"""
Read file tool
"""

import os
from typing import Dict, Any
from .registry import Tool


class ReadTool(Tool):
    """Tool for reading files with optional offset/limit"""
    
    def __init__(self):
        super().__init__(
            name="read",
            description="Read the contents of a file. Supports optional offset/limit for reading specific lines.",
            parameters={
                "type": "object",
                "properties": {
                    "file_path": {
                        "type": "string",
                        "description": "Path to the file to read (relative or absolute)"
                    },
                    "offset": {
                        "type": "integer", 
                        "description": "Line number to start reading from (1-indexed, optional)",
                        "minimum": 1
                    },
                    "limit": {
                        "type": "integer",
                        "description": "Maximum number of lines to read (optional)",
                        "minimum": 1
                    }
                },
                "required": ["file_path"]
            }
        )
    
    async def execute(self, args: Dict[str, Any]) -> str:
        """Execute the read tool"""
        file_path = args.get("file_path")
        offset = args.get("offset", 1)  # 1-indexed
        limit = args.get("limit")
        
        if not file_path:
            return "Error: file_path is required"
        
        try:
            # Convert to absolute path if relative
            if not os.path.isabs(file_path):
                file_path = os.path.abspath(file_path)
            
            if not os.path.exists(file_path):
                return f"Error: File '{file_path}' does not exist"
            
            if not os.path.isfile(file_path):
                return f"Error: '{file_path}' is not a file"
            
            with open(file_path, 'r', encoding='utf-8') as f:
                lines = f.readlines()
            
            # Apply offset (convert from 1-indexed to 0-indexed)
            start_idx = max(0, offset - 1)
            
            # Apply limit
            if limit is not None:
                end_idx = start_idx + limit
                selected_lines = lines[start_idx:end_idx]
            else:
                selected_lines = lines[start_idx:]
            
            content = ''.join(selected_lines)
            
            # Add metadata
            total_lines = len(lines)
            shown_lines = len(selected_lines)
            
            if offset > 1 or limit is not None:
                metadata = f"# File: {file_path} (showing lines {offset}-{offset + shown_lines - 1} of {total_lines})\n\n"
            else:
                metadata = f"# File: {file_path} ({total_lines} lines)\n\n"
            
            return metadata + content
            
        except UnicodeDecodeError:
            try:
                # Try with different encoding
                with open(file_path, 'r', encoding='latin1') as f:
                    content = f.read()
                return f"# File: {file_path} (read with latin1 encoding)\n\n{content}"
            except Exception as e:
                return f"Error: Could not read file '{file_path}': {e}"
        except Exception as e:
            return f"Error: Could not read file '{file_path}': {e}"