Remove unused maxBlocks param from pricenode

As the new fee estimation API does not require this parameter
anymore, remove it and all references to it.

See bisq-network/projects#27

pricenode/src/main/java/bisq/price/mining/providers/BitcoinFeeRateProvider.java

@@ -34,27 +34,22 @@
 import java.time.Duration;
 import java.time.Instant;
 
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Stream;
 
 @Component
 class BitcoinFeeRateProvider extends FeeRateProvider {
 
-    private static final long MIN_FEE_RATE = 10; // satoshi/byte
-    private static final long MAX_FEE_RATE = 1000;
+    static final long MIN_FEE_RATE = 10; // satoshi/byte
+    static final long MAX_FEE_RATE = 1000;
 
-    private static final int DEFAULT_MAX_BLOCKS = 2;
     private static final int DEFAULT_REFRESH_INTERVAL = 2;
 
     private final RestTemplate restTemplate = new RestTemplate();
 
-    private final int maxBlocks;
-
     public BitcoinFeeRateProvider(Environment env) {
         super(Duration.ofMinutes(refreshInterval(env)));
-        this.maxBlocks = maxBlocks(env);
     }
 
     protected FeeRate doGet() {
@@ -63,9 +58,9 @@ protected FeeRate doGet() {
 
     private long getEstimatedFeeRate() {
         return getFeeRatePredictions()
-            .filter(p -> p.get("maxDelay") <= maxBlocks)
+            .filter(p -> p.getKey().equalsIgnoreCase("halfHourFee"))
+            .map(Map.Entry::getValue)
             .findFirst()
-            .map(p -> p.get("maxFee"))
             .map(r -> {
                 log.info("latest fee rate prediction is {} sat/byte", r);
                 return r;
@@ -75,37 +70,30 @@ private long getEstimatedFeeRate() {
             .orElse(MIN_FEE_RATE);
     }
 
-    private Stream<Map<String, Long>> getFeeRatePredictions() {
+    private Stream<Map.Entry<String, Long>> getFeeRatePredictions() {
         return restTemplate.exchange(
             RequestEntity
                 .get(UriComponentsBuilder
-                    // now using /fees/list because /fees/recommended estimates were too high
-                    .fromUriString("https://bitcoinfees.earn.com/api/v1/fees/list")
+                    // Temporarily call mempool.space centralized API endpoint as an
+                    // alternative to the too-expensive bitcoinfees.earn.com until a more
+                    // decentralized solution is available as per
+                    // https://github.com/bisq-network/projects/issues/27
+                    .fromUriString("https://mempool.space/api/v1/fees/recommended")
                     .build().toUri())
-                .header("User-Agent", "") // required to avoid 403
                 .build(),
-            new ParameterizedTypeReference<Map<String, List<Map<String, Long>>>>() {
-            }
-        ).getBody().entrySet().stream()
-            .flatMap(e -> e.getValue().stream());
+            new ParameterizedTypeReference<Map<String, Long>>() { }
+        ).getBody().entrySet().stream();
     }
 
     private static Optional<String[]> args(Environment env) {
         return Optional.ofNullable(
             env.getProperty(CommandLinePropertySource.DEFAULT_NON_OPTION_ARGS_PROPERTY_NAME, String[].class));
     }
 
-    private static int maxBlocks(Environment env) {
+    private static long refreshInterval(Environment env) {
         return args(env)
             .filter(args -> args.length >= 1)
             .map(args -> Integer.valueOf(args[0]))
-            .orElse(DEFAULT_MAX_BLOCKS);
-    }
-
-    private static long refreshInterval(Environment env) {
-        return args(env)
-            .filter(args -> args.length >= 2)
-            .map(args -> Integer.valueOf(args[1]))
             .orElse(DEFAULT_REFRESH_INTERVAL);
     }
 
@@ -115,7 +103,7 @@ class Controller extends PriceController {
 
         @GetMapping(path = "/getParams")
         public String getParams() {
-            return String.format("%s;%s", maxBlocks, refreshInterval.toMillis());
+            return String.format("%s", refreshInterval.toMillis());
         }
     }
 }