jsonlogic 0.5.1

use serde_json::Value;

use super::{Data, Expression};

pub fn compute(args: &[Expression], data: &Data) -> Value {
    let arg = args
        .get(0)
        .map(|arg| arg.compute(data))
        .unwrap_or(Value::Null);

    if arg.is_null() {
        return data.get_plain().clone();
    }

    match &arg {
        // Return the whole data object if there is no argument given or the argument is an empty
        // string.
        Value::Null => data.get_plain().clone(),
        Value::String(s) if s == "" => data.get_plain().clone(),
        _ => data.get_value(&arg).unwrap_or_else(|| {
            args.get(1)
                .map(|arg| arg.compute(data))
                .unwrap_or(Value::Null)
        }),
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::compute_const_with_data;
    use serde_json::json;

    #[test]
    fn invalid_arguments() {
        let data_json = json!({ "a": 5, "b": 6 });
        let data = Data::from_json(&data_json);
        assert_eq!(compute_const_with_data!(&[json!([])], &data), json!(null));
        assert_eq!(compute_const_with_data!(&[json!({})], &data), json!(null));
        assert_eq!(compute_const_with_data!(&[json!(true)], &data), json!(null));
        assert_eq!(
            compute_const_with_data!(&[json!(false)], &data),
            json!(null)
        );
    }

    #[test]
    fn null_arg() {
        let data_json = json!({ "a": 5, "b": 6 });
        let data = Data::from_json(&data_json);
        assert_eq!(compute_const_with_data!(&[], &data), data_json);
        assert_eq!(compute_const_with_data!(&[Value::Null], &data), data_json);
        assert_eq!(compute_const_with_data!(&[json!("")], &data), data_json);
        assert_eq!(compute_const_with_data!(&[json!(" ")], &data), json!(null));
        assert_eq!(
            compute_const_with_data!(&[Value::Null, json!(123)], &data),
            data_json
        );
    }

    #[test]
    fn data_is_object() {
        let data_json = json!({ "a": 5, "b": 6, "1": 1337 });
        let data = Data::from_json(&data_json);
        assert_eq!(
            compute_const_with_data!(&[Value::String(String::from("a"))], &data),
            json!(5)
        );
        assert_eq!(
            compute_const_with_data!(&[Value::String(String::from("b"))], &data),
            json!(6)
        );
        assert_eq!(compute_const_with_data!(&[json!(1)], &data), json!(1337));
    }

    #[test]
    fn data_is_string() {
        let data_json = json!("abcderfg");
        let data = Data::from_json(&data_json);
        assert_eq!(compute_const_with_data!(&[json!(1)], &data), json!("b"));
        assert_eq!(compute_const_with_data!(&[json!("1")], &data), json!("b"));
    }

    #[test]
    fn data_is_array() {
        let data_json = json!(["foo", "bar"]);
        let data = Data::from_json(&data_json);
        assert_eq!(compute_const_with_data!(&[], &data), data_json);
        assert_eq!(compute_const_with_data!(&[json!(0)], &data), json!("foo"));
        assert_eq!(compute_const_with_data!(&[json!(1)], &data), json!("bar"));
        assert_eq!(compute_const_with_data!(&[json!(2)], &data), json!(null));

        assert_eq!(compute_const_with_data!(&[json!("1")], &data), json!("bar"));

        let data_json = json!([{"foo": "bar"}]);
        let data = Data::from_json(&data_json);
        assert_eq!(
            compute_const_with_data!(&[json!(0)], &data),
            json!({"foo": "bar"})
        );
    }

    #[test]
    fn default_value_array_data() {
        let data_json = json!(["foo", "bar"]);
        let data = Data::from_json(&data_json);

        assert_eq!(
            compute_const_with_data!(&[json!(1), json!("def")], &data),
            json!("bar")
        );
        assert_eq!(
            compute_const_with_data!(&[json!(2), json!("def")], &data),
            json!("def")
        );
    }

    #[test]
    fn default_value_obj_data() {
        let data_json = json!({"foo": "bar"});
        let data = Data::from_json(&data_json);

        assert_eq!(
            compute_const_with_data!(&[json!("foo"), json!("def")], &data),
            json!("bar")
        );
        assert_eq!(
            compute_const_with_data!(&[json!("unknown"), json!("def")], &data),
            json!("def")
        );
    }

    #[test]
    fn nested_object() {
        let data_json = json!({ "foo": { "bar": "baz" }});
        let data = Data::from_json(&data_json);

        assert_eq!(
            compute_const_with_data!(&[json!("foo.")], &data),
            json!(null)
        );
        assert_eq!(
            compute_const_with_data!(&[json!("foo.bar")], &data),
            json!("baz")
        );
        assert_eq!(
            compute_const_with_data!(&[json!("foo.bar.baz")], &data),
            json!(null)
        );
        assert_eq!(
            compute_const_with_data!(&[json!("foo")], &data),
            json!({ "bar": "baz" })
        );

        let data_json = json!([{"foo": "bar"}]);
        let data = Data::from_json(&data_json);
        assert_eq!(
            compute_const_with_data!(&[json!("0.foo")], &data),
            json!("bar")
        );
        assert_eq!(compute_const_with_data!(&[json!("1")], &data), json!(null));
        assert_eq!(
            compute_const_with_data!(&[json!("1.foo")], &data),
            json!(null)
        );
        assert_eq!(
            compute_const_with_data!(&[json!("0.foo.1")], &data),
            json!("a")
        );
        assert_eq!(
            compute_const_with_data!(&[json!("0.foo.1.0")], &data),
            json!(null)
        );
    }
}