from reportlab.lib.pagesizes import letter
from reportlab.platypus import (
    SimpleDocTemplate,
    Paragraph,
    Spacer,
)
from reportlab.lib.styles import getSampleStyleSheet
from io import BytesIO


def generate_pdf(user_data, roi_data, synopsis):

    # Create PDF buffer
    buffer = BytesIO()

    # Create document
    doc = SimpleDocTemplate(
        buffer,
        pagesize=letter,
        rightMargin=40,
        leftMargin=40,
        topMargin=40,
        bottomMargin=40,
    )

    # Load styles
    styles = getSampleStyleSheet()

    # Store PDF elements
    elements = []

    # =========================
    # Title
    # =========================

    title = Paragraph(
        "<b>AI ROI Savings Report</b>",
        styles['Title']
    )

    elements.append(title)

    elements.append(Spacer(1, 20))

    # =========================
    # User Details Section
    # =========================

    user_heading = Paragraph(
        "<b>User Details</b>",
        styles['Heading2']
    )

    elements.append(user_heading)

    elements.append(Spacer(1, 10))

    for key, value in user_data.items():

        text = Paragraph(
            f"<b>{key}:</b> {value}",
            styles['BodyText']
        )

        elements.append(text)

        elements.append(Spacer(1, 5))

    elements.append(Spacer(1, 20))

    # =========================
    # ROI Results Section
    # =========================

    roi_heading = Paragraph(
        "<b>ROI Calculation Results</b>",
        styles['Heading2']
    )

    elements.append(roi_heading)

    elements.append(Spacer(1, 10))

    for key, value in roi_data.items():

        text = Paragraph(
            f"<b>{key}:</b> INR {value}",
            styles['BodyText']
        )

        elements.append(text)

        elements.append(Spacer(1, 5))

    elements.append(Spacer(1, 20))

    # =========================
    # Synopsis Section
    # =========================

    synopsis_heading = Paragraph(
        "<b>Project Synopsis</b>",
        styles['Heading2']
    )

    elements.append(synopsis_heading)

    elements.append(Spacer(1, 12))

    # Split synopsis into paragraphs
    paragraphs = synopsis.split("\n")

    for para in paragraphs:

        para = para.strip()

        if para:

            synopsis_para = Paragraph(
                para,
                styles['BodyText']
            )

            elements.append(synopsis_para)

            elements.append(Spacer(1, 8))

    # =========================
    # Footer
    # =========================

    elements.append(Spacer(1, 20))

    footer = Paragraph(
        "<i>Generated using AI ROI Calculator</i>",
        styles['Italic']
    )

    elements.append(footer)

    # Build PDF
    doc.build(elements)

    # Get PDF data
    pdf = buffer.getvalue()

    buffer.close()

    return pdf