import asyncio
import base64
import hashlib
import hmac
import importlib.metadata
import io
import json
import logging
import os
import re
import secrets
import tempfile
import time
import uuid
from contextlib import asynccontextmanager
from datetime import datetime, timezone
from pathlib import Path
from typing import Dict, List, Optional, Union
from urllib.parse import quote, urlparse

from dotenv import load_dotenv

# 加载 .env 文件
load_dotenv(Path(__file__).parent / ".env")

import httpx
import numpy as np
from fastapi import Depends, FastAPI, Header, HTTPException, Request, Response
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse, StreamingResponse
from gemini_webapi import GeminiClient, set_log_level
from gemini_webapi.constants import Model
from PIL import Image
from pydantic import BaseModel

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)
set_log_level("INFO")

gemini_client = None
gemini_client_lock = asyncio.Lock()

# 服务配置（从环境变量读取，修改后需重启服务生效）
HOST = os.environ.get("HOST", "0.0.0.0")
try:
	PORT = int(os.environ.get("PORT", "7860"))
except ValueError:
	raise ValueError(f"Invalid PORT environment variable: '{os.environ.get('PORT')}' must be an integer")


async def _init_gemini_client_background():
	"""Background task: initialize the Gemini client without blocking startup."""
	try:
		await get_gemini_client()
		logger.info("Gemini client initialized successfully in background")
	except Exception as e:
		logger.warning(f"Gemini client init failed (service running without API access): {e}")


@asynccontextmanager
async def lifespan(app: FastAPI):
	"""Start Gemini client init in background; do not block FastAPI startup."""
	init_task = asyncio.create_task(_init_gemini_client_background())
	try:
		yield
	finally:
		# Wait for background init to finish before cleaning up (or cancel if still running)
		if not init_task.done():
			init_task.cancel()
			try:
				await init_task
			except asyncio.CancelledError:
				pass
		global gemini_client
		if gemini_client is not None:
			try:
				await gemini_client.close()
			except Exception as e:
				logger.warning(f"Failed to close Gemini client during shutdown: {e}")
			finally:
				gemini_client = None


app = FastAPI(title="Gemini API FastAPI Server", lifespan=lifespan)

# 管理面板集成（必须在 app 初始化之后，admin.py 依赖 main 模块的配置和 app 实例）
from admin import router as admin_router, setup_middleware
app.include_router(admin_router)
setup_middleware(app)


def get_gemini_webapi_version() -> str:
	"""Return the installed gemini-webapi package version for runtime diagnostics."""
	try:
		return importlib.metadata.version("gemini-webapi")
	except importlib.metadata.PackageNotFoundError:
		return "unknown"


def get_cached_1psidts_path(psid: str) -> str:
	"""Return the cache path for a rotated 1PSIDTS value."""
	if not psid or not re.match("^[\\w\\-\\.]+$", psid):
		return ""
	return os.path.join(GEMINI_COOKIE_PATH, f".cached_1psidts_{psid}.txt")


def load_cached_1psidts(psid: str) -> str:
	"""Load a cached rotated 1PSIDTS value for the given 1PSID."""
	cached_file_path = get_cached_1psidts_path(psid)
	if not cached_file_path:
		return ""

	if os.path.exists(cached_file_path):
		try:
			content = Path(cached_file_path).read_text().strip()
			if content:
				return content
		except Exception as e:
			logger.warning(f"Error reading cache file {cached_file_path}: {e}")

	return ""


def get_cookie_value(cookies, name: str) -> str:
	"""Safely read a cookie value from an httpx cookie jar or mapping."""
	if not cookies:
		return ""

	for domain in (".google.com", ".googleusercontent.com", None):
		try:
			value = cookies.get(name, domain=domain) if domain is not None else cookies.get(name)
		except TypeError:
			value = cookies.get(name)
		except Exception:
			value = ""

		if value:
			return value

	return ""


# Add CORS middleware
app.add_middleware(
	CORSMiddleware,
	allow_origins=["*"],
	allow_credentials=True,
	allow_methods=["*"],
	allow_headers=["*"],
)

# Authentication credentials
SECURE_1PSID = os.environ.get("SECURE_1PSID", "")
SECURE_1PSIDTS = os.environ.get("SECURE_1PSIDTS", "")
API_KEY = os.environ.get("API_KEY", "")
ENABLE_THINKING = os.environ.get("ENABLE_THINKING", "false").lower() == "true"
TEMPORARY_CHAT = os.environ.get("TEMPORARY_CHAT", "false").lower() == "true"
AUTO_DELETE_CHAT = os.environ.get("AUTO_DELETE_CHAT", "true").lower() == "true" and not TEMPORARY_CHAT
PUBLIC_BASE_URL = os.environ.get("PUBLIC_BASE_URL", "").rstrip("/")
SECRET_FILE_PATH = os.path.join(os.path.dirname(__file__), "secrets", "proxy_secret")
GEMINI_COOKIE_PATH = os.path.join(os.path.dirname(__file__), "secrets")
SESSION_VALIDATION_PROMPT = "Reply with exactly OK."
AUTH_FAILURE_TEXT_PATTERNS = (
	"are you signed in",
	"sign in",
	"signed in",
	"log in",
	"logged in",
)
DEFAULT_USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36 Edg/144.0.0.0"

os.environ.setdefault("GEMINI_COOKIE_PATH", GEMINI_COOKIE_PATH)


async def background_delete_chat(client: GeminiClient, cid: str):
	"""Deletes a chat conversation in the background to avoid blocking the main thread."""
	if not cid:
		return
	try:
		await client.delete_chat(cid)
	except Exception as e:
		logger.error(f"Failed to auto-delete chat {cid}: {e}")


def response_indicates_auth_failure(text: str) -> bool:
	"""Return True if the response text looks like a signed-out or degraded session."""
	normalized = (text or "").strip().lower()
	if not normalized:
		return True
	return any(pattern in normalized for pattern in AUTH_FAILURE_TEXT_PATTERNS)


async def fetch_readable_chat_response(client: GeminiClient, cid: str, retry_delays: List[int]) -> Optional[object]:
	"""Poll Gemini history until the chat becomes readable or retries are exhausted."""
	for attempt, delay in enumerate(retry_delays, start=1):
		try:
			if delay:
				await asyncio.sleep(delay)

			recovered = await client.fetch_latest_chat_response(cid)
			if recovered and getattr(recovered, "text", ""):
				return recovered
		except Exception as e:
			logger.exception(
				"Gemini history read failed for cid=%s on retry %s/%s after %ss delay: %s",
				cid,
				attempt,
				len(retry_delays),
				delay,
				e,
			)
			continue

	return None


async def background_verify_chat_persistence(client: GeminiClient, cid: str, source: str):
	"""Best-effort verification that a returned cid is readable from Gemini history."""
	if not cid:
		return

	retry_delays = [1, 3, 8]
	recovered = await fetch_readable_chat_response(client, cid, retry_delays)
	if recovered:
		logger.debug(
			"Gemini history verification succeeded: source=%s cid=%s text_len=%s metadata=%s",
			source,
			cid,
			len(recovered.text),
			getattr(recovered, "metadata", None),
		)
		return

	logger.warning(
		"Gemini history verification exhausted retries for cid=%s source=%s",
		cid,
		source,
	)


async def validate_gemini_client_session(client: GeminiClient, source: str):
	"""Verify that an initialized client can create and read back a normal persistent Gemini chat."""
	validation_cid = None
	try:
		response = await client.generate_content(SESSION_VALIDATION_PROMPT, temporary=False)
		response_text = getattr(response, "text", "") or ""
		metadata = getattr(response, "metadata", None) or []
		validation_cid = metadata[0] if metadata else None

		if response_indicates_auth_failure(response_text):
			raise ValueError("validation probe returned signed-out or empty content")

		if not validation_cid:
			raise ValueError("validation probe returned no persistent chat metadata")

		recovered = await fetch_readable_chat_response(client, validation_cid, [1, 3, 8])
		if not recovered or response_indicates_auth_failure(getattr(recovered, "text", "") or ""):
			raise ValueError("validation probe chat was not readable from Gemini history")

		logger.info("Gemini session validation succeeded using %s credentials", source)
	finally:
		if validation_cid:
			try:
				await client.delete_chat(validation_cid)
			except Exception:
				logger.debug("Failed to delete Gemini validation chat %s", validation_cid)


def load_or_generate_secret() -> str:
	"""
	Load the signature secret from file, or generate a new one if not found.
	"""
	if os.path.exists(SECRET_FILE_PATH):
		try:
			with open(SECRET_FILE_PATH, "r") as f:
				secret = f.read().strip()
				if secret:
					logger.info(f"Loaded proxy secret from {SECRET_FILE_PATH}")
					return secret
		except Exception as e:
			logger.warning(f"Failed to read secret file, trying to generate a new one: {e}")

	# Generate new secret if not found or error occurred
	new_secret = secrets.token_hex(32)
	try:
		# Ensure directory exists
		os.makedirs(os.path.dirname(SECRET_FILE_PATH), exist_ok=True)
		with open(SECRET_FILE_PATH, "w") as f:
			f.write(new_secret)

		# Set restrictive permissions (user-only readable/writable)
		try:
			os.chmod(SECRET_FILE_PATH, 0o600)
		except Exception as e:
			logger.warning(f"Failed to set restrictive permissions on {SECRET_FILE_PATH}: {e}")

		logger.info(f"Generated new proxy secret and saved to {SECRET_FILE_PATH}")
		return new_secret
	except Exception as e:
		logger.error(f"Error writing secret file: {e}")
		# if unable to save, return an in-memory ephemeral secret instead of using API_KEY or SECURE_1PSID
		ephemeral_secret = secrets.token_urlsafe(32)
		logger.warning("Using an in-memory secret to proxy images for this session.")
		return ephemeral_secret


SIGNATURE_SECRET = load_or_generate_secret()

# Watermark removal constants
ASSETS_DIR = os.path.join(os.path.dirname(__file__), "assets")
ALPHA_MAP_CACHE = {}


def get_alpha_map(size: int) -> np.ndarray:
	"""Load and cache the alpha map from the background capture image."""
	if size in ALPHA_MAP_CACHE:
		return ALPHA_MAP_CACHE[size]

	bg_path = os.path.join(ASSETS_DIR, f"bg_{size}.png")
	if not os.path.exists(bg_path):
		logger.warning(f"Watermark asset not found: {bg_path}")
		return None

	try:
		with Image.open(bg_path) as img:
			img_data = np.array(img.convert("RGB"))
			alpha_map = np.max(img_data, axis=2) / 255.0
			ALPHA_MAP_CACHE[size] = alpha_map
			return alpha_map
	except Exception as e:
		logger.error(f"Error loading alpha map {size}: {e}")
		return None


def remove_gemini_watermark(image_bytes: bytes) -> bytes:
	"""Remove Gemini watermark using Reverse Alpha Blending."""
	try:
		with Image.open(io.BytesIO(image_bytes)) as img:
			width, height = img.size
			orig_format = img.format

			if width > 1024 and height > 1024:
				logo_size, margin = 96, 64
			else:
				logo_size, margin = 48, 32

			alpha_map = get_alpha_map(logo_size)
			if alpha_map is None:
				return image_bytes

			x = width - margin - logo_size
			y = height - margin - logo_size
			if x < 0 or y < 0:
				logger.warning(f"Image too small for watermark removal: {width}x{height}")
				return image_bytes

			# Reverse Alpha Blending: original = (watermarked - α × 255) / (1 - α)
			img_array = np.array(img.convert("RGB")).astype(np.float64)
			roi = img_array[y : y + logo_size, x : x + logo_size].copy()

			alpha = np.clip(alpha_map, 0.002, 0.99)
			alpha_expanded = np.expand_dims(alpha, axis=2)
			cleaned_roi = (roi - alpha_expanded * 255.0) / (1.0 - alpha_expanded)
			cleaned_roi = np.clip(np.round(cleaned_roi), 0, 255).astype(np.uint8)

			img_array_uint8 = np.array(img.convert("RGB"))
			img_array_uint8[y : y + logo_size, x : x + logo_size] = cleaned_roi

			out_io = io.BytesIO()
			save_format = orig_format or "PNG"
			if save_format.upper() == "JPEG":
				Image.fromarray(img_array_uint8).save(out_io, format="JPEG", quality=95)
			else:
				Image.fromarray(img_array_uint8).save(out_io, format=save_format)
			return out_io.getvalue()

	except Exception as e:
		logger.error(f"Error removing watermark: {e}")
		return image_bytes


if not SECURE_1PSID or not SECURE_1PSIDTS:
	logger.warning("Gemini credentials are missing; set SECURE_1PSID and SECURE_1PSIDTS before serving requests.")
else:
	logger.info(
		"Startup config: thinking=%s temporary_chat=%s auto_delete_chat=%s public_base_url=%s gemini_webapi=%s",
		ENABLE_THINKING,
		TEMPORARY_CHAT,
		AUTO_DELETE_CHAT,
		bool(PUBLIC_BASE_URL),
		get_gemini_webapi_version(),
	)
	if not re.match("^[\\w\\-\\.]+$", SECURE_1PSID):
		logger.warning(
			"SECURE_1PSID contains characters outside the safe cache filename pattern. This may be valid for auth, but cached 1PSIDTS lookup will fall back to the env value."
		)

if not API_KEY:
	logger.info("API key authentication is disabled.")
else:
	logger.info("API key authentication is enabled.")


def correct_markdown(md_text: str) -> str:
	"""
	修正Markdown文本，移除Google搜索链接包装器，并根据显示文本简化目标URL。
	"""

	def simplify_link_target(text_content: str) -> str:
		match_colon_num = re.match(r"([^:]+:\d+)", text_content)
		if match_colon_num:
			return match_colon_num.group(1)
		return text_content

	def replacer(match: re.Match) -> str:
		outer_open_paren = match.group(1)
		display_text = match.group(2)

		new_target_url = simplify_link_target(display_text)
		new_link_segment = f"[`{display_text}`]({new_target_url})"

		if outer_open_paren:
			return f"{outer_open_paren}{new_link_segment})"
		else:
			return new_link_segment

	pattern = r"(\()?\[`([^`]+?)`\]\((https://www.google.com/search\?q=)(.*?)(?<!\\)\)\)*(\))?"

	fixed_google_links = re.sub(pattern, replacer, md_text)
	# fix wrapped markdownlink
	pattern = r"`(\[[^\]]+\]\([^\)]+\))`"
	return re.sub(pattern, r"\1", fixed_google_links)


# Pydantic models for API requests and responses
class ContentItem(BaseModel):
	type: str
	text: Optional[str] = None
	image_url: Optional[Dict[str, str]] = None


class Message(BaseModel):
	role: str
	content: Union[str, List[ContentItem]]
	name: Optional[str] = None


class ChatCompletionRequest(BaseModel):
	model: str
	messages: List[Message]
	temperature: Optional[float] = 0.7
	top_p: Optional[float] = 1.0
	n: Optional[int] = 1
	stream: Optional[bool] = False
	max_tokens: Optional[int] = None
	presence_penalty: Optional[float] = 0
	frequency_penalty: Optional[float] = 0
	user: Optional[str] = None


class Choice(BaseModel):
	index: int
	message: Message
	finish_reason: str


class Usage(BaseModel):
	prompt_tokens: int
	completion_tokens: int
	total_tokens: int


class ChatCompletionResponse(BaseModel):
	id: str
	object: str = "chat.completion"
	created: int
	model: str
	choices: List[Choice]
	usage: Usage


class ModelData(BaseModel):
	id: str
	object: str = "model"
	created: int
	owned_by: str = "google"


class ModelList(BaseModel):
	object: str = "list"
	data: List[ModelData]


# Authentication dependency
async def verify_api_key(authorization: str = Header(None)):
	"""
	Verify the API key extracted from the Authorization header.
	Also accepts valid admin session tokens for the quick test chat.
	"""
	if not API_KEY:
		# If API_KEY is not set in environment, skip validation (for development)
		return

	if not authorization:
		raise HTTPException(status_code=401, detail="Missing Authorization header")

	# Accept valid admin session tokens (for admin panel quick test)
	if authorization.startswith("Bearer "):
		token = authorization[7:]
		from admin import _admin_sessions, _clean_expired_sessions
		_clean_expired_sessions()
		if token in _admin_sessions:
			return

	try:
		scheme, token = authorization.split()
		if scheme.lower() != "bearer":
			raise HTTPException(
				status_code=401,
				detail="Invalid authentication scheme. Use Bearer token",
			)

		if token != API_KEY:
			raise HTTPException(status_code=401, detail="Invalid API key")
	except ValueError:
		raise HTTPException(
			status_code=401,
			detail="Invalid authorization format. Use 'Bearer YOUR_API_KEY'",
		)

	return token


# Simple error handler middleware
@app.middleware("http")
async def error_handling(request: Request, call_next):
	"""
	Global middleware to catch unhandled exceptions, log the error,
	and return a standardized HTTP 500 response.
	"""
	try:
		return await call_next(request)
	except Exception:
		logger.exception("Request failed")
		return JSONResponse(
			status_code=500,
			content={
				"error": {
					"message": "Internal server error",
					"type": "internal_server_error",
				}
			},
		)


# Get list of available models
@app.get("/v1/models")
async def list_models():
	"""返回 gemini_webapi 中声明的模型列表"""
	now = int(datetime.now(tz=timezone.utc).timestamp())
	data = [
		{
			"id": m.model_name,  # 如 "gemini-2.0-flash"
			"object": "model",
			"created": now,
			"owned_by": "google-gemini-web",
		}
		for m in Model
	]
	return {"object": "list", "data": data}


# Helper to convert between Gemini and OpenAI model names
def map_model_name(openai_model_name: str) -> Model:
	"""根据模型名称字符串查找匹配的 Model 枚举值"""
	normalized_openai_model_name = openai_model_name.lower()

	# 首先尝试直接查找匹配的模型名称
	for m in Model:
		model_name = m.model_name if hasattr(m, "model_name") else str(m)
		if normalized_openai_model_name in model_name.lower():
			return m

	# 如果找不到匹配项，使用默认映射（兼容旧版和新版模型名称）
	model_keywords = {
		"gemini-3-pro": ["3.0", "pro"],
		"gemini-3-flash": ["3.0", "flash"],
		"gemini-pro": ["pro", "2.0"],
		"gemini-pro-vision": ["vision", "pro"],
		"gemini-flash": ["flash", "2.0"],
		"gemini-1.5-pro": ["1.5", "pro"],
		"gemini-1.5-flash": ["1.5", "flash"],
	}

	# 根据关键词模糊匹配
	keywords = None
	for key, candidate_keywords in model_keywords.items():
		normalized_key = key.lower()
		matches_key = normalized_key in normalized_openai_model_name
		matches_any_kw = any(kw.lower() in normalized_openai_model_name for kw in candidate_keywords)
		if matches_key or matches_any_kw:
			keywords = candidate_keywords
			break

	if keywords is None:
		if "flash" in normalized_openai_model_name:
			keywords = ["flash"]
		elif "vision" in normalized_openai_model_name:
			keywords = ["vision"]
		else:
			keywords = ["pro"]

	for m in Model:
		model_name = m.model_name if hasattr(m, "model_name") else str(m)
		if all(kw.lower() in model_name.lower() for kw in keywords):
			return m

	# 如果还是找不到，返回第一个模型
	return next(iter(Model))


# Prepare conversation history from OpenAI messages format
def prepare_conversation(messages: List[Message]) -> tuple:
	"""
	Convert a list of OpenAI-formatted message objects into a
	flat string conversation format suitable for the Gemini API.
	Also extracts and saves base64 images to temporary files.

	Returns:
		A tuple containing the constructed conversation string and a list of paths to temporary image files.
	"""
	conversation = ""
	temp_files = []

	for msg in messages:
		if isinstance(msg.content, str):
			# String content handling
			if msg.role == "system":
				conversation += f"System: {msg.content}\n\n"
			elif msg.role == "user":
				conversation += f"Human: {msg.content}\n\n"
			elif msg.role == "assistant":
				conversation += f"Assistant: {msg.content}\n\n"
		else:
			# Mixed content handling
			if msg.role == "user":
				conversation += "Human: "
			elif msg.role == "system":
				conversation += "System: "
			elif msg.role == "assistant":
				conversation += "Assistant: "

			for item in msg.content:
				if item.type == "text":
					conversation += item.text or ""
				elif item.type == "image_url" and item.image_url:
					# Handle image
					image_url = item.image_url.get("url", "")
					if image_url.startswith("data:image/"):
						# Process base64 encoded image
						try:
							# Extract the base64 part
							base64_data = image_url.split(",")[1]
							image_data = base64.b64decode(base64_data)

							# Create temporary file to hold the image
							with tempfile.NamedTemporaryFile(delete=False, suffix=".png") as tmp:
								tmp.write(image_data)
								temp_files.append(tmp.name)
						except Exception as e:
							logger.error(f"Error processing base64 image: {str(e)}")

			conversation += "\n\n"

	# Add a final prompt for the assistant to respond to
	conversation += "Assistant: "

	return conversation, temp_files


# Dependency to get the initialized Gemini client
async def get_gemini_client():
	"""
	Get or initialize the global GeminiClient instance.

	Raises:
		HTTPException: If initialization fails due to invalid parameters or connection issues.
	"""
	global gemini_client
	if gemini_client is not None:
		return gemini_client

	async with gemini_client_lock:
		if gemini_client is not None:
			return gemini_client

		try:
			psid = SECURE_1PSID
			cached_psidts = load_cached_1psidts(psid)
			attempts = []

			if cached_psidts:
				attempts.append(("cache", cached_psidts))
			if SECURE_1PSIDTS:
				attempts.append(("environment", SECURE_1PSIDTS))

			seen_psidts = set()
			new_attempts = []
			for source, psidts in attempts:
				if not psidts or psidts in seen_psidts:
					continue
				seen_psidts.add(psidts)
				new_attempts.append((source, psidts))
			attempts = new_attempts

			if not attempts:
				raise HTTPException(
					status_code=500,
					detail="Missing SECURE_1PSIDTS and no cached rotated 1PSIDTS is available",
				)

			last_error = None
			for source, psidts in attempts:
				tmp_client = None
				try:
					logger.info("Initializing Gemini client using %s credentials", source)

					tmp_client = GeminiClient(psid, psidts)
					await tmp_client.init(timeout=300)
					await validate_gemini_client_session(tmp_client, source)

					gemini_client = tmp_client
					break
				except Exception as e:
					last_error = e
					logger.warning(f"Gemini session setup failed using {source} 1PSIDTS: {e}")
					if tmp_client is not None:
						try:
							await tmp_client.close()
						except Exception:
							pass

			if gemini_client is None:
				raise last_error

		except Exception as e:
			logger.error(f"Failed to initialize Gemini client: {str(e)}")
			raise HTTPException(status_code=500, detail=f"Failed to initialize Gemini client: {str(e)}")
	return gemini_client


def get_image_signature(url: str) -> str:
	"""
	Generate a HMAC-SHA256 signature for the image URL using the persistent SIGNATURE_SECRET.
	"""
	secret = SIGNATURE_SECRET.encode()
	return hmac.new(secret, url.encode(), hashlib.sha256).hexdigest()


def postprocess_text(text: str) -> str:
	"""Apply text cleanup and markdown corrections to response text."""
	text = text.replace("&lt;", "<").replace("\\<", "<").replace("\\_", "_").replace("\\>", ">")
	return correct_markdown(text)


def extract_image_markdown(response, base_url: str) -> str:
	"""Extract images from a response and return markdown image links."""
	result = ""
	if hasattr(response, "images") and response.images:
		for img in response.images:
			img_url = getattr(img, "url", None)
			if img_url:
				sig = get_image_signature(img_url)
				proxy_url = f"{base_url}/gemini-proxy/image?url={quote(img_url)}&sig={sig}"
				result += f"\n\n![🎨 Loading image...]({proxy_url})"
	return result


@app.post("/v1/chat/completions")
async def create_chat_completion(
	request: ChatCompletionRequest,
	raw_request: Request,
	api_key: str = Depends(verify_api_key),
):
	"""
	Handle chat completion requests, translating from OpenAI API format to Gemini API format.
	Supports both streaming and non-streaming responses, caching, thinking features,
	and background conversation cleanup based on configuration.
	"""
	try:
		# 确保客户端已初始化
		global gemini_client
		gemini_client = await get_gemini_client()

		# 转换消息为对话格式
		conversation, temp_files = prepare_conversation(request.messages)
		logger.info(
			"Chat completion request: stream=%s requested_model=%s messages=%s temp_files=%s",
			request.stream,
			request.model,
			len(request.messages),
			len(temp_files),
		)

		# 获取适当的模型
		model = map_model_name(request.model)

		# 创建响应对象
		completion_id = f"chatcmpl-{uuid.uuid4()}"
		created_time = int(time.time())
		base_url = PUBLIC_BASE_URL or str(raw_request.base_url).rstrip("/")

		# Prepare generate_content arguments
		gen_kwargs = {"model": model}
		if TEMPORARY_CHAT:
			gen_kwargs["temporary"] = True
		if temp_files:
			gen_kwargs["files"] = temp_files

		if request.stream:
			# Real streaming using upstream generate_content_stream
			async def generate_stream():
				try:

					def make_chunk(delta: dict, finish_reason=None):
						return (
							"data: "
							+ json.dumps(
								{
									"id": completion_id,
									"object": "chat.completion.chunk",
									"created": created_time,
									"model": request.model,
									"choices": [
										{
											"index": 0,
											"delta": delta,
											"finish_reason": finish_reason,
										}
									],
								}
							)
							+ "\n\n"
						)

					# Send initial role chunk
					yield make_chunk({"role": "assistant"})

					thinking_started = False
					thinking_ended = False
					yielded_images = 0
					text_buffer = ""
					captured_cid = None
					chunk_count = 0
					last_metadata = None

					async for chunk in gemini_client.generate_content_stream(conversation, **gen_kwargs):
						chunk_count += 1
						if hasattr(chunk, "metadata") and chunk.metadata:
							last_metadata = chunk.metadata
						# Capture conversation ID for auto-deletion
						if AUTO_DELETE_CHAT and captured_cid is None and hasattr(chunk, "metadata") and chunk.metadata and len(chunk.metadata) > 0:
							captured_cid = chunk.metadata[0]

						# Handle thinking/thoughts delta
						if ENABLE_THINKING and hasattr(chunk, "thoughts_delta") and chunk.thoughts_delta:
							if not thinking_started:
								yield make_chunk({"content": "<think>\n"})
								thinking_started = True

							# Also include reasoning_content for full Open WebUI native compatibility
							yield make_chunk(
								{
									"content": chunk.thoughts_delta,
									"reasoning_content": chunk.thoughts_delta,
								}
							)

						# Handle text delta
						if hasattr(chunk, "text_delta") and chunk.text_delta:
							# Close thinking tag before first text content
							if thinking_started and not thinking_ended:
								thinking_ended = True
								yield make_chunk({"content": "\n</think>\n\n"})

							text_buffer += chunk.text_delta
							safe_to_yield = False

							# Yield if buffer ends with whitespace and looks like it's outside a markdown link
							if (
								text_buffer[-1].isspace()
								and text_buffer.count("[") == text_buffer.count("]")
								and text_buffer.count("(") == text_buffer.count(")")
							):
								safe_to_yield = True
							elif len(text_buffer) > 500:
								safe_to_yield = True

							if safe_to_yield:
								yield make_chunk({"content": postprocess_text(text_buffer)})
								text_buffer = ""

						# Handle inline images as they arrive
						if hasattr(chunk, "images") and chunk.images and len(chunk.images) > yielded_images:
							# Close thinking tag if an image arrives before any text
							if thinking_started and not thinking_ended:
								thinking_ended = True
								yield make_chunk({"content": "\n</think>\n\n"})

							new_images = chunk.images[yielded_images:]
							for img in new_images:
								img_url = getattr(img, "url", None)
								if img_url:
									sig = get_image_signature(img_url)
									proxy_url = f"{base_url}/gemini-proxy/image?url={quote(img_url)}&sig={sig}"
									img_md = f"\n\n![🎨 Loading image...]({proxy_url})\n\n"
									yield make_chunk({"content": img_md})
							yielded_images = len(chunk.images)

					# Flush any remaining text
					if text_buffer:
						yield make_chunk({"content": postprocess_text(text_buffer)})

					# Close thinking tag if it was never closed
					if thinking_started and not thinking_ended:
						yield make_chunk({"content": "\n</think>\n\n"})

					# Send finish chunk
					yield make_chunk({}, finish_reason="stop")
					yield "data: [DONE]\n\n"

					logger.info(
						"Streaming response completed: chunks=%s images=%s",
						chunk_count,
						yielded_images,
					)
					if last_metadata and len(last_metadata) > 0 and not AUTO_DELETE_CHAT:
						asyncio.create_task(background_verify_chat_persistence(gemini_client, last_metadata[0], "stream"))
				except Exception as e:
					logger.error(f"Error during streaming: {str(e)}", exc_info=True)
					# Send error as a content chunk so the client sees it
					error_msg = "\n\n[An internal error occurred while streaming]"
					yield make_chunk({"content": error_msg})
					yield make_chunk({}, finish_reason="stop")
					yield "data: [DONE]\n\n"
				finally:
					# Create background task to delete the chat if AUTO_DELETE_CHAT is enabled
					if AUTO_DELETE_CHAT and captured_cid:
						asyncio.create_task(background_delete_chat(gemini_client, captured_cid))

					# 清理临时文件
					for temp_file in temp_files:
						try:
							os.unlink(temp_file)
						except Exception as e:
							logger.warning(f"Failed to delete temp file {temp_file}: {str(e)}")

			return StreamingResponse(generate_stream(), media_type="text/event-stream")
		else:
			# Non-streaming response
			try:
				response = await gemini_client.generate_content(conversation, **gen_kwargs)

				if AUTO_DELETE_CHAT and hasattr(response, "metadata") and response.metadata and len(response.metadata) > 0:
					cid = response.metadata[0]
					asyncio.create_task(background_delete_chat(gemini_client, cid))
				elif hasattr(response, "metadata") and response.metadata and len(response.metadata) > 0:
					asyncio.create_task(background_verify_chat_persistence(gemini_client, response.metadata[0], "non-stream"))
				elif not getattr(response, "metadata", None):
					logger.warning("Non-stream response returned no Gemini metadata. This request may not map to a persistent Gemini chat.")

			finally:
				# 清理临时文件
				for temp_file in temp_files:
					try:
						os.unlink(temp_file)
					except Exception as e:
						logger.warning(f"Failed to delete temp file {temp_file}: {str(e)}")

			# 提取文本响应
			reply_text = ""
			if ENABLE_THINKING and hasattr(response, "thoughts") and response.thoughts:
				reply_text += f"<think>\n{response.thoughts}\n</think>\n\n"
			if hasattr(response, "text"):
				reply_text += response.text
			else:
				reply_text += str(response)

			# 提取并追加图片响应
			reply_text += extract_image_markdown(response, base_url)
			reply_text = postprocess_text(reply_text)

			if not reply_text or reply_text.strip() == "":
				logger.warning("Empty response received from Gemini")
				reply_text = "Server returned an empty response. Please check that Gemini API credentials are valid."

			result = {
				"id": completion_id,
				"object": "chat.completion",
				"created": created_time,
				"model": request.model,
				"choices": [
					{
						"index": 0,
						"message": {"role": "assistant", "content": reply_text},
						"finish_reason": "stop",
					}
				],
				"usage": {
					"prompt_tokens": len(conversation.split()),
					"completion_tokens": len(reply_text.split()),
					"total_tokens": len(conversation.split()) + len(reply_text.split()),
				},
			}

			logger.info("Non-streaming response completed")
			return result

	except Exception as e:
		logger.error(f"Error generating completion: {str(e)}", exc_info=True)
		raise HTTPException(status_code=500, detail=f"Error generating completion: {str(e)}")


@app.get("/gemini-proxy/image")
async def proxy_image(url: str, sig: str):
	"""
	Proxy images from Google domains to bypass browser security policies.
	Requires a valid HMAC signature.
	"""
	# Verify signature
	expected_sig = get_image_signature(url)
	if not hmac.compare_digest(sig, expected_sig):
		logger.warning(f"Invalid signature for proxy request: {url}")
		raise HTTPException(status_code=403, detail="Invalid signature")

	# Prevent open proxying
	allowed_domains = ["google.com", "googleusercontent.com", "gstatic.com"]

	try:
		parsed = urlparse(url)
		if parsed.scheme not in ["http", "https"]:
			logger.warning(f"Invalid scheme in proxy request: {parsed.scheme}")
			raise HTTPException(status_code=400, detail="Invalid URL scheme")

		hostname = parsed.hostname
		if not hostname:
			logger.warning(f"No hostname in proxy request: {url}")
			raise HTTPException(status_code=400, detail="Invalid URL")

		hostname = hostname.lower()
		is_allowed = any(hostname == d or hostname.endswith("." + d) for d in allowed_domains)

		if not is_allowed:
			logger.warning(f"Blocked proxy request for domain: {hostname}")
			raise HTTPException(status_code=403, detail="Domain not allowed")
	except ValueError:
		logger.warning(f"Malformed URL in proxy request: {url}")
		raise HTTPException(status_code=400, detail="Invalid URL")

	# Minimal browser-like headers
	headers = {
		"User-Agent": DEFAULT_USER_AGENT,
		"Accept": "image/avif,image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8",
		"Accept-Language": "en-US,en;q=0.9",
		"Referer": "https://gemini.google.com/",
	}

	# 10MB limit
	MAX_BYTES = 10 * 1024 * 1024

	# Use scoped cookies to prevent leakage during redirects
	jar = httpx.Cookies()

	# Use the freshest available 1PSIDTS without overriding env cookies up front.
	psid = SECURE_1PSID
	psidts = get_cookie_value(getattr(gemini_client, "cookies", None), "__Secure-1PSIDTS") or load_cached_1psidts(psid) or SECURE_1PSIDTS

	jar.set("__Secure-1PSID", psid, domain=".google.com")
	jar.set("__Secure-1PSIDTS", psidts, domain=".google.com")
	jar.set("__Secure-1PSID", psid, domain=".googleusercontent.com")
	jar.set("__Secure-1PSIDTS", psidts, domain=".googleusercontent.com")

	async with httpx.AsyncClient(http2=True, cookies=jar, follow_redirects=True) as client:
		try:
			# Fetch original resolution to keep watermark at expected size/position
			fetch_url = re.sub(r"=s\d+$", "=s0", url) if re.search(r"=s\d+$", url) else url + "=s0"

			async with client.stream("GET", fetch_url, timeout=15.0, headers=headers) as resp:
				if resp.status_code != 200:
					logger.error(f"Google returned {resp.status_code} for image: {url}")

				resp.raise_for_status()

				content = bytearray()
				async for chunk in resp.aiter_bytes():
					content.extend(chunk)
					if len(content) > MAX_BYTES:
						logger.warning(f"Image too large: {url} (exceeded {MAX_BYTES} bytes)")
						raise HTTPException(status_code=413, detail="Image too large")
				# Validate Content-Type to prevent XSS/MIME sniffing
				upstream_content_type = resp.headers.get("content-type", "image/png").lower()
				if not upstream_content_type.startswith("image/"):
					logger.warning(f"Rejected non-image Content-Type: {upstream_content_type} for {url}")
					media_type = "image/png"
				else:
					media_type = upstream_content_type

				# Process watermark removal
				if media_type in ["image/png", "image/jpeg", "image/webp"]:
					processed_content = remove_gemini_watermark(bytes(content))
				else:
					processed_content = bytes(content)

				return Response(
					content=processed_content,
					media_type=media_type,
					headers={
						"Cross-Origin-Resource-Policy": "cross-origin",
						"Access-Control-Allow-Origin": "*",
						"Cache-Control": "public, max-age=86400",  # Cache for 24 hours
						"X-Content-Type-Options": "nosniff",
					},
				)
		except httpx.HTTPStatusError as e:
			logger.error(f"Failed to fetch image: {e.response.status_code} for {url}")
			raise HTTPException(
				status_code=e.response.status_code,
				detail=f"Failed to fetch image: Google returned {e.response.status_code}",
			)
		except HTTPException:
			raise
		except Exception as e:
			logger.error(f"Proxy error: {str(e)}")
			raise HTTPException(status_code=500, detail="Internal proxy error")


@app.get("/")
async def root():
	"""
	Health check endpoint to verify the API server is currently running.
	"""
	return {"status": "online", "message": "Gemini API FastAPI Server is running"}


if __name__ == "__main__":
	import uvicorn

	uvicorn.run("main:app", host=HOST, port=PORT, log_level="info")