app.py

import os
import time
import json
import tempfile
from collections import deque

from flask import Flask, request, jsonify, send_file
from waitress import serve

from google import genai
from google.genai import types

from faster_whisper import WhisperModel

from elevenlabs.client import ElevenLabs
from elevenlabs import save, VoiceSettings


app = Flask(__name__)

# -------------------------
# Config
# -------------------------
MODEL = os.environ.get("GEMINI_MODEL", "gemini-3-flash-preview")
THINKING_LEVEL = os.environ.get("GEMINI_THINKING_LEVEL", "LOW")

SYSTEM_PROMPT = (
    "You should respond like Andy Warhol.\n"
    "Respond in 1-3 sentences and less than 200 characters.\n"
    "You should say uh 0-2 times per response, it can be in different parts of the response.\n"
    "Don't repeat yourself too much.\n"
)


# -------------------------
# Auth
# -------------------------
API_PASSWORD = os.environ.get("API_PASSWORD", "").strip()

def _require_auth():
    """
    Require a shared secret from the client.
    Client must send header: X-API-PASSWORD: <secret>
    """
    if not API_PASSWORD:
        # If you forget to set the secret, fail closed.
        return jsonify({"error": "Server missing API_PASSWORD secret"}), 500

    provided = (request.headers.get("X-API-PASSWORD") or "").strip()
    if not provided or provided != API_PASSWORD:
        return jsonify({"error": "Unauthorized"}), 401

    return None


# STT (we chose base.en)
WHISPER_MODEL_NAME = os.environ.get("WHISPER_MODEL", "base.en")
WHISPER_DEVICE = os.environ.get("WHISPER_DEVICE", "cpu")
WHISPER_COMPUTE_TYPE = os.environ.get("WHISPER_COMPUTE_TYPE", "int8")
WHISPER_LANGUAGE = os.environ.get("WHISPER_LANGUAGE", "en")

# ElevenLabs
ELEVEN_API_KEY = os.environ.get("ELEVEN_API_KEY")
ELEVEN_VOICE_ID = os.environ.get("ELEVEN_VOICE_ID", "kYLLcRUC2uzrEp0Jr2HT")
ELEVEN_MODEL_ID = os.environ.get("ELEVEN_MODEL_ID", "eleven_multilingual_v2")
ELEVEN_OUTPUT_FORMAT = os.environ.get("ELEVEN_OUTPUT_FORMAT", "mp3_44100_128")

# Gemini client (expects GEMINI_API_KEY set as a HF Space Secret)
client = genai.Client(api_key=os.environ.get("GEMINI_API_KEY"))

# Eleven client
eleven = ElevenLabs(api_key=ELEVEN_API_KEY) if ELEVEN_API_KEY else None

# ---- Memory (global, RAM-only, survives refresh, resets on Space restart) ----
MAX_MESSAGES = 20
HISTORY = deque(maxlen=MAX_MESSAGES)

# ---- Whisper model (lazy init) ----
_whisper_model = None


# -------------------------
# Helpers
# -------------------------
def _client_ip() -> str:
    return request.headers.get("x-forwarded-for", request.remote_addr or "unknown")


def _err_details(e: Exception) -> dict:
    d = {"type": type(e).__name__, "repr": repr(e)}
    for k in ["status_code", "body", "message", "response", "details"]:
        if hasattr(e, k):
            try:
                d[k] = getattr(e, k)
            except Exception:
                pass
    return d


def _get_whisper_model() -> WhisperModel:
    global _whisper_model
    if _whisper_model is None:
        print(
            f"[whisper] loading model={WHISPER_MODEL_NAME} "
            f"device={WHISPER_DEVICE} compute_type={WHISPER_COMPUTE_TYPE}"
        )
        _whisper_model = WhisperModel(
            WHISPER_MODEL_NAME,
            device=WHISPER_DEVICE,
            compute_type=WHISPER_COMPUTE_TYPE,
        )
        print("[whisper] loaded")
    return _whisper_model


def _clean_reply(text: str) -> str:
    t = (text or "").strip()
    if not t:
        return t
    if t.endswith(("...", "…", ",")):
        t = t.rstrip(".,… ,").strip()
    if t and t[-1] not in ".?!":
        t += "."
    return t


def _gemini_config() -> types.GenerateContentConfig:
    return types.GenerateContentConfig(
        system_instruction=[types.Part.from_text(text=SYSTEM_PROMPT)],
        thinking_config=types.ThinkingConfig(thinking_level=THINKING_LEVEL),
        #max_output_tokens=256,
        #temperature=0.7,
        safety_settings=[
            types.SafetySetting(
                category=types.HarmCategory.HARM_CATEGORY_HARASSMENT,
                threshold=types.HarmBlockThreshold.OFF,
            ),
            types.SafetySetting(
                category=types.HarmCategory.HARM_CATEGORY_HATE_SPEECH,
                threshold=types.HarmBlockThreshold.OFF,
            ),
            types.SafetySetting(
                category=types.HarmCategory.HARM_CATEGORY_SEXUALLY_EXPLICIT,
                threshold=types.HarmBlockThreshold.OFF,
            ),
            types.SafetySetting(
                category=types.HarmCategory.HARM_CATEGORY_DANGEROUS_CONTENT,
                threshold=types.HarmBlockThreshold.OFF,
            ),
        ],
    )


def llm_chat(user_text: str) -> str:
    user_text = (user_text or "").strip()
    if not user_text:
        raise ValueError("Missing 'text'")

    HISTORY.append(types.Content(role="user", parts=[types.Part.from_text(text=user_text)]))

    try:
        resp = client.models.generate_content(
            model=MODEL,
            contents=list(HISTORY),
            config=_gemini_config(),
        )
        reply_text = _clean_reply(resp.text)

        HISTORY.append(types.Content(role="model", parts=[types.Part.from_text(text=reply_text)]))
        return reply_text

    except Exception:
        if len(HISTORY) > 0 and getattr(HISTORY[-1], "role", None) == "user":
            HISTORY.pop()
        raise


def _tts_to_mp3_file(text: str) -> tuple[str, int]:
    """
    Returns: (mp3_path, tts_ms)
    Raises exception on failure.
    """
    if eleven is None:
        raise RuntimeError("Server missing ELEVEN_API_KEY")

    t0 = time.time()

    audio_stream = eleven.text_to_speech.convert(
        text=text,
        voice_id=ELEVEN_VOICE_ID,
        model_id=ELEVEN_MODEL_ID,
        output_format=ELEVEN_OUTPUT_FORMAT,
        voice_settings=VoiceSettings(
            speed=0.8, 
        ),
    )

    with tempfile.NamedTemporaryFile(delete=False, suffix=".mp3") as tmp_out:
        mp3_path = tmp_out.name

    save(audio_stream, mp3_path)
    tts_ms = int((time.time() - t0) * 1000)
    return mp3_path, tts_ms


# -------------------------
# Endpoints
# -------------------------
@app.get("/health")
def health():
    print(f"[/health] {time.strftime('%Y-%m-%d %H:%M:%S')} ip={_client_ip()} mem={len(HISTORY)}/{MAX_MESSAGES}")
    return jsonify({
        "ok": True,
        "model": MODEL,
        "thinking_level": THINKING_LEVEL,
        "memory_messages": len(HISTORY),
        "max_messages": MAX_MESSAGES,
        "whisper_model": WHISPER_MODEL_NAME,
        "whisper_device": WHISPER_DEVICE,
        "whisper_compute_type": WHISPER_COMPUTE_TYPE,
        "eleven_ok": bool(ELEVEN_API_KEY),
        "eleven_voice_id": ELEVEN_VOICE_ID,
        "eleven_model_id": ELEVEN_MODEL_ID,
        "eleven_output_format": ELEVEN_OUTPUT_FORMAT,
    })


@app.post("/v1/chat")
def chat_text():
    auth_resp = _require_auth()
    if auth_resp:
        return auth_resp
        
    t0 = time.time()
    ip = _client_ip()

    data = request.get_json(silent=True) or {}
    user_text = (data.get("text") or "").strip()

    print(f"[/v1/chat] START {time.strftime('%Y-%m-%d %H:%M:%S')} ip={ip} mem_before={len(HISTORY)}/{MAX_MESSAGES}")

    if not user_text:
        print(f"[/v1/chat] ERROR missing text ip={ip}")
        return jsonify({"error": "Missing 'text'"}), 400

    print(f"[/v1/chat] user_text_len={len(user_text)} user_text={user_text!r}")

    try:
        reply_text = llm_chat(user_text)
        dt_ms = int((time.time() - t0) * 1000)

        print(f"[/v1/chat] bot_reply={reply_text!r}")
        print(f"[/v1/chat] END ip={ip} total_ms={dt_ms} mem_now={len(HISTORY)}/{MAX_MESSAGES}")

        return jsonify({
            "input": user_text,
            "reply_text": reply_text,
            "model": MODEL,
            "memory_messages": len(HISTORY),
            "total_ms": dt_ms,
        })

    except Exception as e:
        dt_ms = int((time.time() - t0) * 1000)
        print("Gemini error:", repr(e))
        print(f"[/v1/chat] FAIL ip={ip} total_ms={dt_ms} mem_now={len(HISTORY)}/{MAX_MESSAGES}")
        return jsonify({"error": "Gemini call failed"}), 500


@app.post("/v1/tts")
def tts_only():
    """
    JSON body: { "text": "hello" }
    Returns: audio/mpeg (mp3)
    Timing headers:
      X-TTS-MS, X-TOTAL-MS
    """
    auth_resp = _require_auth()
    if auth_resp:
        return auth_resp
        
    ip = _client_ip()
    t0 = time.time()

    data = request.get_json(silent=True) or {}
    text = (data.get("text") or "").strip()

    print(f"[/v1/tts] START {time.strftime('%Y-%m-%d %H:%M:%S')} ip={ip} text_len={len(text)}")

    if not text:
        return jsonify({"error": "Missing 'text'"}), 400

    mp3_path = None
    try:
        mp3_path, tts_ms = _tts_to_mp3_file(text)
        total_ms = int((time.time() - t0) * 1000)

        print(f"[/v1/tts] OK tts_ms={tts_ms} total_ms={total_ms}")

        resp = send_file(
            mp3_path,
            mimetype="audio/mpeg",
            as_attachment=False,
            download_name="andy.mp3",
            conditional=False,
        )
        resp.headers["X-TTS-MS"] = str(tts_ms)
        resp.headers["X-TOTAL-MS"] = str(total_ms)
        return resp

    except Exception as e:
        details = _err_details(e)
        total_ms = int((time.time() - t0) * 1000)
        print(f"[/v1/tts] FAIL total_ms={total_ms} details={json.dumps(details, default=str)[:2000]}")
        return jsonify({"error": "ElevenLabs TTS failed", "details": details, "total_ms": total_ms}), 502

    finally:
        if mp3_path:
            try:
                os.remove(mp3_path)
            except Exception:
                pass


@app.post("/v1/utterance")
def utterance_audio_to_audio():
    """
    Accepts: multipart/form-data with field "audio" containing a .wav file
    Returns: audio/mpeg (mp3)

    Timing headers:
      X-STT-MS, X-LLM-MS, X-TTS-MS, X-TOTAL-MS
    """
    auth_resp = _require_auth()
    if auth_resp:
        return auth_resp
        
    t0 = time.time()
    ip = _client_ip()

    print(f"[/v1/utterance] START {time.strftime('%Y-%m-%d %H:%M:%S')} ip={ip}")

    if eleven is None:
        print("[/v1/utterance] ERROR missing ELEVEN_API_KEY")
        return jsonify({"error": "Server missing ELEVEN_API_KEY"}), 500

    if "audio" not in request.files:
        print(f"[/v1/utterance] ERROR missing file field 'audio' ip={ip}")
        return jsonify({"error": "Missing file field 'audio'"}), 400

    f = request.files["audio"]
    filename = (f.filename or "").strip() or "audio.wav"
    if not filename.lower().endswith(".wav"):
        print(f"[/v1/utterance] ERROR non-wav filename={filename!r} ip={ip}")
        return jsonify({"error": "Please upload a .wav file"}), 400

    with tempfile.NamedTemporaryFile(delete=False, suffix=".wav") as tmp_in:
        wav_path = tmp_in.name
        f.save(wav_path)

    mp3_path = None
    stt_ms = llm_ms = tts_ms = 0
    transcript = ""
    reply_text = ""

    try:
        # ---- STT ----
        t_stt = time.time()
        model = _get_whisper_model()

        segments, _info = model.transcribe(
            wav_path,
            language=WHISPER_LANGUAGE,
            vad_filter=True,
            beam_size=1,
        )
        transcript = "".join(seg.text for seg in segments).strip()
        stt_ms = int((time.time() - t_stt) * 1000)

        print(f"[/v1/utterance] transcript_len={len(transcript)} stt_ms={stt_ms}")
        print(f"[/v1/utterance] transcript={transcript!r}")

        if not transcript:
            total_ms = int((time.time() - t0) * 1000)
            print(f"[/v1/utterance] EMPTY transcript total_ms={total_ms}")
            return jsonify({"error": "Empty transcript", "stt_ms": stt_ms, "total_ms": total_ms}), 200

        # ---- LLM ----
        t_llm = time.time()
        reply_text = llm_chat(transcript)
        llm_ms = int((time.time() - t_llm) * 1000)

        print(f"[/v1/utterance] reply_len={len(reply_text)} llm_ms={llm_ms}")
        print(f"[/v1/utterance] bot_reply={reply_text!r}")

        # ---- TTS ----
        try:
            mp3_path, tts_ms = _tts_to_mp3_file(reply_text)
        except Exception as e:
            details = _err_details(e)
            total_ms = int((time.time() - t0) * 1000)
            print(f"[/v1/utterance] TTS FAIL total_ms={total_ms} details={json.dumps(details, default=str)[:2000]}")
            return jsonify({
                "error": "ElevenLabs TTS failed",
                "details": details,
                "transcript": transcript,
                "reply_text": reply_text,
                "stt_ms": stt_ms,
                "llm_ms": llm_ms,
                "total_ms": total_ms,
            }), 502

        total_ms = int((time.time() - t0) * 1000)
        print(f"[/v1/utterance] tts_ms={tts_ms} total_ms={total_ms}")
        print(f"[/v1/utterance] END ip={ip}")

        resp = send_file(
            mp3_path,
            mimetype="audio/mpeg",
            as_attachment=False,
            download_name="andy.mp3",
            conditional=False,
        )
        resp.headers["X-STT-MS"] = str(stt_ms)
        resp.headers["X-LLM-MS"] = str(llm_ms)
        resp.headers["X-TTS-MS"] = str(tts_ms)
        resp.headers["X-TOTAL-MS"] = str(total_ms)
        return resp

    except Exception as e:
        total_ms = int((time.time() - t0) * 1000)
        details = _err_details(e)
        print(f"[/v1/utterance] FAIL ip={ip} total_ms={total_ms} details={json.dumps(details, default=str)[:2000]}")
        return jsonify({"error": "Utterance pipeline failed", "details": details, "total_ms": total_ms}), 500

    finally:
        try:
            os.remove(wav_path)
        except Exception:
            pass
        if mp3_path:
            try:
                os.remove(mp3_path)
            except Exception:
                pass


@app.post("/v1/reset")
def reset():
    auth_resp = _require_auth()
    if auth_resp:
        return auth_resp
        
    ip = _client_ip()
    print(f"[/v1/reset] {time.strftime('%Y-%m-%d %H:%M:%S')} ip={ip} clearing mem (was {len(HISTORY)}/{MAX_MESSAGES})")
    HISTORY.clear()
    return jsonify({"ok": True, "memory_messages": 0})


# -------------------------
# Startup
# -------------------------
if __name__ == "__main__":
    port = int(os.environ.get("PORT", "7860"))
    print(f"[startup] model={MODEL} thinking_level={THINKING_LEVEL} max_messages={MAX_MESSAGES} port={port}")
    print(f"[startup] whisper_model={WHISPER_MODEL_NAME} device={WHISPER_DEVICE} compute={WHISPER_COMPUTE_TYPE}")
    print(f"[startup] eleven_ok={bool(ELEVEN_API_KEY)} voice={ELEVEN_VOICE_ID} model={ELEVEN_MODEL_ID} out={ELEVEN_OUTPUT_FORMAT}")
    serve(app, host="0.0.0.0", port=port)