From cef7b42fac0121b35e67a383339b686ba3362e9c Mon Sep 17 00:00:00 2001
From: Jeremy Wall <jeremy@marzhillstudios.com>
Date: Tue, 12 Mar 2024 20:33:05 -0400
Subject: [PATCH] dev: lay ground for sending filters via get params

---
 src/dashboard.rs  | 11 +++++++++--
 src/main.rs       |  2 +-
 src/query/prom.rs |  8 ++++++++
 src/routes.rs     | 23 ++++++++++++++++++++---
 4 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/src/dashboard.rs b/src/dashboard.rs
index 65749f1..cede8d0 100644
--- a/src/dashboard.rs
+++ b/src/dashboard.rs
@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 // Copyright 2023 Jeremy Wall
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -120,12 +121,13 @@ pub struct LogStream {
     pub query_type: QueryType,
 }
 
-pub async fn prom_query_data(
+pub async fn prom_query_data<'a>(
     graph: &Graph,
     dash: &Dashboard,
     query_span: Option<GraphSpan>,
+    filters: &Option<HashMap<&'a str, &'a str>>,
 ) -> Result<Vec<QueryResult>> {
-    let connections = graph.get_query_connections(&dash.span, &query_span);
+    let connections = graph.get_query_connections(&dash.span, &query_span, filters);
     let mut data = Vec::new();
     for conn in connections {
         data.push(prom_to_samples(
@@ -205,12 +207,14 @@ impl Graph {
         &'graph self,
         graph_span: &'graph Option<GraphSpan>,
         query_span: &'graph Option<GraphSpan>,
+        filters: &'graph Option<HashMap<&'graph str, &'graph str>>,
     ) -> Vec<PromQueryConn<'conn>> {
         let mut conns = Vec::new();
         for plot in self.plots.iter() {
             debug!(
                 query = plot.query,
                 source = plot.source,
+                filters = ?filters,
                 "Getting query connection for graph",
             );
             let mut conn = PromQueryConn::new(
@@ -219,6 +223,9 @@ impl Graph {
                 self.query_type.clone(),
                 plot.meta.clone(),
             );
+            if let Some(filters) = filters {
+                conn = conn.with_filters(filters);
+            }
             // Query params take precendence over all other settings. Then graph settings take
             // precedences and finally the dashboard settings take precendence
             if let Some((end, duration, step_duration)) = graph_span_to_tuple(query_span) {
diff --git a/src/main.rs b/src/main.rs
index 6a15458..b2a99c7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -53,7 +53,7 @@ struct Cli {
 async fn validate(dash: &Dashboard) -> anyhow::Result<()> {
     if let Some(ref graphs) = dash.graphs {
         for graph in graphs.iter() {
-            let data = prom_query_data(graph, &dash, None).await;
+            let data = prom_query_data(graph, &dash, None, &None).await;
             if data.is_err() {
                 error!(err=?data, "Invalid dashboard graph query or queries");
             }
diff --git a/src/query/prom.rs b/src/query/prom.rs
index ace9c88..d05d1b2 100644
--- a/src/query/prom.rs
+++ b/src/query/prom.rs
@@ -30,6 +30,7 @@ pub struct PromQueryConn<'conn> {
     query: &'conn str,
     span: Option<TimeSpan>,
     query_type: QueryType,
+    filters: Option<&'conn HashMap<&'conn str, &'conn str>>,
     pub meta: PlotMeta,
 }
 
@@ -46,9 +47,16 @@ impl<'conn> PromQueryConn<'conn> {
             query_type,
             meta,
             span: None,
+            filters: None,
+
         }
     }
 
+    pub fn with_filters(mut self, filters: &'conn HashMap<&'conn str, &'conn str>) -> Self {
+        self.filters = Some(filters);
+        self
+    }
+
     pub fn with_span(
         mut self,
         end: DateTime<Utc>,
diff --git a/src/routes.rs b/src/routes.rs
index 6348728..4747825 100644
--- a/src/routes.rs
+++ b/src/routes.rs
@@ -54,7 +54,7 @@ pub async fn loki_query(
         .expect("No logs in this dashboard")
         .get(loki_idx)
         .expect(&format!("No such log query {}", loki_idx));
-    let plots = vec![loki_query_data(log, dash, query_to_graph_span(query))
+    let plots = vec![loki_query_data(log, dash, query_to_graph_span(&query))
         .await
         .expect("Unable to get log query results")];
     Json(GraphPayload {
@@ -79,7 +79,8 @@ pub async fn graph_query(
         .expect("No graphs in this dashboard")
         .get(graph_idx)
         .expect(&format!("No such graph in dasboard {}", dash_idx));
-    let plots = prom_query_data(graph, dash, query_to_graph_span(query))
+    let filters = query_to_filterset(&query);
+    let plots = prom_query_data(graph, dash, query_to_graph_span(&query), &filters)
         .await
         .expect("Unable to get query results");
     Json(GraphPayload {
@@ -89,7 +90,23 @@ pub async fn graph_query(
     })
 }
 
-fn query_to_graph_span(query: HashMap<String, String>) -> Option<GraphSpan> {
+fn query_to_filterset<'v, 'a: 'v>(query: &'a HashMap<String, String>) -> Option<HashMap<&'v str, &'v str>> {
+    let mut label_set = HashMap::new();
+    for (k, v) in query.iter() {
+        if k.starts_with("filter-") {
+            if let Some(label) = k.strip_prefix("filter-") {
+                label_set.insert(label, v.as_str());
+            }
+        }
+    }
+    if label_set.is_empty() {
+        None
+    } else {
+        Some(label_set)
+    }
+}
+
+fn query_to_graph_span<'a>(query: &'a HashMap<String, String>) -> Option<GraphSpan> {
     let query_span = {
         if query.contains_key("end")
             && query.contains_key("duration")