feat(agent): integrate procurement AI agent with Bale bot, real-time draft sync, and git history bundle

ai procurement/app/stt.py

@@ -0,0 +1,62 @@
+"""Speech-to-text via an OpenAI-compatible /audio/transcriptions endpoint.
+
+Bale voice notes arrive as OGG/Opus which not every provider accepts, so the
+audio is first converted to mono 16 kHz MP3 with ffmpeg (installed in the bot
+image). Any OpenAI-compatible provider works (OpenAI, GLM, OpenRouter proxies,
+self-hosted whisper servers exposing the same contract).
+"""
+import asyncio
+import logging
+import subprocess
+import tempfile
+from pathlib import Path
+
+import httpx
+
+from app.config import Settings
+
+logger = logging.getLogger("bot.stt")
+
+_CONVERT_TIMEOUT = 60
+_STT_TIMEOUT = 120
+
+
+def _to_mp3(raw: bytes, suffix: str) -> bytes:
+    """Convert arbitrary audio bytes to mono 16 kHz MP3 using ffmpeg."""
+    with tempfile.TemporaryDirectory() as tmp:
+        src = Path(tmp) / f"in{suffix or '.ogg'}"
+        dst = Path(tmp) / "out.mp3"
+        src.write_bytes(raw)
+        proc = subprocess.run(
+            ["ffmpeg", "-y", "-i", str(src), "-vn", "-ac", "1", "-ar", "16000", "-b:a", "64k", str(dst)],
+            capture_output=True,
+            timeout=_CONVERT_TIMEOUT,
+        )
+        if proc.returncode != 0 or not dst.exists():
+            raise RuntimeError(f"ffmpeg failed: {proc.stderr[-400:]!r}")
+        return dst.read_bytes()
+
+
+async def transcribe(settings: Settings, audio: bytes, mime_type: str | None = None,
+                     filename: str | None = None) -> str:
+    """Return the Persian transcript for a voice note (empty string on silence)."""
+    if not settings.stt_base_url or not settings.stt_api_key:
+        raise RuntimeError("STT provider is not configured (PROCUREMENT_BOT_STT_BASE_URL / _AI_BASE_URL)")
+
+    suffix = Path(filename or "").suffix
+    if not suffix and mime_type:
+        suffix = {"audio/ogg": ".ogg", "audio/opus": ".ogg", "audio/mpeg": ".mp3",
+                  "audio/mp4": ".m4a", "audio/wav": ".wav"}.get(mime_type.split(";")[0].strip(), ".ogg")
+    converted = await asyncio.to_thread(_to_mp3, audio, suffix)
+
+    url = f"{settings.stt_base_url.rstrip('/')}/audio/transcriptions"
+    async with httpx.AsyncClient(timeout=_STT_TIMEOUT) as client:
+        resp = await client.post(
+            url,
+            headers={"Authorization": f"Bearer {settings.stt_api_key}"},
+            files={"file": ("voice.mp3", converted, "audio/mpeg")},
+            data={"model": settings.STT_MODEL, "language": settings.STT_LANGUAGE},
+        )
+    if resp.status_code != 200:
+        raise RuntimeError(f"STT provider returned HTTP {resp.status_code}: {resp.text[:300]}")
+    return str((resp.json() or {}).get("text") or "").strip()