#!/usr/bin/env python3
"""
MSVC (Microsoft Visual C++) compiler implementation.
Used for Windows native builds.
"""

from pathlib import Path
from typing import List, Optional
from .base import Compiler, CompileResult
from build_system.utils import run
import subprocess


class MSVCCompiler(Compiler):
    """Microsoft Visual C++ compiler implementation."""
    
    def __init__(self, executable: str = "cl"):
        """
        Initialize MSVC compiler.
        
        Args:
            executable: Compiler executable name ("cl")
        """
        super().__init__("MSVC", executable)
    
    def compile(self,
                source: Path,
                output: Path,
                flags: Optional[List[str]] = None,
                defines: Optional[List[str]] = None,
                include_dirs: Optional[List[Path]] = None,
                dependency_file: Optional[Path] = None) -> CompileResult:
        """
        Compile a source file using MSVC.
        
        Args:
            source: Source file path
            output: Output object file path
            flags: Additional compiler flags
            defines: Preprocessor defines
            include_dirs: Additional include directories
            dependency_file: Path for dependency file (not used by MSVC)
        
        Returns:
            CompileResult with object file path
        
        Raises:
            subprocess.CalledProcessError: If compilation fails
        """
        # Ensure output directory exists
        output.parent.mkdir(parents=True, exist_ok=True)
        
        # Build command
        cmd = [self.executable]
        
        # Add flags
        if flags:
            cmd.extend(flags)
        
        # Add compile-only flag
        cmd.append(self.get_compile_only_flag())
        
        # Add defines
        if defines:
            cmd.extend([self.get_define_flag(d) for d in defines])
        
        # Add include directories
        if include_dirs:
            cmd.extend([self.get_include_flag(d) for d in include_dirs])
        
        # Add output file (MSVC uses /Fo)
        cmd.extend(self.get_output_flag(output))
        
        # Add source file
        cmd.append(str(source))
        
        # Run compilation
        run(cmd) # type: ignore
        
        return CompileResult(
            object_file=output,
            dependency_file=None,  # MSVC doesn't generate .d files
            success=True
        )
    
    def link(self,
             objects: List[Path],
             output: Path,
             flags: Optional[List[str]] = None,
             libraries: Optional[List[str]] = None,
             library_dirs: Optional[List[Path]] = None) -> bool:
        """
        Link object files into an executable using MSVC.
        
        Args:
            objects: List of object file paths
            output: Output executable path
            flags: Additional linker flags
            libraries: Libraries to link against
            library_dirs: Additional library search directories
        
        Returns:
            True if linking succeeded
        
        Raises:
            subprocess.CalledProcessError: If linking fails
        """
        # Ensure output directory exists
        output.parent.mkdir(parents=True, exist_ok=True)
        
        # Build command
        cmd = [self.executable]
        
        # Add object files
        cmd.extend([str(obj) for obj in objects])
        
        # Add output file (MSVC uses /Fe)
        cmd.append(f"/Fe{output}")
        
        # Add linker flags
        if flags:
            cmd.extend(flags)
        
        # Add library directories
        if library_dirs:
            cmd.extend([f"/LIBPATH:{lib_dir}" for lib_dir in library_dirs])
        
        # Add libraries (MSVC uses .lib extension)
        if libraries:
            for lib in libraries:
                # Add .lib if not present
                lib_name = lib if lib.endswith('.lib') else f"{lib}.lib"
                cmd.append(lib_name)
        
        # Run linker
        run(cmd) # type: ignore
        
        return True
    
    def get_object_extension(self) -> str:
        """Get object file extension for MSVC."""
        return ".obj"
    
    def get_dependency_extension(self) -> str:
        """Get dependency file extension for MSVC."""
        return ".d"  # Not actually used by MSVC
    
    def supports_dependency_generation(self) -> bool:
        """MSVC does not support automatic dependency generation like GCC."""
        return False
    
    def get_define_flag(self, define: str) -> str:
        """Get the MSVC flag for a preprocessor define."""
        return f"/D{define}"
    
    def get_include_flag(self, include_dir: Path) -> str:
        """Get the MSVC flag for an include directory."""
        return f"/I{include_dir}"
    
    def get_output_flag(self, output: Path) -> List[str]:
        """Get the MSVC flag for specifying output file."""
        return [f"/Fo{output}"]
    
    def get_compile_only_flag(self) -> str:
        """Get the MSVC flag to compile without linking."""
        return "/c"
    
    def get_version(self) -> Optional[str]:
        """
        Get the MSVC version string.
        
        Returns:
            Version string if available, None otherwise
        """
        try:
            result = subprocess.run(
                [self.executable],
                capture_output=True,
                text=True,
                check=False
            )
            # MSVC prints version info to stderr when called with no args
            if result.stderr:
                lines = result.stderr.strip().split('\n')
                for line in lines:
                    if "Microsoft" in line or "Version" in line:
                        return line.strip()
        except Exception:
            pass
        
        return None


def detect_msvc_compiler() -> Optional[MSVCCompiler]:
    """
    Detect and return an available MSVC compiler.
    
    Returns:
        MSVCCompiler instance if found, None otherwise
    """
    from build_system.utils import which
    
    # Try to find MSVC
    if which("cl"):
        return MSVCCompiler()
    
    return None


def check_msvc_environment() -> bool:
    """
    Check if MSVC environment is properly set up.
    
    Returns:
        True if MSVC is available and environment is configured, False otherwise
    """
    from build_system.utils import check_tool
    
    if check_tool("cl"):
        return True
    else:
        print("Make sure to run from a Visual Studio Developer Command Prompt")
        print("or run vcvarsall.bat to set up the environment.")
        return False