app.py

# app.py – Unified Panel App with Semantic Search + Filterable Tabulator

import os, io, gc
import panel as pn
import pandas as pd
import boto3, torch
import psycopg2
from sentence_transformers import SentenceTransformer, util

pn.extension('tabulator')

# ──────────────────────────────────────────────────────────────────────
# 1) Database and Resource Loading
# ──────────────────────────────────────────────────────────────────────
DB_HOST = os.getenv("DB_HOST")
DB_PORT = os.getenv("DB_PORT", "5432")
DB_NAME = os.getenv("DB_NAME")
DB_USER = os.getenv("DB_USER")
DB_PASSWORD = os.getenv("DB_PASSWORD")

@pn.cache()
def get_data():
    conn = psycopg2.connect(
        host=DB_HOST, port=DB_PORT,
        dbname=DB_NAME, user=DB_USER, password=DB_PASSWORD,
        sslmode="require"
    )
    df_ = pd.read_sql_query("""
        SELECT id, country, year, section,
               question_code, question_text,
               answer_code,  answer_text
          FROM survey_info;
    """, conn)
    conn.close()

    # Ensure year column is int, show blank instead of NaN
    if "year" in df_.columns:
        df_["year"] = pd.to_numeric(df_["year"], errors="coerce").astype("Int64")
    return df_

df = get_data()

@pn.cache()
def load_embeddings():
    BUCKET, KEY = "cgd-embeddings-bucket", "survey_info_embeddings.pt"
    buf = io.BytesIO()
    boto3.client("s3").download_fileobj(BUCKET, KEY, buf)
    buf.seek(0)
    ckpt = torch.load(buf, map_location="cpu")
    buf.close(); gc.collect()
    return ckpt["ids"], ckpt["embeddings"]

@pn.cache()
def get_st_model():
    return SentenceTransformer("sentence-transformers/all-MiniLM-L6-v2", device="cpu")

@pn.cache()
def get_semantic_resources():
    model = get_st_model()
    ids_list, emb_tensor = load_embeddings()
    return model, ids_list, emb_tensor

# ──────────────────────────────────────────────────────────────────────
# 2) Widgets
# ──────────────────────────────────────────────────────────────────────
country_opts = sorted(df["country"].dropna().unique())
year_opts = sorted(df["year"].dropna().unique())

w_countries = pn.widgets.MultiSelect(name="Countries", options=country_opts)
w_years = pn.widgets.MultiSelect(name="Years", options=year_opts)
w_keyword = pn.widgets.TextInput(name="Keyword Search", placeholder="Search questions or answers with exact string matching")
w_group = pn.widgets.Checkbox(name="Group by Question Text", value=False)

w_semquery = pn.widgets.TextInput(name="Semantic Query", placeholder="LLM-powered semantic search")
w_search_button = pn.widgets.Button(name="Search", button_type="primary")
w_clear_filters = pn.widgets.Button(name="Clear Filters", button_type="warning")

# ──────────────────────────────────────────────────────────────────────
# 3) Unified Results Table (Tabulator)
# ──────────────────────────────────────────────────────────────────────
result_table = pn.widgets.Tabulator(
    pagination='remote',
    page_size=15,
    sizing_mode="stretch_width",
    layout='fit_columns',
    show_index=False
)

# ──────────────────────────────────────────────────────────────────────
# 4) Semantic Search with Filtering
# ──────────────────────────────────────────────────────────────────────
def semantic_search(event=None):
    """Run filtered view if no semantic query; otherwise do semantic within filtered subset."""
    query = w_semquery.value.strip()

    # 1) Apply filters first (country/year/keyword)
    filt = df.copy()
    if w_countries.value:
        filt = filt[filt["country"].isin(w_countries.value)]
    if w_years.value:
        filt = filt[filt["year"].isin(w_years.value)]
    if w_keyword.value:
        filt = filt[
            filt["question_text"].str.contains(w_keyword.value, case=False, na=False) |
            filt["answer_text"].str.contains(w_keyword.value, case=False, na=False) |
            filt["question_code"].astype(str).str.contains(w_keyword.value, case=False, na=False)
        ]

    # 2) If no semantic query, just show the filtered data (no Score column)
    if not query:
        if filt.empty:
            result_table.value = pd.DataFrame(columns=["country", "year", "question_text", "answer_text"])
        else:
            result_table.value = filt[["country", "year", "question_text", "answer_text"]]
        return

    # 3) Otherwise, do semantic search *within* the filtered subset
    model, ids_list, emb_tensor = get_semantic_resources()

    filtered_ids = filt["id"].tolist()
    id_to_index = {id_: i for i, id_ in enumerate(ids_list)}
    filtered_indices = [id_to_index[id_] for id_ in filtered_ids if id_ in id_to_index]

    if not filtered_indices:
        result_table.value = pd.DataFrame(columns=["Score", "country", "year", "question_text", "answer_text"])
        return

    filtered_embs = emb_tensor[filtered_indices]

    q_vec = model.encode(query, convert_to_tensor=True, device="cpu").cpu()
    sims = util.cos_sim(q_vec, filtered_embs)[0]
    top_vals, top_idx = torch.topk(sims, k=50)

    top_filtered_ids = [filtered_ids[i] for i in top_idx.tolist()]
    sem_rows = filt[filt["id"].isin(top_filtered_ids)].copy()
    score_map = dict(zip(top_filtered_ids, top_vals.tolist()))
    sem_rows["Score"] = sem_rows["id"].map(score_map)
    sem_rows = sem_rows.sort_values("Score", ascending=False)

    result_table.value = sem_rows[["Score", "country", "year", "question_text", "answer_text"]]


def clear_filters(event=None):
    w_countries.value = []
    w_years.value = []
    w_keyword.value = ""
    w_semquery.value = ""
    result_table.value = df[["country", "year", "question_text", "answer_text"]].copy()

w_search_button.on_click(semantic_search)
w_clear_filters.on_click(clear_filters)

# ──────────────────────────────────────────────────────────────────────
# 5) Layout
# ──────────────────────────────────────────────────────────────────────
sidebar = pn.Column(
    "## 🔎 Filters",
    w_countries, w_years, w_keyword, w_group,
    pn.Spacer(height=20),
    "## 🧠 Semantic Search",
    w_semquery, w_search_button,
    pn.Spacer(height=20),
    w_clear_filters,
    width=300
)

main = pn.Column(
    pn.pane.Markdown("## 🌍 CGD Survey Explorer"),
    result_table
)

pn.template.FastListTemplate(
    title="CGD Survey Explorer",
    sidebar=sidebar,
    main=main,
    theme_toggle=True,
).servable()