from shiny import App, ui, render
import requests
from bs4 import BeautifulSoup
import pandas as pd
import torch
from transformers import BertTokenizer, BertModel
import numpy as np
from sklearn.metrics.pairwise import cosine_similarity

# Step 1: Scrape the free courses from Analytics Vidhya
url = "https://courses.analyticsvidhya.com/pages/all-free-courses"
response = requests.get(url)
soup = BeautifulSoup(response.content, 'html.parser')

courses = []

# Extracting course title, image, and course link
for course_card in soup.find_all('header', class_='course-card__img-container'):
    img_tag = course_card.find('img', class_='course-card__img')
    
    if img_tag:
        title = img_tag.get('alt')
        image_url = img_tag.get('src')
        
        link_tag = course_card.find_previous('a')
        if link_tag:
            course_link = link_tag.get('href')
            if not course_link.startswith('http'):
                course_link = 'https://courses.analyticsvidhya.com' + course_link

            courses.append({
                'title': title,
                'image_url': image_url,
                'course_link': course_link
            })

# Step 2: Create DataFrame
df = pd.DataFrame(courses)

# Load pre-trained BERT model and tokenizer
tokenizer = BertTokenizer.from_pretrained('bert-base-uncased')
model = BertModel.from_pretrained('bert-base-uncased')

# Function to generate embeddings using BERT
def get_bert_embedding(text):
    inputs = tokenizer(text, return_tensors='pt', truncation=True, padding=True)
    with torch.no_grad():
        outputs = model(**inputs)
    return outputs.last_hidden_state.mean(dim=1).numpy()

# Create embeddings for course titles
df['embedding'] = df['title'].apply(lambda x: get_bert_embedding(x))

# Function to perform search using BERT-based similarity
def search_courses(query):
    query_embedding = get_bert_embedding(query)
    course_embeddings = np.vstack(df['embedding'].values)
    
    # Compute cosine similarity between query embedding and course embeddings
    similarities = cosine_similarity(query_embedding, course_embeddings).flatten()
    
    # Add the similarity scores to the DataFrame
    df['score'] = similarities
    
    # Sort by similarity score in descending order and return top results
    top_results = df.sort_values(by='score', ascending=False).head(10)
    return top_results[['title', 'image_url', 'course_link', 'score']].to_dict(orient='records')

# Shiny UI and Server
app_ui = ui.page_fluid(
    ui.tags.style(
        """
        @import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;500;700&display=swap');

        body {
            font-family: 'Poppins', sans-serif;
            background-color: #f4f6f9;
        }

        .container {
            padding: 20px;
        }
        
        h2 {
            color: #ff6f61;
            font-weight: 700;
            text-align: center;
        }

        .result-container {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            justify-content: center;
        }
        
        .course-card {
            background-color: #ffffff;
            border-radius: 12px;
            box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
            overflow: hidden;
            width: calc(50% - 10px);
            transition: transform 0.3s, box-shadow 0.3s;
        }
        
        .course-card:hover {
            transform: scale(1.05);
            box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
        }

        .course-image {
            width: 100%;
            height: 180px;
            object-fit: cover;
            border-top-left-radius: 12px;
            border-top-right-radius: 12px;
        }

        .course-info {
            padding: 15px;
        }
        
        .course-info h3 {
            font-size: 20px;
            color: #333;
            margin-top: 0;
        }

        .course-info p {
            color: #666;
            font-size: 16px;
            margin-bottom: 10px;
        }

        .course-link {
            background-color: #ff6f61;
            color: white;
            padding: 8px 12px;
            text-decoration: none;
            border-radius: 6px;
            font-size: 15px;
            display: inline-block;
            margin-top: 10px;
            transition: background-color 0.2s;
        }

        .course-link:hover {
            background-color: #e85a50;
        }

        .no-results {
            text-align: center;
            color: #888;
            font-style: italic;
        }
        """
    ),
    ui.h2("Analytics Vidhya Smart Course Search"),
    ui.input_text("query", "Enter your search query", placeholder="e.g., machine learning, data science, python"),
    ui.output_text("search_info"),
    ui.output_ui("results")
)

def server(input, output, session):
    @output
    @render.ui
    def results():
        if not input.query():
            return ui.p("Enter a search query to get started!", class_="no-results")
        
        # Perform the search
        query = input.query()
        results = search_courses(query)
        
        if results:
            result_ui = []
            for item in results:
                course_title = item['title']
                course_image = item['image_url']
                course_link = item['course_link']
                relevance_score = round(item['score'] * 100, 2)
                
                # Create course card UI
                result_ui.append(
                    ui.div(
                        ui.img(src=course_image, class_="course-image"),
                        ui.div(
                            ui.h3(course_title),
                            ui.p(f"Relevance: {relevance_score}%"),
                            ui.a("View Course", href=course_link, target="_blank", class_="course-link"),
                            class_="course-info"
                        ),
                        class_="course-card"
                    )
                )
            return ui.div(*result_ui, class_="result-container")
        else:
            return ui.p("No results found.", class_="no-results")
    
    @output
    @render.text
    def search_info():
        return f"Results for '{input.query()}'" if input.query() else "Search for courses by typing a query above."

app = App(app_ui, server)