Cohere: Add CohereClient and CohereChatModel to support Chat

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/ChatHistory.java

@@ -0,0 +1,16 @@
+package dev.langchain4j.model.cohere;
+
+
+import lombok.Builder;
+import lombok.NonNull;
+
+@Builder
+public class ChatHistory {
+
+    @NonNull
+    CohereRole role;
+
+    @NonNull
+    String message;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/Citation.java

@@ -0,0 +1,18 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Getter;
+import lombok.ToString;
+
+import java.util.List;
+
+@Getter
+@ToString
+public class Citation {
+    Integer start;
+
+    Integer end;
+
+    String text;
+
+    List<String> documentIds;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereApi.java

@@ -8,6 +8,10 @@
 
 interface CohereApi {
 
+    @POST("chat")
+    @Headers({"Content-Type: application/json"})
+    Call<CohereChatResponse> chat(@Body CohereChatRequest request, @Header("Authorization") String authorizationHeader);
+
     @POST("rerank")
     @Headers({"Content-Type: application/json"})
     Call<RerankResponse> rerank(@Body RerankRequest request, @Header("Authorization") String authorizationHeader);

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereChatRequest.java

@@ -0,0 +1,53 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+import java.util.List;
+import java.util.Map;
+
+@Builder
+public class CohereChatRequest {
+
+    @NonNull
+    String message;
+
+    String model;
+
+    boolean stream;
+
+    String preamble;
+
+    List<ChatHistory> chatHistory;
+
+    String conversationId;
+
+    String promptTruncation;
+
+    List<Connector> connectors;
+
+    boolean searchQueriesOnly;
+
+    List<Map<String, String>> documents;
+
+    Double temperature;
+
+    int maxTokens;
+
+    Integer k;
+
+    Double p;
+
+    Double seed;
+
+    List<String> stopSequences;
+
+    Double frequencyPenalty;
+
+    Double presencePenalty;
+
+    List<Tool> tools;
+
+    List<ToolResult> toolResults;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereChatResponse.java

@@ -0,0 +1,33 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Getter;
+
+import java.util.List;
+import java.util.Map;
+
+@Getter
+public class CohereChatResponse {
+
+    String text;
+
+    String generationId;
+
+    List<Citation> citations;
+
+    List<Map<String, String>> documents;
+
+    boolean isSearchRequired;
+
+    List<SearchQuery> searchQueries;
+
+    List<SearchResult> searchResults;
+
+    String finishReason;
+
+    List<ToolCall> toolCalls;
+
+    List<ChatHistory> chatHistory;
+
+    Meta meta;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereClient.java

@@ -4,6 +4,7 @@
 import com.google.gson.GsonBuilder;
 import lombok.Builder;
 import okhttp3.OkHttpClient;
+import retrofit2.Call;
 import retrofit2.Retrofit;
 import retrofit2.converter.gson.GsonConverterFactory;
 
@@ -49,10 +50,18 @@ class CohereClient {
         this.authorizationHeader = "Bearer " + ensureNotBlank(apiKey, "apiKey");
     }
 
+    public CohereChatResponse chat(CohereChatRequest request) {
+        return execute(cohereApi.chat(request, authorizationHeader));
+    }
+
     public RerankResponse rerank(RerankRequest request) {
+        return execute(cohereApi.rerank(request, authorizationHeader));
+    }
+
+    private <T> T execute(Call<T> retrofitCall) {
         try {
-            retrofit2.Response<RerankResponse> retrofitResponse
-                    = cohereApi.rerank(request, authorizationHeader).execute();
+            retrofit2.Response<T> retrofitResponse
+                    = retrofitCall.execute();
 
             if (retrofitResponse.isSuccessful()) {
                 return retrofitResponse.body();

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/CohereRole.java

@@ -0,0 +1,11 @@
+package dev.langchain4j.model.cohere;
+
+public enum CohereRole {
+
+    CHATBOX,
+
+    SYSTEM,
+
+    USER
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/Connector.java

@@ -0,0 +1,20 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+import java.util.Map;
+
+@Builder
+public class Connector {
+
+    @NonNull
+    String id;
+
+    String userAccessToken;
+
+    boolean continueOnFailure;
+
+    Map<String, String> options;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/ParameterDefinition.java

@@ -0,0 +1,15 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+@Builder
+public class ParameterDefinition {
+
+    String description;
+
+    @NonNull
+    String type;
+
+    boolean required;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/SearchQuery.java

@@ -0,0 +1,12 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Getter;
+
+@Getter
+public class SearchQuery {
+
+    String text;
+
+    String generationId;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/SearchResult.java

@@ -0,0 +1,20 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Getter;
+
+import java.util.List;
+
+@Getter
+public class SearchResult {
+
+    SearchQuery searchQuery;
+
+    Connector connector;
+
+    List<String> documentIds;
+
+    String errorMessage;
+
+    boolean continueOnFailure;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/Tool.java

@@ -0,0 +1,19 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+import lombok.NonNull;
+
+import java.util.Map;
+
+@Builder
+public class Tool {
+
+    @NonNull
+    String name;
+
+    @NonNull
+    String description;
+
+    Map<String, ParameterDefinition> parameterDefinitions;
+
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/ToolCall.java

@@ -0,0 +1,11 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+
+import java.util.Map;
+
+@Builder
+public class ToolCall {
+    String name;
+    Map<String, String> parameters;
+}

langchain4j-cohere/src/main/java/dev/langchain4j/model/cohere/ToolResult.java

@@ -0,0 +1,13 @@
+package dev.langchain4j.model.cohere;
+
+import lombok.Builder;
+
+import java.util.List;
+import java.util.Map;
+
+@Builder
+public class ToolResult {
+
+    ToolCall call;
+    List<Map<String, String>> outputs;
+}