# -*- coding: utf-8 -*-
"""
Created on Sat Apr 11 15:03:04 2026

@author: THYAGHARAJAN
"""
#line 20 import avoids circular error
from utils.core_imports import get_current_user

from fastapi import APIRouter, Depends, HTTPException
import os
import shutil
import threading   #used for rebuild_faiss_index line 54


router = APIRouter()  #the app acted as a proxy to Ollama in main file

@router.delete("/admin/delete-document")
def delete_document(filename: str,current_user: str = Depends(get_current_user)):
    from utils.core_imports import get_db, rebuild_faiss_index, get_upload_folder  #lazy import

    filename = filename.strip()  

    conn = get_db()
    cursor = conn.cursor()

    # Check existence
    cursor.execute(
        "SELECT faiss_id FROM document_chunks WHERE TRIM(source)=?",
        (filename,)
    )

    rows = cursor.fetchall()

    if not rows:
        conn.close()
        raise HTTPException(status_code=404, detail="Document not found")

    # ✅ DELETE (this was missing in your code)
    cursor.execute(
        "DELETE FROM document_chunks WHERE TRIM(source)=?",
        (filename,)
    )

    conn.commit()
    conn.close()

    # Delete physical file
    file_path = os.path.join(get_upload_folder(), filename)
    if os.path.exists(file_path):
        os.remove(file_path)
        rebuild_faiss_index()

    # Rebuild FAISS in background
    threading.Thread(target=rebuild_faiss_index).start()
    
    '''
    #used for debugging. Found & was not converted to %26
    print(f"Incoming filename: [{filename}]")

    cursor.execute("SELECT DISTINCT source FROM document_chunks")
    all_sources = cursor.fetchall()

    print("DB sources:")
    for s in all_sources:
        print(f"[{s[0]}]")
    '''
    
    return {"message": f"{filename} removed from index"}



@router.delete("/admin/delete-folder")
def delete_folder(folder: str,current_user: str = Depends(get_current_user)):
    from utils.core_imports import get_db, rebuild_faiss_index
    conn = get_db()
    cursor = conn.cursor()

    cursor.execute(
        "DELETE FROM document_chunks WHERE source LIKE ?",
        (f"%{folder}%",)
    )
    
    deleted_count = cursor.rowcount
    conn.commit()
    conn.close()
    if deleted_count == 0:
        raise HTTPException(status_code=404, detail="Folder not found")
    
    threading.Thread(target=rebuild_faiss_index).start()

    return {"message": f"{folder} folder removed from index"}



@router.delete("/admin/reset-index")
def reset_index(confirm: bool = False,current_user: str = Depends(get_current_user)):
    from utils.core_imports import get_db, rebuild_faiss_index, get_upload_folder   #lazy import to avoid circular import 
    #confirm button will be displayed
    if not confirm:
        return {"message": "Set confirm=true to reset index"}

    conn = get_db()
    cursor = conn.cursor()

    cursor.execute("DELETE FROM document_chunks")
    # delete ALL rows in document_chunks table

    conn.commit()
    conn.close()
  
    #delete the files in the UPLOAD dir doc_ingestion folder
    upload_dir = get_upload_folder()
    
    shutil.rmtree(upload_dir)
    os.makedirs(upload_dir, exist_ok=True)
    
    threading.Thread(target=rebuild_faiss_index).start()

    return {"message": "Index reset completed"}



@router.get("/admin/list-documents")
def list_documents(current_user: str = Depends(get_current_user)):
    from utils.core_imports import get_db

    conn = get_db()
    cursor = conn.cursor()

    cursor.execute("""
        SELECT source, COUNT(*) as chunks
        FROM document_chunks
        GROUP BY source
    """)

    rows = cursor.fetchall()
    conn.close()

    docs = [{"document": r[0], "chunks": r[1]} for r in rows]

    return {"documents": docs}