tools.py

"""
tools.py — All tool definitions for the Multi-Tool Agent.
Tools: web_search, calculator, file_reader
"""

import json
import math
import re
import os
from io import BytesIO

import requests


# ─────────────────────────────────────────────
# 1. WEB SEARCH
# ─────────────────────────────────────────────

def web_search(query: str, max_results: int = 5) -> str:
    """Search the web using Google (via SerpAPI) and return summarised results."""
    
    # 1. Grab the API key from your environment
    api_key = os.getenv("SERPAPI_KEY")
    if not api_key or api_key == "your_serpapi_key_here":
        return "Error: SERPAPI_KEY is not set. Please add it to your .env file."

    # 2. Set up the API request parameters
    params = {
        "engine": "google",
        "q": query,
        "api_key": api_key,
        "num": max_results
    }

    try:
        # 3. Make the request to SerpAPI
        response = requests.get("https://serpapi.com/search", params=params, timeout=15)
        response.raise_for_status() # Raises an error for bad HTTP status codes
        
        data = response.json()
        organic_results = data.get("organic_results", [])
        
        if not organic_results:
            return "No results found for the query."
        
        # 4. Format the JSON data into a clean string for the LLM
        output = []
        for i, r in enumerate(organic_results[:max_results], 1):
            title = r.get("title", "No title")
            url = r.get("link", "")
            snippet = r.get("snippet", "No snippet")
            
            output.append(f"[{i}] {title}\n    URL: {url}\n    {snippet}")
            
        return "\n\n".join(output)

    except requests.exceptions.RequestException as e:
        return f"Web search network error: {str(e)}"
    except Exception as e:
        return f"Web search processing error: {str(e)}"


# ─────────────────────────────────────────────
# 2. CALCULATOR
# ─────────────────────────────────────────────

def calculator(expression: str) -> str:
    """
    Safely evaluate a mathematical expression.
    Supports: +, -, *, /, **, sqrt, sin, cos, tan, log, pi, e, abs, round, etc.
    """
    try:
        # Allow only safe characters
        safe_chars = re.compile(r'^[\d\s\+\-\*\/\(\)\.\,\%\^a-zA-Z\_]+$')
        if not safe_chars.match(expression):
            return "Error: Expression contains invalid characters."

        # Build a safe namespace
        safe_ns = {
            "abs": abs, "round": round,
            "sqrt": math.sqrt, "log": math.log, "log10": math.log10,
            "log2": math.log2, "exp": math.exp,
            "sin": math.sin, "cos": math.cos, "tan": math.tan,
            "asin": math.asin, "acos": math.acos, "atan": math.atan,
            "pi": math.pi, "e": math.e, "inf": math.inf,
            "ceil": math.ceil, "floor": math.floor,
            "factorial": math.factorial, "gcd": math.gcd,
            "pow": pow,
        }

        # Replace ^ with ** for user convenience
        expression = expression.replace("^", "**")

        result = eval(expression, {"__builtins__": {}}, safe_ns)  # noqa: S307
        return f"Result: {result}"
    except ZeroDivisionError:
        return "Error: Division by zero."
    except Exception as e:
        return f"Calculator error: {str(e)}"


# ─────────────────────────────────────────────
# 3. FILE READER
# ─────────────────────────────────────────────

def file_reader(file_path: str) -> str:
    """
    Read a local file and return its contents as text.
    Supports: .txt, .md, .py, .js, .json, .csv, .pdf, .docx
    """
    if not os.path.exists(file_path):
        return f"Error: File not found at path '{file_path}'."

    ext = os.path.splitext(file_path)[1].lower()

    try:
        # ── Plain text-based files ──────────────────────
        if ext in {".txt", ".md", ".py", ".js", ".ts", ".html", ".css",
                   ".json", ".yaml", ".yml", ".env", ".sh", ".bat"}:
            with open(file_path, "r", encoding="utf-8", errors="replace") as f:
                content = f.read()
            if len(content) > 8000:
                content = content[:8000] + "\n\n[... file truncated at 8000 chars ...]"
            return content

        # ── CSV ─────────────────────────────────────────
        elif ext == ".csv":
            with open(file_path, "r", encoding="utf-8", errors="replace") as f:
                lines = f.readlines()
            preview = "".join(lines[:50])
            note = f"\n\n[Showing first 50 rows of {len(lines)} total rows]" if len(lines) > 50 else ""
            return preview + note

        # ── PDF ─────────────────────────────────────────
        elif ext == ".pdf":
            try:
                import PyPDF2
                with open(file_path, "rb") as f:
                    reader = PyPDF2.PdfReader(f)
                    pages = [reader.pages[i].extract_text() for i in range(min(10, len(reader.pages)))]
                text = "\n\n".join(filter(None, pages))
                if len(text) > 8000:
                    text = text[:8000] + "\n\n[... truncated ...]"
                return text or "PDF appears to contain no extractable text."
            except ImportError:
                return "PyPDF2 not installed. Run: pip install PyPDF2"

        # ── DOCX ────────────────────────────────────────
        elif ext == ".docx":
            try:
                from docx import Document
                doc = Document(file_path)
                paragraphs = [p.text for p in doc.paragraphs if p.text.strip()]
                text = "\n\n".join(paragraphs)
                if len(text) > 8000:
                    text = text[:8000] + "\n\n[... truncated ...]"
                return text or "DOCX file appears empty."
            except ImportError:
                return "python-docx not installed. Run: pip install python-docx"

        else:
            return f"Unsupported file type '{ext}'. Supported: .txt, .md, .py, .js, .json, .csv, .pdf, .docx"

    except Exception as e:
        return f"File reader error: {str(e)}"


# ─────────────────────────────────────────────
# TOOL REGISTRY — used by the agent
# ─────────────────────────────────────────────

TOOL_DEFINITIONS = [
    {
        "type": "function",
        "function": {
            "name": "web_search",
            "description": (
                "Search the internet for current information, news, facts, or any topic. "
                "Use when the user asks about recent events, factual questions, or anything "
                "that requires up-to-date data from the web."
            ),
            "parameters": {
                "type": "object",
                "properties": {
                    "query": {
                        "type": "string",
                        "description": "The search query to look up on the web."
                    }
                    # NOTICE: max_results has been completely deleted from here!
                },
                "required": ["query"]
            }
        }
    },
    {
        "type": "function",
        "function": {
            "name": "calculator",
            "description": (
                "Evaluate mathematical expressions and perform calculations. "
                "Supports arithmetic, algebra, trigonometry, logarithms, and more. "
                "Use for any math problem."
            ),
            "parameters": {
                "type": "object",
                "properties": {
                    "expression": {
                        "type": "string",
                        "description": (
                            "A valid mathematical expression to evaluate. "
                            "Examples: '2 + 2', 'sqrt(144)', 'sin(pi/2)', '(3**2 + 4**2)**0.5'"
                        )
                    }
                },
                "required": ["expression"]
            }
        }
    },
    {
        "type": "function",
        "function": {
            "name": "file_reader",
            "description": (
                "Read and return the contents of a local file. "
                "Supports text, Python, JSON, CSV, PDF, and DOCX files. "
                "Use when the user wants to analyze, summarize, or ask questions about a local file."
            ),
            "parameters": {
                "type": "object",
                "properties": {
                    "file_path": {
                        "type": "string",
                        "description": (
                            "The absolute or relative path to the file. "
                            "Example: './data/report.pdf' or 'C:/Users/John/notes.txt'"
                        )
                    }
                },
                "required": ["file_path"]
            }
        }
    }
]


TOOL_FUNCTION_MAP = {
    "web_search": web_search,
    "calculator": calculator,
    "file_reader": file_reader,
}


def execute_tool(tool_name: str, tool_args: dict) -> str:
    """Dispatch a tool call and return its string result."""
    fn = TOOL_FUNCTION_MAP.get(tool_name)
    if fn is None:
        return f"Error: Unknown tool '{tool_name}'."
    try:
        return fn(**tool_args)
    except TypeError as e:
        return f"Tool argument error for '{tool_name}': {str(e)}"