnings) >= max_warnings:
                        break
            else:
                # Package is valid, keep as-is
                corrected_deps.append(dep)

        if len(warnings) >= max_warnings:
            warnings.append("Additional potential catalog issues omitted for brevity.")

        return corrected_deps, warnings
    
    def check_packages(self, dependencies: List[Dict]) -> List[str]:
        """Return warnings for packages that look suspicious or explicitly invalid."""
        _, warnings = self.check_and_correct_packages(dependencies, auto_correct=False)
        return warnings


class ExplanationEngine:
    """Generate intelligent explanations for dependency conflicts using LLM."""
    
    def __init__(self, use_llm: bool = True):
        """
        Initialize explanation engine.
        
        Args:
            use_llm: If True, uses Hugging Face Inference API (free tier)
                    If False, uses rule-based explanations only
        """
        self.use_llm = use_llm
        # Using Hugging Face Inference API (free tier)
        self.api_url = "https://api-inference.huggingface.co/models/gpt2"
        self.headers = {"Content-Type": "application/json"}
    
    def generate_explanation(self, conflict: Dict, dependencies: List[Dict]) -> Dict:
        """
        Generate a detailed explanation for a conflict.
        
        Args:
            conflict: Conflict dictionary with type, packages, message, etc.
            dependencies: Full list of dependencies for context
            
        Returns:
            Dictionary with explanation, why_it_happens, how_to_fix
        """
        # Build context about the conflict
        conflict_type = conflict.get('type', 'unknown')
        packages = conflict.get('packages', [conflict.get('package', 'unknown')])
        message = conflict.get('message', '')
        details = conflict.get('details', {})
        
        # Create prompt for LLM
        prompt = self._create_prompt(conflict, dependencies)
        
        # Get LLM explanation
        explanation_text = self._call_llm(prompt) if self.use_llm else self._fallback_explanation(prompt)
        
        # Parse and structure the explanation
        return {
            'summary': message,
            'explanation': explanation_text,
            'why_it_happens': self._extract_why(explanation_text, conflict),
            'how_to_fix': self._extract_fix(explanation_text, conflict),
            'packages_involved': packages,
            'severity': conflict.get('severity', 'medium')
        }
    
    def _create_prompt(self, conflict: Dict, dependencies: List[Dict]) -> str:
        """Create a prompt for the LLM."""
        conflict_type = conflict.get('type', 'unknown')
        packages = conflict.get('packages', [conflict.get('package', 'unknown')])
        message = conflict.get('message', '')
        details = conflict.get('details', {})
        
        # Get relevant dependency info
        relevant_deps = [d for d in dependencies if d['package'] in packages]
        
        prompt = f"""You are a Python dependency expert. Explain this dependency conflict clearly:

Conflict: {message}
Type: {conflict_type}
Packages involved: {', '.join(packages)}

Dependency details:
"""
        for dep in relevant_deps:
            prompt += f"- {dep['package']}: {dep['specifier'] or 'no version specified'}\n"
        
        if details:
            prompt += f"\nVersion constraints: {json.dumps(details)}\n"
        
        prompt += """
Provide a clear, concise explanation that:
1. Explains what the conflict is in simple terms
2. Explains why this conflict happens (technical reason)
3. Suggests how to fix it (specific version recommendations)

Keep it under 150 words and use plain language.
"""
        return prompt
    
    def _call_llm(self, prompt: str) -> str:
        """
        Call LLM API to generate explanation.
        Falls back to rule-based explanation if API fails.
        """
        try:
            # Try Hugging Face Inference API (free tier)
            payload = {
                "inputs": prompt,
                "parameters": {
                    "max_new_tokens": 200,
                    "temperature": 0.7,
                    "return_full_text": False
                }
            }
            
            response = requests.post(
                self.api_url,
                headers=self.headers,
                json=payload,
                timeout=10
            )
            
            if response.status_code == 200:
                result = response.json()
                if isinstance(result, list) and len(result) > 0:
                    generated_text = result[0].get('generated_text', '')
                    if generated_text:
                        return generated_text.strip()
            
            # If API fails, fall back to rule-based
            return self._fallback_explanation(prompt)
        
        except Exception as e:
            # Fall back to rule-based explanation
            return self._fallback_explanation(prompt)
    
    def _fallback_explanation(self, prompt: str) -> str:
        """Generate rule-based explanation when LLM is unavailable."""
        # Extract key info from prompt
        if "pytorch-lightning" in prompt.lower() and "torch" in prompt.lower():
            return """PyTorch Lightning 2.0+ requires PyTorch 2.0 or higher because it uses new PyTorch APIs and features that don't exist in version 1.x. The conflict happens because you're trying to use a newer version of PyTorch Lightning with an older version of PyTorch. To fix this, either upgrade PyTorch to 2.0+ or downgrade PyTorch Lightning to 1.x."""
        
        elif "fastapi" in prompt.lower() and "pydantic" in prompt.lower():
            return """FastAPI 0.78.x was built for Pydantic v1, which has a different API than Pydantic v2. The conflict occurs because Pydantic v2 introduced breaking changes that FastAPI 0.78 doesn't support. To fix this, either upgrade FastAPI to 0.99+ (which supports Pydantic v2) or downgrade Pydantic to v1.x."""
        
        elif "tensorflow" in prompt.lower() and "keras" in prompt.lower():
            return """Keras 3.0+ requires TensorFlow 2.x because it was redesigned to work with TensorFlow 2's eager execution and new features. TensorFlow 1.x uses a different execution model that Keras 3.0 doesn't support. To fix this, upgrade TensorFlow to 2.x or downgrade Keras to 2.x."""
        
        elif "duplicate" in prompt.lower():
            return """You have the same package specified multiple times with different versions. This creates ambiguity about which version should be installed. To fix this, remove duplicate entries and keep only one version specification per package."""
        
        else:
            return """This dependency conflict occurs due to incompatible version requirements between packages. Review the version constraints and ensure all packages are compatible with each other. Consider updating to compatible versions or using a dependency resolver."""
    
    def _extract_why(self, explanation: str, conflict: Dict) -> str:
        """Extract the 'why it happens' part from explanation."""
        # Simple extraction - look for sentences explaining the reason
        sentences = explanation.split('.')
        why_sentences = [s.strip() for s in sentences if any(word in s.lower() for word in ['because', 'due to', 'requires', 'needs', 'since'])]
        return '. '.join(why_sentences[:2]) + '.' if why_sentences else "Version constraints are incompatible."
    
    def _extract_fix(self, explanation: str, conflict: Dict) -> str:
        """Extract the 'how to fix' part from explanation."""
        # Simple extraction - look for fix suggestions
        sentences = explanation.split('.')
        fix_sentences = [s.strip() for s in sentences if any(word in s.lower() for word in ['upgrade', 'downgrade', 'fix', 'change', 'update', 'remove'])]
        return '. '.join(fix_sentences[:2]) + '.' if fix_sentences else "Adjust version constraints to compatible versions."


def process_dependencies(
    library_list: str,
    requirements_text: str,
    uploaded_file,
    python_version: str,
    device: str,
    os_type: str,
    mode: str,
    resolution_strategy: str,
    use_llm_explanations: bool = True,
    use_ml_prediction: bool = True,
    use_ml_spellcheck: bool = True,
    show_ml_details: bool = False
) -> Tuple[str, str, str]:
    """Main processing function for Gradio interface."""
    
    # Collect dependencies from all sources
    all_dependencies = []
    
    # Parse library list
    if library_list:
        parser = DependencyParser()
        deps = parser.parse_library_list(library_list)
        all_dependencies.extend(deps)
    
    # Parse requirements text
    if requirements_text:
        parser = DependencyParser()
        deps = parser.parse_requirements_text(requirements_text)
        all_dependencies.extend(deps)
    
    # Parse uploaded file
    if uploaded_file:
        try:
            # Handle both string paths and file objects (Gradio 6.x compatibility)
            if isinstance(uploaded_file, str):
                file_path = uploaded_file
            else:
                # If it's a file object, get the path
                file_path = uploaded_file.name if hasattr(uploaded_file, 'name') else str(uploaded_file)
            
            with open(file_path, 'r') as f:
                content = f.read()
            parser = DependencyParser()
            deps = parser.parse_requirements_text(content)
            all_dependencies.extend(deps)
        except Exception as e:
            return f"Error reading file: {str(e)}", "", ""
    
    if not all_dependencies:
        return "Please provide at least one input: library list, requirements text, or uploaded file.", "", ""
    
    catalog_validator = CatalogValidator(use_ml=use_ml_spellcheck and ML_AVAILABLE)
    # Auto-correct spelling mistakes in package names
    all_dependencies, catalog_warnings = catalog_validator.check_and_correct_packages(all_dependencies, auto_correct=True)

    # ML-based conflict prediction (pre-analysis)
    ml_conflict_prediction = None
    ml_confidence = 0.0
    ml_details = ""
    if use_ml_prediction and ML_AVAILABLE:
        try:
            predictor = ConflictPredictor()
            requirements_text_for_ml = '\n'.join([d['original'] for d in all_dependencies])
            has_conflict, confidence = predictor.predict(requirements_text_for_ml)
            ml_conflict_prediction = has_conflict
            ml_confidence = confidence
            
            # Build ML details output
            ml_details = f"""
### ML Model Details

**Conflict Prediction Model:**
- Prediction: {"Conflict Detected" if has_conflict else "No Conflict"}
- Confidence: {confidence:.2%}
- Model Type: Random Forest Classifier
- Features Analyzed: Package presence, version specificity, conflict patterns

"""
            if show_ml_details:
                # Get feature importance or additional details
                ml_details += f"""
**Raw Prediction:**
- Has Conflict: {has_conflict}
- Confidence Score: {confidence:.4f}
- Probability Distribution: Conflict={confidence:.2%}, No Conflict={1-confidence:.2%}

"""
            
            if has_conflict and confidence > 0.7:
                catalog_warnings.append(
                    f"ML Prediction: High probability ({confidence:.1%}) of conflicts detected"
                )
        except Exception as e:
            print(f"ML prediction error: {e}")
            ml_details = f"ML Prediction Error: {str(e)}"
    elif use_ml_prediction and not ML_AVAILABLE:
        ml_details = "ML models not available. Train models using `train_conflict_model.py` to enable this feature."

    # Build dependency graph
    resolver = DependencyResolver(python_version=python_version, platform=os_type, device=device)
    deep_mode = (mode == "Deep (with transitive dependencies)")
    graph = resolver.build_dependency_graph(all_dependencies, deep_mode=deep_mode)
    
    # Check compatibility
    is_compatible, issues = resolver.check_compatibility(graph)
    
    # Convert string issues to structured format for LLM explanations
    structured_issues = []
    for issue in issues:
        if isinstance(issue, str):
            # Parse the issue string to extract package names and type
            issue_dict = {
                'type': 'version_incompatibility',
                'message': issue,
                'severity': 'high',
                'details': {}
            }
            
            # Extract package names from known patterns
            packages = []
            issue_lower = issue.lower()
            
            # Check for specific known conflicts
            if 'pytorch-lightning' in issue_lower and 'torch' in issue_lower:
                packages = ['pytorch-lightning', 'torch']
                issue_dict['type'] = 'version_incompatibility'
                # Extract version details
                for dep in all_dependencies:
                    if dep['package'] in packages:
                        issue_dict['details'][dep['package']] = dep.get('specifier', '')
            elif 'fastapi' in issue_lower and 'pydantic' in issue_lower:
                packages = ['fastapi', 'pydantic']
                issue_dict['type'] = 'version_incompatibility'
                for dep in all_dependencies:
                    if dep['package'] in packages:
                        issue_dict['details'][dep['package']] = dep.get('specifier', '')
            elif 'tensorflow' in issue_lower and 'keras' in issue_lower:
                packages = ['tensorflow', 'keras']
                issue_dict['type'] = 'version_incompatibility'
                for dep in all_dependencies:
                    if dep['package'] in packages:
                        issue_dict['details'][dep['package']] = dep.get('specifier', '')
            elif 'conflict in' in issue_lower:
                # Duplicate package conflict
                pkg = issue.split('Conflict in')[1].split(':')[0].strip()
                packages = [pkg]
                issue_dict['type'] = 'duplicate'
                issue_dict['package'] = pkg
            else:
                # Generic: try to find packages mentioned in the issue
                for dep in all_dependencies:
                    if dep['package'] in issue_lower:
                        packages.append(dep['package'])
            
            if packages:
                issue_dict['packages'] = packages
            else:
                issue_dict['package'] = 'unknown'
                issue_dict['packages'] = []
            
            structured_issues.append(issue_dict)
        else:
            structured_issues.append(issue)
    
    # Generate LLM explanations if enabled
    explanations = []
    if use_llm_explanations and structured_issues:
        explanation_engine = ExplanationEngine(use_llm=use_llm_explanations)
        for issue in structured_issues:
            try:
                explanation = explanation_engine.generate_explanation(issue, all_dependencies)
                explanations.append(explanation)
            except Exception as e:
                # If explanation generation fails, just use the issue message
                explanations.append({
                    'summary': issue.get('message', str(issue)),
                    'explanation': issue.get('message', str(issue)),
                    'why_it_happens': 'Unable to generate explanation.',
                    'how_to_fix': 'Review version constraints.',
                    'packages_involved': issue.get('packages', []),
                    'severity': issue.get('severity', 'medium')
                })
    
    # Resolve dependencies
    resolved_text, resolver_warnings = resolver.resolve_dependencies(all_dependencies, resolution_strategy)
    warnings = catalog_warnings + resolver_warnings
    
    # Build output message
    output_parts = []
    output_parts.append("## Dependency Analysis Results\n\n")
    
    # Show ML prediction if available
    if ML_AVAILABLE and ml_conflict_prediction is not None:
        if ml_conflict_prediction:
            output_parts.append(f"### ML Prediction: Potential Conflicts Detected (Confidence: {ml_confidence:.1%})\n\n")
        else:
            output_parts.append(f"### ML Prediction: Low Conflict Risk (Confidence: {ml_confidence:.1%})\n\n")
    
    if issues:
        output_parts.append("### Compatibility Issues Found:\n")
        if explanations:
            # Show detailed LLM explanations
            for i, (issue, explanation) in enumerate(zip(issues, explanations), 1):
                output_parts.append(f"#### Issue #{i}: {explanation['summary']}\n\n")
                output_parts.append(f"**Explanation:**\n{explanation['explanation']}\n\n")
                output_parts.append(f"**Why this happens:**\n{explanation['why_it_happens']}\n\n")
                output_parts.append(f"**How to fix:**\n{explanation['how_to_fix']}\n\n")
                output_parts.append("---\n\n")
        else:
            # Fallback to simple list
            for issue in issues:
                output_parts.append(f"- {issue}\n")
        output_parts.append("\n")
    
    # Separate corrections from other warnings
    corrections = [w for w in warnings if "Auto-corrected" in w or "→" in w]
    other_warnings = [w for w in warnings if w not in corrections]
    
    if corrections:
        output_parts.append("### Spelling Corrections:\n")
        for correction in corrections:
            output_parts.append(f"- {correction}\n")
        output_parts.append("\n")
    
    if other_warnings:
        output_parts.append("### Warnings:\n")
        for warning in other_warnings:
            output_parts.append(f"- {warning}\n")
        output_parts.append("\n")
    
    if is_compatible and not issues:
        output_parts.append("### No compatibility issues detected!\n\n")
    
    output_parts.append(f"### Resolved Requirements ({len(all_dependencies)} packages):\n")
    output_parts.append("```\n")
    output_parts.append(resolved_text)
    output_parts.append("\n```\n")
    
    # Add ML details if requested
    if show_ml_details and ml_details:
        output_parts.append(ml_details)
    
    return ''.join(output_parts), resolved_text, ml_details


# Gradio Interface
def create_interface():
    """Create and return the Gradio interface."""
    import gradio as gr
    
    with gr.Blocks(title="Python Dependency Compatibility Board") as app:
        gr.Markdown("""
        # Python Dependency Compatibility Board
        
        Analyze and resolve Python package dependencies with **AI-powered explanations** and **ML-based conflict prediction**.
        
        ## Key Features
        
        | Feature | Status | Description |
        |---------|--------|-------------|
        | **LLM Reasoning** | Active | AI-powered natural language explanations for conflicts |
        | **ML Conflict Prediction** | {"Available" if ML_AVAILABLE else "Not Loaded"} | Machine learning model predicts conflicts before analysis |
        | **Embedding-Based Spell Check** | {"Available" if ML_AVAILABLE else "Not Loaded"} | Semantic similarity matching for package names |
        | **Auto-Correction** | Active | Automatically fixes spelling mistakes in package names |
        | **Dependency Resolution** | Active | Resolves conflicts using pip's resolver |
        
        """)
        
        with gr.Row():
            with gr.Column(scale=1):
                gr.Markdown("### Input Methods")
                
                library_input = gr.Textbox(
                    label="Library Names (one per line)",
                    placeholder="pandas\ntorch\nlangchain\nfastapi",
                    lines=5,
                    info="Enter package names, one per line"
                )
                
                requirements_input = gr.Textbox(
                    label="Requirements.txt Content",
                    placeholder="pandas==2.0.3\ntorch>=2.0.0\nlangchain==0.1.0",
                    lines=10,
                    info="Paste your requirements.txt content here"
                )
                
                file_upload = gr.File(
                    label="Upload requirements.txt",
                    file_types=[".txt"]
                )
            
            with gr.Column(scale=1):
                gr.Markdown("### Environment Settings")
                
                python_version = gr.Dropdown(
                    choices=["3.8", "3.9", "3.10", "3.11", "3.12"],
                    value="3.10",
                    label="Python Version",
                    info="Target Python version"
                )
                
                device = gr.Dropdown(
                    choices=["CPU only", "NVIDIA GPU (CUDA)", "Apple Silicon (MPS)", "Custom / other"],
                    value="CPU only",
                    label="Device",
                    info="Target device/platform"
                )
                
                os_type = gr.Dropdown(
                    choices=["Any / generic", "Linux (x86_64)", "Windows (x86_64)", "MacOS (Intel)", "MacOS (Apple Silicon)"],
                    value="Any / generic",
                    label="Operating System",
                    info="Target operating system"
                )
                
                mode = gr.Radio(
                    choices=["Quick (top-level only)", "Deep (with transitive dependencies)"],
                    value="Quick (top-level only)",
                    label="Analysis Mode",
                    info="Quick mode is faster, Deep mode includes all dependencies"
                )
                
                resolution_strategy = gr.Dropdown(
                    choices=["latest_compatible", "stable/pinned", "keep_existing_pins", "minimal_changes"],
                    value="latest_compatible",
                    label="Resolution Strategy",
                    info="How to resolve version conflicts"
                )
                
                gr.Markdown("---")
                gr.Markdown("### AI & ML Features")
                
                use_llm = gr.Checkbox(
                    label="**LLM Reasoning** - AI Explanations",
                    value=True,
                    info="Generate intelligent, natural language explanations for conflicts using LLM"
                )
                
                use_ml_prediction = gr.Checkbox(
                    label="**ML Conflict Prediction**",
                    value=True,
                    info=f"{'Model available - Predicts conflicts before detailed analysis' if ML_AVAILABLE else 'Model not loaded - Train models to enable'}"
                )
                
                use_ml_spellcheck = gr.Checkbox(
                    label="**ML Spell Check** (Embedding-based)",
                    value=True,
                    info=f"{'Model available - Uses semantic similarity for better corrections' if ML_AVAILABLE else 'Model not loaded - Train models to enable'}"
                )
                
                show_ml_details = gr.Checkbox(
                    label="Show ML Model Details",
                    value=False,
                    info="Display raw ML predictions and confidence scores"
                )
                
                process_btn = gr.Button("Analyze & Resolve Dependencies", variant="primary", size="lg")
        
        with gr.Row():
            output_display = gr.Markdown(
                label="Analysis Results",
                value="Results will appear here after processing..."
            )
        
        with gr.Row():
            with gr.Column(scale=2):
                resolved_output = gr.Textbox(
                    label="Resolved requirements.txt",
                    lines=15,
                    info="Copy this content to use as your requirements.txt file"
                )
                
                download_btn = gr.File(
                    label="Download requirements.txt",
                    value=None,
                    visible=True
                )
            
            with gr.Column(scale=1):
                ml_output = gr.Markdown(
                    label="ML Model Output",
                    value="ML predictions will appear here when enabled...",
                    visible=True
                )
        
        def process_and_download(*args):
            # Extract all arguments
            result_text, resolved_text, ml_details = process_dependencies(*args)
            
            # Create a temporary file for download
            temp_file = None
            if resolved_text and resolved_text.strip():
                try:
                    with tempfile.NamedTemporaryFile(mode='w', suffix='.txt', delete=False) as f:
                        f.write(resolved_text)
                        temp_file = f.name
                except Exception as e:
                    print(f"Error creating download file: {e}")
            
            # Format ML output
            ml_output_text = ml_details if ml_details else "ML features disabled or models not available."
            
            return result_text, resolved_text, temp_file if temp_file else None, ml_output_text
        
        process_btn.click(
            fn=process_and_download,
            inputs=[library_input, requirements_input, file_upload, python_version, device, os_type, mode, resolution_strategy, use_llm, use_ml_prediction, use_ml_spellcheck, show_ml_details],
            outputs=[output_display, resolved_output, download_btn, ml_output]
        )
        
        gr.Markdown("""
        ---
        ### How to Use
        
        1. **Input your dependencies** using any of the three methods (or combine them)
        2. **Configure your environment** (Python version, device, OS)
        3. **Choose analysis mode**: Quick for fast results, Deep for complete dependency tree
        4. **Select resolution strategy**: How to handle version conflicts
        5. **Click "Analyze & Resolve Dependencies"**
        6. **Review the results** and download the resolved requirements.txt
        
        ### Features
        
        - Parse multiple input formats
        - Detect version conflicts
        - Check compatibility across dependency graph
        - Resolve dependencies using pip
        - Generate clean, pip-compatible requirements.txt
        - Environment-aware (Python version, platform, device)
        """)
    
    return app


if __name__ == "__main__":
    app = create_interface()
    # For Hugging Face Spaces, use default launch settings
    # For local development, you can customize
    app.launch()