import streamlit as st
from transformers import pipeline
from graphviz import Digraph
import pdfplumber
from fpdf import FPDF
import tempfile
import os
import requests

# ------------- PAGE SETUP -------------
st.set_page_config(page_title="Visual Summarizer", page_icon="🧠", layout="centered")

# ------------- THEME TOGGLE -------------
theme = st.sidebar.radio("🌗 Theme", ["Light", "Dark"])
summary_type = st.sidebar.selectbox("📏 Summary Length", ["Brief", "Standard", "Detailed"])
translate_to = st.sidebar.selectbox("🌐 Translate Summary To", ["None", "Urdu", "French", "Spanish"])

if theme == "Dark":
    bg_color = "#212121"
    text_color = "white"
    card_bg = "#424242"
else:
    bg_color = "#f7fafd"
    text_color = "#333"
    card_bg = "#e3f2fd"

st.markdown(f"""
    <style>
    body {{ background-color: {bg_color}; color: {text_color}; }}
    .summary-card {{
        background-color: {card_bg};
        padding: 15px;
        border-radius: 10px;
        box-shadow: 2px 2px 6px #aaa;
        color: {text_color};
    }}
    .title {{ text-align: center; font-size: 32px; color: #4A148C; }}
    .subtitle {{ text-align: center; color: gray; }}
    </style>
""", unsafe_allow_html=True)

# ------------- LOAD SUMMARIZER -------------
@st.cache_resource
def load_model():
    return pipeline("summarization", model="facebook/bart-large-cnn")

summarizer = load_model()

# ------------- HEADER -------------
st.markdown("<h1 class='title'>🧠 Visual Text Summarizer & Learner</h1>", unsafe_allow_html=True)
st.markdown("<p class='subtitle'>Summarize, visualize, download, translate, and even explore YouTube to learn more!</p>", unsafe_allow_html=True)
st.markdown("---")

# ------------- INPUT SECTION -------------
text_input = st.text_area("📥 Paste your text here (or upload a file below):", height=250)
uploaded_file = st.file_uploader("📄 Upload a .txt or .pdf file", type=["txt", "pdf"])

def extract_text(file):
    if file.name.endswith(".txt"):
        return file.read().decode("utf-8")
    elif file.name.endswith(".pdf"):
        with pdfplumber.open(file) as pdf:
            return "\n".join([page.extract_text() for page in pdf.pages if page.extract_text()])
    return ""

input_text = extract_text(uploaded_file) if uploaded_file else text_input

# ------------- SUMMARY LENGTH CONFIG -------------
if summary_type == "Brief":
    max_len, min_len = 60, 20
elif summary_type == "Detailed":
    max_len, min_len = 200, 50
else:
    max_len, min_len = 130, 30

# ------------- TRANSLATION FUNCTION -------------
def translate_text(text, lang_code):
    try:
        url = "https://translate.googleapis.com/translate_a/single"
        params = {
            "client": "gtx",
            "sl": "en",
            "tl": lang_code,
            "dt": "t",
            "q": text
        }
        response = requests.get(url, params=params)
        translated = response.json()[0]
        return ''.join([i[0] for i in translated])
    except:
        return "⚠️ Translation failed."

# ------------- MAIN LOGIC -------------
if st.button("✨ Summarize & Visualize"):
    if len(input_text.strip()) < 20:
        st.warning("⚠️ Please provide more content.")
    else:
        with st.spinner("🔎 Summarizing..."):
            summary = summarizer(input_text, max_length=max_len, min_length=min_len, do_sample=False)[0]["summary_text"]

        # ----- Summary Display -----
        st.markdown("### ✍️ Summary:")
        st.markdown(f"<div class='summary-card'>{summary}</div>", unsafe_allow_html=True)

        # ----- Visual Diagram -----
        st.markdown("### 🧠 Visual Mind Map:")
        dot = Digraph()
        dot.node("Summary", "Summary", shape="box", style="filled", color="skyblue")

        for i, sent in enumerate(summary.split(". ")[:6]):
            dot.node(f"node{i}", sent.strip(), shape="ellipse", style="filled", color="lightgreen")
            dot.edge("Summary", f"node{i}")

        st.graphviz_chart(dot)

        # ----- PDF Export -----
        pdf = FPDF()
        pdf.add_page()
        pdf.set_font("Arial", size=12)
        pdf.multi_cell(0, 10, "Summary Report\n", align="C")
        pdf.set_font("Arial", size=11)
        pdf.multi_cell(0, 10, summary)

        with tempfile.NamedTemporaryFile(delete=False, suffix=".pdf") as tmp_pdf:
            pdf.output(tmp_pdf.name)
            with open(tmp_pdf.name, "rb") as f:
                st.download_button("📄 Download as PDF", f, file_name="summary.pdf", mime="application/pdf")
            os.remove(tmp_pdf.name)

        # ----- Translation -----
        if translate_to != "None":
            lang_map = {"Urdu": "ur", "French": "fr", "Spanish": "es"}
            translated = translate_text(summary, lang_map[translate_to])
            st.markdown(f"### 🌐 Translated Summary ({translate_to}):")
            st.success(translated)

        # ----- YouTube Video Search -----
        st.markdown("### 📺 Learn More on YouTube:")
        query = summary.split(".")[0]
        youtube_link = f"https://www.youtube.com/results?search_query={query.replace(' ', '+')}"
        st.markdown(f"[🔗 Click to search YouTube for: `{query}`]({youtube_link})")

# ------------- FOOTER -------------
st.markdown("---")
st.markdown("<p style='text-align:center; color:gray;'>Made with ❤️ by a 4th Semester Software Engineer 🚀</p>", unsafe_allow_html=True)