nodes.py

import yaml
from pocketflow import Node

from utils import callLLM, callWebSearch

class Decide(Node):
    def setLogger(self,logger):
        self.logger = logger

    def prep(self,shared):
        context = shared.get("context","No previous search")
        question = shared["question"]
        return question,context
    
    def exec(self,inputs):
        question,context = inputs
        prompt = f"""
### CONTEXT
You are a research assistant that can search the web
Question: {question}
Previous research: {context}

### ACTION SPACE
[1] search
  Description: Look up more information on the web
  Parameters:
  - query (str): what to search for

[2] answer
  Description: Answer the question with current knowledge
  Parameters:
  - answer (str): final answer to the question

### NEXT ACTION
Decide the next action based on the context and available actions.
Return your response in the following format:
```yaml
thinking: |
  <your step-by-step reasoning process>
action: search OR answer
reason: <why you choose this action>
search_query: <specific search query if action is search>
```
IMPORTANT: Make sure to:
1. Use proper indentation (4 spaces) for all multi-line fields
2. Use the | character for multi-line text fields
3. Keep single-line fields without the | character
"""
        response = callLLM(prompt)
        self.logger.debug(f"=== CALLING LLM\n{prompt}\n=== LLM RESPONSE\n{response}\n\n==========\n\n")
        yaml_str = response.replace("|","") #.split("```yaml")[1].split("```")[0].strip()
        decision = yaml.safe_load(yaml_str)
        return decision
    
    def post(self,shared,prep_res,exec_res):
        if exec_res["action"] == "search":
            shared["search_query"] = exec_res["search_query"]
        return exec_res["action"]
    

class Search(Node):
    def setLogger(self,logger):
        self.logger = logger

    def prep(self,shared):
        return shared["search_query"]
    
    def exec(self,search_query):
        results = callWebSearch(search_query)
        self.logger.debug(f"*** SEARCHING\n{search_query}\n*** SEARCH RESULTS\n{results}\n\n**********\n\n")
        return results
    
    def post(self,shared,prep_res,exec_res):
        previous = shared.get("context","")
        shared["context"] = f"{previous}\n\nSEARCH: {shared['search_query']}\n\nRESULTS: {exec_res}"
        return "decide"


class Answer(Node):
    def setLogger(self,logger):
        self.logger = logger

    def prep(self,shared):
        return shared["question"],shared.get("context","")
    
    def exec(self,inputs):
        question,context = inputs
        prompt = f'''
### CONTEXT
Based on the following information, answer the question.
Question: {question}
Research: {context}

### YOUR ANSWER
Provide a comprehensive answer using research results
'''
        response = callLLM(prompt)
        self.logger.debug(f"### CALLING LLM\n{prompt}\n### LLM RESPONSE\n{response}\n\n##########\n\n")
        return response
    
    def post(self,shared,prep_res,exec_res):
        shared["answer"] = exec_res