use std::env;
use std::error::Error;
use std::fs::File;
use std::io::{{BufReader, BufWriter, Write}};
use std::path::Path;

use wordfreq::WordFreq;

fn build(file_base: &str) -> Result<(), Box<dyn Error>> {{
    let build_dir = env::var_os("OUT_DIR").unwrap();
    let wf = if file_base == "example_en" {{
        let word_weight_text = "las 10\nvegas 30\n";
        WordFreq::new(wordfreq::word_weights_from_text(
            word_weight_text.as_bytes(),
        )?)
    }} else {{
        let file_name = Path::new(file_base).with_extension("txt.zst");
        let input_file_path = Path::new(&build_dir).join(file_name);
        if !input_file_path.exists() {{
            let tmp_path = input_file_path.with_extension("download");
            let download_url = format!("https://github.com/kampersanda/wordfreq-rs/releases/download/models-v1/{{file_base}}.txt.zst");
            let resp = ureq::get(&download_url).call()?;
            let mut dest = File::create(&tmp_path)?;
            std::io::copy(&mut resp.into_reader(), &mut dest)?;
            dest.flush()?;
            std::fs::rename(tmp_path, &input_file_path).expect("Failed to rename temporary file");
        }}
        let reader = BufReader::new(zstd::Decoder::new(File::open(input_file_path)?)?);
        WordFreq::new(wordfreq::word_weights_from_text(reader)?)
    }};
    let model = wf.serialize()?;
    let output_file_path = Path::new(&build_dir).join(file_base).with_extension("bin");
    let mut writer = BufWriter::new(File::create(output_file_path)?);
    writer.write_all(&model)?;
    Ok(())
}}

fn main() -> Result<(), Box<dyn Error>> {{
    println!("cargo:rerun-if-changed=build.rs");
    println!("cargo:rerun-if-changed=Cargo.toml");

    build("example_en")?;
{main_block}

    Ok(())
}}