main.py

from fastapi import (
    FastAPI,
    Request,
    Depends,
    HTTPException,
    status,
    UploadFile,
    File,
    Form,
)
from fastapi.middleware.cors import CORSMiddleware
import os, shutil

# from chromadb.utils import embedding_functions

from langchain_community.document_loaders import (
    WebBaseLoader,
    TextLoader,
    PyPDFLoader,
    CSVLoader,
    Docx2txtLoader,
    UnstructuredEPubLoader,
    UnstructuredWordDocumentLoader,
    UnstructuredMarkdownLoader,
    UnstructuredXMLLoader,
    UnstructuredRSTLoader,
)
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_community.vectorstores import Chroma
from langchain.chains import RetrievalQA


from pydantic import BaseModel
from typing import Optional

import uuid
import time

from utils.misc import calculate_sha256
from utils.utils import get_current_user
from config import UPLOAD_DIR, EMBED_MODEL, CHROMA_CLIENT, CHUNK_SIZE, CHUNK_OVERLAP
from constants import ERROR_MESSAGES

# EMBEDDING_FUNC = embedding_functions.SentenceTransformerEmbeddingFunction(
#     model_name=EMBED_MODEL
# )

app = FastAPI()

origins = ["*"]

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


class CollectionNameForm(BaseModel):
    collection_name: Optional[str] = "test"


class StoreWebForm(CollectionNameForm):
    url: str


def store_data_in_vector_db(data, collection_name) -> bool:
    text_splitter = RecursiveCharacterTextSplitter(
        chunk_size=CHUNK_SIZE, chunk_overlap=CHUNK_OVERLAP
    )
    docs = text_splitter.split_documents(data)

    texts = [doc.page_content for doc in docs]
    metadatas = [doc.metadata for doc in docs]

    try:
        collection = CHROMA_CLIENT.create_collection(name=collection_name)

        collection.add(
            documents=texts, metadatas=metadatas, ids=[str(uuid.uuid1()) for _ in texts]
        )
        return True
    except Exception as e:
        print(e)
        if e.__class__.__name__ == "UniqueConstraintError":
            return True

        return False


@app.get("/")
async def get_status():
    return {"status": True}


@app.get("/query/{collection_name}")
def query_collection(
    collection_name: str,
    query: str,
    k: Optional[int] = 4,
    user=Depends(get_current_user),
):
    try:
        collection = CHROMA_CLIENT.get_collection(
            name=collection_name,
        )
        result = collection.query(query_texts=[query], n_results=k)

        return result
    except Exception as e:
        print(e)
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=ERROR_MESSAGES.DEFAULT(e),
        )


@app.post("/web")
def store_web(form_data: StoreWebForm, user=Depends(get_current_user)):
    # "https://www.gutenberg.org/files/1727/1727-h/1727-h.htm"
    try:
        loader = WebBaseLoader(form_data.url)
        data = loader.load()
        store_data_in_vector_db(data, form_data.collection_name)
        return {
            "status": True,
            "collection_name": form_data.collection_name,
            "filename": form_data.url,
        }
    except Exception as e:
        print(e)
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail=ERROR_MESSAGES.DEFAULT(e),
        )


@app.post("/doc")
def store_doc(
    collection_name: Optional[str] = Form(None),
    file: UploadFile = File(...),
    user=Depends(get_current_user),
):
    # "https://www.gutenberg.org/files/1727/1727-h/1727-h.htm"

    print(file.content_type)
    
    text_xml=["xml"]
    octet_markdown=["md"]
    known_source_ext=[
        "go", "py", "java", "sh", "bat", "ps1", "cmd", "js", "ts",
        "css", "cpp", "hpp","h", "c", "cs", "sql", "log", "ini",
        "pl", "pm", "r", "dart", "dockerfile", "env", "php", "hs",
        "hsc", "lua", "nginxconf", "conf", "m", "mm", "plsql", "perl",
        "rb", "rs", "db2", "scala", "bash", "swift", "vue", "svelte"
        ]
    docx_type="application/vnd.openxmlformats-officedocument.wordprocessingml.document"
    known_doc_ext=["doc","docx"]
    file_ext=file.filename.split(".")[-1].lower()
    known_type=True
    
    try:
        filename = file.filename
        file_path = f"{UPLOAD_DIR}/{filename}"
        contents = file.file.read()
        with open(file_path, "wb") as f:
            f.write(contents)
            f.close()

        f = open(file_path, "rb")
        if collection_name == None:
            collection_name = calculate_sha256(f)[:63]
        f.close()

        if file_ext=="pdf":
            loader = PyPDFLoader(file_path)
        elif (file.content_type ==docx_type or file_ext in known_doc_ext):
            loader = Docx2txtLoader(file_path)
        elif file_ext=="csv":
            loader = CSVLoader(file_path)
        elif file_ext=="rst":
            loader = UnstructuredRSTLoader(file_path, mode="elements")
        elif file_ext in text_xml:
            loader=UnstructuredXMLLoader(file_path)
        elif file_ext in known_source_ext or file.content_type.find("text/")>=0:
            loader = TextLoader(file_path)
        elif file_ext in octet_markdown:
            loader = UnstructuredMarkdownLoader(file_path)
        elif file.content_type == "application/epub+zip":
            loader = UnstructuredEPubLoader(file_path)
        else:
            loader = TextLoader(file_path)
            known_type=False


        data = loader.load()
        result = store_data_in_vector_db(data, collection_name)

        if result:
            return {
                "status": True,
                "collection_name": collection_name,
                "filename": filename,
                "known_type":known_type,
            }
        else:
            raise HTTPException(
                status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
                detail=ERROR_MESSAGES.DEFAULT(),
            )
    except Exception as e:
        print(e)
        if "No pandoc was found" in str(e):
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=ERROR_MESSAGES.PANDOC_NOT_INSTALLED,
            )
        else:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail=ERROR_MESSAGES.DEFAULT(e),
            )


@app.get("/reset/db")
def reset_vector_db(user=Depends(get_current_user)):
    if user.role == "admin":
        CHROMA_CLIENT.reset()
    else:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
        )


@app.get("/reset")
def reset(user=Depends(get_current_user)) -> bool:
    if user.role == "admin":
        folder = f"{UPLOAD_DIR}"
        for filename in os.listdir(folder):
            file_path = os.path.join(folder, filename)
            try:
                if os.path.isfile(file_path) or os.path.islink(file_path):
                    os.unlink(file_path)
                elif os.path.isdir(file_path):
                    shutil.rmtree(file_path)
            except Exception as e:
                print("Failed to delete %s. Reason: %s" % (file_path, e))

        try:
            CHROMA_CLIENT.reset()
        except Exception as e:
            print(e)

        return True
    else:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
        )