app.py

# app.py
# Mutual Fund Churn Explorer - final version with collapsible sidebar + deep green theme
# Save as app.py and run with: python app.py
# requirements.txt should include: gradio, networkx, plotly, pandas, numpy

import gradio as gr
import pandas as pd
import networkx as nx
import plotly.graph_objects as go
import numpy as np
from collections import defaultdict
import io

# ---------------------------
# Default sample data
# ---------------------------
DEFAULT_AMCS = [
    "SBI MF", "ICICI Pru MF", "HDFC MF", "Nippon India MF", "Kotak MF",
    "UTI MF", "Axis MF", "Aditya Birla SL MF", "Mirae MF", "DSP MF"
]

DEFAULT_COMPANIES = [
    "HDFC Bank", "ICICI Bank", "Bajaj Finance", "Bajaj Finserv", "Adani Ports",
    "Tata Motors", "Shriram Finance", "HAL", "TCS", "AU Small Finance Bank",
    "Pearl Global", "Hindalco", "Tata Elxsi", "Cummins India", "Vedanta"
]

SAMPLE_BUY = {
    "SBI MF": ["Bajaj Finance", "AU Small Finance Bank"],
    "ICICI Pru MF": ["HDFC Bank"],
    "HDFC MF": ["Tata Elxsi", "TCS"],
    "Nippon India MF": ["Hindalco"],
    "Kotak MF": ["Bajaj Finance"],
    "UTI MF": ["Adani Ports", "Shriram Finance"],
    "Axis MF": ["Tata Motors", "Shriram Finance"],
    "Aditya Birla SL MF": ["AU Small Finance Bank"],
    "Mirae MF": ["Bajaj Finance", "HAL"],
    "DSP MF": ["Tata Motors", "Bajaj Finserv"]
}

SAMPLE_SELL = {
    "SBI MF": ["Tata Motors"],
    "ICICI Pru MF": ["Bajaj Finance", "Adani Ports"],
    "HDFC MF": ["HDFC Bank"],
    "Nippon India MF": ["Hindalco"],
    "Kotak MF": ["AU Small Finance Bank"],
    "UTI MF": ["Hindalco", "TCS"],
    "Axis MF": ["TCS"],
    "Aditya Birla SL MF": ["Adani Ports"],
    "Mirae MF": ["TCS"],
    "DSP MF": ["HAL", "Shriram Finance"]
}

SAMPLE_COMPLETE_EXIT = {
    "DSP MF": ["Shriram Finance"]
}

SAMPLE_FRESH_BUY = {
    "HDFC MF": ["Tata Elxsi"],
    "UTI MF": ["Adani Ports"],
    "Mirae MF": ["HAL"]
}

# ---------------------------
# CSV -> maps utility
# ---------------------------
def maps_from_dataframe(df, amc_col="AMC", company_col="Company", action_col="Action"):
    amcs = sorted(df[amc_col].dropna().unique().tolist())
    companies = sorted(df[company_col].dropna().unique().tolist())

    buy_map = defaultdict(list)
    sell_map = defaultdict(list)
    complete_exit = defaultdict(list)
    fresh_buy = defaultdict(list)

    for _, row in df.iterrows():
        a = str(row[amc_col]).strip()
        c = str(row[company_col]).strip()
        act = str(row[action_col]).strip().lower()
        if act in ("buy", "b"):
            buy_map[a].append(c)
        elif act in ("sell", "s"):
            sell_map[a].append(c)
        elif act in ("complete_exit", "exit", "complete"):
            complete_exit[a].append(c)
        elif act in ("fresh_buy", "fresh", "new"):
            fresh_buy[a].append(c)
        else:
            # fallback heuristics
            if "sell" in act:
                sell_map[a].append(c)
            elif "exit" in act:
                complete_exit[a].append(c)
            else:
                buy_map[a].append(c)
    return amcs, companies, dict(buy_map), dict(sell_map), dict(complete_exit), dict(fresh_buy)

def sanitize_map(m, companies_list):
    out = {}
    for k, vals in m.items():
        out[k] = [v for v in vals if v in companies_list]
    return out

def load_default_dataset():
    AMCS = DEFAULT_AMCS.copy()
    COMPANIES = DEFAULT_COMPANIES.copy()
    BUY_MAP = sanitize_map(SAMPLE_BUY, COMPANIES)
    SELL_MAP = sanitize_map(SAMPLE_SELL, COMPANIES)
    COMPLETE_EXIT = sanitize_map(SAMPLE_COMPLETE_EXIT, COMPANIES)
    FRESH_BUY = sanitize_map(SAMPLE_FRESH_BUY, COMPANIES)
    return AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY

# ---------------------------
# Infer transfers AMC->AMC
# ---------------------------
def infer_amc_transfers(buy_map, sell_map):
    transfers = defaultdict(int)
    company_to_sellers = defaultdict(list)
    company_to_buyers = defaultdict(list)
    for amc, comps in sell_map.items():
        for c in comps:
            company_to_sellers[c].append(amc)
    for amc, comps in buy_map.items():
        for c in comps:
            company_to_buyers[c].append(amc)
    for c in set(list(company_to_sellers.keys()) + list(company_to_buyers.keys())):
        sellers = company_to_sellers.get(c, [])
        buyers = company_to_buyers.get(c, [])
        for s in sellers:
            for b in buyers:
                transfers[(s,b)] += 1
    edge_list = []
    for (s,b), w in transfers.items():
        edge_list.append((s,b, {"action": "transfer", "weight": w, "company_count": w}))
    return edge_list

# ---------------------------
# Graph builder
# ---------------------------
def build_graph(AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY, include_transfers=True):
    G = nx.DiGraph()
    for a in AMCS:
        G.add_node(a, type="amc", label=a)
    for c in COMPANIES:
        G.add_node(c, type="company", label=c)

    def add_edge(a,c,action,weight=1):
        if not G.has_node(a) or not G.has_node(c):
            return
        if G.has_edge(a,c):
            G[a][c]["weight"] += weight
            G[a][c]["actions"].append(action)
        else:
            G.add_edge(a,c, weight=weight, actions=[action])

    for a, comps in BUY_MAP.items():
        for c in comps:
            add_edge(a,c,"buy",1)
    for a, comps in SELL_MAP.items():
        for c in comps:
            add_edge(a,c,"sell",1)
    for a, comps in COMPLETE_EXIT.items():
        for c in comps:
            add_edge(a,c,"complete_exit",3)
    for a, comps in FRESH_BUY.items():
        for c in comps:
            add_edge(a,c,"fresh_buy",3)

    if include_transfers:
        transfers = infer_amc_transfers(BUY_MAP, SELL_MAP)
        for s,b,attrs in transfers:
            if not G.has_node(s) or not G.has_node(b):
                continue
            if G.has_edge(s,b):
                G[s][b]["weight"] += attrs.get("weight",1)
                G[s][b]["actions"].append("transfer")
            else:
                G.add_edge(s,b, weight=attrs.get("weight",1), actions=["transfer"])
    return G

# ---------------------------
# Plotly visualizer (coerce width/height -> int with minimums)
# ---------------------------
def graph_to_plotly(G,
                    node_color_amc="#0f5132",       # deep green theme: use darker green for AMCs by default
                    node_color_company="#ffc107",    # amber for companies — user can change
                    node_shape_amc="circle",
                    node_shape_company="circle",
                    edge_color_buy="#28a745",
                    edge_color_sell="#dc3545",
                    edge_color_transfer="#6c757d",
                    edge_thickness_base=1.2,
                    show_labels=True,
                    width=1400,
                    height=900):
    # ensure width/height are native ints and sensible
    try:
        width = int(float(width))
    except Exception:
        width = 1400
    try:
        height = int(float(height))
    except Exception:
        height = 900
    if width < 600:
        width = 600
    if height < 360:
        height = 360

    # layout: spring layout for clarity
    pos = nx.spring_layout(G, seed=42, k=1.4)

    node_x = []
    node_y = []
    node_text = []
    node_color = []
    node_size = []
    for n, d in G.nodes(data=True):
        x, y = pos[n]
        node_x.append(x)
        node_y.append(y)
        node_text.append(n)
        if d["type"] == "amc":
            node_color.append(node_color_amc)
            node_size.append(44)
        else:
            node_color.append(node_color_company)
            node_size.append(64)

    node_trace = go.Scatter(
        x=node_x, y=node_y,
        mode='markers+text' if show_labels else 'markers',
        marker=dict(color=node_color, size=node_size, line=dict(width=2, color="#222")),
        text=node_text if show_labels else None,
        textposition="top center",
        hoverinfo='text'
    )

    # edges rendered individually so they can be styled
    edge_traces = []
    for u, v, attrs in G.edges(data=True):
        x0, y0 = pos[u]
        x1, y1 = pos[v]
        actions = attrs.get("actions", [])
        weight = float(attrs.get("weight", 1.0))
        # priority styling
        if "complete_exit" in actions:
            color = edge_color_sell
            dash = "solid"
            width_px = max(float(edge_thickness_base) * 3.5, 3.0)
        elif "fresh_buy" in actions:
            color = edge_color_buy
            dash = "solid"
            width_px = max(float(edge_thickness_base) * 3.5, 3.0)
        elif "transfer" in actions:
            color = edge_color_transfer
            dash = "dash"
            width_px = max(float(edge_thickness_base) * (1.0 + np.log1p(weight)), 1.5)
        elif "sell" in actions:
            color = edge_color_sell
            dash = "dot"
            width_px = max(float(edge_thickness_base) * (1.0 + np.log1p(weight)), 1.0)
        else:
            color = edge_color_buy
            dash = "solid"
            width_px = max(float(edge_thickness_base) * (1.0 + np.log1p(weight)), 1.0)

        edge_traces.append(
            go.Scatter(
                x=[x0, x1, None],
                y=[y0, y1, None],
                mode='lines',
                line=dict(width=float(width_px), color=color, dash=dash),
                hoverinfo='text',
                text=", ".join(actions)
            )
        )

    fig = go.Figure(data=edge_traces + [node_trace],
                    layout=go.Layout(
                        title_text="Mutual Fund Churn Network (AMCs: green, Companies: amber)",
                        title_x=0.5,
                        showlegend=False,
                        margin=dict(b=20,l=5,r=5,t=40),
                        xaxis=dict(showgrid=False, zeroline=False, showticklabels=False),
                        yaxis=dict(showgrid=False, zeroline=False, showticklabels=False),
                        height=height,
                        width=width
                    ))
    return fig

# ---------------------------
# Analysis helpers
# ---------------------------
def company_trade_summary(company_name, BUY_MAP, SELL_MAP, FRESH_BUY, COMPLETE_EXIT):
    buyers = [amc for amc, comps in BUY_MAP.items() if company_name in comps]
    sellers = [amc for amc, comps in SELL_MAP.items() if company_name in comps]
    fresh = [amc for amc, comps in FRESH_BUY.items() if company_name in comps]
    exits = [amc for amc, comps in COMPLETE_EXIT.items() if company_name in comps]

    rows = []
    for b in buyers:
        rows.append({"Role": "Buyer", "AMC": b})
    for s in sellers:
        rows.append({"Role": "Seller", "AMC": s})
    for f in fresh:
        rows.append({"Role": "Fresh Buy", "AMC": f})
    for e in exits:
        rows.append({"Role": "Complete Exit", "AMC": e})

    df = pd.DataFrame(rows)
    if df.empty:
        return None, pd.DataFrame([], columns=["Role","AMC"])
    counts = df['Role'].value_counts().reindex(["Buyer","Seller","Fresh Buy","Complete Exit"]).fillna(0)
    colors = {"Buyer":"green","Seller":"red","Fresh Buy":"orange","Complete Exit":"black"}
    bar = go.Figure()
    bar.add_trace(go.Bar(x=counts.index, y=counts.values, marker_color=[colors.get(i,"grey") for i in counts.index]))
    bar.update_layout(title=f"Trade Summary for {company_name}", height=360, width=700)
    return bar, df

def amc_transfer_summary(amc_name, BUY_MAP, SELL_MAP):
    sold = SELL_MAP.get(amc_name, [])
    transfers = []
    for s in sold:
        buyers = [amc for amc, comps in BUY_MAP.items() if s in comps]
        for b in buyers:
            transfers.append({"security": s, "buyer_amc": b})
    df = pd.DataFrame(transfers)
    if df.empty:
        return None, pd.DataFrame([], columns=["security","buyer_amc"])
    counts = df['buyer_amc'].value_counts().reset_index()
    counts.columns = ['Buyer AMC', 'Count']
    fig = go.Figure(go.Bar(x=counts['Buyer AMC'], y=counts['Count'], marker_color='lightslategray'))
    fig.update_layout(title_text=f"Inferred transfers from {amc_name}", height=360, width=700)
    return fig, df

def detect_loops(G, max_length=6):
    amc_nodes = [n for n,d in G.nodes(data=True) if d['type']=='amc']
    H = nx.DiGraph()
    for u,v,d in G.edges(data=True):
        if u in amc_nodes and v in amc_nodes and "transfer" in d.get("actions",[]):
            H.add_edge(u,v, weight=d.get("weight",1))
    try:
        cycles = list(nx.simple_cycles(H))
    except Exception:
        cycles = []
    loops = [c for c in cycles if 2 <= len(c) <= max_length]
    return loops

# ---------------------------
# Build initial dataset + graph
# ---------------------------
def build_initial_graph_and_data():
    AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY = load_default_dataset()
    G = build_graph(AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY, include_transfers=True)
    fig = graph_to_plotly(G)
    return (AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY, G, fig)

(AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY, G_initial, initial_fig) = build_initial_graph_and_data()

# ---------------------------
# GRADIO UI: deep-green theme + collapsible sidebar
# ---------------------------
# Create a deep green theme using gradio theme API (primary hue green, darker accents)
deep_green_theme = gr.themes.Soft(primary_hue="green", secondary_hue="teal", spacing_size="md")

with gr.Blocks(theme=deep_green_theme) as demo:
    gr.Markdown("# Mutual Fund Churn Explorer — Deep Green Theme")
    with gr.Row():
        # Collapsible sidebar using Accordion
        with gr.Accordion("⚙️ Settings (click to expand / collapse)", open=False):
            with gr.Column():
                gr.Markdown("### Data Input")
                csv_uploader = gr.File(label="Upload CSV (optional). Columns: AMC,Company,Action", file_types=['.csv'])
                gr.Markdown("### Node Appearance")
                node_color_company = gr.ColorPicker(value="#ffc107", label="Company node color")
                node_color_amc = gr.ColorPicker(value="#0f5132", label="AMC node color")
                node_shape_company = gr.Dropdown(choices=["circle","square","diamond"], value="circle", label="Company node shape")
                node_shape_amc = gr.Dropdown(choices=["circle","square","diamond"], value="circle", label="AMC node shape")
                gr.Markdown("### Edge Appearance")
                edge_color_buy = gr.ColorPicker(value="#28a745", label="BUY edge color")
                edge_color_sell = gr.ColorPicker(value="#dc3545", label="SELL edge color")
                edge_color_transfer = gr.ColorPicker(value="#6c757d", label="Transfer edge color")
                edge_thickness = gr.Slider(minimum=0.5, maximum=8.0, value=1.4, step=0.1, label="Edge thickness base")
                include_transfers_chk = gr.Checkbox(value=True, label="Infer AMC→AMC transfers (show loops)")
                update_btn = gr.Button("Update network")
                gr.Markdown("### Inspect")
                # do not set default value to avoid mismatch warnings after dropdown choices update
                company_selector = gr.Dropdown(choices=COMPANIES, label="Select Company (show buyers/sellers)")
                amc_selector = gr.Dropdown(choices=AMCS, label="Select AMC (inferred transfers)")
        # Graph column
        with gr.Column():
            network_plot = gr.Plot(value=initial_fig, label="Network graph (drag to zoom)")

    # outputs for inspection
    company_plot = gr.Plot(label="Company trade summary")
    company_table = gr.Dataframe(headers=["Role","AMC"], interactive=False, label="Trades (company)")
    amc_plot = gr.Plot(label="AMC inferred transfers")
    amc_table = gr.Dataframe(headers=["security","buyer_amc"], interactive=False, label="Inferred transfers (AMC)")
    loops_text = gr.Markdown()

    # CSV loader helper
    def load_dataset_from_csv(file_obj):
        if file_obj is None:
            return AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY
        try:
            raw = file_obj.read()
            if isinstance(raw, bytes):
                raw = raw.decode('utf-8', errors='ignore')
            df = pd.read_csv(io.StringIO(raw))
            cols = [c.strip().lower() for c in df.columns]
            col_map = {}
            for c in df.columns:
                if c.strip().lower() in ("amc","fund","manager"):
                    col_map[c] = "AMC"
                elif c.strip().lower() in ("company","security","stock"):
                    col_map[c] = "Company"
                elif c.strip().lower() in ("action","trade","type"):
                    col_map[c] = "Action"
            df = df.rename(columns=col_map)
            required = {"AMC","Company","Action"}
            if not required.issubset(set(df.columns)):
                return AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY
            amcs, companies, buy_map, sell_map, complete_exit, fresh_buy = maps_from_dataframe(df, "AMC", "Company", "Action")
            return amcs, companies, buy_map, sell_map, complete_exit, fresh_buy
        except Exception as e:
            print("CSV load error:", e)
            return AMCS, COMPANIES, BUY_MAP, SELL_MAP, COMPLETE_EXIT, FRESH_BUY

    # Update callback builds new graph, detects loops and refreshes dropdown choices
    def on_update(csv_file, node_color_company_val, node_color_amc_val, node_shape_company_val, node_shape_amc_val,
                  edge_color_buy_val, edge_color_sell_val, edge_color_transfer_val, edge_thickness_val, include_transfers_val):
        amcs, companies, buy_map, sell_map, complete_exit, fresh_buy = load_dataset_from_csv(csv_file)
        G = build_graph(amcs, companies, buy_map, sell_map, complete_exit, fresh_buy, include_transfers=include_transfers_val)
        fig = graph_to_plotly(G,
                              node_color_amc=node_color_amc_val,
                              node_color_company=node_color_company_val,
                              node_shape_amc=node_shape_amc_val,
                              node_shape_company=node_shape_company_val,
                              edge_color_buy=edge_color_buy_val,
                              edge_color_sell=edge_color_sell_val,
                              edge_color_transfer=edge_color_transfer_val,
                              edge_thickness_base=edge_thickness_val,
                              show_labels=True)
        loops = detect_loops(G, max_length=6)
        if loops:
            loops_md = "### Detected AMC transfer loops (inferred):\n"
            for i, loop in enumerate(loops, 1):
                loops_md += f"- Loop {i}: " + " → ".join(loop) + "\n"
        else:
            loops_md = "No small transfer loops detected (based on current inferred transfer edges)."
        return fig, loops_md, companies, amcs

    update_btn.click(on_update,
                     inputs=[csv_uploader, node_color_company, node_color_amc, node_shape_company, node_shape_amc,
                             edge_color_buy, edge_color_sell, edge_color_transfer, edge_thickness, include_transfers_chk],
                     outputs=[network_plot, loops_text, company_selector, amc_selector])

    # Defensive normalizer for dropdown values (sometimes Gradio returns list)
    def normalize_dropdown_value(val):
        if val is None:
            return None
        if isinstance(val, list):
            return val[0] if len(val) > 0 else None
        try:
            return str(val)
        except Exception:
            return None

    def on_company_sel(company_name, csv_file):
        cname = normalize_dropdown_value(company_name)
        if cname is None:
            return None, pd.DataFrame([], columns=["Role","AMC"])
        amcs, companies, buy_map, sell_map, complete_exit, fresh_buy = load_dataset_from_csv(csv_file)
        fig, df = company_trade_summary(cname, buy_map, sell_map, fresh_buy, complete_exit)
        if fig is None:
            return None, pd.DataFrame([], columns=["Role","AMC"])
        return fig, df

    company_selector.change(on_company_sel, inputs=[company_selector, csv_uploader], outputs=[company_plot, company_table])

    def on_amc_sel(amc_name, csv_file):
        aname = normalize_dropdown_value(amc_name)
        if aname is None:
            return None, pd.DataFrame([], columns=["security","buyer_amc"])
        amcs, companies, buy_map, sell_map, complete_exit, fresh_buy = load_dataset_from_csv(csv_file)
        fig, df = amc_transfer_summary(aname, buy_map, sell_map)
        if fig is None:
            return None, pd.DataFrame([], columns=["security","buyer_amc"])
        return fig, df

    amc_selector.change(on_amc_sel, inputs=[amc_selector, csv_uploader], outputs=[amc_plot, amc_table])

    gr.Markdown("---")
    gr.Markdown("**Notes:** This app *infers* direct AMC→AMC transfers when one fund sells a security and another buys the same security in the dataset. That inference is not proof of a direct bilateral trade, but it describes likely liquidity flows used to exit or absorb positions.")

if __name__ == "__main__":
    demo.queue().launch(share=False)