package cmd

import (
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"testing"

	"go.moleculesai.app/cli/internal/client"
)

// fakeOfferedModelsServer returns a server that responds to GET
// /admin/llm/offered-models?runtime=... with a fixed menu.
func fakeOfferedModelsServer(t *testing.T, runtime string, models []string) *httptest.Server {
	t.Helper()
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/admin/llm/offered-models" {
			http.Error(w, `{"error":"not found"}`, http.StatusNotFound)
			return
		}
		if r.URL.Query().Get("runtime") != runtime {
			http.Error(w, `{"error":"unknown runtime"}`, http.StatusNotFound)
			return
		}
		out := map[string]interface{}{
			"runtime": runtime,
			"models":  []map[string]string{},
		}
		for _, m := range models {
			out["models"] = append(out["models"].([]map[string]string), map[string]string{
				"model":    m,
				"provider": "platform",
			})
		}
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(out)
	}))
}

func TestRequireModelCompatibleWithRuntime_AllowsKnownGood(t *testing.T) {
	server := fakeOfferedModelsServer(t, "claude-code", []string{"claude-sonnet-4-6", "claude-opus-4-7"})
	defer server.Close()

	cl := client.NewWithAuth(server.URL, "token", "org")
	if err := requireModelCompatibleWithRuntime(cl, "claude-sonnet-4-6", "claude-code"); err != nil {
		t.Fatalf("expected compatible model to pass, got: %v", err)
	}
}

func TestRequireModelCompatibleWithRuntime_RejectsKnownBad(t *testing.T) {
	server := fakeOfferedModelsServer(t, "claude-code", []string{"claude-sonnet-4-6", "claude-opus-4-7"})
	defer server.Close()

	cl := client.NewWithAuth(server.URL, "token", "org")
	err := requireModelCompatibleWithRuntime(cl, "gpt-5.5", "claude-code")
	if err == nil {
		t.Fatal("expected incompatible model to fail")
	}
	var ee *exitError
	if !errors.As(err, &ee) {
		t.Fatalf("expected exitError, got %T", err)
	}
	if ee.code != 1 {
		t.Errorf("expected exit code 1, got %d", ee.code)
	}
}

func TestRequireModelCompatibleWithRuntime_EmptyModelAllowed(t *testing.T) {
	server := fakeOfferedModelsServer(t, "claude-code", []string{"claude-sonnet-4-6"})
	defer server.Close()

	cl := client.NewWithAuth(server.URL, "token", "org")
	if err := requireModelCompatibleWithRuntime(cl, "", "claude-code"); err != nil {
		t.Fatalf("empty model should be allowed: %v", err)
	}
}

func TestRequireModelCompatibleWithRuntime_UnknownRuntimeAllowed(t *testing.T) {
	// Unknown runtimes (e.g. federated / third-party) return 404 from the
	// offered-models endpoint. We fail-open there to match the server's
	// federation contract.
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, `{"error":"unknown runtime"}`, http.StatusNotFound)
	}))
	defer server.Close()

	cl := client.NewWithAuth(server.URL, "token", "org")
	if err := requireModelCompatibleWithRuntime(cl, "anything", "external"); err != nil {
		t.Fatalf("unknown runtime should fail-open: %v", err)
	}
}

func TestRequireModelCompatibleWithRuntime_TransientErrorFailsClosed(t *testing.T) {
	// Any non-404 error from the offered-models endpoint must be treated as
	// ambiguous and fail-closed; otherwise a transient 5xx/network blip lets
	// an unsafe runtime switch through.
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, `{"error":"internal server error"}`, http.StatusInternalServerError)
	}))
	defer server.Close()

	cl := client.NewWithAuth(server.URL, "token", "org")
	err := requireModelCompatibleWithRuntime(cl, "claude-sonnet-4-6", "claude-code")
	if err == nil {
		t.Fatal("expected transient error to fail closed")
	}
	var ee *exitError
	if !errors.As(err, &ee) {
		t.Fatalf("expected exitError, got %T", err)
	}
	if ee.code != 1 {
		t.Errorf("expected exit code 1, got %d", ee.code)
	}
}