app.py

"""
🧬 Darwin-9B-NEG — API Serving (OpenAI-compatible)
No local GPU. Streams from the VIDRAFT inference API (api.1street.ai).
Custom frontend (index.html) preserved exactly — only the backend is API-based.
"""
import sys
print(f"[BOOT] Python {sys.version}", flush=True)

import base64, os, re, json
from typing import Generator, Optional

import gradio as gr
print(f"[BOOT] gradio {gr.__version__}", flush=True)

import requests, httpx, uvicorn
from fastapi import FastAPI, Request
from fastapi.responses import HTMLResponse, RedirectResponse, JSONResponse
from urllib.parse import urlencode
import pathlib, secrets

import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

# ══════════════════════════════════════════════════════════════════════════════
# 1.  MODEL / API CONFIG
# ══════════════════════════════════════════════════════════════════════════════
API_BASE   = os.getenv("VIDRAFT_API_BASE", "https://api.1street.ai")
API_MODEL  = os.getenv("VIDRAFT_API_MODEL", "vidraft/darwin-9b-neg")
API_KEY    = os.getenv("VIDRAFT_API_KEY", "")   # optional bearer; empty = no auth

MODEL_ID   = "FINAL-Bench/Darwin-9B-NEG"
MODEL_NAME = "Darwin-9B-NEG"
MODEL_CAP  = {
    "arch": "Qwen3.5 Dense", "active": "9B",
    "ctx": "131K", "thinking": True, "vision": False,
    "max_tokens": 8192, "temp_max": 1.5,
}

PRESETS = {
    "general":   "You are Darwin-9B-NEG, a highly capable reasoning model created by VIDRAFT via Negentropy distillation. Think step by step for complex questions.",
    "code":      "You are an expert software engineer. Write clean, efficient, well-commented code. Explain your approach before writing. Use modern best practices.",
    "math":      "You are a world-class mathematician. Break problems step-by-step. Show full working. Use LaTeX where helpful.",
    "creative":  "You are a brilliant creative writer. Be imaginative, vivid, and engaging. Adapt tone and style to the request.",
    "translate": "You are a professional translator. Provide accurate, natural-sounding translations with cultural context.",
    "research":  "You are a rigorous research analyst. Provide structured, well-reasoned analysis. Identify assumptions and acknowledge uncertainty.",
}

print(f"[API] base={API_BASE} model={API_MODEL} auth={'yes' if API_KEY else 'no'}", flush=True)

# ══════════════════════════════════════════════════════════════════════════════
# 2.  THINKING MODE HELPERS  (unchanged — drives the reasoning-chain UI)
# ══════════════════════════════════════════════════════════════════════════════
def parse_think_blocks(text: str) -> tuple[str, str]:
    m = re.search(r"<think>(.*?)</think>\s*", text, re.DOTALL)
    return (m.group(1).strip(), text[m.end():].strip()) if m else ("", text)

def _is_thinking_line(line: str) -> bool:
    l = line.strip()
    if not l:
        return True
    think_starts = [
        "The user", "the user", "This is", "this is", "I should", "I need to",
        "Let me", "let me", "My task", "my task", "I'll ", "I will",
        "Since ", "since ", "Now,", "now,", "So,", "so,", "First,", "first,",
        "Okay", "okay", "Alright", "Hmm", "Wait", "Actually",
        "The question", "the question", "The input", "the input",
        "The request", "the request", "The prompt", "the prompt",
        "Thinking Process", "Thinking process", "**Thinking",
        "Step ", "step ", "Approach:", "Analysis:", "Reasoning:",
        "1. **", "2. **", "3. **", "4. **", "5. **",
    ]
    for s in think_starts:
        if l.startswith(s):
            return True
    if l.startswith(("- ", "* ", "○ ")) and any(c.isascii() and c.isalpha() for c in l[:20]):
        if not any(ord(c) > 0x1100 for c in l[:30]):
            return True
    return False

def _split_thinking_answer(raw: str) -> tuple:
    lines = raw.split("\n")
    answer_start = -1
    for i, line in enumerate(lines):
        if not _is_thinking_line(line):
            if any(ord(c) > 0x1100 for c in line.strip()[:10]):
                answer_start = i
                break
            if i > 2 and not _is_thinking_line(line):
                if all(not lines[j].strip() for j in range(max(0, i - 2), i)):
                    answer_start = i
                    break
    if answer_start > 0:
        return "\n".join(lines[:answer_start]).strip(), "\n".join(lines[answer_start:]).strip()
    return "", raw

def format_response(raw: str) -> str:
    chain, answer = parse_think_blocks(raw)
    if chain:
        return (
            "<details>\n<summary>🧠 Reasoning Chain — click to expand</summary>\n\n"
            f"{chain}\n\n</details>\n\n{answer}"
        )
    if "<think>" in raw and "</think>" not in raw:
        think_len = len(raw) - raw.index("<think>") - 7
        return f"🧠 Reasoning... ({think_len} chars)"
    first_line = raw.strip().split("\n")[0] if raw.strip() else ""
    if _is_thinking_line(first_line) and len(raw) > 20:
        thinking, answer = _split_thinking_answer(raw)
        if thinking and answer:
            return (
                f"<details>\n<summary>🧠 Reasoning Chain ({len(thinking)} chars)</summary>\n\n"
                f"{thinking}\n\n</details>\n\n{answer}"
            )
        elif thinking and not answer:
            return f"🧠 Reasoning... ({len(raw)} chars)"
    return raw

# ══════════════════════════════════════════════════════════════════════════════
# 3.  GENERATION — streamed from the VIDRAFT OpenAI-compatible API
# ══════════════════════════════════════════════════════════════════════════════
def generate_reply(
    message:        str,
    history:        list,
    thinking_mode:  str,
    image_input,
    system_prompt:  str,
    max_new_tokens: int,
    temperature:    float,
    top_p:          float,
) -> Generator[str, None, None]:

    max_new_tokens = min(int(max_new_tokens), MODEL_CAP["max_tokens"])
    temperature    = min(float(temperature),  MODEL_CAP["temp_max"])

    # ── Build the message list ──
    messages: list[dict] = []
    if system_prompt.strip():
        messages.append({"role": "system", "content": system_prompt.strip()})

    for turn in history:
        if isinstance(turn, dict):
            role = turn.get("role", "")
            raw  = turn.get("content") or ""
            text = (" ".join(p.get("text", "") for p in raw
                              if isinstance(p, dict) and p.get("type") == "text")
                    if isinstance(raw, list) else str(raw))
            if role == "user":
                messages.append({"role": "user", "content": text})
            elif role == "assistant":
                _, clean = parse_think_blocks(text)
                messages.append({"role": "assistant", "content": clean})
        else:
            try:
                u, a = (turn[0] or None), (turn[1] if len(turn) > 1 else None)
            except (IndexError, TypeError):
                continue
            def _txt(v):
                if v is None: return None
                if isinstance(v, list):
                    return " ".join(p.get("text", "") for p in v
                                    if isinstance(p, dict) and p.get("type") == "text")
                return str(v)
            ut, at = _txt(u), _txt(a)
            if ut: messages.append({"role": "user", "content": ut})
            if at:
                _, clean = parse_think_blocks(at)
                messages.append({"role": "assistant", "content": clean})

    messages.append({"role": "user", "content": message})

    payload = {
        "model": API_MODEL,
        "messages": messages,
        "max_tokens": max_new_tokens,
        "temperature": max(float(temperature), 0.0),
        "top_p": float(top_p),
        "stream": True,
        "stream_options": {"include_usage": True},
    }
    headers = {"Content-Type": "application/json"}
    if API_KEY:
        headers["Authorization"] = f"Bearer {API_KEY}"

    print(f"[GEN] -> {API_BASE} model={API_MODEL} max_new={max_new_tokens} temp={temperature}", flush=True)

    output = ""
    try:
        with httpx.Client(timeout=httpx.Timeout(300.0, connect=15.0)) as client:
            with client.stream("POST", f"{API_BASE}/v1/chat/completions",
                                json=payload, headers=headers) as r:
                if r.status_code != 200:
                    body = r.read().decode(errors="ignore")[:300]
                    yield f"**❌ API error {r.status_code}:** `{body}`"
                    return
                for line in r.iter_lines():
                    if not line:
                        continue
                    if line.startswith("data: "):
                        line = line[6:]
                    if line.strip() == "[DONE]":
                        break
                    try:
                        chunk = json.loads(line)
                    except Exception:
                        continue
                    choices = chunk.get("choices") or []
                    if choices:
                        delta = choices[0].get("delta") or {}
                        piece = delta.get("content") or ""
                        if piece:
                            output += piece
                            yield format_response(output)
    except Exception as e:
        if output:
            yield format_response(output)
        else:
            yield f"**❌ Generation error:** `{e}`"
        return

    if output:
        print(f"[GEN] Done — {len(output)} chars", flush=True)
        yield format_response(output)
    else:
        yield "**⚠️ The model returned an empty response.** Please try again."


# ══════════════════════════════════════════════════════════════════════════════
# 4.  GRADIO BLOCKS  (api_name="chat" — index.html calls /gradio_api/call/chat)
# ══════════════════════════════════════════════════════════════════════════════
with gr.Blocks(title=MODEL_NAME) as gradio_demo:
    thinking_toggle = gr.Radio(
        choices=["⚡ Fast Mode  (direct answer)",
                 "🧠 Thinking Mode  (chain-of-thought reasoning)"],
        value="⚡ Fast Mode  (direct answer)",
        visible=False,
    )
    image_input    = gr.Textbox(value="", visible=False)
    system_prompt  = gr.Textbox(value=PRESETS["general"], visible=False)
    max_new_tokens = gr.Slider(minimum=64, maximum=8192, value=4096, visible=False)
    temperature    = gr.Slider(minimum=0.0, maximum=1.5, value=0.6,  visible=False)
    top_p          = gr.Slider(minimum=0.1, maximum=1.0, value=0.9,  visible=False)

    gr.ChatInterface(
        fn=generate_reply,
        api_name="chat",
        additional_inputs=[
            thinking_toggle, image_input,
            system_prompt, max_new_tokens, temperature, top_p,
        ],
    )

# ══════════════════════════════════════════════════════════════════════════════
# 5.  FASTAPI — index.html + OAuth + utility APIs  (unchanged structure)
# ══════════════════════════════════════════════════════════════════════════════
fapp    = FastAPI()
SESSIONS: dict[str, dict] = {}
HTML    = pathlib.Path(__file__).parent / "index.html"

CLIENT_ID     = os.getenv("OAUTH_CLIENT_ID", "")
CLIENT_SECRET = os.getenv("OAUTH_CLIENT_SECRET", "")
SPACE_HOST    = os.getenv("SPACE_HOST", "localhost:7860")
REDIRECT_URI  = f"https://{SPACE_HOST}/login/callback"

print(f"[OAuth] CLIENT_ID set: {bool(CLIENT_ID)}")
print(f"[OAuth] SPACE_HOST: {SPACE_HOST}")
HF_AUTH_URL   = "https://huggingface.co/oauth/authorize"
HF_TOKEN_URL  = "https://huggingface.co/oauth/token"
HF_USER_URL   = "https://huggingface.co/oauth/userinfo"
SCOPES        = os.getenv("OAUTH_SCOPES", "openid profile")

def _sid(req: Request) -> Optional[str]:
    return req.cookies.get("mc_session")
def _user(req: Request) -> Optional[dict]:
    sid = _sid(req)
    return SESSIONS.get(sid) if sid else None

@fapp.get("/")
async def root(request: Request):
    html = HTML.read_text(encoding="utf-8") if HTML.exists() else "<h2>index.html missing</h2>"
    return HTMLResponse(html)

@fapp.get("/oauth/user")
async def oauth_user(request: Request):
    u = _user(request)
    return JSONResponse(u) if u else JSONResponse({"logged_in": False}, status_code=401)

@fapp.get("/oauth/login")
async def oauth_login(request: Request):
    if not CLIENT_ID:
        return RedirectResponse("/?oauth_error=not_configured")
    state = secrets.token_urlsafe(16)
    params = {"response_type": "code", "client_id": CLIENT_ID, "redirect_uri": REDIRECT_URI, "scope": SCOPES, "state": state}
    return RedirectResponse(f"{HF_AUTH_URL}?{urlencode(params)}", status_code=302)

@fapp.get("/login/callback")
async def oauth_callback(code: str = "", error: str = "", state: str = ""):
    if error or not code:
        return RedirectResponse("/?auth_error=1")
    basic = base64.b64encode(f"{CLIENT_ID}:{CLIENT_SECRET}".encode()).decode()
    async with httpx.AsyncClient() as client:
        tok = await client.post(HF_TOKEN_URL, data={"grant_type": "authorization_code", "code": code, "redirect_uri": REDIRECT_URI},
                                headers={"Accept": "application/json", "Authorization": f"Basic {basic}"})
        if tok.status_code != 200:
            return RedirectResponse("/?auth_error=1")
        access_token = tok.json().get("access_token", "")
        if not access_token:
            return RedirectResponse("/?auth_error=1")
        uinfo = await client.get(HF_USER_URL, headers={"Authorization": f"Bearer {access_token}"})
        if uinfo.status_code != 200:
            return RedirectResponse("/?auth_error=1")
        user = uinfo.json()
    sid = secrets.token_urlsafe(32)
    SESSIONS[sid] = {
        "logged_in": True,
        "username": user.get("preferred_username", user.get("name", "User")),
        "name": user.get("name", ""),
        "avatar": user.get("picture", ""),
        "profile": f"https://huggingface.co/{user.get('preferred_username', '')}",
    }
    resp = RedirectResponse("/")
    resp.set_cookie("mc_session", sid, httponly=True, samesite="lax", secure=True, max_age=60 * 60 * 24 * 7)
    return resp

@fapp.get("/oauth/logout")
async def oauth_logout(request: Request):
    sid = _sid(request)
    if sid and sid in SESSIONS: del SESSIONS[sid]
    resp = RedirectResponse("/")
    resp.delete_cookie("mc_session")
    return resp

@fapp.get("/health")
async def health():
    return {"status": "ok", "model": MODEL_ID, "serving": "api", "api_base": API_BASE}

# ── Web Search API (Brave) ──
BRAVE_API_KEY = os.getenv("BRAVE_API_KEY", "")

@fapp.post("/api/search")
async def api_search(request: Request):
    body = await request.json()
    query = body.get("query", "").strip()
    if not query:
        return JSONResponse({"error": "empty query"}, status_code=400)
    if not BRAVE_API_KEY:
        return JSONResponse({"error": "BRAVE_API_KEY not set"}, status_code=500)
    try:
        r = requests.get(
            "https://api.search.brave.com/res/v1/web/search",
            headers={"X-Subscription-Token": BRAVE_API_KEY, "Accept": "application/json"},
            params={"q": query, "count": 5}, timeout=10,
        )
        r.raise_for_status()
        results = r.json().get("web", {}).get("results", [])
        items = [{"title": it.get("title", ""), "desc": it.get("description", ""), "url": it.get("url", "")} for it in results[:5]]
        return JSONResponse({"results": items})
    except Exception as e:
        return JSONResponse({"error": str(e)}, status_code=500)

# ── PDF Text Extraction ──
@fapp.post("/api/extract-pdf")
async def api_extract_pdf(request: Request):
    try:
        body = await request.json()
        b64 = body.get("data", "")
        if "," in b64:
            b64 = b64.split(",", 1)[1]
        pdf_bytes = base64.b64decode(b64)
        text = ""
        try:
            import fitz
            doc = fitz.open(stream=pdf_bytes, filetype="pdf")
            for page in doc:
                text += page.get_text() + "\n"
        except ImportError:
            content = pdf_bytes.decode("utf-8", errors="ignore")
            text = re.sub(r'[^\x20-\x7E\n\r]', '', content)
        text = text.strip()[:8000]
        return JSONResponse({"text": text, "chars": len(text)})
    except Exception as e:
        return JSONResponse({"error": str(e)}, status_code=500)

# ══════════════════════════════════════════════════════════════════════════════
# 6.  MOUNT & RUN
# ══════════════════════════════════════════════════════════════════════════════
app = gr.mount_gradio_app(fapp, gradio_demo, path="/gradio")

if __name__ == "__main__":
    print(f"[BOOT] {MODEL_NAME} · API serving · Ready", flush=True)
    uvicorn.run(app, host="0.0.0.0", port=7860)