// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

/// A description for the [`StringListMetric`](crate::metrics::StringListMetric) type.
///
/// When changing this trait, make sure all the operations are
/// implemented in the related type in `../metrics/`.
pub trait StringList {
    /// Adds a new string to the list.
    ///
    /// # Arguments
    ///
    /// * `value` - The string to add.
    ///
    /// ## Notes
    ///
    /// Truncates the value if it is longer than `MAX_STRING_LENGTH` bytes and logs an error.
    fn add<S: Into<String>>(&self, value: S);

    /// Sets to a specific list of strings.
    ///
    /// # Arguments
    ///
    /// * `value` - The list of string to set the metric to.
    ///
    /// ## Notes
    ///
    /// If passed an empty list, records an error and returns.
    /// Truncates the list if it is longer than `MAX_LIST_LENGTH` and logs an error.
    /// Truncates any value in the list if it is longer than `MAX_STRING_LENGTH` and logs an error.
    fn set(&self, value: Vec<String>);

    /// **Exported for test purposes.**
    ///
    /// Gets the currently-stored values.
    ///
    /// This doesn't clear the stored value.
    ///
    /// # Arguments
    ///
    /// * `ping_name` - represents the optional name of the ping to retrieve the
    ///   metric for. Defaults to the first value in `send_in_pings`.
    fn test_get_value<'a, S: Into<Option<&'a str>>>(&self, ping_name: S) -> Option<Vec<String>>;

    /// **Exported for test purposes.**
    ///
    /// Gets the currently-stored values as a JSON String of the format
    /// ["string1", "string2", ...]
    ///
    /// This doesn't clear the stored value.
    ///
    /// # Arguments
    ///
    /// * `ping_name` - represents the optional name of the ping to retrieve the
    ///   metric for. Defaults to the first value in `send_in_pings`.
    fn test_get_value_as_json_string<'a, S: Into<Option<&'a str>>>(
        &self,
        ping_name: S,
    ) -> Option<String>;
}
