import gradio as gr
from reportlab.lib.pagesizes import A4
from reportlab.platypus import (
    SimpleDocTemplate, Table, TableStyle,
    Paragraph, Spacer, Image
)
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib import colors
from datetime import datetime
import pandas as pd
import os

LOGO_PATH = "assets/logo.png"


# ================= PDF =================
def generate_pdf(shetkari, sauda_date, entries, entity_type):
    # Change 1: Dynamic PDF filename based on shetkari name
    pdf_filename = f"{shetkari.replace(' ', '_')}_auction_confirmation_slip.pdf"
    
    doc = SimpleDocTemplate(pdf_filename, pagesize=A4)
    styles = getSampleStyleSheet()
    elements = []

    title_style = ParagraphStyle(
        "title",
        fontSize=16,
        alignment=1,
        fontName="Helvetica-Bold"
    )

    center_style = ParagraphStyle(
        "center",
        alignment=1
    )

    # ----- HEADER -----
    logo = Image(LOGO_PATH, width=80, height=55) if os.path.exists(LOGO_PATH) else ""

    header_text = Paragraph(
        "<b>Shree Gajanan Cold Storage Pvt. Ltd.</b><br/><br/>"
        "<b>Ashirvad Trading Company</b><br/><br/>"
        "Tasgaon-Sangli Road, Kavthe Ekand, Sangli<br/><br/>"
        "Prasad Vijay Patil - [Contact : 9359533780]",
        ParagraphStyle("header", fontSize=16, alignment=1)
    )

    header = Table([[logo, header_text]], colWidths=[90, 420])
    header.setStyle(TableStyle([
        ("VALIGN", (0, 0), (-1, -1), "MIDDLE")
    ]))

    elements.extend([header, Spacer(1, 12)])
    elements.append(Paragraph("Auction Confirmation Slip", title_style))
    elements.append(Spacer(1, 12))

    # ----- SHETKARI/VENDOR -----
    # Change 5: Dynamic label based on entity_type
    # Change 6: Increased font size to 14 (similar to Prasad Vijay Patil which is 16)
    entity_label = "Shetkari" if entity_type == "Shetkari" else "Vendor"
    shetkari_info = Paragraph(
        f"<b>{entity_label}:</b> <b>{shetkari}</b> &nbsp;&nbsp;&nbsp;"
        f"<b>Sauda Date:</b> {sauda_date}",
        ParagraphStyle("shetkari_style", fontSize=14)
    )
    
    # Wrap in table to align with main table
    info_table = Table([[shetkari_info]], colWidths=[545])
    elements.append(info_table)
    elements.append(Spacer(1, 10))

    # ----- TABLE -----
    table_data = [
        ["Sr.", "Storage Name", "Lot No", "Quantity", "Rate", "Details"]
    ]

    total_qty = 0

    for i, e in enumerate(entries, 1):
        total_qty += e["quantity"]
        table_data.append([
            i,
            e["storage"],
            e["lot"].upper(),
            e["quantity"],
            Paragraph(f"<b>{e['rate']}</b>", center_style),
            e["details"]
        ])

    table_data.append([
        "",
        "",
        Paragraph("<b>Total</b>", center_style),
        Paragraph(f"<b>{total_qty}</b>", center_style),
        "",
        ""
    ])

    table = Table(
        table_data,
        colWidths=[35, 120, 80, 60, 60, 190]
    )

    table.setStyle(TableStyle([
        ("GRID", (0, 0), (-1, -1), 1, colors.black),
        ("BACKGROUND", (0, 0), (-1, 0), colors.lightgrey),
        ("ALIGN", (0, 0), (-1, -1), "CENTER"),
        ("FONT", (0, 0), (-1, 0), "Helvetica-Bold"),
        ("TOPPADDING", (0, 0), (-1, -1), 6),
        ("BOTTOMPADDING", (0, 0), (-1, -1), 6),
    ]))

    elements.append(table)
    doc.build(elements)
    return pdf_filename


# ================= UX LOGIC =================
def add_entry(storage, lot, qty, rate, details, entries, prev_storage, prev_lot, prev_qty, prev_rate):
    # Change 2: Use previous storage if empty
    if not storage and prev_storage:
        storage = prev_storage
    
    # Change 2: Use previous values if empty for lot, qty, rate
    if not lot and prev_lot:
        lot = prev_lot
    if qty is None and prev_qty is not None:
        qty = prev_qty
    if rate is None and prev_rate is not None:
        rate = prev_rate

    entries.append({
        "storage": storage,
        "lot": lot,
        "quantity": int(qty),
        "details": details,
        "rate": float(rate)
    })

    df = create_display_dataframe(entries)
    
    # Change 2: Return empty/None values for lot, qty, rate to reset them
    # Return current values to be stored as "previous"
    return entries, storage, lot, qty, rate, df, "", None, None, ""


def create_display_dataframe(entries):
    """Create dataframe with index column for selection"""
    if not entries:
        return pd.DataFrame(columns=["Select", "Storage", "Lot", "Quantity", "Rate", "Details"])
    
    display_data = []
    for i, e in enumerate(entries):
        display_data.append({
            "Select": i,
            "Storage": e["storage"],
            "Lot": e["lot"],
            "Quantity": e["quantity"],
            "Rate": e["rate"],
            "Details": e["details"]
        })
    
    return pd.DataFrame(display_data)


def delete_entry(row_to_delete, entries):
    """Delete entry by row index"""
    if row_to_delete is None or row_to_delete < 0:
        return entries, create_display_dataframe(entries), None
    
    if row_to_delete < len(entries):
        entries.pop(row_to_delete)
    
    return entries, create_display_dataframe(entries), None


def generate(shetkari, sauda_date, entries, entity_type):
    return generate_pdf(shetkari, sauda_date, entries, entity_type)


# ================= UI =================
with gr.Blocks(title="Auction Confirmation Slip") as demo:
    gr.Markdown("## 🧾 Create New Auction Confirmation Slip")

    with gr.Row():
        # Change 5: Added dropdown for entity type selection
        entity_type = gr.Dropdown(
            choices=["Shetkari", "Vendor"],
            value="Shetkari",
            label="Entity Type"
        )
        shetkari = gr.Textbox(label="Shetkari/Vendor Name")
        sauda_date = gr.Textbox(
            label="Sauda Date",
            value=datetime.today().strftime("%d/%m/%Y")
        )

    entries_state = gr.State([])
    prev_storage = gr.State("")
    # Change 2: Added state variables for previous lot, qty, rate
    prev_lot = gr.State("")
    prev_qty = gr.State(None)
    prev_rate = gr.State(None)

    gr.Markdown("### ➕ Add Entry")

    with gr.Row():
        storage = gr.Textbox(label="Storage Name (leave empty to reuse)")
        # Change 3: Added elem_id for JavaScript to enable caps lock
        lot = gr.Textbox(label="Lot Number", elem_id="lot_number_input")

    with gr.Row():
        qty = gr.Number(label="Quantity", precision=0)
        rate = gr.Number(label="Rate")

    details = gr.Textbox(
        label="Details",
        lines=3,
        placeholder="Enter detailed description"
    )

    add_btn = gr.Button("Add Entry")

    preview = gr.Dataframe(
        headers=["Select", "Storage", "Lot", "Quantity", "Rate", "Details"],
        interactive=False,
        row_count="dynamic",
        label="Entries Preview (Note the 'Select' index number)"
    )

    gr.Markdown("### 🗑️ Delete Entry")
    with gr.Row():
        delete_index = gr.Number(
            label="Enter row number to delete (from 'Select' column)",
            precision=0,
            minimum=0
        )
        delete_btn = gr.Button("Delete Entry")

    generate_btn = gr.Button("Confirm & Generate PDF")
    pdf_output = gr.File(label="Download PDF")

    # Change 2 & 3: Updated add_entry click handler
    add_btn.click(
        add_entry,
        inputs=[storage, lot, qty, rate, details, entries_state, prev_storage, prev_lot, prev_qty, prev_rate],
        outputs=[entries_state, prev_storage, prev_lot, prev_qty, prev_rate, preview, lot, qty, rate, details]
    )

    delete_btn.click(
        delete_entry,
        inputs=[delete_index, entries_state],
        outputs=[entries_state, preview, delete_index]
    )

    generate_btn.click(
        generate,
        inputs=[shetkari, sauda_date, entries_state, entity_type],
        outputs=pdf_output
    )
    
    # Change 3: JavaScript to auto-capitalize lot number input
    demo.load(js="""
    function() {
        const lotInput = document.getElementById('lot_number_input');
        if (lotInput) {
            lotInput.addEventListener('input', function(e) {
                this.value = this.value.toUpperCase();
            });
        }
    }
    """)

demo.launch()