feat: add configurable AgentRouter AI provider

internal/aiprovider/agentrouter_test.go

@@ -0,0 +1,51 @@
+package aiprovider
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestAgentRouterUsesChatCompletionsContract(t *testing.T) {
+	var received map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/v1/chat/completions" {
+			t.Fatalf("path = %q", r.URL.Path)
+		}
+		if r.Header.Get("Authorization") != "Bearer test-key" {
+			t.Fatal("authorization header missing")
+		}
+		if r.Header.Get("User-Agent") != agentRouterUserAgent {
+			t.Fatalf("user-agent = %q", r.Header.Get("User-Agent"))
+		}
+		if err := json.NewDecoder(r.Body).Decode(&received); err != nil {
+			t.Fatal(err)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"id":"chat-1","choices":[{"finish_reason":"stop","message":{"role":"assistant","content":"{\"answer\":\"ok\"}"}}],"usage":{"prompt_tokens":12,"completion_tokens":4}}`))
+	}))
+	defer server.Close()
+
+	client := NewAgentRouter(Config{BaseURL: server.URL, APIKey: "test-key", Model: "gpt-test", Timeout: time.Second}, server.Client())
+	var generator Generator = client
+	result, usage, err := generator.Generate(context.Background(), Request{
+		SchemaName: "answer", Schema: map[string]any{"type": "object", "additionalProperties": false},
+		Instructions: "system rules", Input: json.RawMessage(`{"safe":"aggregate"}`), MaxOutputTokens: 200,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(result) != `{"answer":"ok"}` || usage.ProviderRequestID != "chat-1" || usage.InputTokens != 12 || usage.OutputTokens != 4 {
+		t.Fatalf("result=%s usage=%+v", result, usage)
+	}
+	if received["model"] != "gpt-test" || received["reasoning_effort"] != "medium" || received["parallel_tool_calls"] != false || received["max_tokens"] != float64(200) {
+		t.Fatalf("request controls = %#v", received)
+	}
+	format := received["response_format"].(map[string]any)
+	if format["type"] != "json_schema" {
+		t.Fatalf("response_format = %#v", format)
+	}
+}