// 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/.

use super::{BaseMetricId, CommonMetricData};
use crate::ipc::need_ipc;
use inherent::inherent;
use std::sync::Arc;

/// A text metric.
///
/// Record a string value with arbitrary content. Supports non-ASCII
/// characters.
///
/// # Example
///
/// The following piece of code will be generated by `glean_parser`:
///
/// ```rust,ignore
/// use glean::metrics::{TextMetric, CommonMetricData, Lifetime};
/// use once_cell::sync::Lazy;
///
/// mod browser {
///     pub static bread_recipe: Lazy<TextMetric> = Lazy::new(|| TextMetric::new(CommonMetricData {
///         name: "bread_recipe".into(),
///         category: "browser".into(),
///         lifetime: Lifetime::Ping,
///         disabled: false,
///         dynamic_label: None
///     }));
/// }
/// ```
///
/// It can then be used with:
///
/// ```rust,ignore
/// browser::bread_recipe.set("The 'baguette de tradition française' is made from wheat flour, water, yeast, and common salt. It may contain up to 2% broad bean flour, up to 0.5% soya flour, and up to 0.3% wheat malt flour.");
/// ```
#[derive(Clone)]
pub enum TextMetric {
    Parent {
        /// The metric's ID. Used for testing and profiler markers. Text
        /// metrics canot be labeled, so we only store a BaseMetricId. If this
        /// changes, this should be changed to a MetricId to distinguish
        /// between metrics and sub-metrics.
        id: BaseMetricId,
        inner: Arc<glean::private::TextMetric>,
    },
    Child(TextMetricIpc),
}

define_metric_metadata_getter!(TextMetric, TEXT_MAP);
define_metric_namer!(TextMetric, PARENT_ONLY);

#[derive(Clone, Debug)]
pub struct TextMetricIpc;

impl TextMetric {
    /// Create a new text metric.
    pub fn new(id: BaseMetricId, meta: CommonMetricData) -> Self {
        if need_ipc() {
            TextMetric::Child(TextMetricIpc)
        } else {
            TextMetric::Parent {
                id,
                inner: Arc::new(glean::private::TextMetric::new(meta)),
            }
        }
    }

    #[cfg(test)]
    pub(crate) fn child_metric(&self) -> Self {
        match self {
            TextMetric::Parent { .. } => TextMetric::Child(TextMetricIpc),
            TextMetric::Child(_) => panic!("Can't get a child metric from a child process"),
        }
    }
}

#[inherent]
impl glean::traits::Text for TextMetric {
    /// Sets to the specified value.
    ///
    /// # Arguments
    ///
    /// * `value` - The text to set the metric to.
    pub fn set<S: Into<std::string::String>>(&self, value: S) {
        match self {
            #[allow(unused)]
            TextMetric::Parent { id, inner } => {
                let value = value.into();
                #[cfg(feature = "with_gecko")]
                gecko_profiler::lazy_add_marker!(
                    "Text::set",
                    super::profiler_utils::TelemetryProfilerCategory,
                    super::profiler_utils::StringLikeMetricMarker::<TextMetric>::new(
                        (*id).into(),
                        &value
                    )
                );
                inner.set(value);
            }
            TextMetric::Child(_) => {
                log::error!("Unable to set text metric in non-main process. This operation will be ignored.");
                // If we're in automation we can panic so the instrumentor knows they've gone wrong.
                // This is a deliberate violation of Glean's "metric APIs must not throw" design.
                assert!(!crate::ipc::is_in_automation(), "Attempted to set text metric in non-main process, which is forbidden. This panics in automation.");
            }
        }
    }

    /// **Exported for test purposes.**
    ///
    /// Gets the number of recorded errors for the given metric and error type.
    ///
    /// # Arguments
    ///
    /// * `error` - The type of error
    /// * `ping_name` - represents the optional name of the ping to retrieve the
    ///   metric for. Defaults to the first value in `send_in_pings`.
    ///
    /// # Returns
    ///
    /// The number of errors reported.
    pub fn test_get_num_recorded_errors(&self, error: glean::ErrorType) -> i32 {
        match self {
            TextMetric::Parent { inner, .. } => inner.test_get_num_recorded_errors(error),
            TextMetric::Child(_) => panic!(
                "Cannot get the number of recorded errors for text metric in non-main process!"
            ),
        }
    }
}

#[inherent]
impl glean::TestGetValue for TextMetric {
    type Output = std::string::String;

    /// **Exported for test purposes.**
    ///
    /// Gets the currently stored value as a string.
    ///
    /// 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`.
    pub fn test_get_value(&self, ping_name: Option<String>) -> Option<std::string::String> {
        match self {
            TextMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
            TextMetric::Child(_) => {
                panic!("Cannot get test value for text metric in non-main process!")
            }
        }
    }
}

#[cfg(test)]
mod test {
    use crate::{common_test::*, ipc, metrics};

    #[test]
    fn sets_text_value() {
        let _lock = lock_test();

        let metric = &metrics::test_only_ipc::a_text;

        metric.set("test_text_value");

        assert_eq!(
            "test_text_value",
            metric
                .test_get_value(Some("test-ping".to_string()))
                .unwrap()
        );
    }

    #[test]
    fn text_ipc() {
        // TextMetric doesn't support IPC.
        let _lock = lock_test();

        let parent_metric = &metrics::test_only_ipc::a_text;

        parent_metric.set("test_parent_value");

        {
            let child_metric = parent_metric.child_metric();

            let _raii = ipc::test_set_need_ipc(true);

            // Instrumentation calls do not panic.
            child_metric.set("test_child_value");

            // (They also shouldn't do anything,
            // but that's not something we can inspect in this test)
        }

        assert!(ipc::replay_from_buf(&ipc::take_buf().unwrap()).is_ok());

        assert!(
            "test_parent_value"
                == parent_metric
                    .test_get_value(Some("test-ping".to_string()))
                    .unwrap(),
            "Text metrics should only work in the parent process"
        );
    }
}