Exception Handling

class PipenvException(Exception):
    """
    Base exception class for all pipenv-specific errors.
    
    All pipenv exceptions inherit from this class, allowing for
    broad exception catching when needed.
    """

from pipenv.exceptions import PipenvException

try:
    # Some pipenv operation
    pass
except PipenvException as e:
    print(f"Pipenv error occurred: {e}")
except Exception as e:
    print(f"Unexpected error: {e}")

class PipenvCmdError(PipenvException):
    """
    Command execution errors.
    
    Raised when external commands (pip, python, etc.) fail
    or return non-zero exit codes.
    """

class PipenvUsageError(PipenvException):
    """
    Usage and argument errors.
    
    Raised when commands are called with invalid arguments
    or in inappropriate contexts.
    """

from pipenv.exceptions import PipenvCmdError, PipenvUsageError
import subprocess

def run_pip_command(args):
    try:
        result = subprocess.run(["pip"] + args, check=True, capture_output=True, text=True)
        return result.stdout
    except subprocess.CalledProcessError as e:
        raise PipenvCmdError(f"Pip command failed: {e}")

def validate_python_version(version):
    if not version or not version.replace(".", "").isdigit():
        raise PipenvUsageError(f"Invalid Python version specification: {version}")

# Usage
try:
    run_pip_command(["install", "nonexistent-package"])
except PipenvCmdError as e:
    print(f"Command error: {e}")

try:
    validate_python_version("invalid.version")
except PipenvUsageError as e:
    print(f"Usage error: {e}")

class PipenvFileError(PipenvException):
    """
    File operation errors.
    
    Raised when file read/write operations fail or
    when required files are corrupted or inaccessible.
    """

class PipfileNotFound(PipenvException):
    """
    Pipfile not found error.
    
    Raised when operations require a Pipfile but none
    can be found in the current directory or parents.
    """

class LockfileNotFound(PipenvException):
    """
    Lockfile not found error.
    
    Raised when operations require a Pipfile.lock but
    none exists or is inaccessible.
    """

from pipenv.exceptions import PipenvFileError, PipfileNotFound, LockfileNotFound
import json
from pathlib import Path

def load_pipfile(path="Pipfile"):
    pipfile_path = Path(path)
    if not pipfile_path.exists():
        raise PipfileNotFound(f"Pipfile not found at {pipfile_path}")
    
    try:
        with open(pipfile_path, 'r') as f:
            return f.read()
    except (IOError, OSError) as e:
        raise PipenvFileError(f"Cannot read Pipfile: {e}")

def load_lockfile(path="Pipfile.lock"):
    lockfile_path = Path(path)
    if not lockfile_path.exists():
        raise LockfileNotFound(f"Pipfile.lock not found at {lockfile_path}")
    
    try:
        with open(lockfile_path, 'r') as f:
            return json.load(f)
    except (IOError, OSError, json.JSONDecodeError) as e:
        raise PipenvFileError(f"Cannot read or parse Pipfile.lock: {e}")

# Usage
try:
    pipfile_content = load_pipfile()
    lockfile_data = load_lockfile()
except PipfileNotFound as e:
    print(f"Pipfile missing: {e}")
except LockfileNotFound as e:
    print(f"Lockfile missing: {e}")
except PipenvFileError as e:
    print(f"File error: {e}")

class VirtualenvCreationException(PipenvException):
    """
    Virtual environment creation errors.
    
    Raised when virtual environment creation fails due to
    permissions, disk space, or other system issues.
    """

from pipenv.exceptions import VirtualenvCreationException
import subprocess
import os

def create_virtualenv(path, python_version=None):
    """Create virtual environment with error handling."""
    cmd = ["python", "-m", "venv", path]
    if python_version:
        cmd[0] = f"python{python_version}"
    
    try:
        result = subprocess.run(cmd, check=True, capture_output=True, text=True)
        return path
    except subprocess.CalledProcessError as e:
        raise VirtualenvCreationException(
            f"Failed to create virtual environment at {path}: {e.stderr}"
        )
    except FileNotFoundError:
        python_exe = cmd[0]
        raise VirtualenvCreationException(
            f"Python executable not found: {python_exe}"
        )

# Usage
try:
    venv_path = create_virtualenv("/tmp/test_venv", "3.9")
    print(f"Virtual environment created at: {venv_path}")
except VirtualenvCreationException as e:
    print(f"Virtualenv creation failed: {e}")

class InstallError(PipenvException):
    """
    Package installation errors.
    
    Raised when package installation fails due to dependency
    conflicts, network issues, or other installation problems.
    """

class UninstallError(PipenvException):
    """
    Package uninstall errors.
    
    Raised when package removal fails due to dependencies
    or system restrictions.
    """

from pipenv.exceptions import InstallError, UninstallError
import subprocess

def install_package(package_name, environment_path=None):
    """Install package with error handling."""
    cmd = ["pip", "install", package_name]
    env = os.environ.copy()
    
    if environment_path:
        env["VIRTUAL_ENV"] = environment_path
        cmd = [f"{environment_path}/bin/pip", "install", package_name]
    
    try:
        result = subprocess.run(cmd, check=True, capture_output=True, text=True, env=env)
        return result.stdout
    except subprocess.CalledProcessError as e:
        raise InstallError(f"Failed to install {package_name}: {e.stderr}")

def uninstall_package(package_name, environment_path=None):
    """Uninstall package with error handling."""
    cmd = ["pip", "uninstall", "-y", package_name]
    env = os.environ.copy()
    
    if environment_path:
        env["VIRTUAL_ENV"] = environment_path
        cmd = [f"{environment_path}/bin/pip", "uninstall", "-y", package_name]
    
    try:
        result = subprocess.run(cmd, check=True, capture_output=True, text=True, env=env)
        return result.stdout
    except subprocess.CalledProcessError as e:
        raise UninstallError(f"Failed to uninstall {package_name}: {e.stderr}")

# Usage
try:
    install_package("requests")
    print("Package installed successfully")
except InstallError as e:
    print(f"Installation failed: {e}")

try:
    uninstall_package("requests")
    print("Package uninstalled successfully")
except UninstallError as e:
    print(f"Uninstall failed: {e}")

class ResolutionFailure(PipenvException):
    """
    Dependency resolution errors.
    
    Raised when pip resolver cannot find a compatible
    set of package versions that satisfy all requirements.
    """

class DependencyConflict(PipenvException):
    """
    Dependency conflict errors.
    
    Raised when package dependencies have incompatible
    version requirements that cannot be resolved.
    """

class RequirementError(PipenvException):
    """
    Requirement specification errors.
    
    Raised when package requirement specifications are
    invalid or cannot be parsed.
    """

class JSONParseError(PipenvException):
    """
    JSON parsing errors.
    
    Raised when JSON files (lockfiles, etc.) cannot be
    parsed due to syntax errors or corruption.
    """

class DeployException(PipenvException):
    """
    Deployment errors.
    
    Raised when deployment operations fail due to
    missing requirements or environment issues.
    """

class PipenvOptionsError(PipenvException):
    """
    Options validation errors.
    
    Raised when command-line options or configuration
    values are invalid or conflicting.
    """

class SystemUsageError(PipenvException):
    """
    System usage errors.
    
    Raised when pipenv is used inappropriately on the
    system or in unsupported configurations.
    """

class SetupException(PipenvException):
    """
    Setup and initialization errors.
    
    Raised when project setup or initialization
    operations fail.
    """

class VirtualenvException(PipenvException):
    """
    Virtual environment errors.
    
    Raised when virtual environment operations fail
    beyond creation (activation, deactivation, etc.).
    """

class VirtualenvActivationException(VirtualenvException):
    """
    Virtual environment activation errors.
    
    Raised specifically when virtual environment
    activation fails or is not supported.
    """

from pipenv.exceptions import ResolutionFailure

def resolve_dependencies(requirements):
    """Resolve package dependencies with error handling."""
    # Simulate dependency resolution
    conflicts = []
    
    # Check for version conflicts
    for req1 in requirements:
        for req2 in requirements:
            if req1 != req2 and req1.name == req2.name:
                if req1.version != req2.version:
                    conflicts.append((req1, req2))
    
    if conflicts:
        conflict_msg = ", ".join([
            f"{req1.name} {req1.version} vs {req2.version}"
            for req1, req2 in conflicts
        ])
        raise ResolutionFailure(f"Version conflicts detected: {conflict_msg}")
    
    return requirements

# Example requirement class
class Requirement:
    def __init__(self, name, version):
        self.name = name
        self.version = version

# Usage
try:
    requirements = [
        Requirement("requests", "2.25.0"),
        Requirement("requests", "2.24.0"),  # Conflict!
    ]
    resolved = resolve_dependencies(requirements)
except ResolutionFailure as e:
    print(f"Resolution failed: {e}")

from pipenv.exceptions import (
    PipenvException, PipenvCmdError, PipenvFileError,
    PipfileNotFound, LockfileNotFound, VirtualenvCreationException,
    InstallError, UninstallError, ResolutionFailure
)

def robust_pipenv_operation():
    """Example of comprehensive error handling."""
    try:
        # Attempt pipenv operations
        load_pipfile()
        create_virtualenv("/tmp/venv")
        install_package("requests")
        
    except PipfileNotFound as e:
        print(f"Setup required: {e}")
        # Could create new Pipfile here
        
    except LockfileNotFound as e:
        print(f"Lock file missing: {e}")
        # Could generate lock file here
        
    except VirtualenvCreationException as e:
        print(f"Environment setup failed: {e}")
        # Could try alternative environment creation
        
    except (InstallError, UninstallError) as e:
        print(f"Package operation failed: {e}")
        # Could retry with different options
        
    except ResolutionFailure as e:
        print(f"Dependency conflict: {e}")
        # Could suggest resolution strategies
        
    except PipenvCmdError as e:
        print(f"Command failed: {e}")
        # Could provide command-specific help
        
    except PipenvFileError as e:
        print(f"File operation failed: {e}")
        # Could check permissions or disk space
        
    except PipenvException as e:
        print(f"General pipenv error: {e}")
        # Catch-all for other pipenv errors
        
    except Exception as e:
        print(f"Unexpected error: {e}")
        # Handle non-pipenv errors

import time
from pipenv.exceptions import InstallError, PipenvCmdError

def install_with_retry(package_name, max_retries=3):
    """Install package with retry logic."""
    for attempt in range(max_retries):
        try:
            return install_package(package_name)
        except (InstallError, PipenvCmdError) as e:
            if attempt == max_retries - 1:
                raise e
            print(f"Install attempt {attempt + 1} failed: {e}")
            print(f"Retrying in {2 ** attempt} seconds...")
            time.sleep(2 ** attempt)
    
    raise InstallError(f"Failed to install {package_name} after {max_retries} attempts")

from pipenv.exceptions import PipenvException
import logging

class PipenvErrorHandler:
    """Context-aware error handler for pipenv operations."""
    
    def __init__(self, context=""):
        self.context = context
        self.logger = logging.getLogger(__name__)
    
    def handle_error(self, error, operation=""):
        """Handle pipenv errors with context."""
        full_context = f"{self.context} - {operation}" if operation else self.context
        
        if isinstance(error, PipfileNotFound):
            self.logger.error(f"{full_context}: Pipfile not found. Run 'pipenv install' to initialize.")
        elif isinstance(error, VirtualenvCreationException):
            self.logger.error(f"{full_context}: Virtual environment creation failed. Check Python installation.")
        elif isinstance(error, ResolutionFailure):
            self.logger.error(f"{full_context}: Dependency resolution failed. Check version requirements.")
        elif isinstance(error, PipenvException):
            self.logger.error(f"{full_context}: Pipenv error - {error}")
        else:
            self.logger.error(f"{full_context}: Unexpected error - {error}")

# Usage
handler = PipenvErrorHandler("Project Setup")

try:
    # Pipenv operations
    pass
except Exception as e:
    handler.handle_error(e, "Installing dependencies")

from pipenv.exceptions import PipenvException, InstallError

class ProjectSetupError(PipenvException):
    """Custom exception for project setup failures."""
    pass

class DependencyConflictError(ResolutionFailure):
    """Enhanced dependency conflict error with resolution suggestions."""
    
    def __init__(self, message, conflicts=None, suggestions=None):
        super().__init__(message)
        self.conflicts = conflicts or []
        self.suggestions = suggestions or []
    
    def get_resolution_help(self):
        """Get suggested resolutions for conflicts."""
        if not self.suggestions:
            return "No automatic resolution suggestions available."
        
        help_text = "Suggested resolutions:\n"
        for i, suggestion in enumerate(self.suggestions, 1):
            help_text += f"{i}. {suggestion}\n"
        return help_text

# Usage
try:
    # Some operation that might conflict
    pass
except ResolutionFailure as e:
    # Convert to enhanced exception
    enhanced_error = DependencyConflictError(
        str(e),
        conflicts=["requests 2.25.0 vs 2.24.0"],
        suggestions=["Update all packages to compatible versions", "Use dependency_links for specific versions"]
    )
    print(enhanced_error.get_resolution_help())