import gradio as gr
from datasets import load_dataset
from datetime import datetime
import io
from fpdf import FPDF

# Constants
SCORES_DATASET = "agents-course/unit4-students-scores"
CERTIFICATES_DATASET = "agents-course/course-certificates-of-excellence"
THRESHOLD_SCORE = 45

# Function to check user score
def check_user_score(username):
    score_data = load_dataset(SCORES_DATASET, split="train", download_mode="force_redownload")
    matches = [row for row in score_data if row["username"] == username]
    return matches[0] if matches else None

# Function to check if certificate entry exists
def has_certificate_entry(username):
    cert_data = load_dataset(CERTIFICATES_DATASET, split="train", download_mode="force_redownload")
    return any(row["username"] == username for row in cert_data)

# Function to add certificate entry
def add_certificate_entry(username, name):
    new_entry = {
        "username": username,
        "name": name,
        "date": datetime.now().strftime("%Y-%m-%d"),
    }
    ds = load_dataset(CERTIFICATES_DATASET, split="train")
    ds = ds.add_item(new_entry)
    ds.push_to_hub(CERTIFICATES_DATASET)

# Function to generate certificate PDF
def generate_certificate(name, score):
    pdf = FPDF()
    pdf.add_page()
    pdf.set_font("Arial", size=24)
    pdf.cell(200, 20, txt="Certificate of Excellence", ln=True, align="C")
    pdf.set_font("Arial", size=16)
    pdf.cell(200, 10, txt=f"Presented to {name}", ln=True, align="C")
    pdf.cell(200, 10, txt=f"For passing Unit 4 with a score of {score}", ln=True, align="C")
    pdf.cell(200, 10, txt=f"Date: {datetime.now().strftime('%Y-%m-%d')}", ln=True, align="C")
    pdf_output = io.BytesIO()
    pdf.output(pdf_output)
    pdf_output.seek(0)
    return pdf_output

# Main function to handle certificate generation
def handle_certificate(name, profile: gr.OAuthProfile):
    if profile is None:
        return "You must be logged in with your Hugging Face account.", None

    username = profile.username
    user_score = check_user_score(username)

    if not user_score:
        return "You need to complete Unit 4 first.", None

    score = user_score["score"]

    if score < THRESHOLD_SCORE:
        return f"Your score is {score}. You need at least {THRESHOLD_SCORE} to pass.", None

    if not has_certificate_entry(username):
        add_certificate_entry(username, name)

    certificate = generate_certificate(name, score)
    return "Congratulations! Here's your certificate:", certificate

# Gradio interface
with gr.Blocks() as demo:
    gr.Markdown("# 🎓 Unit 4 Certificate Generator")
    gr.LoginButton()
    with gr.Row():
        name_input = gr.Text(label="Enter your name")
    generate_btn = gr.Button("Get my certificate")
    output_text = gr.Textbox(label="Result")
    cert_file = gr.File(label="Your Certificate", file_types=[".pdf"])

    generate_btn.click(
        fn=handle_certificate,
        inputs=[name_input, gr.OAuthProfile()],
        outputs=[output_text, cert_file]
    )

demo.launch()