app/main.py

#!/usr/bin/env python
# coding: utf-8
from os import listdir
from os.path import isdir
from fastapi import FastAPI, HTTPException, Request, responses, Body
from fastapi.middleware.cors import CORSMiddleware
from llama_cpp import Llama

from pydantic import BaseModel
from enum import Enum
from typing import Optional, Literal, Dict, List

# MODEL LOADING, FUNCTIONS, AND TESTING

print("Loading model...")
PHllm = Llama(model_path="/models/final-Physics_llama3.gguf", use_mmap=False, use_mlock=True)
# MIllm = Llama(model_path="/models/final-LlamaTuna_Q8_0.gguf", use_mmap=False, use_mlock=True)
      # n_gpu_layers=28, # Uncomment to use GPU acceleration
      # seed=1337, # Uncomment to set a specific seed
      # n_ctx=2048, # Uncomment to increase the context window
#)

print("Loading Translators.")
from pythainlp.translate.en_th import EnThTranslator, ThEnTranslator
t = EnThTranslator()
e = ThEnTranslator()

def extract_restext(response, is_chat=False):
  return response['choices'][0]['text' if is_chat else 'message'].strip()

def ask_llama(llm: Llama, question: str, max_new_tokens=200, temperature=0.5, repeat_penalty=2.0):
  result = extract_restext(llm.create_chat_completion({"role": "user", "content": question}, max_tokens=max_new_tokens, temperature=temperature, repeat_penalty=repeat_penalty, stop=["<|eot_id|>", "<|end_of_text|>"]), is_chat=True)
  return result

def chat_llama(llm: Llama, chat_history: dict, max_new_tokens=200, temperature=0.5, repeat_penalty=2.0):
  result = extract_restext(llm.create_chat_completion(chat_history, max_tokens=max_new_tokens, temperature=temperature, repeat_penalty=repeat_penalty, stop=["<|eot_id|>", "<|end_of_text|>"]), is_chat=True)
  return result

# TESTING THE MODEL
print("Testing model...")
assert ask_llama(PHllm, ["Hello!, How are you today?"], max_new_tokens=5) #Just checking that it can run
print("Checking Translators.")
assert t.translate("Hello!") == "สวัสดี!"
assert e.translate("สวัสดี!") == "Hello!"
print("Ready.")


# START OF FASTAPI APP
app = FastAPI(
    title = "Gemma Finetuned API",
    description="Gemma Finetuned API for Thai Open-ended question answering.",
    version="1.0.0",
)

origins = ["*"]
app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"]
)


# API DATA CLASSES
class QuestionResponse(BaseModel):
  code: int = 200
  question: Optional[str] = None
  answer: str = None
  config: Optional[dict] = None

class ChatHistoryResponse(BaseModel):
  code: int = 200
  chat_history: Dict[str] = None
  answer: str = None
  config: Optional[dict] = None

class LlamaChatMessage(BaseModel):
  role: Literal["user", "assistant"]
  content: str


# API ROUTES
@app.get('/')
def docs():
  "Redirects the user from the main page to the docs."
  return responses.RedirectResponse('./docs')

@app.post('/questions/physics')
async def ask_gemmaPhysics(
    prompt: str = Body(..., embed=True, example="Why do ice cream melt so fast?"),
    temperature: float = Body(0.5, embed=True), 
    repeat_penalty: float = Body(1.0, embed=True),
    max_new_tokens: int = Body(200, embed=True),
    translate_from_thai: bool = Body(False, embed=True)
) -> QuestionResponse:
  """
  Ask a finetuned Gemma an physics question. 
  NOTICE: Answers may be random / inaccurate. Always do your research & confirm its responses before doing anything.
  """
  if prompt:
    try:
      print(f'Asking LlamaPhysics with the question "{prompt}", translation is {"enabled" if translate_from_thai else "disabled"}')
      if translate_from_thai:
        prompt = e.translate(prompt)
      result = ask_llama(PHllm, prompt, max_new_tokens=max_new_tokens, temperature=temperature, repeat_penalty=repeat_penalty)
      print(f"Result: {result}")
      if translate_from_thai:
        result = t.translate(result)
      return QuestionResponse(answer=result, question=prompt, config={"temperature": temperature, "max_new_tokens": max_new_tokens, "repeat_penalty": repeat_penalty})
    except Exception as e:
      return HTTPException(500, QuestionResponse(code=500, answer=str(e), question=prompt))
  else:
    return HTTPException(400, QuestionResponse(code=400, answer="Request argument 'prompt' not provided."))


# @app.post('/chat/multiturn')
# async def ask_llama3_Tuna(
#     chat_history: List[LlamaChatMessage] = Body(..., embed=True),
#     temperature: float = Body(0.5, embed=True), 
#     repeat_penalty: float = Body(2.0, embed=True),
#     max_new_tokens: int = Body(200, embed=True)
# ) -> ChatHistoryResponse:
#   """
#   Chat with a finetuned Llama-3 model (in Thai).
#   Answers may be random / inaccurate. Always do your research & confirm its responses before doing anything.
#   NOTICE: YOU MUST APPLY THE LLAMA3 PROMPT YOURSELF!
#   """
#   if chat_history:
#     try:
#       print(f'Asking Llama3Tuna with the question "{chat_history}"')
#       result = chat_llama(MIllm, chat_history, max_new_tokens=max_new_tokens, temperature=temperature, repeat_penalty=repeat_penalty)
#       print(f"Result: {result}")
#       return ChatHistoryResponse(answer=result, config={"temperature": temperature, "max_new_tokens": max_new_tokens, "repeat_penalty": repeat_penalty})
#     except Exception as e:
#       return HTTPException(500, QuestionResponse(code=500, answer=str(e), question=chat_history))
#   else:
#     return HTTPException(400, QuestionResponse(code=400, answer="Request argument 'prompt' not provided."))