import streamlit as st
import networkx as nx
import pickle
import os
import json
from pyvis.network import Network
import streamlit.components.v1 as components
# --- CONFIGURATION ---
CACHE_FILE = "mastodon_network.pkl"
LABELS_FILE = "topic_labels.json"
# --- PAGE CONFIG ---
st.set_page_config(layout="wide", page_title="Topic Pathfinder")
st.title("🔗 Topic Pathfinder")
st.markdown("Find the **strongest social bridge** between two topics through shared users.")
# --- 1. LOAD DATA ---
@st.cache_resource
def load_data():
data = {"G": None, "labels": {}}
if os.path.exists(CACHE_FILE):
with open(CACHE_FILE, 'rb') as f:
data["G"] = pickle.load(f)
if os.path.exists(LABELS_FILE):
with open(LABELS_FILE, 'r') as f:
data["labels"] = json.load(f)
return data
data = load_data()
G = data["G"]
labels_map = data["labels"]
if G is None:
st.error(f"Cache file '{CACHE_FILE}' not found!")
st.stop()
OUTLIER_ID = "Topic_0"
if G.has_node(OUTLIER_ID):
G.remove_node(OUTLIER_ID)
# --- HELPER: Compute Costs ---
# We invert the weight so that High Posts = Low Cost (Short Path)
# This trick lets Dijkstra's algorithm find the "Strongest" path
for u, v, d in G.edges(data=True):
weight = d.get('weight', 1)
# Avoid division by zero, prioritize heavy weights
# 1 post = cost 1.0
# 100 posts = cost 0.01
d['cost'] = 1 / weight
# --- HELPER: Labeling ---
def get_label(node_id):
if node_id.startswith("Topic_") and node_id in labels_map:
return f"{labels_map[node_id]} ({node_id})"
if node_id.startswith("User_"):
return f"User {node_id.replace('User_', '')}"
return node_id
# --- SIDEBAR SELECTION ---
st.sidebar.header("Select Path Endpoints")
# Filter for Topic Nodes only
topic_nodes = [n for n in G.nodes if n.startswith("Topic_")]
topic_options = {get_label(n): n for n in topic_nodes}
sorted_options = sorted(topic_options.keys())
start_label = st.sidebar.selectbox("Start Topic", sorted_options, index=0)
end_label = st.sidebar.selectbox("End Topic", sorted_options, index=len(sorted_options)-1)
start_node = topic_options[start_label]
end_node = topic_options[end_label]
if st.sidebar.button("Find Connection"):
if start_node == end_node:
st.warning("Start and End topics are the same!")
st.stop()
try:
# 1. Calculate STRONGEST Path (Weighted by activity)
path_strongest = nx.shortest_path(G, source=start_node, target=end_node, weight='cost')
# 2. Calculate SHORTEST Path (Fewest hops/intermediaries)
path_shortest = nx.shortest_path(G, source=start_node, target=end_node) # No weight = BFS
# Create Tabs for the two views
tab1, tab2 = st.tabs(["💪 Strongest Connection", "⚡ Shortest Connection"])
# ==========================================
# TAB 1: STRONGEST CONNECTION (Your original logic)
# ==========================================
with tab1:
st.subheader("Strongest Social Bridge (Most Activity)")
st.caption("This path follows the users with the highest post counts.")
# --- Visualization Pipeline (Strongest) ---
steps = []
total_posts = 0
with st.container():
col_list = st.columns(len(path_strongest))
for i, node in enumerate(path_strongest):
# Calculate edge weight to previous node
posts_in = 0
if i > 0:
prev = path_strongest[i-1]
posts_in = G[prev][node]['weight']
total_posts += posts_in
# Display Node
clean_name = get_label(node)
is_user = node.startswith("User_")
with col_list[i]:
if is_user:
st.markdown(f"""
👤
{clean_name}
""", unsafe_allow_html=True)
if i < len(path_strongest)-1:
st.markdown(f"", unsafe_allow_html=True)
else:
color = "#00FF00" if i == 0 or i == len(path_strongest)-1 else "#FB7E81"
st.markdown(f"""
📚
{clean_name.split('(')[0]}
""", unsafe_allow_html=True)
if i < len(path_strongest)-1:
st.markdown(f"", unsafe_allow_html=True)
# --- PyVis Graph (Strongest) ---
st.divider()
nt = Network(height="500px", width="100%", bgcolor="#222222", font_color="white")
for node in path_strongest:
attr = G.nodes[node]
label = get_label(node).split('(')[0]
if node == start_node or node == end_node:
nt.add_node(node, label=label, color="#00FF00", size=30)
elif node.startswith("User_"):
nt.add_node(node, label=label, color="#97C2FC", size=15)
else:
nt.add_node(node, label=label, color="#FB7E81", size=20)
for i in range(len(path_strongest) - 1):
u = path_strongest[i]
v = path_strongest[i+1]
weight = G[u][v]['weight']
nt.add_edge(u, v, value=weight, title=f"{weight} posts", color="#FFFF00")
nt.barnes_hut()
nt.save_graph("strongest_graph.html")
with open("strongest_graph.html", 'r', encoding='utf-8') as f:
components.html(f.read(), height=520)
# ==========================================
# TAB 2: SHORTEST CONNECTION (New Logic)
# ==========================================
with tab2:
st.subheader("Shortest Connection Graph (Fewest Hops)")
st.caption("This path finds the quickest way to connect topics, even if the users aren't very active.")
# --- Visualization Pipeline (Shortest) ---
with st.container():
col_list_s = st.columns(len(path_shortest))
for i, node in enumerate(path_shortest):
clean_name = get_label(node)
is_user = node.startswith("User_")
with col_list_s[i]:
if is_user:
st.markdown(f"""
""", unsafe_allow_html=True)
# if i < len(path_shortest)-1:
# st.markdown(f"
➜
", unsafe_allow_html=True)
# --- PyVis Graph (Shortest) ---
st.divider()
nt_short = Network(height="500px", width="100%", bgcolor="#222222", font_color="white")
for node in path_shortest:
attr = G.nodes[node]
label = get_label(node).split('(')[0]
if node == start_node or node == end_node:
nt_short.add_node(node, label=label, color="#00FF00", size=30)
elif node.startswith("User_"):
nt_short.add_node(node, label=label, color="#97C2FC", size=15)
else:
nt_short.add_node(node, label=label, color="#FB7E81", size=20)
for i in range(len(path_shortest) - 1):
u = path_shortest[i]
v = path_shortest[i+1]
weight = G[u][v]['weight']
# Use CYAN for the shortest path to distinguish it
nt_short.add_edge(u, v, value=1, title=f"{weight} posts", color="#00FFFF")
nt_short.barnes_hut()
nt_short.save_graph("shortest_graph.html")
with open("shortest_graph.html", 'r', encoding='utf-8') as f:
components.html(f.read(), height=520)
except nx.NetworkXNoPath:
st.error(f"No path found between **{start_label}** and **{end_label}**. These communities might be completely disconnected.")
else:
st.info("👈 Select two topics from the sidebar and click **Find Connection**.")