refactor: consolidate HTML extraction into app/utils.py

Rename _strip_html/_extract_body to strip_html/extract_body (public API).
Remove duplicate _TextExtractor, strip_html, and _extract_body from
imap_fetch.py; import from app.utils instead. Update test_label_tool.py
to use the new public names.

app/imap_fetch.py

@@ -1,6 +1,6 @@
 """Avocet — IMAP fetch utilities.
 
-Shared between app/api.py (FastAPI SSE endpoint) and app/label_tool.py (Streamlit).
+Shared between app/api.py (FastAPI SSE endpoint) and the label UI.
 No Streamlit imports here — stdlib + imaplib only.
 """
 from __future__ import annotations
@@ -8,36 +8,11 @@ from __future__ import annotations
 import email as _email_lib
 import hashlib
 import imaplib
-import re
 from datetime import datetime, timedelta
 from email.header import decode_header as _raw_decode
-from html.parser import HTMLParser
 from typing import Any, Iterator
 
-
+from app.utils import extract_body, strip_html  # noqa: F401 (strip_html re-exported for callers)
-# ── HTML → plain text ────────────────────────────────────────────────────────
-
-class _TextExtractor(HTMLParser):
-    def __init__(self):
-        super().__init__()
-        self._parts: list[str] = []
-
-    def handle_data(self, data: str) -> None:
-        stripped = data.strip()
-        if stripped:
-            self._parts.append(stripped)
-
-    def get_text(self) -> str:
-        return " ".join(self._parts)
-
-
-def strip_html(html_str: str) -> str:
-    try:
-        ex = _TextExtractor()
-        ex.feed(html_str)
-        return ex.get_text()
-    except Exception:
-        return re.sub(r"<[^>]+>", " ", html_str).strip()
 
 
 # ── IMAP decode helpers ───────────────────────────────────────────────────────
@@ -55,37 +30,6 @@ def _decode_str(value: str | None) -> str:
     return " ".join(out).strip()
 
 
-def _extract_body(msg: Any) -> str:
-    if msg.is_multipart():
-        html_fallback: str | None = None
-        for part in msg.walk():
-            ct = part.get_content_type()
-            if ct == "text/plain":
-                try:
-                    charset = part.get_content_charset() or "utf-8"
-                    return part.get_payload(decode=True).decode(charset, errors="replace")
-                except Exception:
-                    pass
-            elif ct == "text/html" and html_fallback is None:
-                try:
-                    charset = part.get_content_charset() or "utf-8"
-                    raw = part.get_payload(decode=True).decode(charset, errors="replace")
-                    html_fallback = strip_html(raw)
-                except Exception:
-                    pass
-        return html_fallback or ""
-    else:
-        try:
-            charset = msg.get_content_charset() or "utf-8"
-            raw = msg.get_payload(decode=True).decode(charset, errors="replace")
-            if msg.get_content_type() == "text/html":
-                return strip_html(raw)
-            return raw
-        except Exception:
-            pass
-    return ""
-
-
 def entry_key(e: dict) -> str:
     """Stable MD5 content-hash for dedup — matches label_tool.py _entry_key."""
     key = (e.get("subject", "") + (e.get("body", "") or "")[:100])
@@ -193,7 +137,7 @@ def fetch_account_stream(
             subj      = _decode_str(msg.get("Subject", ""))
             from_addr = _decode_str(msg.get("From", ""))
             date      = _decode_str(msg.get("Date", ""))
-            body      = _extract_body(msg)[:800]
+            body      = extract_body(msg)[:800]
             entry     = {"subject": subj, "body": body, "from_addr": from_addr,
                          "date": date, "account": name}
             k = entry_key(entry)

app/utils.py

@@ -43,7 +43,7 @@ class _TextExtractor(HTMLParser):
         return "\n".join(ln for ln in lines if ln)
 
 
-def _strip_html(html_str: str) -> str:
+def strip_html(html_str: str) -> str:
     """Convert HTML email body to plain text. Pure stdlib, no dependencies."""
     try:
         extractor = _TextExtractor()
@@ -53,7 +53,7 @@ def _strip_html(html_str: str) -> str:
         return re.sub(r"<[^>]+>", " ", html_str).strip()
 
 
-def _extract_body(msg: Any) -> str:
+def extract_body(msg: Any) -> str:
     """Return plain-text body. Strips HTML when no text/plain part exists."""
     if msg.is_multipart():
         html_fallback: str | None = None
@@ -69,7 +69,7 @@ def _extract_body(msg: Any) -> str:
                 try:
                     charset = part.get_content_charset() or "utf-8"
                     raw = part.get_payload(decode=True).decode(charset, errors="replace")
-                    html_fallback = _strip_html(raw)
+                    html_fallback = strip_html(raw)
                 except Exception:
                     pass
         return html_fallback or ""
@@ -78,7 +78,7 @@ def _extract_body(msg: Any) -> str:
             charset = msg.get_content_charset() or "utf-8"
             raw = msg.get_payload(decode=True).decode(charset, errors="replace")
             if msg.get_content_type() == "text/html":
-                return _strip_html(raw)
+                return strip_html(raw)
             return raw
         except Exception:
             pass

tests/test_label_tool.py

@@ -5,83 +5,83 @@ These functions are stdlib-only and safe to test without an IMAP connection.
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 
-from app.utils import _extract_body, _strip_html
+from app.utils import extract_body, strip_html
 
 
-# ── _strip_html ──────────────────────────────────────────────────────────────
+# ── strip_html ──────────────────────────────────────────────────────────────
 
 def test_strip_html_removes_tags():
-    assert _strip_html("<p>Hello <b>world</b></p>") == "Hello world"
+    assert strip_html("<p>Hello <b>world</b></p>") == "Hello world"
 
 
 def test_strip_html_skips_script_content():
-    result = _strip_html("<script>doEvil()</script><p>real</p>")
+    result = strip_html("<script>doEvil()</script><p>real</p>")
     assert "doEvil" not in result
     assert "real" in result
 
 
 def test_strip_html_skips_style_content():
-    result = _strip_html("<style>.foo{color:red}</style><p>visible</p>")
+    result = strip_html("<style>.foo{color:red}</style><p>visible</p>")
     assert ".foo" not in result
     assert "visible" in result
 
 
 def test_strip_html_handles_br_as_newline():
-    result = _strip_html("line1<br>line2")
+    result = strip_html("line1<br>line2")
     assert "line1" in result
     assert "line2" in result
 
 
 def test_strip_html_decodes_entities():
     # convert_charrefs=True on HTMLParser handles &amp; etc.
-    result = _strip_html("<p>Hello &amp; welcome</p>")
+    result = strip_html("<p>Hello &amp; welcome</p>")
     assert "&amp;" not in result
     assert "Hello" in result
     assert "welcome" in result
 
 
 def test_strip_html_empty_string():
-    assert _strip_html("") == ""
+    assert strip_html("") == ""
 
 
 def test_strip_html_plain_text_passthrough():
-    assert _strip_html("no tags here") == "no tags here"
+    assert strip_html("no tags here") == "no tags here"
 
 
-# ── _extract_body ────────────────────────────────────────────────────────────
+# ── extract_body ────────────────────────────────────────────────────────────
 
 def test_extract_body_prefers_plain_over_html():
     msg = MIMEMultipart("alternative")
     msg.attach(MIMEText("plain body", "plain"))
     msg.attach(MIMEText("<html><body>html body</body></html>", "html"))
-    assert _extract_body(msg) == "plain body"
+    assert extract_body(msg) == "plain body"
 
 
 def test_extract_body_falls_back_to_html_when_no_plain():
     msg = MIMEMultipart("alternative")
     msg.attach(MIMEText("<html><body><p>HTML only email</p></body></html>", "html"))
-    result = _extract_body(msg)
+    result = extract_body(msg)
     assert "HTML only email" in result
     assert "<" not in result  # no raw HTML tags leaked through
 
 
 def test_extract_body_non_multipart_html_stripped():
     msg = MIMEText("<html><body><p>Solo HTML</p></body></html>", "html")
-    result = _extract_body(msg)
+    result = extract_body(msg)
     assert "Solo HTML" in result
     assert "<html>" not in result
 
 
 def test_extract_body_non_multipart_plain_unchanged():
     msg = MIMEText("just plain text", "plain")
-    assert _extract_body(msg) == "just plain text"
+    assert extract_body(msg) == "just plain text"
 
 
 def test_extract_body_empty_message():
     msg = MIMEText("", "plain")
-    assert _extract_body(msg) == ""
+    assert extract_body(msg) == ""
 
 
 def test_extract_body_multipart_empty_returns_empty():
     msg = MIMEMultipart("alternative")
-    assert _extract_body(msg) == ""
+    assert extract_body(msg) == ""