import gradio as gr
from openai import OpenAI
import os
from dotenv import load_dotenv
import PyPDF2
import tempfile

# Load API Key
load_dotenv()
client = OpenAI(api_key=os.getenv("OPENAI_API_KEY"))

# -------------------------------
# Translate text using OpenAI
# -------------------------------
def translate_text(input_text, source_lang, target_lang):
    if not input_text.strip():
        return "⚠️ Please enter text to translate."

    if source_lang == target_lang:
        return "⚠️ Source and target languages must be different."

    prompt = f"Translate the following text from {source_lang} to {target_lang}:\n\n{input_text}"

    try:
        resp = client.responses.create(
            model="gpt-4.1-mini",
            input=prompt
        )
        translation = resp.output[0].content[0].text
        return translation
    except Exception as e:
        return f"❌ Error: {str(e)}"


# -------------------------------
# Process PDF → extract → translate
# -------------------------------
def translate_pdf(pdf_file, source_lang, target_lang):
    if pdf_file is None:
        return "⚠️ Please upload a PDF.", None

    if source_lang == target_lang:
        return "⚠️ Source and target languages must be different.", None

    try:
        # Extract text from PDF
        reader = PyPDF2.PdfReader(pdf_file.name)
        text = ""
        for page in reader.pages:
            text += page.extract_text() + "\n"

        # Translate using OpenAI
        prompt = f"Translate the following PDF text from {source_lang} to {target_lang}:\n\n{text[:12000]}"

        resp = client.responses.create(
            model="gpt-4.1-mini",
            input=prompt
        )
        translated_text = resp.output[0].content[0].text

        # Save translated file
        temp_file = tempfile.NamedTemporaryFile(delete=False, suffix=".txt")
        with open(temp_file.name, "w", encoding="utf-8") as f:
            f.write(translated_text)

        return translated_text, temp_file.name

    except Exception as e:
        return f"❌ Error processing PDF: {str(e)}", None


# -------------------------------
# GRADIO UI
# -------------------------------
language_list = ["English", "Spanish", "French", "German", "Hindi", "Chinese", "Japanese","Telugu"]

with gr.Blocks(theme=gr.themes.Soft(primary_hue="blue", secondary_hue="indigo")) as demo:
    gr.Markdown(
        """
        #  **AI Translation App**
        Translate text or full PDF documents into any language using OpenAI.
        """
    )

    with gr.Tabs():
        # ------------------ TEXT TRANSLATOR ------------------
        with gr.Tab("✍️ Text Translator"):
            with gr.Row():
                source_lang = gr.Dropdown(language_list, label="Source Language", value="English")
                target_lang = gr.Dropdown(language_list, label="Target Language", value="Spanish")

            input_box = gr.Textbox(
                label="Enter text to translate",
                placeholder="Type or paste your text here...",
                lines=6
            )

            translate_btn = gr.Button("Translate", variant="primary")

            output_box = gr.Textbox(
                label="Translated Text",
                lines=6
            )

            translate_btn.click(
                translate_text,
                inputs=[input_box, source_lang, target_lang],
                outputs=output_box
            )

        # ------------------ PDF TRANSLATOR ------------------
        with gr.Tab("📄 PDF Translator"):
            with gr.Row():
                source_lang_pdf = gr.Dropdown(language_list, label="Source Language", value="English")
                target_lang_pdf = gr.Dropdown(language_list, label="Target Language", value="French")

            pdf_file = gr.File(label="Upload PDF", file_types=[".pdf"])

            translate_pdf_btn = gr.Button("Translate PDF", variant="primary")

            pdf_output = gr.Textbox(label="Translated PDF Text", lines=12)
            download_btn = gr.File(label="Download translated file")

            def pdf_translate_wrapper(pdf, src, tgt):
                text, file_path = translate_pdf(pdf, src, tgt)
                return text, file_path

            translate_pdf_btn.click(
                pdf_translate_wrapper,
                inputs=[pdf_file, source_lang_pdf, target_lang_pdf],
                outputs=[pdf_output, download_btn]
            )



# Run the app
demo.launch()