use crate::commands::from_delimited_data::from_delimited_data;
use crate::commands::WholeStreamCommand;
use crate::prelude::*;
use nu_errors::ShellError;
use nu_protocol::Signature;

pub struct FromTSV;

#[derive(Deserialize)]
pub struct FromTSVArgs {
    headerless: bool,
}

#[async_trait]
impl WholeStreamCommand for FromTSV {
    fn name(&self) -> &str {
        "from tsv"
    }

    fn signature(&self) -> Signature {
        Signature::build("from tsv").switch(
            "headerless",
            "don't treat the first row as column names",
            None,
        )
    }

    fn usage(&self) -> &str {
        "Parse text as .tsv and create table."
    }

    async fn run(
        &self,
        args: CommandArgs,
        registry: &CommandRegistry,
    ) -> Result<OutputStream, ShellError> {
        from_tsv(args, registry)
    }
}

fn from_tsv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
    let registry = registry.clone();
    let name = args.call_info.name_tag.clone();
    let stream = async_stream! {
        let (FromTSVArgs { headerless }, mut input) = args.process(&registry).await?;
        let mut result = from_delimited_data(headerless, '\t', "TSV", input, name)?;

        while let Some(output) = result.next().await {
            yield output;
        }
    };

    Ok(stream.to_output_stream())
}

#[cfg(test)]
mod tests {
    use super::FromTSV;

    #[test]
    fn examples_work_as_expected() {
        use crate::examples::test as test_examples;

        test_examples(FromTSV {})
    }
}
