Add new CoreHelpService and method help docs

Adds all the gRPC server boilerplate, and a simple help service
that serves method help in man page format.  Help text is maintained
in text files located in core/src/main/resources/help.

Only some of the method help text files are defined in this
change, more to be added.

core/src/main/java/bisq/core/api/CoreApi.java

@@ -62,6 +62,7 @@ public class CoreApi {
     @Getter
     private final Config config;
     private final CoreDisputeAgentsService coreDisputeAgentsService;
+    private final CoreHelpService coreHelpService;
     private final CoreOffersService coreOffersService;
     private final CorePaymentAccountsService paymentAccountsService;
     private final CorePriceService corePriceService;
@@ -72,7 +73,7 @@ public class CoreApi {
     @Inject
     public CoreApi(Config config,
                    CoreDisputeAgentsService coreDisputeAgentsService,
-                   CoreOffersService coreOffersService,
+                   CoreHelpService coreHelpService, CoreOffersService coreOffersService,
                    CorePaymentAccountsService paymentAccountsService,
                    CorePriceService corePriceService,
                    CoreTradesService coreTradesService,
@@ -80,6 +81,7 @@ public class CoreApi {
                    TradeStatisticsManager tradeStatisticsManager) {
         this.config = config;
         this.coreDisputeAgentsService = coreDisputeAgentsService;
+        this.coreHelpService = coreHelpService;
         this.coreOffersService = coreOffersService;
         this.paymentAccountsService = paymentAccountsService;
         this.coreTradesService = coreTradesService;
@@ -101,6 +103,15 @@ public class CoreApi {
         coreDisputeAgentsService.registerDisputeAgent(disputeAgentType, registrationKey);
     }
 
+
+    ///////////////////////////////////////////////////////////////////////////////////////////
+    // Help
+    ///////////////////////////////////////////////////////////////////////////////////////////
+
+    public String getMethodHelp(String methodName) {
+        return coreHelpService.getMethodHelp(methodName);
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////
     // Offers
     ///////////////////////////////////////////////////////////////////////////////////////////

core/src/main/java/bisq/core/api/CoreHelpService.java

@@ -0,0 +1,103 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.core.api;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+import lombok.extern.slf4j.Slf4j;
+
+import static java.io.File.separator;
+import static java.lang.String.format;
+import static java.lang.System.out;
+
+@Singleton
+@Slf4j
+class CoreHelpService {
+
+    @Inject
+    public CoreHelpService() {
+    }
+
+    public String getMethodHelp(String methodName) {
+        switch (methodName) {
+            case "createoffer":
+            case "getfundingaddresses":
+            case "getpaymentaccts":
+            case "getpaymentmethods":
+            case "gettxfeerate":
+            case "getunusedbsqaddress":
+            case "getversion":
+            case "lockwallet":
+            case "takeoffer":
+            case "unsettxfeerate":
+                return getHelpText(methodName);
+            default:
+                throw new IllegalStateException("no help found for " + methodName);
+        }
+    }
+
+    private String getHelpText(String methodName) {
+        String resourceFile = "/help" + separator + methodName + "-" + "help.txt";
+        try {
+            return readHelpFile(resourceFile);
+        } catch (NullPointerException ex) {
+            log.error("", ex);
+            throw new IllegalStateException(format("could not find %s help doc", methodName));
+        } catch (IOException ex) {
+            log.error("", ex);
+            throw new IllegalStateException(format("could not read %s help doc", methodName));
+        }
+    }
+
+    private String readHelpFile(String resourceFile) throws NullPointerException, IOException {
+        // The deployed text file is in the core.jar file, so use
+        // Class.getResourceAsStream to read it.
+        InputStream is = getClass().getResourceAsStream(resourceFile);
+        BufferedReader br = new BufferedReader(new InputStreamReader(is));
+        String line;
+        StringBuilder builder = new StringBuilder();
+        while ((line = br.readLine()) != null)
+            builder.append(line).append("\n");
+
+        return builder.toString();
+    }
+
+    // Main method for devs to view help text without running the server.
+    @SuppressWarnings("CommentedOutCode")
+    public static void main(String[] args) {
+        CoreHelpService coreHelpService = new CoreHelpService();
+        // out.println(coreHelpService.getMethodHelp("getversion"));
+        // out.println(coreHelpService.getMethodHelp("getfundingaddresses"));
+        // out.println(coreHelpService.getMethodHelp("getfundingaddresses"));
+        // out.println(coreHelpService.getMethodHelp("getunusedbsqaddress"));
+        // out.println(coreHelpService.getMethodHelp("unsettxfeerate"));
+        // out.println(coreHelpService.getMethodHelp("getpaymentmethods"));
+        // out.println(coreHelpService.getMethodHelp("getpaymentaccts"));
+        // out.println(coreHelpService.getMethodHelp("lockwallet"));
+        // out.println(coreHelpService.getMethodHelp("gettxfeerate"));
+        out.println(coreHelpService.getMethodHelp("createoffer"));
+        // out.println(coreHelpService.getMethodHelp("takeoffer"));
+        // out.println(coreHelpService.getMethodHelp("garbage"));
+    }
+}

core/src/main/resources/help/createoffer-help.txt

@@ -0,0 +1,64 @@
+createoffer
+
+NAME
+----
+createoffer - create offer to buy or sell BTC
+
+SYNOPSIS
+--------
+createoffer
+		--payment-account=<payment-acct-id>
+		--direction=<buy|sell>
+		--currency-code=<eur|usd>
+		--market-price-margin=<percent> | --fixed-price=<btc-price>
+		--amount=<btc-amount>
+		--min-amount=<btc-amount>
+		--security-deposit=<percent>
+		[--fee-currency=<bsq|btc>]
+
+DESCRIPTION
+-----------
+Create and place an offer to buy or sell BTC using a fiat account.
+
+OPTIONS
+-------
+--payment-account
+		The ID of the fiat payment account used to send or receive funds during the trade.
+
+--direction
+		The direction of the trade (BUY or SELL).
+
+--currency-code
+		The three letter code for the fiat used to buy or sell BTC, e.g., EUR, USD, BRL, ...
+
+--market-price-margin
+		The % above or below market BTC price, e.g., 1.00 (1%).
+		If --market-price-margin is not present, --fixed-price must be.
+
+--fixed-price
+		The fixed BTC price in fiat used to buy or sell BTC, e.g., 34000 (USD).
+		If --fixed-price is not present, --market-price-margin must be.
+
+--amount
+		The amount of BTC to buy or sell, e.g., 0.125.
+
+--min-amount
+		The minimum amount of BTC to buy or sell, e.g., 0.006.
+		If --min-amount is not present, it defaults to the --amount value.
+
+--security-deposit
+		The percentage of the BTC amount being traded for the security deposit, e.g., 60.0 (60%).
+
+--fee-currency
+		The wallet currency used to pay the Bisq trade maker fee (BSQ|BTC).  Default is BTC
+
+EXAMPLES
+--------
+To create a BUY 0.125 BTC with EUR offer
+	at the current market price,
+	using a payment account with ID 7413d263-225a-4f1b-837a-1e3094dc0d77,
+	putting up a 30 percent security deposit,
+	and paying the Bisq maker trading fee in BSQ:
+$ ./bisq-cli --password=xyz --port=9998 createoffer --payment-account=7413d263-225a-4f1b-837a-1e3094dc0d77 --direction=buy --currency-code=eur --amount=0.125 --market-price-margin=0.00 --security-deposit=30.0 --fee-currency=bsq
+
+ (TODO another 3 examples: selling @ mkt price, buying a fixed price, selling at fixed price...)

core/src/main/resources/help/getfundingaddresses-help.txt

@@ -0,0 +1,17 @@
+getfundingaddresses
+
+NAME
+----
+getfundingaddresses - list BTC receiving address
+
+SYNOPSIS
+--------
+getfundingaddresses
+
+DESCRIPTION
+-----------
+Returns a list of receiving BTC addresses.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 getfundingaddresses

core/src/main/resources/help/getpaymentaccts-help.txt

@@ -0,0 +1,17 @@
+getpaymentaccts
+
+NAME
+----
+getpaymentaccts - list user payment accounts
+
+SYNOPSIS
+--------
+getpaymentaccts
+
+DESCRIPTION
+-----------
+Returns the list of user payment accounts.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 getpaymentaccts

core/src/main/resources/help/getpaymentmethods-help.txt

@@ -0,0 +1,17 @@
+getpaymentmethods
+
+NAME
+----
+getpaymentmethods - list fiat payment methods
+
+SYNOPSIS
+--------
+getpaymentmethods
+
+DESCRIPTION
+-----------
+Returns a list of currently supported fiat payment method IDs.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 getpaymentmethods

core/src/main/resources/help/gettxfeerate-help.txt

@@ -0,0 +1,17 @@
+gettxfeerate
+
+NAME
+----
+gettxfeerate - get transaction fee rate
+
+SYNOPSIS
+--------
+gettxfeerate
+
+DESCRIPTION
+-----------
+Returns the most recent bitcoin network transaction fee the Bisq server could find.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 gettxfeerate

core/src/main/resources/help/getunusedbsqaddress-help.txt

@@ -0,0 +1,17 @@
+getunusedbsqaddress
+
+NAME
+----
+getunusedbsqaddress - get BSQ receiving address
+
+SYNOPSIS
+--------
+getunusedbsqaddress
+
+DESCRIPTION
+-----------
+Returns an unused BSQ receiving address.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 getunusedbsqaddress

core/src/main/resources/help/getversion-help.txt

@@ -0,0 +1,17 @@
+getversion
+
+NAME
+----
+getversion - get server version
+
+SYNOPSIS
+--------
+getversion
+
+DESCRIPTION
+-----------
+Returns the Bisq server version.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 getversion

core/src/main/resources/help/lockwallet-help.txt

@@ -0,0 +1,17 @@
+lockwallet
+
+NAME
+----
+lockwallet - lock Bisq wallet
+
+SYNOPSIS
+--------
+lockwallet
+
+DESCRIPTION
+-----------
+Locks an unlocked wallet before an unlockwallet timeout expires.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 lockwallet

core/src/main/resources/help/takeoffer-help.txt

@@ -0,0 +1,35 @@
+takeoffer
+
+NAME
+----
+takeoffer - take an offer to buy or sell BTC
+
+SYNOPSIS
+--------
+takeoffer
+		--offer-id=<offer-id>
+		--payment-account=<payment-acct-id>
+		--fee-currency=<eur|usd>
+
+DESCRIPTION
+-----------
+Take an existing offer using a matching payment method.  The Bisq trade fee can be paid in BSQ or BTC.
+
+OPTIONS
+-------
+--offer-id
+		The ID of the buy or sell offer to take.
+
+--payment-account
+		The ID of the fiat payment account used to send or receive funds during the trade.
+		The payment account's payment method must match that of the offer.
+
+--fee-currency
+		The wallet currency used to pay the Bisq trade taker fee (BSQ|BTC).  Default is BTC
+
+EXAMPLES
+--------
+To take an offer with ID 83e8b2e2-51b6-4f39-a748-3ebd29c22aea
+	using a payment account with ID fe20cdbd-22be-4b8a-a4b6-d2608ff09d6e,
+	and paying the Bisq trading fee in BSQ:
+$ ./bisq-cli --password=xyz --port=9998 takeoffer -offer-id=83e8b2e2-51b6-4f39-a748-3ebd29c22aea -payment-account=fe20cdbd-22be-4b8a-a4b6-d2608ff09d6e -fee-currency=bsq

core/src/main/resources/help/unsettxfeerate-help.txt

@@ -0,0 +1,17 @@
+unsettxfeerate
+
+NAME
+----
+unsettxfeerate - unset transaction fee rate preference
+
+SYNOPSIS
+--------
+unsettxfeerate
+
+DESCRIPTION
+-----------
+Unsets (removes) the transaction fee rate user preference.
+
+EXAMPLES
+--------
+$ ./bisq-cli --password=xyz --port=9998 unsettxfeerate

daemon/src/main/java/bisq/daemon/grpc/GrpcHelpService.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.daemon.grpc;
+
+import bisq.core.api.CoreApi;
+
+import bisq.proto.grpc.GetMethodHelpReply;
+import bisq.proto.grpc.GetMethodHelpRequest;
+import bisq.proto.grpc.HelpGrpc;
+
+import io.grpc.stub.StreamObserver;
+
+import javax.inject.Inject;
+
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+class GrpcHelpService extends HelpGrpc.HelpImplBase {
+
+    private final CoreApi coreApi;
+    private final GrpcExceptionHandler exceptionHandler;
+
+    @Inject
+    public GrpcHelpService(CoreApi coreApi, GrpcExceptionHandler exceptionHandler) {
+        this.coreApi = coreApi;
+        this.exceptionHandler = exceptionHandler;
+    }
+
+    @Override
+    public void getMethodHelp(GetMethodHelpRequest req,
+                              StreamObserver<GetMethodHelpReply> responseObserver) {
+        try {
+            String helpText = coreApi.getMethodHelp(req.getMethodName());
+            var reply = GetMethodHelpReply.newBuilder().setMethodHelp(helpText).build();
+            responseObserver.onNext(reply);
+            responseObserver.onCompleted();
+        } catch (Throwable cause) {
+            exceptionHandler.handleException(cause, responseObserver);
+        }
+    }
+}

daemon/src/main/java/bisq/daemon/grpc/GrpcServer.java

@@ -50,6 +50,7 @@ public class GrpcServer {
                       Config config,
                       PasswordAuthInterceptor passwordAuthInterceptor,
                       GrpcDisputeAgentsService disputeAgentsService,
+                      GrpcHelpService helpService,
                       GrpcOffersService offersService,
                       GrpcPaymentAccountsService paymentAccountsService,
                       GrpcPriceService priceService,
@@ -60,6 +61,7 @@ public class GrpcServer {
         this.server = ServerBuilder.forPort(config.apiPort)
                 .executor(UserThread.getExecutor())
                 .addService(disputeAgentsService)
+                .addService(helpService)
                 .addService(offersService)
                 .addService(paymentAccountsService)
                 .addService(priceService)

proto/src/main/proto/grpc.proto

@@ -40,6 +40,23 @@ message RegisterDisputeAgentRequest {
 message RegisterDisputeAgentReply {
 }
 
+///////////////////////////////////////////////////////////////////////////////////////////
+// Help
+///////////////////////////////////////////////////////////////////////////////////////////
+
+service Help {
+    rpc GetMethodHelp (GetMethodHelpRequest) returns (GetMethodHelpReply) {
+    }
+}
+
+message GetMethodHelpRequest {
+    string methodName = 1;
+}
+
+message GetMethodHelpReply {
+    string methodHelp = 1;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////
 // Offers
 ///////////////////////////////////////////////////////////////////////////////////////////