from flask import Blueprint, render_template, request, redirect, url_for, flash
from models import Product, Node

user_bp = Blueprint('user', __name__)

@user_bp.route('/')
def home():
    products = Product.query.all()
    return render_template('home.html', products=products)

@user_bp.route('/product/<int:product_id>')
def product_detail(product_id):
    product = Product.query.get_or_404(product_id)
    
    # If the product has a root node, redirect directly to the decision tree
    if product.root_node:
        return redirect(url_for('user.decision_node', product_id=product.id, node_id=product.root_node_id))
    
    # Otherwise, show the product detail page with a message
    flash("This product doesn't have a decision tree yet.", "warning")
    return render_template('product_detail.html', product=product)

# New route for starting the decision tree
@user_bp.route('/product/<int:product_id>/start')
def start_decision_tree(product_id):
    product = Product.query.get_or_404(product_id)
    if not product.root_node:
        flash("This product doesn't have a decision tree yet.", "warning")
        return redirect(url_for('user.product_detail', product_id=product_id))
    
    return redirect(url_for('user.decision_node', product_id=product_id, node_id=product.root_node_id))

@user_bp.route('/product/<int:product_id>/node/<int:node_id>')
def decision_node(product_id, node_id):
    product = Product.query.get_or_404(product_id)
    node = Node.query.get_or_404(node_id)
    
    # Verify that this node belongs to the product's decision tree
    if not is_node_in_product_tree(product, node):
        flash("This node does not belong to the selected product.", "danger")
        return redirect(url_for('user.product_detail', product_id=product_id))
    
    return render_template('decision_tree.html', product=product, current_node=node)

# Backward compatibility route - redirects old URLs to new format
@user_bp.route('/node/<int:node_id>')
def legacy_node_redirect(node_id):
    node = Node.query.get_or_404(node_id)
    
    # Find which product this node belongs to
    for product in Product.query.all():
        if is_node_in_product_tree(product, node):
            return redirect(url_for('user.decision_node', product_id=product.id, node_id=node.id))
    
    # If we can't find the product, redirect to home
    flash("Could not determine which product this node belongs to.", "warning")
    return redirect(url_for('user.home'))

# Helper function to check if a node belongs to a product's decision tree
def is_node_in_product_tree(product, node):
    if not product.root_node:
        return False
    
    # Check if this is the root node
    if product.root_node_id == node.id:
        return True
    
    # Otherwise, traverse the tree
    return is_node_in_tree(product.root_node, node.id)

# Helper function to check if a node is in a tree
def is_node_in_tree(root, node_id):
    if not root:
        return False
    
    if root.id == node_id:
        return True
    
    # Check yes branch
    if root.yes_node_id and is_node_in_tree(root.yes_node, node_id):
        return True
    
    # Check no branch
    if root.no_node_id and is_node_in_tree(root.no_node, node_id):
        return True
    
    return False