app/graph.py

from app.state.state import EmailAgentState
from app.nodes.triage_node import *
from langgraph.prebuilt import ToolNode ,tools_condition
from app.nodes.archive_node import  archive_node
from app.nodes.email_writing_node import *
from langgraph.graph import StateGraph,END,START
from app.tools.email_writing_agent_tools import create_gmail_draft, send_draft
from app.nodes.safety_check_node import *
from app.nodes.parse_node import parse_response_node
from app.nodes.context_node import prepare_context_node
from app.nodes.store_memory_data_node import store_memory_and_data_node
from app.nodes.unsafe_email_node import unsafe_emails_node
from app.nodes.check_email_exist_node import *
from langgraph.types import RetryPolicy
from app.nodes.summarise_email_body_node import summarise_email_body_node
from app.nodes.check_token_count_node import *
from psycopg import OperationalError # Or sqlalchemy.exc.OperationalError depending on your driver
from app.tools.email_writing_agent_tools import email_writing_agent_tools 
from IPython.display import Image, display
from app.persistance.memory_store_checkpointer_config import memory_store, checkpointer
from langchain_google_community import GmailToolkit
from app.database.connection import pool
from app.utils.embeddings import remote_embeddings
from langgraph.checkpoint.postgres import PostgresSaver
from langgraph.store.postgres import PostgresStore
from app.tools.email_writing_agent_tools import email_writing_agent_tools

# Define a standard retry policy for database-heavy nodes
db_retry_policy = RetryPolicy(
    retry_on=OperationalError,
    max_attempts=4,
    backoff_factor=1 # Waits 2s, then 4s, then 8s between retries
)

tool_node_retry_policy = RetryPolicy(
    max_attempts=4,
    initial_interval=1.0,
    backoff_factor=2.0,
    jitter=True
)


builder = StateGraph(EmailAgentState)

# Nodes
builder = StateGraph(EmailAgentState)

# Nodes
builder.add_node("safety_check_node", safety_classifier_node)  
builder.add_node("check_previous_email_exist_node", check_previous_email_exist_node)
builder.add_node("check_token_count_node", check_token_count_node)
builder.add_node("summarise_email_body_node", summarise_email_body_node)
builder.add_node("triage_node", triage_node)
builder.add_node("prepare_context_node", prepare_context_node)
builder.add_node("email_writing_agent", email_writing_agent_node)

# --- APPLY RETRY POLICIES HERE ---
builder.add_node(
    "store_memory_and_data_node", 
    store_memory_and_data_node, 
    retry=db_retry_policy
)         
builder.add_node(
    "unsafe_emails_node", 
    unsafe_emails_node, 
    retry=db_retry_policy
)

builder.add_node("archive_node", archive_node,retry=db_retry_policy)   

builder.add_node("tools", ToolNode(email_writing_agent_tools), retry=tool_node_retry_policy)

# Edges (Same as your original logic)
builder.add_edge(START, "safety_check_node")

builder.add_conditional_edges(
    "safety_check_node", 
    after_safety, 
    {
        "unsafe": "unsafe_emails_node",
        "safe": "check_token_count_node" 
    }
)

builder.add_conditional_edges(
    "check_token_count_node", 
    check_token_limit_router, 
    {
        "summarize": "summarise_email_body_node",
        "triage": "triage_node" 
    }
)

builder.add_edge("summarise_email_body_node", "triage_node")



builder.add_conditional_edges("triage_node", route_after_triage, {
    "check_previous_email_exist_node": "check_previous_email_exist_node", 
    "archive_node": "archive_node",
})

builder.add_conditional_edges(
    "check_previous_email_exist_node",
    after_mail_check,
    {
        "email_writing_agent": "email_writing_agent", 
        "prepare_context_node": "prepare_context_node" 
    }
)
builder.add_edge("prepare_context_node", "email_writing_agent")


builder.add_conditional_edges(
    "email_writing_agent",
    tools_condition,
    {
        "tools": "tools", 
        END: END
    }
)

builder.add_conditional_edges(
    "tools",
    route_after_tools,
    {
        "store_memory_and_data_node": "store_memory_and_data_node",
        "email_writing_agent": "email_writing_agent"
    }
)


builder.add_edge("store_memory_and_data_node", END)
builder.add_edge("unsafe_emails_node", END)
builder.add_edge("archive_node", END)


toolkit = GmailToolkit()
graph=builder.compile(checkpointer=checkpointer, store=memory_store,debug=True)






# try:
#     # This creates a PNG and saves it to your project folder
#     graph_png = graph.get_graph().draw_mermaid_png()
#     with open("graph.png", "wb") as f:
#         f.write(graph_png)
#     print("--- Graph image saved as 'graph.png' ---")
# except Exception as e:
#     # This happens if you don't have the 'pypydot' or 'graphviz' dependencies
#     print(f"Could not generate graph image: {e}")