From 7a46877bd81749f5770cbff8530a9c74e017f353 Mon Sep 17 00:00:00 2001
From: Gabriel Comte <gabriel.comte@gmail.com>
Date: Wed, 4 Dec 2024 14:00:41 +0100
Subject: [PATCH] Refactor exchange rate caching

---
 Cargo.lock           |  1 +
 Cargo.toml           |  1 +
 src/currency/fiat.rs | 19 +++++++++++++------
 3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index b139b39..196d8f7 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -140,6 +140,7 @@ dependencies = [
  "env_logger",
  "exitcode",
  "home-config",
+ "lazy_static",
  "log",
  "regex",
  "reqwest",
diff --git a/Cargo.toml b/Cargo.toml
index f70ec64..9fc6309 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ tabled = "0.16.0"
 thiserror = "2.0.3"
 thousands = "0.2.0"
 typetag = "0.2"
+lazy_static = "1.5.0"
 
 [dev-dependencies]
 assert_cmd = "2.0.16"
diff --git a/src/currency/fiat.rs b/src/currency/fiat.rs
index c77b743..3600f2a 100644
--- a/src/currency/fiat.rs
+++ b/src/currency/fiat.rs
@@ -1,16 +1,20 @@
 use crate::fiat_rates::blockchain_info_consumer;
+use lazy_static::lazy_static;
 use serde::{Deserialize, Serialize};
+use std::sync::Mutex;
 use strum_macros::{Display, EnumString};
 
 use crate::currency::Currency;
 use crate::fiat_rates::exchange_rate_provider::ExchangeRateProvider;
 
 // Static to have an easy way of caching the exchange rates.
-static mut EXCHANGE_RATE_PROVIDER: ExchangeRateProvider<blockchain_info_consumer::ApiConsumer> =
-    ExchangeRateProvider {
-        data_source: blockchain_info_consumer::ApiConsumer,
-        data: None,
-    };
+lazy_static! {
+    static ref EXCHANGE_RATE_PROVIDER: Mutex<ExchangeRateProvider<blockchain_info_consumer::ApiConsumer>> =
+        Mutex::new(ExchangeRateProvider {
+            data_source: blockchain_info_consumer::ApiConsumer,
+            data: None,
+        });
+}
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Hash, EnumString, Display)]
 #[strum(ascii_case_insensitive, serialize_all = "UPPERCASE")]
@@ -47,7 +51,10 @@ pub enum Fiat {
 #[typetag::serde]
 impl Currency for Fiat {
     fn btc_value(&self) -> f64 {
-        unsafe { EXCHANGE_RATE_PROVIDER.btc_value(self) }
+        EXCHANGE_RATE_PROVIDER
+            .lock()
+            .expect("Failed to lock EXCHANGE_RATE_PROVIDER")
+            .btc_value(self)
     }
 
     fn decimal_places(&self) -> u8 {