Create screener.py

app/screener.py

@@ -0,0 +1,159 @@
+import requests
+import pandas as pd
+from bs4 import BeautifulSoup
+from typing import List, Tuple
+
+from . import persist
+
+
+# ===============================
+# Screener name → URL mapping
+# ===============================
+SCREENER_MAP = {
+    "top_gainers": "https://www.screener.in/screens/7054/top-gainers/",
+    "top_losers": "https://www.screener.in/screens/7055/top-losers/",
+    "high_volume": "https://www.screener.in/screens/3352/high-volume-stocks/",
+    "breakout_stocks": "https://www.screener.in/screens/1849/breakout-stocks/",
+    "fifty_two_wk_high": "https://www.screener.in/screens/3588/52-week-high/",
+    "fifty_two_wk_low": "https://www.screener.in/screens/3589/52-week-low/",
+    "new_highs": "https://www.screener.in/screens/4921/new-highs/",
+    "new_lows": "https://www.screener.in/screens/4922/new-lows/",
+    "rsi_oversold": "https://www.screener.in/screens/1751/rsi-oversold-stocks/",
+    "rsi_overbought": "https://www.screener.in/screens/1750/rsi-overbought-stocks/",
+    "price_above_sma": "https://www.screener.in/screens/1764/price-above-sma/",
+    "large_cap": "https://www.screener.in/screens/3360/large-cap-stocks/",
+    "mid_cap": "https://www.screener.in/screens/3361/mid-cap-stocks/",
+    "small_cap": "https://www.screener.in/screens/3362/small-cap-stocks/",
+}
+
+
+# ===============================
+# Public API
+# ===============================
+def fetch_screener(screen_name: str) -> str:
+    """
+    Returns a fully styled HTML table for a given screener name.
+    Uses disk persistence (HTML primary, CSV secondary).
+    """
+
+    if screen_name not in SCREENER_MAP:
+        return _error_html(f"Invalid screener: {screen_name}")
+
+    cache_name = f"SCREENER_{screen_name.upper()}"
+
+    # 1️⃣ Cache hit
+    if persist.exists(cache_name, "html"):
+        return persist.load(cache_name, "html")
+
+    # 2️⃣ Fetch live
+    headers, rows = _fetch_table(SCREENER_MAP[screen_name])
+
+    if not headers or not rows:
+        return _error_html("No data available")
+
+    # 3️⃣ Build outputs
+    html = _build_html(headers, rows)
+    csv_df = pd.DataFrame(rows, columns=headers)
+
+    # 4️⃣ Persist
+    persist.save(cache_name, html, "html")
+    persist.save(cache_name, csv_df, "csv")
+
+    return html
+
+
+# ===============================
+# Internal helpers
+# ===============================
+def _fetch_table(url: str) -> Tuple[List[str], List[List[str]]]:
+    r = requests.get(
+        url,
+        headers={"User-Agent": "Mozilla/5.0"},
+        timeout=15
+    )
+    r.raise_for_status()
+
+    soup = BeautifulSoup(r.text, "html.parser")
+    table = soup.find("table")
+    if not table:
+        return [], []
+
+    thead = table.find("thead")
+    header_row = thead.find("tr") if thead else table.find("tr")
+    headers = [th.get_text(strip=True) for th in header_row.find_all("th")]
+
+    rows = []
+    for tr in table.find_all("tr")[1:]:
+        cells = tr.find_all("td")
+        if cells:
+            rows.append([td.get_text(strip=True) for td in cells])
+
+    return headers, rows
+
+
+def _build_html(headers: List[str], rows: List[List[str]]) -> str:
+    style = """
+    <style>
+        .screener-wrap {
+            width: 100%;
+            overflow-x: auto;
+            font-family: Arial, sans-serif;
+        }
+        table.screener {
+            border-collapse: collapse;
+            width: 100%;
+            min-width: 900px;
+            font-size: 13px;
+        }
+        table.screener th {
+            position: sticky;
+            top: 0;
+            background: #1e293b;
+            color: #ffffff;
+            padding: 8px;
+            border: 1px solid #334155;
+            white-space: nowrap;
+        }
+        table.screener td {
+            padding: 6px 8px;
+            border: 1px solid #e5e7eb;
+            white-space: nowrap;
+        }
+        table.screener tr:nth-child(even) {
+            background: #f8fafc;
+        }
+        table.screener tr:hover {
+            background: #e0f2fe;
+        }
+    </style>
+    """
+
+    html = [style, "<div class='screener-wrap'>", "<table class='screener'>"]
+
+    html.append("<tr>")
+    for h in headers:
+        html.append(f"<th>{h}</th>")
+    html.append("</tr>")
+
+    for row in rows:
+        html.append("<tr>")
+        for cell in row:
+            html.append(f"<td>{cell}</td>")
+        html.append("</tr>")
+
+    html.append("</table></div>")
+    return "".join(html)
+
+
+def _error_html(msg: str) -> str:
+    return f"""
+    <div style="
+        color:#b91c1c;
+        background:#fee2e2;
+        padding:12px;
+        border-radius:6px;
+        font-family:Arial;
+    ">
+        ❌ {msg}
+    </div>
+    """