rewrite

tools/fetch-rates.sh

@@ -0,0 +1,78 @@
+#!/bin/sh
+# Fetch the ECB euro reference rates and write content/rates.json.
+#
+# Feeds the indicative national-currency line on the order page ("≈ CA$920 ·
+# ECB reference rate 2026-08-04"). Indicative is the contract: every charge is
+# in euros, the buyer's bank sets the real conversion — so build-time daily
+# reference rates are exactly the right freshness, and no rate service is ever
+# called at page-view time (nothing third-party runs against visitors).
+#
+# Values are emitted as INTEGER micro-units of target currency per euro
+# (1 EUR = 1.0834 USD -> 1083400), so the C++ side never parses a decimal and
+# no float ever touches a money path.
+#
+# Like fetch-posts.sh: exits 0 on network failure, leaving any previous
+# rates.json in place — a stale indicative rate labelled with its date beats a
+# failed deploy.
+
+set -eu
+
+OUT="content/rates.json"
+URL="https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml"
+
+TMP="$(mktemp)"
+trap 'rm -f "$TMP"' EXIT
+
+if ! curl -fsSL --max-time 30 \
+        -A 'catcrafts.net-buildfetch/1.0 (+https://catcrafts.net)' \
+        "$URL" -o "$TMP" 2>/dev/null; then
+    echo "fetch-rates: ECB unreachable; keeping existing $OUT" >&2
+    exit 0
+fi
+
+# The XML is a flat list: <Cube currency='USD' rate='1.1515'/> under one
+# <Cube time='2026-08-04'>. The ECB emits single-quoted attributes today;
+# normalising quotes first keeps this working if they ever switch to double.
+tr "'" '"' < "$TMP" > "$TMP.n" && mv "$TMP.n" "$TMP"
+
+DATE=$(grep -o 'time="[0-9-]*"' "$TMP" | head -n1 | cut -d'"' -f2)
+if [ -z "$DATE" ]; then
+    echo "fetch-rates: unexpected ECB payload; keeping existing $OUT" >&2
+    exit 0
+fi
+
+RATES=$(grep -o 'currency="[A-Z]*" rate="[0-9.]*"' "$TMP" | awk -F'"' '
+    {
+        cur = $2; rate = $4
+        # decimal -> integer micros, without floats: split on the point and
+        # right-pad the fraction to exactly six digits.
+        n = split(rate, parts, ".")
+        intpart = parts[1]
+        frac = (n > 1) ? parts[2] : ""
+        frac = substr(frac "000000", 1, 6)
+        micro = intpart frac
+        # strip leading zeros (but keep at least one digit)
+        sub(/^0+/, "", micro); if (micro == "") micro = "0"
+        printf "%s\"%s\":%s", (out++ ? "," : ""), cur, micro
+    }')
+
+if [ -z "$RATES" ]; then
+    echo "fetch-rates: no rates parsed; keeping existing $OUT" >&2
+    exit 0
+fi
+
+printf '{"date":"%s","micro_per_eur":{%s}}\n' "$DATE" "$RATES" > "$OUT.new"
+
+# Sanity: the file must parse and contain USD, or something upstream changed
+# shape and the old file is the safer one.
+if command -v jq >/dev/null 2>&1; then
+    if ! jq -e '.micro_per_eur.USD > 500000' "$OUT.new" >/dev/null 2>&1; then
+        echo "fetch-rates: output failed sanity check; keeping existing $OUT" >&2
+        rm -f "$OUT.new"
+        exit 0
+    fi
+fi
+
+mv "$OUT.new" "$OUT"
+count=$(grep -o ':' "$OUT" | wc -l)
+echo "fetch-rates: wrote $OUT ($DATE, $((count - 1)) currencies)"