langchain agent with tools sample code

import asyncio

from langchain_openai import ChatOpenAI
from langchain.agents import tool
from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
from langchain.agents.format_scratchpad.openai_tools import (
    format_to_openai_tool_messages,
)
from langchain.agents.output_parsers.openai_tools import OpenAIToolsAgentOutputParser
from langchain.agents import AgentExecutor

from dotenv import load_dotenv
import os

from sqlalchemy import Boolean

import base64
import httpx
from email import encoders
from email.header import Header
from email.mime.text import MIMEText
from email.utils import parseaddr, formataddr
import smtplib


def _format_addr(s):
    name, addr = parseaddr(s)
    return formataddr((Header(name, "utf-8").encode(), addr))

def _send_email(content: str):
    from_addr = "xxx@gmail.com"
    password = ""
    to_addr = "xxx@gmail.com"
    smtp_server = "smtp.gmail.com"

    msg = MIMEText(content, "plain", "utf-8")
    msg["From"] = _format_addr("FIRE ALARMER <%s>" % from_addr)
    msg["To"] = _format_addr("ADMIN <%s>" % to_addr)
    msg["Subject"] = Header("You got one fire alarm!", "utf-8").encode()
    print("---- before login 11-----")
    server = smtplib.SMTP_SSL(smtp_server, 465)
    print("---- before login 1122-----")
    server.set_debuglevel(1)
    print("---- before login -----")
    server.login(from_addr, password)
    print("---- after login -----")
    server.sendmail(from_addr, [to_addr], msg.as_string())
    server.quit()

load_dotenv()

# llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0)
llm = ChatOpenAI(model="gpt-4o-mini", temperature=0)


@tool
def get_word_length(word: str) -> int:
    """Returns the length of a word."""
    return len(word)

# print(get_word_length.invoke("abc"))


@tool
def turn_on_light() -> Boolean:
    """
    turn on light

    Return the result of turning on light.
    """
    return True

@tool
def send_one_email(content: str) -> Boolean:
    """
    send one email to admin.

    Return the result of sending one email.
    """
    _send_email(content)

    return True

tools = [get_word_length, turn_on_light, send_one_email]


prompt = ChatPromptTemplate.from_messages(
    [
        (
            "system",
            "You are very powerful assistant, but don't know current events",
        ),
        ("user", "{input}"),
        MessagesPlaceholder(variable_name="agent_scratchpad"),
    ]
)

#
#
# prompt = ChatPromptTemplate.from_messages(
#     [
#         (
#             "system",
#             "You are very powerful assistant, but don't know current events",
#         ),
#         (
#             "user",
#             [
#                 {
#                     "type": "text",
#                     "text": "{input}"
#                 },
#                 {
#                     "type": "image_url",
#                     "image_url": {"url": "data:image/jpeg;base64,{image_data}"},
#                 }
#             ],
#         ),
#         MessagesPlaceholder(variable_name="agent_scratchpad"),
#     ]
# )


llm_with_tools = llm.bind_tools(tools)

agent = (
    {
        "input": lambda x: x["input"],
        "image_data": lambda x: x['image_data'],
        "agent_scratchpad": lambda x: format_to_openai_tool_messages(
            x["intermediate_steps"]
        ),
    }
    | prompt
    | llm_with_tools
    | OpenAIToolsAgentOutputParser()
)


agent_executor = AgentExecutor(agent=agent, tools=tools, verbose=True)

# image_url = "https://upload.wikimedia.org/wikipedia/commons/thumb/d/dd/Gfp-wisconsin-madison-the-nature-boardwalk.jpg/2560px-Gfp-wisconsin-madison-the-nature-boardwalk.jpg"
image_url = "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQhSUzTow_Xta3T3VF8op28XCTCM4D3boxhaA3ZrNyS5xkQXEpTNvsrUhmvfkwKOb5Z7jY&usqp=CAU"
image_data = base64.b64encode(httpx.get(image_url).content).decode("utf-8")


# async def main():
#     resp = agent_executor.stream({"input": "How many letters in the word eudca"})
#     async for one in resp:
#         print(one)
#
# asyncio.run(main())


print(agent_executor.invoke({"input": "How many letters in the word eudca", "image_data": ""}))

# list(agent_executor.stream({"input": "How many letters in the word eudca"}))

# list(agent_executor.stream({"input": "Please turn on light in this room."}))

# list(agent_executor.stream({"input": '''
# Please send one email with the following text as content:
# The fire is too heavy, please take action immediately.
# '''}))

# list(agent_executor.stream({"input": "please understand this image as of fire alarm, if any fire risk then send email with that fire description, otherwise do not send alarm email.", "image_data": image_data}))

# _send_email("The fire is too heavy, please take action immediately.")