# app.py

import streamlit as st
import base64
from annotations import analyze_pdf

def display_pdf_iframe(pdf_bytes):
    """Displays the PDF using an iframe tag."""
    if pdf_bytes and len(pdf_bytes) > 0:
        base64_pdf = base64.b64encode(pdf_bytes).decode('utf-8')
        pdf_display = f"""
            <iframe src="data:application/pdf;base64,{base64_pdf}" width="100%" height="800px" type="application/pdf"></iframe>
        """
        st.components.v1.html(pdf_display, height=800, width=700, scrolling=True)
    else:
        st.info("No annotated PDF to display.")

def display_pdf_object(pdf_bytes):
    """Displays the PDF using an object tag."""
    if pdf_bytes and len(pdf_bytes) > 0:
        base64_pdf = base64.b64encode(pdf_bytes).decode('utf-8')
        pdf_display = f"""
            <object data="data:application/pdf;base64,{base64_pdf}" type="application/pdf" width="100%" height="800px">
                <p>Your browser does not support PDFs.
                <a href="data:application/pdf;base64,{base64_pdf}">Download the PDF</a>.</p>
            </object>
        """
        st.components.v1.html(pdf_display, height=800, width=700, scrolling=True)
    else:
        st.info("No annotated PDF to display.")

def display_pdf_pdfjs(pdf_bytes):
    """Displays the PDF using PDF.js embedded in an iframe."""
    if pdf_bytes and len(pdf_bytes) > 0:
        base64_pdf = base64.b64encode(pdf_bytes).decode('utf-8')
        pdfjs_viewer_url = f"https://mozilla.github.io/pdf.js/web/viewer.html?file=data:application/pdf;base64,{base64_pdf}"
        pdf_display = f"""
            <iframe src="{pdfjs_viewer_url}" width="100%" height="800px"></iframe>
        """
        st.components.v1.html(pdf_display, height=800, width=700, scrolling=True)
    else:
        st.info("No annotated PDF to display.")

def display_pdf_new_tab(pdf_bytes):
    """Provides a link to view the PDF in a new browser tab."""
    if pdf_bytes and len(pdf_bytes) > 0:
        base64_pdf = base64.b64encode(pdf_bytes).decode('utf-8')
        href = f"data:application/pdf;base64,{base64_pdf}"
        pdf_display = f"""
            <a href="{href}" target="_blank">🔍 View Annotated PDF</a>
        """
        st.markdown(pdf_display, unsafe_allow_html=True)
    else:
        st.info("No annotated PDF to display.")

def main():
    st.set_page_config(
        page_title="PDF Analyzer",
        page_icon="📄",
        layout="wide",
    )

    st.title("📄 PDF Analyzer")
    st.markdown("""
    Upload a PDF to analyze its language, highlight errors, and view detailed error reports.
    """)

    uploaded_file = st.file_uploader("Upload your PDF file", type=["pdf"])

    if uploaded_file is not None:
        with st.spinner("Analyzing PDF..."):
            # Reset file pointer before reading
            uploaded_file.seek(0)
            language_results, annotated_pdf = analyze_pdf(uploaded_file)

        if "error" in language_results:
            st.error("An error occurred during analysis:")
            st.code(language_results["error"])
        else:
            st.success("Analysis complete!")

            # Debugging: Show the size of annotated_pdf
            if annotated_pdf and len(annotated_pdf) > 0:
                st.write(f"Annotated PDF size: {len(annotated_pdf)} bytes")
            else:
                st.write("Annotated PDF is empty.")

            # Select embedding method
            embedding_option = st.selectbox(
                "Select PDF Display Method",
                options=["Iframe", "Object Tag", "PDF.js", "Open in New Tab"],
                index=0
            )

            st.subheader("📄 Annotated PDF")

            if embedding_option == "Iframe":
                display_pdf_iframe(annotated_pdf)
            elif embedding_option == "Object Tag":
                display_pdf_object(annotated_pdf)
            elif embedding_option == "PDF.js":
                display_pdf_pdfjs(annotated_pdf)
            elif embedding_option == "Open in New Tab":
                display_pdf_new_tab(annotated_pdf)
            else:
                st.info("Select a display method to view the PDF.")

            # Sidebar for error details
            st.sidebar.header("📝 Error Details")

            if language_results.get("total_issues", 0) > 0:
                for idx, issue in enumerate(language_results["issues"], 1):
                    with st.sidebar.expander(f"Issue {idx}"):
                        st.markdown(f"**Message:** {issue['message']}")
                        st.markdown(f"**Category:** {issue['category']}")
                        st.markdown(f"**Suggestions:** {', '.join(issue['suggestions']) if issue['suggestions'] else 'No suggestions'}")
                        st.markdown(f"**Sentence:** {issue['context']}")
            else:
                st.sidebar.success("No language issues found!")

            # Option to download the annotated PDF
            if annotated_pdf and len(annotated_pdf) > 0:
                st.download_button(
                    label="📥 Download Annotated PDF",
                    data=annotated_pdf,
                    file_name="annotated.pdf",
                    mime="application/pdf",
                )
            else:
                st.info("No annotated PDF available for download.")

if __name__ == "__main__":
    main()