Add service module with stubbed LocalGuessMarketContext

GuessMarketContext gained a richer surface (loadEvents/listEvents/
buyShares/closeEvent/account/save-restoreState) backed by new
EventDetailDTO, MarketStateDTO, OptionStateDTO and PurchaseReceiptDTO.
The old engine-module provider implemented the previous shape and is
removed; market.guess.service.LocalGuessMarketContext replaces it as a
stub, each method throwing UnsupportedOperationException pending a
real implementation.

5 files changed, 48 insertions, 6 deletions

diff --git a/api/src/main/java/market/guess/api/EventDetailDTO.java b/api/src/main/java/market/guess/api/EventDetailDTO.java
new file mode 100644
index 0000000..893f153
--- /dev/null
+++ b/api/src/main/java/market/guess/api/EventDetailDTO.java
@@ -0,0 +1,9 @@
+package market.guess.api;
+
+import java.util.List;
+
+public record EventDetailDTO(
+    EventSummaryDTO summary,
+    MarketStateDTO state,
+    List<TradeRowDTO> history,
+    String winningOption) {}
diff --git a/api/src/main/java/market/guess/api/GuessMarketContext.java b/api/src/main/java/market/guess/api/GuessMarketContext.java
index d3954cd..f010e1c 100644
--- a/api/src/main/java/market/guess/api/GuessMarketContext.java
+++ b/api/src/main/java/market/guess/api/GuessMarketContext.java
@@ -1,17 +1,27 @@
 package market.guess.api;
 
+import java.nio.file.Path;
 import java.util.List;
+import market.guess.exception.GuessMarketException;
 
 public interface GuessMarketContext {
-  LoadResultDTO LoadAsync();
+  LoadResultDTO loadEvents(Path path);
 
-  void SaveChangesAsync();
+  List<EventSummaryDTO> listEvents();
 
-  List<EventSummaryDTO> GetAllEventsAsync();
+  boolean isLoaded();
 
-  void GetEventInfoByIdAsync();
+  EventDetailDTO getEvent(String eventKey);
 
-  void CreateEventAsync();
+  PurchaseReceiptDTO buyShares(String userName, String eventKey, String optionKey, long quantity)
+      throws GuessMarketException;
 
-  void UpdateEventAsync();
+  EventDetailDTO closeEvent(String userName, String eventKey, String winningOptionKey)
+      throws GuessMarketException;
+
+  AccountDTO account(String userName);
+
+  void saveState(Path path) throws GuessMarketException;
+
+  LoadResultDTO restoreState(Path path);
 }
diff --git a/api/src/main/java/market/guess/api/MarketStateDTO.java b/api/src/main/java/market/guess/api/MarketStateDTO.java
new file mode 100644
index 0000000..f49b2aa
--- /dev/null
+++ b/api/src/main/java/market/guess/api/MarketStateDTO.java
@@ -0,0 +1,10 @@
+package market.guess.api;
+
+import java.util.List;
+
+public record MarketStateDTO(
+    String eventKey,
+    MechanismType mechanism,
+    List<OptionStateDTO> options,
+    String accountBalance,
+    String commissionCollected) {}
diff --git a/api/src/main/java/market/guess/api/OptionStateDTO.java b/api/src/main/java/market/guess/api/OptionStateDTO.java
new file mode 100644
index 0000000..c002fdd
--- /dev/null
+++ b/api/src/main/java/market/guess/api/OptionStateDTO.java
@@ -0,0 +1,3 @@
+package market.guess.api;
+
+public record OptionStateDTO(String optionKey, String name, String price, long sharesOutstanding) {}
diff --git a/api/src/main/java/market/guess/api/PurchaseReceiptDTO.java b/api/src/main/java/market/guess/api/PurchaseReceiptDTO.java
new file mode 100644
index 0000000..bd5b2f7
--- /dev/null
+++ b/api/src/main/java/market/guess/api/PurchaseReceiptDTO.java
@@ -0,0 +1,10 @@
+package market.guess.api;
+
+public record PurchaseReceiptDTO(
+    String eventKey,
+    String optionName,
+    long quantity,
+    String sharesCost,
+    String commission,
+    String totalPaid,
+    MarketStateDTO stateAfter) {}