feat: added Google GenAI client; simplified IAI/clients API surface. (#829)

* refactor: Simplified IAI; made caching and processing consisent.


Signed-off-by: bwplotka <bwplotka@gmail.com>

* feat: Added Google AI API e.g. for Gemini models.

Signed-off-by: bwplotka <bwplotka@gmail.com>

---------

Signed-off-by: bwplotka <bwplotka@gmail.com>
Co-authored-by: Alex Jones <alexsimonjones@gmail.com>
Co-authored-by: Thomas Schuetz <38893055+thschue@users.noreply.github.com>

pkg/ai/iai.go

@@ -15,8 +15,6 @@ package ai
 
 import (
 	"context"
-
-	"github.com/k8sgpt-ai/k8sgpt/pkg/cache"
 )
 
 var (
@@ -28,25 +26,38 @@ var (
 		&CohereClient{},
 		&AmazonBedRockClient{},
 		&SageMakerAIClient{},
+		&GoogleGenAIClient{},
 	}
 	Backends = []string{
 		"openai",
 		"localai",
 		"azureopenai",
-		"noopai",
 		"cohere",
 		"amazonbedrock",
 		"amazonsagemaker",
+		googleAIClientName,
+		"noopai",
 	}
 )
 
+// IAI is an interface all clients (representing backends) share.
 type IAI interface {
-	Configure(config IAIConfig, language string) error
-	GetCompletion(ctx context.Context, prompt string, promptTmpl string) (string, error)
-	Parse(ctx context.Context, prompt []string, cache cache.ICache, promptTmpl string) (string, error)
+	// Configure sets up client for given configuration. This is expected to be
+	// executed once per client life-time (e.g. analysis CLI command invocation).
+	Configure(config IAIConfig) error
+	// GetCompletion generates text based on prompt.
+	GetCompletion(ctx context.Context, prompt string) (string, error)
+	// GetName returns name of the backend/client.
 	GetName() string
+	// Close cleans all the resources. No other methods should be used on the
+	// objects after this method is invoked.
+	Close()
 }
 
+type nopCloser struct{}
+
+func (nopCloser) Close() {}
+
 type IAIConfig interface {
 	GetPassword() string
 	GetModel() string