// load the configuration for a specific client from the configuration file
let config = xrechnung::config::load("examples/config.toml", "Client Company")?;

// create invoice metadata from the configuration, invoice number and dates
let bill = xrechnung::data::Bill::new(
    "2025-0001".to_string(), // invoice number
    chrono::NaiveDate::from_ymd_opt(2025, 1, 31).unwrap(), // issue date of the invoice
    Some(xrechnung::data::Period {
        start: chrono::NaiveDate::from_ymd_opt(2025, 1, 1).unwrap(),
        // billing period usually ends on the issue date
        end: chrono::NaiveDate::from_ymd_opt(2025, 1, 31).unwrap(),
    }),
    &config,
);

// create some invoice hours elements
// those elements could also be read from a CSV file or other data source
let invoice_hours = vec![
    xrechnung::data::InvoiceLineElement {
        name: "Example Service".to_string(),
        quantity: 7.0,
        value: 110.0,
        date: Some("2025-01-02".to_string()),
    },
    xrechnung::data::InvoiceLineElement {
        name: "Another Service".to_string(),
        quantity: 6.5,
        value: 110.0,
        date: Some("2025-01-03".to_string()),
    },
];

// create XML structure for the invoice from the supplier, buyer, invoice metadata and invoice hours
let xml_root = xrechnung::create(config.supplier, config.buyer, bill, invoice_hours, None)?;

// finally write the XML structure to a file
xrechnung::write("invoice.xml", &xml_root)?;