usage-lib 3.2.0

use crate::complete::CompleteOptions;
use heck::ToSnakeCase;

pub fn complete_fish(opts: &CompleteOptions) -> String {
    let usage_bin = &opts.usage_bin;
    let bin = &opts.bin;
    let bin_snake = bin.to_snake_case();
    let spec_variable = if let Some(cache_key) = &opts.cache_key {
        format!("_usage_spec_{bin_snake}_{}", cache_key.to_snake_case())
    } else {
        format!("_usage_spec_{bin_snake}")
    };
    let generated_comment = if let Some(source_file) = &opts.source_file {
        format!("# @generated by usage-cli from {source_file}")
    } else {
        "# @generated by usage-cli from usage spec".to_string()
    };
    let mut out = vec![
        generated_comment,
        format!(
            r#"
# if "{usage_bin}" is not installed show an error
if ! type -p {usage_bin} &> /dev/null
    echo >&2
    echo "Error: {usage_bin} CLI not found. This is required for completions to work in {bin}." >&2
    echo "See https://usage.jdx.dev for more information." >&2
    return 1
end"#
        ),
    ];

    if let Some(spec) = &opts.spec {
        let spec_escaped = spec.to_string().replace("'", r"\'");
        out.push(format!(
            r#"
set {spec_variable} '{spec_escaped}'"#
        ));
    }

    // Build logic to write spec directly to file without storing in shell variables
    let file_write_logic = if let Some(usage_cmd) = &opts.usage_cmd {
        if opts.cache_key.is_some() {
            format!(
                r#"if not test -f "$spec_file"
    {usage_cmd} | string collect > "$spec_file"
end"#
            )
        } else {
            format!(r#"{usage_cmd} | string collect > "$spec_file""#)
        }
    } else if let Some(_spec) = &opts.spec {
        if opts.cache_key.is_some() {
            format!(
                r#"if not test -f "$spec_file"
    echo ${spec_variable} > "$spec_file"
end"#
            )
        } else {
            format!(r#"echo ${spec_variable} > "$spec_file""#)
        }
    } else {
        String::new()
    };

    out.push(format!(
        r#"
set -l tmpdir (if set -q TMPDIR; echo $TMPDIR; else; echo /tmp; end)
set -l spec_file "$tmpdir/usage_{spec_variable}.spec"
{file_write_logic}

set -l tokens
if commandline -x >/dev/null 2>&1
    complete -xc {bin} -a "(command {usage_bin} complete-word --shell fish -f \"$spec_file\" -- (commandline -xpc) (commandline -t))"
else
    complete -xc {bin} -a "(command {usage_bin} complete-word --shell fish -f \"$spec_file\" -- (commandline -opc) (commandline -t))"
end
"#
    ).trim().to_string());

    out.join("\n")
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::test::SPEC_KITCHEN_SINK;
    use insta::assert_snapshot;

    #[test]
    fn test_complete_fish() {
        assert_snapshot!(complete_fish(&CompleteOptions {
            usage_bin: "usage".to_string(),
            shell: "fish".to_string(),
            bin: "mycli".to_string(),
            cache_key: None,
            spec: None,
            usage_cmd: Some("mycli complete --usage".to_string()),
            include_bash_completion_lib: false,
            source_file: None,
        }));
        assert_snapshot!(complete_fish(&CompleteOptions {
            usage_bin: "usage".to_string(),
            shell: "fish".to_string(),
            bin: "mycli".to_string(),
            cache_key: Some("1.2.3".to_string()),
            spec: None,
            usage_cmd: Some("mycli complete --usage".to_string()),
            include_bash_completion_lib: false,
            source_file: None,
        }));
        assert_snapshot!(complete_fish(&CompleteOptions {
            usage_bin: "usage".to_string(),
            shell: "fish".to_string(),
            bin: "mycli".to_string(),
            cache_key: None,
            spec: Some(SPEC_KITCHEN_SINK.clone()),
            usage_cmd: None,
            include_bash_completion_lib: false,
            source_file: None,
        }));
    }
}