app/xero_routes.py

import logging
import traceback
import urllib.parse
import json
from flask import Blueprint, render_template, jsonify, request, flash, redirect, url_for, current_app, session, Response, stream_with_context
from pymongo import UpdateOne
from collections import defaultdict
from bson.binary import Binary
import random
import requests

# This part of the code assumes the Zoho client functions are in a file named `xero_client.py`
from .xero_client import (
    zoho_token_required,
    is_zoho_token_available,
    initialize_zoho_sdk,
    clear_zoho_token,
    make_zoho_api_request
)
from .extensions import mongo
from utils import jsonify as jsonify_custom
from search_engine import search_and_filter_images, categorise

zoho_bp = Blueprint('zoho', __name__)
logger = logging.getLogger(__name__)


@zoho_bp.context_processor
def inject_zoho_status():
    """Makes the Zoho token status available to all templates."""
    return dict(is_zoho_token_available=is_zoho_token_available)


@zoho_bp.route("/WEBUI")
def index():
    """Renders the home page with a welcome message."""
    welcome_message = """
Welcome to the Zoho Books Integration Dashboard.

Use the navigation bar above to:
- Sync Inventory: Pull all items from Zoho, find images, and save to our database.
- Edit Inventory: Manually override image URLs for specific products.

Your current Zoho Token Status is: {}
    """.format("Available" if is_zoho_token_available() else "Not Available. Please login.")

    return render_template(
        "code.html",
        title="Home",
        sub_title="Welcome to the Zoho Integration",
        code=welcome_message,
        language="text"
    )


@zoho_bp.route("/login")
def login():
    config = current_app.config
    params = {
        'scope': 'ZohoBooks.fullaccess.all',
        'client_id': config['ZOHO_CLIENT_ID'],
        'response_type': 'code',
        'access_type': 'offline',
        'redirect_uri': config['ZOHO_REDIRECT_URL'],
        # Force consent so that Zoho returns a refresh token when possible
        'prompt': 'consent'
    }
    accounts_url = 'https://accounts.zohocloud.ca/oauth/v2/auth'
    auth_url = f"{accounts_url}?{urllib.parse.urlencode(params)}"
    return redirect(auth_url)


@zoho_bp.route("/callback")
def oauth_callback():
    grant_token = request.args.get('code')
    accounts_server = request.args.get('accounts-server')

    if not grant_token:
        flash("Authorization failed: No grant token received from Zoho.", "error")
        return redirect(url_for('zoho.index'))
    try:
        initialize_zoho_sdk(grant_token=grant_token, accounts_server_url=accounts_server)
        flash("Successfully authenticated with Zoho Books!", "success")
        next_url = session.pop('next_url', url_for('zoho.index'))
        return redirect(next_url)
    except Exception as e:
        logger.error(f"Error during Zoho OAuth callback: {e}", exc_info=True)
        flash(f"An error occurred during authentication: {e}", "error")
        return redirect(url_for('zoho.index'))


@zoho_bp.route("/logout")
def logout():
    clear_zoho_token()
    flash("You have been logged out from Zoho.", "info")
    return redirect(url_for("zoho.index"))


@zoho_bp.route("/api/inventory")
# @zoho_token_required
def inventory_sync_page():
    """Renders the page that will display the sync progress bar."""
    return render_template("inventory_sync.html", title="Inventory Sync")


@zoho_bp.route("/api/inventory/stream")
# @zoho_token_required
def fetch_inventory_stream():
    """
    Performs the inventory sync and streams progress updates to the client.
    """
    def generate_sync_updates():
        try:
            yield f"data: {json.dumps({'progress': 0, 'message': 'Starting synchronization...'})}\n\n"

            # Step 1: Fetch all items from Zoho
            all_zoho_items = []
            page = 1
            has_more_pages = True
            while has_more_pages:
                yield f"data: {json.dumps({'progress': 5, 'message': f'Fetching page {page} of items from Zoho...'})}\n\n"
                params = {'page': page, 'per_page': 200}
                response_data, _ = make_zoho_api_request('GET', '/items', params=params)
                
                if not response_data: break
                page_items = response_data.get('items', [])
                if not page_items: break

                all_zoho_items.extend(item for item in page_items if item.get('status') == 'active')
                has_more_pages = response_data.get('page_context', {}).get('has_more_page', False)
                page += 1
            
            total_items = len(all_zoho_items)
            yield f"data: {json.dumps({'progress': 15, 'message': f'Found {total_items} active items. Grouping by product name...'})}\n\n"

            # Step 2: Group items by name
            grouped_products = defaultdict(lambda: {
                'modes': {}, 'description': '', 'zoho_id_for_image': None, 'name': None, 'category': None
            })
            for item in all_zoho_items:
                name = item.get('name')
                unit = item.get('unit', 'piece').lower()
                if not grouped_products[name]['description'] and item.get('description'): grouped_products[name]['description'] = item.get('description')
                if not grouped_products[name]['category'] and item.get('cf_type'): grouped_products[name]['category'] = item.get('cf_type')
                if not grouped_products[name]['zoho_id_for_image'] and item.get('image_document_id'): grouped_products[name]['zoho_id_for_image'] = item.get('item_id')
                grouped_products[name]['name'] = name
                grouped_products[name]['modes'][unit] = {'price': float(item.get('rate', 0.0)), 'zoho_id': item.get('item_id'), 'sku': item.get('sku')}

            # Step 3: Process and sync with MongoDB
            db_products_map = {p['name']: p for p in mongo.db.products.find({}, {'name': 1})}
            products_to_insert, bulk_update_ops = [], []
            total_to_process = len(grouped_products)

            for i, (name, fetched_p) in enumerate(grouped_products.items()):
                progress = 15 + int(((i + 1) / total_to_process) * 80)
                yield f"data: {json.dumps({'progress': progress, 'message': f'Processing: {name}'})}\n\n"

                image_data, image_content_type, fallback_image_url = None, None, None
                zoho_image_id = fetched_p.get('zoho_id_for_image')

                if zoho_image_id:
                    try:
                        content, headers = make_zoho_api_request('GET', f'/items/{zoho_image_id}/image')
                        if content and headers:
                            image_data = Binary(content)
                            image_content_type = headers.get('Content-Type', 'image/jpeg')
                            yield f"data: {json.dumps({'progress': progress, 'message': f'Downloaded existing image for {name} from Zoho.'})}\n\n"
                    except Exception:
                        yield f"data: {json.dumps({'progress': progress, 'message': f'Failed to get Zoho image for {name}. Will search online.'})}\n\n"
                
                if not image_data:
                    yield f"data: {json.dumps({'progress': progress, 'message': f'Searching for new image for: {name}...'})}\n\n"
                    try:
                        results = search_and_filter_images(str(name))
                        if results:
                            fallback_image_url = str(results[0]["image_url"])
                            yield f"data: {json.dumps({'progress': progress, 'message': f'Downloading new image for: {name}...'})}\n\n"
                            response = requests.get(fallback_image_url, timeout=15)
                            response.raise_for_status()
                            image_content_from_url, content_type_from_url = response.content, response.headers.get('Content-Type', 'image/jpeg')
                            image_data, image_content_type = Binary(image_content_from_url), content_type_from_url
                            
                            for mode_details in fetched_p['modes'].values():
                                item_id = mode_details.get('zoho_id')
                                if item_id:
                                    yield f"data: {json.dumps({'progress': progress, 'message': f'Uploading image for {name} to Zoho Item ID {item_id}...'})}\n\n"
                                    files = {'image': (f"{name.replace(' ', '_')}.jpg", image_content_from_url, content_type_from_url)}
                                    make_zoho_api_request('POST', f'/items/{item_id}/image', files=files)
                        else:
                            yield f"data: {json.dumps({'progress': progress, 'message': f'No image results found for: {name}'})}\n\n"
                    except Exception as e:
                        yield f"data: {json.dumps({'progress': progress, 'message': f'Error fetching new image for {name}: {e}'})}\n\n"
                        image_data, image_content_type = None, None

                update_fields = {
                    "name": name, "modes": fetched_p["modes"], "description": fetched_p.get('description', ''),
                    "image_data": image_data, "image_content_type": image_content_type, "image_url": fallback_image_url,
                    "category": fetched_p.get('category') or str(categorise(name)), "code": random.randint(1,100000),
                }

                if not db_products_map: products_to_insert.append(update_fields)
                else: bulk_update_ops.append(UpdateOne({'name': name}, {'$set': update_fields}, upsert=True))

            yield f"data: {json.dumps({'progress': 95, 'message': 'Finalizing database updates...'})}\n\n"
            db_names, fetched_names = set(db_products_map.keys()), set(grouped_products.keys())
            names_to_delete = list(db_names - fetched_names)
            if names_to_delete: mongo.db.products.delete_many({'name': {'$in': names_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)

            summary = f"Sync complete. Inserted/Updated: {len(products_to_insert) + len(bulk_update_ops)}, Deleted: {len(names_to_delete)}"
            final_code = jsonify_custom(list(grouped_products.values()))
            yield f"data: {json.dumps({'progress': 100, 'message': summary, 'status': 'complete', 'final_code': final_code})}\n\n"

        except Exception as e:
            logger.error("Inventory sync stream failed: %s", e, exc_info=True)
            error_message = f"Error during sync: {e}\n{traceback.format_exc()}"
            yield f"data: {json.dumps({'progress': 100, 'message': error_message, 'status': 'error'})}\n\n"

    return Response(stream_with_context(generate_sync_updates()), mimetype='text/event-stream')


@zoho_bp.route("/api/edit_inventory", methods=["GET", "POST"])
def edit_inventory():
    if request.method == "POST":
        product_name, new_image_url = request.form.get("product_name"), request.form.get("image_url")
        if not product_name or not new_image_url:
            flash("Product name and a new image URL are required.", "error")
        else:
            result = mongo.db.products.update_one(
                {"name": product_name}, {"$set": {"image_url": new_image_url, "image_data": None, "image_content_type": None}}
            )
            flash(f"Image for '{product_name}' updated successfully!" if result.matched_count else f"Product '{product_name}' not found.", "success" if result.matched_count else "error")
        return redirect(url_for("zoho.edit_inventory"))
    
    products = list(mongo.db.products.find({}, {"_id": 0, "name": 1, "image_url": 1}).sort("name", 1))
    return render_template("edit_inventory.html", title="Edit Inventory Image", products=products)