"""
MSVC (Microsoft Visual C++) compiler implementation.

This module implements the Compiler interface for Microsoft's MSVC compiler,
which has a completely different command-line syntax from GCC/Clang.
"""

from pathlib import Path
from typing import List, Optional
import subprocess

from .base import Compiler


class MSVCCompiler(Compiler):
    """
    Microsoft Visual C++ compiler implementation.
    
    MSVC uses different command-line syntax and conventions:
    - Flags start with / instead of -
    - Different flag names (/Fo vs -o, /Fe vs -o for linking)
    - .obj instead of .o for object files
    - .exe extension for executables
    """
    
    def __init__(self, executable: str = "cl"):
        """
        Initialize MSVC compiler.
        
        Args:
            executable: MSVC compiler executable (default: "cl")
        """
        super().__init__(executable)
    
    def compile(
        self,
        source: Path,
        output: Path,
        *,
        includes: Optional[List[Path]] = None,
        defines: Optional[dict] = None,
        flags: Optional[List[str]] = None,
        generate_deps: bool = True,
        is_test: bool = False
    ) -> Path:
        """
        Compile a source file using MSVC.
        
        Args:
            source: Path to source file
            output: Path to output object file
            includes: Include directories
            defines: Preprocessor defines
            flags: Additional compiler flags
            generate_deps: Generate dependency file (not used by MSVC)
            is_test: Test build (disables optimization)
        
        Returns:
            Path to compiled object file
        """
        cmd = [self.executable]
        
        # Add user flags first
        if flags:
            cmd.extend(flags)
        
        # Standard flags
        cmd.extend([
            "/std:c11",     # C11 standard (closest to c99)
            "/W4",          # Warning level 4 (similar to -Wall -Wextra)
            "/WX",          # Treat warnings as errors (like -Werror)
            "/Zi",          # Generate debug info (like -g)
        ])
        
        # Test builds: disable optimization
        if is_test:
            cmd.append("/Od")  # Disable optimization
        
        # Include directories
        if includes:
            for inc in includes:
                cmd.append(f"/I{inc}")
        
        # Defines
        if defines:
            for name, value in defines.items():
                if value is None:
                    cmd.append(f"/D{name}")
                else:
                    # MSVC handles string escaping differently
                    if isinstance(value, str):
                        # Use backslash to escape quotes in MSVC
                        escaped = value.replace('"', '\\"')
                        cmd.append(f"/D{name}=\"{escaped}\"")
                    else:
                        cmd.append(f"/D{name}={value}")
        
        # Compile only (don't link)
        cmd.append("/c")
        
        # Output file (note: /Fo with no space)
        cmd.append(f"/Fo{output}")
        
        # Source file
        cmd.append(str(source))
        
        # Ensure output directory exists
        output.parent.mkdir(parents=True, exist_ok=True)
        
        # Run compilation
        self._run(cmd)
        
        return output
    
    def link(
        self,
        objects: List[Path],
        output: Path,
        *,
        libraries: Optional[List[str]] = None,
        library_paths: Optional[List[Path]] = None,
        flags: Optional[List[str]] = None
    ) -> Path:
        """
        Link object files into an executable using MSVC.
        
        Args:
            objects: Object files to link
            output: Output executable path
            libraries: Libraries to link (e.g., ['kernel32', 'user32'])
            library_paths: Library search paths
            flags: Additional linker flags
        
        Returns:
            Path to linked executable
        """
        cmd = [self.executable]
        
        # Add user flags first
        if flags:
            cmd.extend(flags)
        
        # Object files
        cmd.extend(str(obj) for obj in objects)
        
        # Library paths
        if library_paths:
            for path in library_paths:
                cmd.append(f"/LIBPATH:{path}")
        
        # Libraries (MSVC uses .lib extension)
        if libraries:
            for lib in libraries:
                # Add .lib if not present
                if not lib.endswith('.lib'):
                    lib = f"{lib}.lib"
                cmd.append(lib)
        
        # Output file (note: /Fe with no space)
        cmd.append(f"/Fe{output}")
        
        # Link flag
        cmd.append("/link")
        
        # Ensure output directory exists
        output.parent.mkdir(parents=True, exist_ok=True)
        
        # Run linker
        self._run(cmd)
        
        return output
    
    def get_object_extension(self) -> str:
        """Get object file extension for MSVC."""
        return ".obj"
    
    def get_executable_extension(self) -> str:
        """Get executable extension for Windows."""
        return ".exe"
    
    def _run(self, cmd: List[str]):
        """
        Execute a command and handle errors.
        
        Args:
            cmd: Command to execute
        
        Raises:
            subprocess.CalledProcessError: If compilation/linking fails
        """
        print(">>", " ".join(str(c) for c in cmd))
        subprocess.check_call(cmd)