from pathlib import Path
from typing import List, Optional, Dict, Any
import datetime
from dataclasses import dataclass
import pathspec
from rich.tree import Tree
from rich.console import Console
from rich.panel import Panel
from rich.markdown import Markdown
from langchain_core.tools import tool
import fnmatch

console = Console()

@dataclass
class DirScanConfig:
    """Configuration for directory scanning"""
    max_depth: int
    follow_links: bool
    show_size: bool
    show_modified: bool
    exclude_patterns: List[str]

def format_size(size_bytes: int) -> str:
    """Format file size in human readable format"""
    for unit in ['B', 'KB', 'MB', 'GB']:
        if size_bytes < 1024:
            return f"{size_bytes:.1f}{unit}"
        size_bytes /= 1024
    return f"{size_bytes:.1f}TB"

def format_time(timestamp: float) -> str:
    """Format timestamp as readable date"""
    dt = datetime.datetime.fromtimestamp(timestamp)
    return dt.strftime("%Y-%m-%d %H:%M")

# Default patterns to exclude
DEFAULT_EXCLUDE_PATTERNS = [
    ".*",  # Hidden files
    "__pycache__",  # Python cache
    "*.pyc",  # Python bytecode
    "node_modules",  # Node.js modules
    "*.swp",  # Vim swap files
    "*.swo",  # Vim swap files
    "*.swn",  # Vim swap files
    "*.class",  # Java bytecode
    "*.o",  # Object files
    "*.so",  # Shared libraries
    "*.dll",  # Dynamic libraries
    "*.exe",  # Executables
    "*.log",  # Log files
    "*.bak",  # Backup files
    "*.tmp",  # Temporary files
    "*.cache",  # Cache files
]

def load_gitignore_patterns(path: Path) -> pathspec.PathSpec:
    """Load gitignore patterns from .gitignore file or use defaults.
    
    Args:
        path: Directory path to search for .gitignore
        
    Returns:
        PathSpec object configured with the loaded patterns
    """
    gitignore_path = path / '.gitignore'
    patterns = []
    
    # Load patterns from .gitignore if it exists
    if gitignore_path.exists():
        with open(gitignore_path) as f:
            patterns.extend(line.strip() for line in f 
                          if line.strip() and not line.startswith('#'))
            
    # Add default patterns
    patterns.extend(DEFAULT_EXCLUDE_PATTERNS)
    
    return pathspec.PathSpec.from_lines(pathspec.patterns.GitWildMatchPattern, patterns)

def should_ignore(path: str, spec: pathspec.PathSpec) -> bool:
    """Check if a path should be ignored based on gitignore patterns"""
    return spec.match_file(path)

def should_exclude(name: str, patterns: List[str]) -> bool:
    """Check if a file/directory name matches any exclude patterns"""
    return any(fnmatch.fnmatch(name, pattern) for pattern in patterns)

def build_tree(
    path: Path,
    tree: Tree,
    config: DirScanConfig,
    current_depth: int = 0,
    spec: Optional[pathspec.PathSpec] = None
) -> None:
    """Recursively build a Rich tree representation of the directory"""
    if current_depth >= config.max_depth:
        return

    try:
        # Get sorted list of directory contents
        entries = sorted(path.iterdir(), key=lambda p: (not p.is_dir(), p.name.lower()))
        
        for entry in entries:
            # Get relative path from root for pattern matching
            rel_path = entry.relative_to(path)
            
            # Skip if path matches exclude patterns
            if spec and should_ignore(str(rel_path), spec):
                continue
            if should_exclude(entry.name, config.exclude_patterns):
                continue
                
            # Skip if symlink and not following links
            if entry.is_symlink() and not config.follow_links:
                continue

            try:
                if entry.is_dir():
                    # Add directory node
                    branch = tree.add(
                        f"📁 {entry.name}/"
                    )
                    
                    # Recursively process subdirectory
                    build_tree(entry, branch, config, current_depth + 1, spec)
                else:
                    # Add file node with optional metadata
                    meta = []
                    if config.show_size:
                        meta.append(format_size(entry.stat().st_size))
                    if config.show_modified:
                        meta.append(format_time(entry.stat().st_mtime))
                        
                    label = entry.name
                    if meta:
                        label = f"{label} ({', '.join(meta)})"
                    
                    tree.add(label)
                    
            except PermissionError:
                tree.add(f"🔒 {entry.name} (Permission denied)")
                
    except PermissionError:
        tree.add("🔒 (Permission denied)")

@tool
def list_directory_tree(
    path: str = ".",
    *,
    max_depth: int = 1,  # Default to no recursion
    follow_links: bool = False,
    show_size: bool = False,  # Default to not showing size
    show_modified: bool = False,  # Default to not showing modified time
    exclude_patterns: List[str] = None
) -> str:
    """List directory contents in a tree format with optional metadata.
    
    Args:
        path: Directory path to list
        max_depth: Maximum depth to traverse (default: 1 for no recursion)
        follow_links: Whether to follow symbolic links
        show_size: Show file sizes (default: False)
        show_modified: Show last modified times (default: False)
        exclude_patterns: List of patterns to exclude (uses gitignore syntax)
        
    Returns:
        Rendered tree string
    """
    root_path = Path(path).resolve()
    if not root_path.exists():
        raise ValueError(f"Path does not exist: {path}")
    if not root_path.is_dir():
        raise ValueError(f"Path is not a directory: {path}")

    # Load .gitignore patterns if present
    spec = load_gitignore_patterns(root_path)
    
    # Create tree
    tree = Tree(f"📁 {root_path}/")
    config = DirScanConfig(
        max_depth=max_depth,
        follow_links=follow_links,
        show_size=show_size,
        show_modified=show_modified,
        exclude_patterns=DEFAULT_EXCLUDE_PATTERNS + (exclude_patterns or [])
    )
    
    # Build tree
    build_tree(root_path, tree, config, 0, spec)
    
    # Capture tree output
    with console.capture() as capture:
        console.print(tree)
    tree_str = capture.get()
    
    # Display panel
    console.print(Panel(
        Markdown(f"```\n{tree_str}\n```"),
        title="📂 Directory Tree",
        border_style="bright_blue"
    ))
    
    return tree_str