Display balance evolution chart

moneymgr_backend/src/controllers/stats_controller.rs

@@ -1,7 +1,10 @@
 use crate::controllers::HttpResult;
 use crate::extractors::auth_extractor::AuthExtractor;
-use crate::services::{files_service, movements_service};
-use actix_web::HttpResponse;
+use crate::models::accounts::Account;
+use crate::services::{accounts_service, files_service, movements_service};
+use crate::utils::time_utils::time;
+use actix_web::{HttpResponse, web};
+use std::collections::HashMap;
 
 #[derive(serde::Serialize)]
 struct GlobalStats {
@@ -23,3 +26,75 @@ pub async fn global(auth: AuthExtractor) -> HttpResult {
         total_files_size: files.iter().fold(0, |sum, m| sum + m.file_size as u64),
     }))
 }
+
+#[derive(serde::Deserialize)]
+pub struct BalanceVariationQuery {
+    #[serde(skip_serializing_if = "Option::is_none")]
+    interval: Option<u64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    start: Option<i64>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    end: Option<i64>,
+}
+
+/// Statistic dataset entry
+#[derive(serde::Serialize, Debug, Clone)]
+struct StatEntry {
+    time: i64,
+    /// Account balances. Note: due to JSON limitation, we had to turn account id into strings
+    #[serde(flatten)]
+    balances: HashMap<String, f32>,
+}
+
+impl StatEntry {
+    fn init_first(time: i64, accounts: &[Account]) -> Self {
+        Self {
+            time,
+            balances: accounts
+                .iter()
+                .map(|a| (a.id().0.to_string(), 0.0))
+                .collect(),
+        }
+    }
+}
+
+/// Accounts balance variation
+pub async fn balance_variation(
+    auth: AuthExtractor,
+    query: web::Query<BalanceVariationQuery>,
+) -> HttpResult {
+    let start = query.start.unwrap_or((time() - 3600 * 24 * 30) as i64);
+    let end = query.end.unwrap_or(time() as i64);
+    let interval = query.interval.unwrap_or(3600 * 24);
+
+    let accounts = accounts_service::get_list_user(auth.user.id()).await?;
+    let mut movements = movements_service::get_all_movements_user(auth.user.id()).await?;
+    movements.sort_by(|a, b| a.time.cmp(&b.time));
+
+    let mut dataset = vec![];
+    let mut stat_entry = StatEntry::init_first(start, &accounts);
+
+    // Iter movements
+    for m in movements {
+        if m.time > end {
+            break;
+        }
+
+        // Check if it is time to go the the next entry
+        while m.time > stat_entry.time {
+            dataset.push(stat_entry.clone());
+            stat_entry.time += interval as i64;
+        }
+
+        let target_account_id = m.account_id().0.to_string();
+        let old_amount = *stat_entry.balances.get(&target_account_id).unwrap_or(&0.0);
+        stat_entry
+            .balances
+            .insert(target_account_id, old_amount + m.amount);
+    }
+
+    // Final push
+    dataset.push(stat_entry);
+
+    Ok(HttpResponse::Ok().json(dataset))
+}