import json
from typing import Optional, Iterator
from pydantic import BaseModel, Field
from phi.agent import Agent
from phi.model.openai import OpenAIChat
from phi.workflow import Workflow, RunResponse, RunEvent
from phi.storage.workflow.sqlite import SqlWorkflowStorage
from phi.tools.duckduckgo import DuckDuckGo
from phi.utils.pprint import pprint_run_response
from phi.utils.log import logger
class NewsArticle(BaseModel):
title: str = Field(..., description="Title of the article.")
url: str = Field(..., description="Link to the article.")
summary: Optional[str] = Field(..., description="Summary of the article if available.")
class SearchResults(BaseModel):
articles: list[NewsArticle]
class BlogPostGenerator(Workflow):
# Define an Agent that will search the web for a topic
searcher: Agent = Agent(
model=OpenAIChat(id="gpt-4o-mini"),
tools=[DuckDuckGo()],
instructions=["Given a topic, search for the top 5 articles."],
response_model=SearchResults,
structured_outputs=True,
)
# Define an Agent that will write the blog post
writer: Agent = Agent(
model=OpenAIChat(id="gpt-4o"),
instructions=[
"You will be provided with a topic and a list of top articles on that topic.",
"Carefully read each article and generate a New York Times worthy blog post on that topic.",
"Break the blog post into sections and provide key takeaways at the end.",
"Make sure the title is catchy and engaging.",
"Always provide sources, do not make up information or sources.",
],
markdown=True,
)
def run(self, topic: str, use_cache: bool = True) -> Iterator[RunResponse]:
"""This is where the main logic of the workflow is implemented."""
logger.info(f"Generating a blog post on: {topic}")
# Step 1: Use the cached blog post if use_cache is True
if use_cache:
cached_blog_post = self.get_cached_blog_post(topic)
if cached_blog_post:
yield RunResponse(content=cached_blog_post, event=RunEvent.workflow_completed)
return
# Step 2: Search the web for articles on the topic
search_results: Optional[SearchResults] = self.get_search_results(topic)
# If no search_results are found for the topic, end the workflow
if search_results is None or len(search_results.articles) == 0:
yield RunResponse(
event=RunEvent.workflow_completed,
content=f"Sorry, could not find any articles on the topic: {topic}",
)
return
# Step 3: Write a blog post
yield from self.write_blog_post(topic, search_results)
def get_cached_blog_post(self, topic: str) -> Optional[str]:
"""Get the cached blog post for a topic."""
logger.info("Checking if cached blog post exists")
return self.session_state.get("blog_posts", {}).get(topic)
def add_blog_post_to_cache(self, topic: str, blog_post: Optional[str]):
"""Add a blog post to the cache."""
logger.info(f"Saving blog post for topic: {topic}")
self.session_state.setdefault("blog_posts", {})
self.session_state["blog_posts"][topic] = blog_post
def get_search_results(self, topic: str) -> Optional[SearchResults]:
"""Get the search results for a topic."""
MAX_ATTEMPTS = 3
for attempt in range(MAX_ATTEMPTS):
try:
searcher_response: RunResponse = self.searcher.run(topic)
# Check if we got a valid response
if not searcher_response or not searcher_response.content:
logger.warning(f"Attempt {attempt + 1}/{MAX_ATTEMPTS}: Empty searcher response")
continue
# Check if the response is of the expected SearchResults type
if not isinstance(searcher_response.content, SearchResults):
logger.warning(f"Attempt {attempt + 1}/{MAX_ATTEMPTS}: Invalid response type")
continue
article_count = len(searcher_response.content.articles)
logger.info(f"Found {article_count} articles on attempt {attempt + 1}")
return searcher_response.content
except Exception as e:
logger.warning(f"Attempt {attempt + 1}/{MAX_ATTEMPTS} failed: {str(e)}")
logger.error(f"Failed to get search results after {MAX_ATTEMPTS} attempts")
return None
def write_blog_post(self, topic: str, search_results: SearchResults) -> Iterator[RunResponse]:
"""Write a blog post on a topic."""
logger.info("Writing blog post")
# Prepare the input for the writer
writer_input = {"topic": topic, "articles": [v.model_dump() for v in search_results.articles]}
# Run the writer and yield the response
yield from self.writer.run(json.dumps(writer_input, indent=4), stream=True)
# Save the blog post in the cache
self.add_blog_post_to_cache(topic, self.writer.run_response.content)
# Run the workflow if the script is executed directly
if __name__ == "__main__":
from rich.prompt import Prompt
# Get topic from user
topic = Prompt.ask(
"[bold]Enter a blog post topic[/bold]\n✨",
default="Why Cats Secretly Run the Internet",
)
# Convert the topic to a URL-safe string for use in session_id
url_safe_topic = topic.lower().replace(" ", "-")
# Initialize the blog post generator workflow
# - Creates a unique session ID based on the topic
# - Sets up SQLite storage for caching results
generate_blog_post = BlogPostGenerator(
session_id=f"generate-blog-post-on-{url_safe_topic}",
storage=SqlWorkflowStorage(
table_name="generate_blog_post_workflows",
db_file="tmp/workflows.db",
),
)
# Execute the workflow with caching enabled
# Returns an iterator of RunResponse objects containing the generated content
blog_post: Iterator[RunResponse] = generate_blog_post.run(topic=topic, use_cache=True)
# Print the response
pprint_run_response(blog_post, markdown=True)
