"""Export extracted invoices to JSON and Excel formats."""

from __future__ import annotations

import json
from io import BytesIO
from pathlib import Path
from typing import Any

import pandas as pd

from docflow.models import ExtractedInvoice, ValidationReport


def to_json(invoice: ExtractedInvoice, validation: ValidationReport | None = None) -> str:
    payload: dict[str, Any] = {
        "invoice": invoice.to_export_dict(),
        "validation": validation.model_dump() if validation else None,
    }
    return json.dumps(payload, ensure_ascii=False, indent=2)


def to_excel_bytes(invoice: ExtractedInvoice, validation: ValidationReport | None = None) -> bytes:
    buffer = BytesIO()

    summary = pd.DataFrame(
        [
            {"Field": "Vendor", "Value": invoice.vendor_name},
            {"Field": "Tax ID", "Value": invoice.vendor_tax_id},
            {"Field": "Invoice #", "Value": invoice.invoice_number},
            {"Field": "Date (Jalali)", "Value": invoice.invoice_date_jalali},
            {"Field": "Buyer", "Value": invoice.buyer_name},
            {"Field": "Subtotal", "Value": invoice.subtotal},
            {"Field": "Tax", "Value": invoice.tax_amount},
            {"Field": "Total", "Value": invoice.total_amount},
            {"Field": "Currency", "Value": invoice.currency},
            {"Field": "Confidence", "Value": invoice.confidence},
        ]
    )

    items = pd.DataFrame([item.model_dump() for item in invoice.line_items])
    if items.empty:
        items = pd.DataFrame(columns=["description", "quantity", "unit_price", "total", "confidence"])

    validation_df = pd.DataFrame()
    if validation and validation.issues:
        validation_df = pd.DataFrame([i.model_dump() for i in validation.issues])

    with pd.ExcelWriter(buffer, engine="openpyxl") as writer:
        summary.to_excel(writer, sheet_name="Summary", index=False)
        items.to_excel(writer, sheet_name="Line Items", index=False)
        if not validation_df.empty:
            validation_df.to_excel(writer, sheet_name="Validation", index=False)

    buffer.seek(0)
    return buffer.read()


def save_json(path: str | Path, invoice: ExtractedInvoice, validation: ValidationReport | None = None) -> None:
    Path(path).write_text(to_json(invoice, validation), encoding="utf-8")