import gradio as gr
import numpy as np
import pandas as pd
import re
from sklearn.metrics.pairwise import cosine_similarity


# === Helper Functions ===
def encode_input_text(text, model):
    return model.encode([text])[0]

def extract_keywords(text):
    words = re.findall(r'\b\w{5,}\b', text.lower())
    return set(words)

def generate_explanation(user_keywords, movie_text):
    movie_words = extract_keywords(movie_text)
    matched = user_keywords & movie_words
    return ", ".join(sorted(matched)) if matched else "No strong keyword match"

def compute_similar_movies(user_embedding, df, top_k=5):
    valid_df = df[df['fullplot_embedding'].notnull()].copy()
    movie_embeddings = np.stack(valid_df['fullplot_embedding'].values)
    similarities = cosine_similarity([user_embedding], movie_embeddings)[0]
    valid_df['similarity'] = similarities
    top_indices = similarities.argsort()[::-1][:top_k]
    return valid_df.iloc[top_indices]

feedback_list = []

def submit_feedback(movie_title, feedback):
    feedback_list.append((movie_title, feedback))
    print(f"Feedback received: {movie_title} => {feedback}")
    return f"✅ Feedback received for: {movie_title}"

def format_movie_output(df, user_input):
    user_keywords = extract_keywords(user_input)
    blocks = []
    for _, row in df.iterrows():
        title = f"⭐ **{row['title']}**"
        genres = f"🎭 *Genres:* {', '.join(row['genres']) if isinstance(row['genres'], list) else row['genres']}"
        similarity = f"📈 *Similarity:* {row['similarity']:.3f}"
        movie_text = ' '.join(str(row.get(field, '')) for field in ['fullplot', 'summary', 'tagline'])
        explanation = generate_explanation(user_keywords, movie_text)
        plot = f"<details><summary>📝 Plot</summary>{row['fullplot']}</details>"
        blocks.append(f"{title}\n{genres}\n{similarity}\n🔍 *Matched on:* {explanation}\n{plot}")
    return "\n\n---\n\n".join(blocks), df['title'].tolist()

def recommend_movies(user_input, top_k, use_example):
    if use_example:
        user_input = "A group of unlikely heroes band together to save the galaxy from a powerful villain."
    if not user_input.strip():
        return "⚠️ Please enter a description.", gr.update(choices=[], value="None")

    user_emb = encode_input_text(user_input, model)
    top_df = compute_similar_movies(user_emb, df, top_k=top_k)
    result_text, titles = format_movie_output(top_df, user_input)
    return result_text, gr.update(choices=titles, value=titles[0] if titles else "None")

def clear_all():
    return "", 5, False, "", gr.update(choices=[], value="None")

# === UI ===
with gr.Blocks() as iface:
    gr.Markdown("## 🎬 Movie Recommender")

    with gr.Row():
        with gr.Column(scale=1):
            user_input = gr.Textbox(label="Describe a Movie Plot", lines=4, placeholder="e.g. A team of misfits saves the world.")
            use_example = gr.Checkbox(label="Use Example Description")
            top_k = gr.Slider(1, 10, value=5, step=1, label="Top K Recommendations")
            recommend_btn = gr.Button("🔍 Recommend")
            clear_btn = gr.Button("🧹 Clear")

            gr.Markdown("### 🙋 Feedback")
            feedback_title = gr.Dropdown(choices=[], label="Select Movie to Rate")
            feedback_choice = gr.Radio(["👍", "👎"], label="Your Feedback")
            feedback_btn = gr.Button("Submit Feedback")
            feedback_output = gr.Textbox(label="Feedback Result", interactive=False)

        with gr.Column(scale=2):
            output = gr.Markdown(label="Recommendations")

    recommend_btn.click(
        fn=recommend_movies,
        inputs=[user_input, top_k, use_example],
        outputs=[output, feedback_title]
    )

    clear_btn.click(
        fn=clear_all,
        inputs=[],
        outputs=[user_input, top_k, use_example, output, feedback_title]
    )

    feedback_btn.click(
        fn=submit_feedback,
        inputs=[feedback_title, feedback_choice],
        outputs=feedback_output
    )

iface.launch()


# === Gradio UI ===
with gr.Blocks() as demo:
    gr.Markdown("## 🎬 Movie Recommendation with Explanation")
    input_text = gr.Textbox(label="Enter a movie plot description", placeholder="Type a story or plot...")
    output = gr.Textbox(label="Top recommended movies with explanation", lines=10)
    btn = gr.Button("Recommend")

    def full_pipeline(user_text):
        from sentence_transformers import SentenceTransformer
        import pickle

        # Load data and model
        df = pd.read_pickle("movies_with_embeddings.pkl")
        model = SentenceTransformer("sentence-transformers/all-MiniLM-L6-v2")

        # Encode
        user_emb = encode_input_text(user_text, model)
        user_keywords = extract_keywords(user_text)

        # Compute recommendations
        top_df = compute_similar_movies(user_emb, df)
        results = []
        for _, row in top_df.iterrows():
            explanation = generate_explanation(user_keywords, row["fullplot"])
            results.append(f"🎬 {row['title']} (🎯 score={row['similarity']:.2f})\n🔍 {explanation}")
        return "\n\n".join(results)

    btn.click(fn=full_pipeline, inputs=[input_text], outputs=[output])

demo.launch()