use std::{fs::File, io, path::Path};

use icu_locid::LanguageIdentifier;
use xml::{writer::XmlEvent, EmitterConfig, EventWriter};

use crate::{Bundle, Message, WriteError};

pub fn export_file(
    bundle: &Bundle,
    locale: LanguageIdentifier,
    path: &Path,
) -> Result<(), WriteError> {
    let mut file = File::create(path).unwrap();
    export_fh(bundle, locale, &mut file)
}

pub fn export_fh(
    bundle: &Bundle,
    locale: LanguageIdentifier,
    fh: &mut File,
) -> Result<(), WriteError> {
    let output = io::stdout();
    let mut writer = EmitterConfig::new()
        .perform_indent(true)
        .create_writer(output);

    writer.write(XmlEvent::start_element("xliff")).unwrap();
    writer.write(XmlEvent::start_element("file")).unwrap();

    for (key, message) in bundle.message_iter() {
        write_message(&mut writer, message, &locale);
    }

    writer.write(XmlEvent::end_element()).unwrap();
    writer.write(XmlEvent::end_element()).unwrap();
    Ok(())
}

fn write_message<T>(writer: &mut EventWriter<T>, message: &Message, locale: &LanguageIdentifier)
where
    T: std::io::Write,
{
    writer.write(XmlEvent::start_element("unit")).unwrap();
    writer.write(XmlEvent::start_element("segment")).unwrap();
    writer.write(XmlEvent::characters(message.variant(locale).unwrap().content())).unwrap();
    writer.write(XmlEvent::end_element()).unwrap();
    writer.write(XmlEvent::end_element()).unwrap();
}