feat: realtime user analytics (#5098)

Co-authored-by: Sampras Lopes <Sampras.lopes@juspay.in>

crates/api_models/src/analytics/active_payments.rs

@@ -0,0 +1,77 @@
+use std::{
+    collections::hash_map::DefaultHasher,
+    hash::{Hash, Hasher},
+};
+
+use super::NameDescription;
+
+#[derive(
+    Clone,
+    Debug,
+    Hash,
+    PartialEq,
+    Eq,
+    serde::Serialize,
+    serde::Deserialize,
+    strum::Display,
+    strum::EnumIter,
+    strum::AsRefStr,
+)]
+#[strum(serialize_all = "snake_case")]
+#[serde(rename_all = "snake_case")]
+pub enum ActivePaymentsMetrics {
+    ActivePayments,
+}
+
+pub mod metric_behaviour {
+    pub struct ActivePayments;
+}
+
+impl From<ActivePaymentsMetrics> for NameDescription {
+    fn from(value: ActivePaymentsMetrics) -> Self {
+        Self {
+            name: value.to_string(),
+            desc: String::new(),
+        }
+    }
+}
+
+#[derive(Debug, serde::Serialize, Eq)]
+pub struct ActivePaymentsMetricsBucketIdentifier {
+    pub time_bucket: Option<String>,
+}
+
+impl ActivePaymentsMetricsBucketIdentifier {
+    pub fn new(time_bucket: Option<String>) -> Self {
+        Self { time_bucket }
+    }
+}
+
+impl Hash for ActivePaymentsMetricsBucketIdentifier {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.time_bucket.hash(state);
+    }
+}
+
+impl PartialEq for ActivePaymentsMetricsBucketIdentifier {
+    fn eq(&self, other: &Self) -> bool {
+        let mut left = DefaultHasher::new();
+        self.hash(&mut left);
+        let mut right = DefaultHasher::new();
+        other.hash(&mut right);
+        left.finish() == right.finish()
+    }
+}
+
+#[derive(Debug, serde::Serialize)]
+pub struct ActivePaymentsMetricsBucketValue {
+    pub active_payments: Option<u64>,
+}
+
+#[derive(Debug, serde::Serialize)]
+pub struct MetricsBucketResponse {
+    #[serde(flatten)]
+    pub values: ActivePaymentsMetricsBucketValue,
+    #[serde(flatten)]
+    pub dimensions: ActivePaymentsMetricsBucketIdentifier,
+}