import json
import logging
from flask import Blueprint, render_template, redirect, url_for, jsonify, request
from pymongo import UpdateOne
from xero_python.accounting import AccountingApi
from utils import jsonify as jsonify_xero
from search_engine import search_and_filter_images, categorise
from .xero_client import xero, api_client, store_xero_oauth2_token, obtain_xero_oauth2_token, xero_token_required, get_xero_tenant_id
from .extensions import mongo # <-- IMPORT MONGO

xero_bp = Blueprint('xero', __name__)
logger = logging.getLogger(__name__)


@xero_bp.route("/")
def index():
    xero_access = dict(obtain_xero_oauth2_token() or {})
    return render_template(
        "code.html",
        title="Home | OAuth Token",
        code=json.dumps(xero_access, sort_keys=True, indent=4),
    )

@xero_bp.route("/login")
def login():
    redirect_url = url_for("xero.oauth_callback", _external=True)
    return xero.authorize(callback_uri=redirect_url)

@xero_bp.route("/callback")
def oauth_callback():
    try:
        response = xero.authorized_response()
    except Exception as e:
        logger.error("OAuth callback failed: %s", e)
        return "OAuth callback failed.", 500
    
    if response is None or response.get("access_token") is None:
        return "Access denied: response=%s" % response
    
    store_xero_oauth2_token(response)
    return redirect(url_for("xero.index", _external=True))

@xero_bp.route("/logout")
def logout():
    store_xero_oauth2_token(None)
    return redirect(url_for("xero.index", _external=True))

@xero_bp.route("/api/inventory")
@xero_token_required
def fetch_inventory():
    try:
        xero_tenant_id = get_xero_tenant_id()
        accounting_api = AccountingApi(api_client)
        
        xero_items = accounting_api.get_items(xero_tenant_id=xero_tenant_id).items
        fetched_products = [{
            "code": item.code, "name": item.name,
            "price": float(item.sales_details.unit_price) if item.sales_details else 0.0,
            "unit": item.description, "on_hand": item.quantity_on_hand
        } for item in xero_items]

        # Use mongo.db directly
        db_products = list(mongo.db.products.find({}))
        db_products_map = {p['code']: p for p in db_products if 'code' in p}
        fetched_products_map = {p['code']: p for p in fetched_products}

        products_to_insert = []
        bulk_update_ops = []
        
        for code, fetched_p in fetched_products_map.items():
            db_p = db_products_map.get(code)
            if not db_p:
                new_doc = { "code": fetched_p["code"], "name": fetched_p["name"], "price": fetched_p["price"], "unit": fetched_p["unit"],
                    "category": str(categorise(fetched_p["name"])),
                    "image_url": str(search_and_filter_images(str(fetched_p["name"]))[0]["image_url"]),}
                products_to_insert.append(new_doc)
            elif (fetched_p['name'] != db_p.get('name') or fetched_p['price'] != db_p.get('price') or fetched_p['unit'] != db_p.get('unit')):
                update_fields = { "name": fetched_p["name"], "price": fetched_p["price"], "unit": fetched_p["unit"] }
                if fetched_p['name'] != db_p.get('name'):
                    update_fields["category"] = str(categorise(fetched_p["name"]))
                    update_fields["image_url"] = str(search_and_filter_images(str(fetched_p["name"]))[0]["image_url"])
                bulk_update_ops.append(UpdateOne({'code': code}, {'$set': update_fields}))
        
        db_codes = set(db_products_map.keys())
        fetched_codes = set(fetched_products_map.keys())
        codes_to_delete = list(db_codes - fetched_codes)
        
        # Use mongo.db directly
        if codes_to_delete: mongo.db.products.delete_many({'code': {'$in': codes_to_delete}})
        if products_to_insert: mongo.db.products.insert_many(products_to_insert)
        if bulk_update_ops: mongo.db.products.bulk_write(bulk_update_ops)

        sub_title = (f"Sync complete. Inserted: {len(products_to_insert)}, "
                     f"Updated: {len(bulk_update_ops)}, Deleted: {len(codes_to_delete)}")
        code_to_display = jsonify_xero(fetched_products)

    except Exception as e:
        logger.error("Inventory sync failed: %s", e)
        sub_title = f"Error during sync: {e}"
        code_to_display = jsonify({"error": str(e)})

    return render_template("code.html", title="Inventory Sync", sub_title=sub_title, code=code_to_display)