add json mode and codestral support

lib/mistral_rb.rb

@@ -20,7 +20,7 @@ def initialize(api_key: ENV["MISTRAL_API_KEY"], base_uri: "https://api.mistral.a
     self.class.base_uri base_uri
   end
 
-  def create_chat_completion(model:, messages:, temperature: 0.7, top_p: 1, max_tokens: nil, stream: false, safe_prompt: false, random_seed: nil, tools: nil, tool_choice: nil)
+  def create_chat_completion(model:, messages:, temperature: 0.7, top_p: 1, max_tokens: nil, stream: false, safe_prompt: false, random_seed: nil, tools: nil, tool_choice: nil, response_format: nil)
     body = {
       model: model,
       messages: messages,
@@ -31,12 +31,10 @@ def create_chat_completion(model:, messages:, temperature: 0.7, top_p: 1, max_to
       safe_prompt: safe_prompt,
       random_seed: random_seed,
       tools: tools,
-      tool_choice: tool_choice
+      tool_choice: tool_choice,
+      response_format: response_format
     }.compact.to_json
 
-    # Debugging: print the request body
-    puts "Request Body: #{body}"
-
     if stream
       # Use on_data callback for streaming
       self.class.post("/chat/completions", body: body, headers: @headers, stream_body: true) do |fragment, _, _|
@@ -51,6 +49,32 @@ def create_chat_completion(model:, messages:, temperature: 0.7, top_p: 1, max_to
     end
   end
 
+  def create_fim_completion(prompt:, suffix:, model:, temperature: 0.7, top_p: 1, max_tokens: nil, min_tokens: 0, stream: false, random_seed: nil, stop: [])
+    body = {
+      prompt: prompt,
+      suffix: suffix,
+      model: model,
+      temperature: temperature,
+      top_p: top_p,
+      max_tokens: max_tokens,
+      min_tokens: min_tokens,
+      stream: stream,
+      random_seed: random_seed,
+      stop: stop
+    }.compact.to_json
+
+    if stream
+      self.class.post("/fim/completions", body: body, headers: @headers, stream_body: true) do |fragment, _, _|
+        processed_chunk = handle_stream_chunk(fragment)
+        yield(processed_chunk) if block_given? && processed_chunk
+      end
+    else
+      response = self.class.post("/fim/completions", body: body, headers: @headers)
+      parsed_response = handle_response(response)
+      MistralModels::CompletionResponse.new(parsed_response)
+    end
+  end
+
   def create_embeddings(model:, input:, encoding_format: "float")
     body = {
       model: model,