Add LLM interface

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

pkg/probod/llm.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package probod
+
+import (
+	"fmt"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"go.gearno.de/kit/httpclient"
+	"go.gearno.de/kit/log"
+	"go.opentelemetry.io/otel/trace"
+	"go.probo.inc/probo/pkg/llm"
+	llmopenai "go.probo.inc/probo/pkg/llm/openai"
+)
+
+func buildLLMClient(cfg LLMConfig, l *log.Logger, tp trace.TracerProvider, r prometheus.Registerer) (*llm.Client, error) {
+	provider := cfg.Provider
+	if provider == "" {
+		provider = "openai"
+	}
+
+	httpClient := httpclient.DefaultPooledClient(
+		httpclient.WithLogger(l),
+		httpclient.WithTracerProvider(tp),
+		httpclient.WithRegisterer(r),
+	)
+
+	switch provider {
+	case "openai":
+		p := llmopenai.NewProvider(cfg.APIKey,
+			llmopenai.WithHTTPClient(httpClient),
+		)
+		return llm.NewClient(p, "openai",
+			llm.WithLogger(l),
+			llm.WithTracerProvider(tp),
+		), nil
+	case "anthropic":
+		return nil, fmt.Errorf("anthropic provider not yet wired; add import and construct here")
+	case "bedrock":
+		return nil, fmt.Errorf("bedrock provider not yet wired; requires aws.Config")
+	default:
+		return nil, fmt.Errorf("unsupported LLM provider: %q", provider)
+	}
+}