src/graph/nodes/reducer_sub_node.py

import logging
from src.models.ImageSpec_model import State,GlobalImagePlan
from src.utils.asyncHandler import asyncHandler
from langchain.messages import SystemMessage,HumanMessage
from src.prompts import IMAGE_PLACEHOLDER_GENERATION
from src.llm import llm
from src.exception import MyException
import sys
import os
from src.components.image_generation import ImageGeneration
@asyncHandler
async def reducer_sub_llm(state:State)->State:
    logging.info("Calling LLM for image placeholder planning")
    output=await llm.with_structured_output(GlobalImagePlan)\
    .ainvoke(
        [
        SystemMessage(content=IMAGE_PLACEHOLDER_GENERATION),
        HumanMessage(content=state['prompt_markdown'])
        ]
    )
    if not output:
        logging.error("LLM failed to return a valid image placeholder plan (output is None)")
        raise MyException("Failed to generate image placeholder plan from LLM", sys)
    
    state['output']=output
    logging.info("Successfully generated image placeholder plan")
    return state

@asyncHandler
async def reducer_sub_image(state:State)->State:
    output=state['output']
    image_generator=ImageGeneration()
    if not output:
        raise MyException("output from reducer_sub not found",sys)
    
    os.makedirs("images",exist_ok=True)

    logging.info(f"Starting image generation for {len(output.images)} images")
    for image_con in output.images:
        logging.debug(f"Generating image: {image_con.filename} with prompt: {image_con.prompt[:50]}...")
        image=await image_generator.generateImage(prompt=image_con.prompt)
        image.save(image_con.filename)
    logging.info("All images generated successfully")
    return state

@asyncHandler
async def merge_images_and_md(state: State) -> State:
    output = state["output"]
    md = output.md_with_placeholders
    
    logging.info(f"Merging {len(output.images)} images into Markdown")
    for im in output.images:
        alt_text = (
            im.filename.split("/")[-1]
            .replace(".png", "")
            .replace("_", " ")
        )

        md_image_tag = f"![{alt_text}](../{im.filename})"
        md = md.replace(im.placeholder, md_image_tag)

    state["final_md"] = md
    logging.info("Markdown merging completed")
    return state