From a9c81eb584328e4034e29383761f9f3e97dde71c Mon Sep 17 00:00:00 2001
From: Gabriel Comte <gabriel.comte@gmail.com>
Date: Mon, 30 Mar 2026 07:57:31 +0200
Subject: [PATCH] Add GitHub Action to check currency list against API

Runs monthly (and on manual trigger) to detect currencies that the
blockchain.info ticker API provides but that we don't support yet.
HRK (Croatian Kuna, replaced by EUR) is excluded.
---
 .github/workflows/currency-sync-check.yml | 92 +++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 .github/workflows/currency-sync-check.yml

diff --git a/.github/workflows/currency-sync-check.yml b/.github/workflows/currency-sync-check.yml
new file mode 100644
index 0000000..c59b671
--- /dev/null
+++ b/.github/workflows/currency-sync-check.yml
@@ -0,0 +1,92 @@
+name: Currency Sync Check
+
+on:
+  schedule:
+    - cron: '0 0 1 * *' # First day of every month
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  check-currencies:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Check currency list against API
+        run: |
+          set -euo pipefail
+
+          # Currencies to exclude from the check (present in API but intentionally unsupported)
+          EXCLUDED=(HRK) # Croatian Kuna — replaced by EUR
+
+          # Extract supported currencies from the Fiat enum in source code
+          SUPPORTED=$(sed -n '/^pub enum Fiat/,/^}/p' src/currency/fiat.rs | grep -oP '^\s+[A-Z]{3}\b' | tr -d ' ')
+
+          if [ -z "$SUPPORTED" ]; then
+            echo "::error::Failed to extract any currencies from src/currency/fiat.rs"
+            exit 1
+          fi
+
+          # Fetch currencies from the blockchain.info ticker API (with retries)
+          API_RESPONSE=""
+          for attempt in 1 2 3; do
+            API_RESPONSE=$(curl -sf --connect-timeout 10 --max-time 30 https://blockchain.info/ticker) && break
+            echo "::warning::API fetch attempt $attempt failed, retrying..."
+            sleep 5
+          done
+
+          if [ -z "$API_RESPONSE" ]; then
+            echo "::error::Failed to fetch blockchain.info ticker API after 3 attempts"
+            exit 1
+          fi
+
+          API_CURRENCIES=$(echo "$API_RESPONSE" | jq -r 'keys[]') || {
+            echo "::error::Failed to parse API response as JSON"
+            exit 1
+          }
+
+          # Filter out excluded currencies from API list
+          for exc in "${EXCLUDED[@]}"; do
+            API_CURRENCIES=$(echo "$API_CURRENCIES" | grep -v "^${exc}$")
+          done
+
+          # Find currencies in API but not in code
+          MISSING_IN_CODE=""
+          while IFS= read -r currency; do
+            if ! echo "$SUPPORTED" | grep -q "^${currency}$"; then
+              MISSING_IN_CODE="${MISSING_IN_CODE} ${currency}"
+            fi
+          done <<< "$API_CURRENCIES"
+
+          # Find currencies in code but not in API
+          MISSING_IN_API=""
+          while IFS= read -r currency; do
+            if ! echo "$API_CURRENCIES" | grep -q "^${currency}$"; then
+              MISSING_IN_API="${MISSING_IN_API} ${currency}"
+            fi
+          done <<< "$SUPPORTED"
+
+          # Report results
+          EXIT=0
+
+          if [ -n "$MISSING_IN_CODE" ]; then
+            echo "::error::Currencies in API but not in code:${MISSING_IN_CODE}"
+            EXIT=1
+          fi
+
+          if [ -n "$MISSING_IN_API" ]; then
+            echo "::warning::Currencies in code but not in API:${MISSING_IN_API}"
+          fi
+
+          if [ ${#EXCLUDED[@]} -gt 0 ]; then
+            echo "::notice::Excluded currencies: ${EXCLUDED[*]}"
+          fi
+
+          if [ $EXIT -eq 0 ]; then
+            echo "Currency list is in sync with the API."
+          fi
+
+          exit $EXIT