package runtime

import (
	"reflect"
	"testing"

	"github.com/karmada-io/karmada/pkg/scheduler/framework"
)

func mockPluginFactory() (framework.Plugin, error) {
	return nil, nil
}

func TestRegistry_Filter(t *testing.T) {
	plugins := []string{"bar", "foo", "fuzz"}
	var r = make(Registry)
	for _, name := range plugins {
		_ = r.Register(name, mockPluginFactory)
	}

	tests := []struct {
		name            string
		curPlugins      []string
		r               Registry
		expectedPlugins []string
	}{
		{
			name:            "enable foo",
			curPlugins:      []string{"foo"}, // --plugins=foo
			r:               r,
			expectedPlugins: []string{"foo"},
		},
		{
			name:            "enable all",
			curPlugins:      []string{"*"}, // --plugins=*
			r:               r,
			expectedPlugins: []string{"bar", "foo", "fuzz"},
		},
		{
			name:            "disable foo",
			curPlugins:      []string{"*", "-foo"}, // --plugins=*,-foo
			r:               r,
			expectedPlugins: []string{"bar", "fuzz"},
		},
		{
			name:            "disable foo",
			curPlugins:      []string{"-foo", "*"}, // --plugins=-foo,*
			r:               r,
			expectedPlugins: []string{"bar", "fuzz"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := tt.r.Filter(tt.curPlugins); !reflect.DeepEqual(got.FactoryNames(), tt.expectedPlugins) {
				t.Errorf("Filter() = %v, want %v", got.FactoryNames(), tt.expectedPlugins)
			}
		})
	}
}

func TestRegistry_Register(t *testing.T) {
	tests := []struct {
		name              string
		initialPlugins    []string
		registeringPlugin string
		wantErr           bool
		expectedPlugins   []string
	}{
		{
			name:              "Plugin registered to an empty Registry",
			initialPlugins:    nil,
			registeringPlugin: "p1",
			wantErr:           false,
			expectedPlugins:   []string{"p1"},
		},
		{
			name:              "Plugin registered to a non empty Registry",
			initialPlugins:    []string{"p1"},
			registeringPlugin: "p2",
			wantErr:           false,
			expectedPlugins:   []string{"p1", "p2"},
		},
		{
			name:              "Duplicate plugin registration",
			initialPlugins:    []string{"p1", "p2"},
			registeringPlugin: "p1",
			wantErr:           true,
			expectedPlugins:   []string{"p1", "p2"},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			var r = make(Registry)
			for _, name := range tt.initialPlugins {
				_ = r.Register(name, mockPluginFactory)
			}

			err := r.Register(tt.registeringPlugin, mockPluginFactory)

			if (err != nil) != tt.wantErr {
				t.Errorf("Register() error = %v, wantErr %v", err, tt.wantErr)
				return
			}

			if !reflect.DeepEqual(r.FactoryNames(), tt.expectedPlugins) {
				t.Errorf("Filter() = %v, want %v", r.FactoryNames(), tt.expectedPlugins)
			}
		})
	}
}

func TestRegistry_Unregister(t *testing.T) {
	tests := []struct {
		name            string
		initialPlugins  []string
		removingPlugin  string
		wantErr         bool
		expectedPlugins []string
	}{
		{
			name:            "Remove not exist plugin",
			initialPlugins:  []string{"p1"},
			removingPlugin:  "p2",
			wantErr:         true,
			expectedPlugins: []string{"p1"},
		},
		{
			name:            "Remove exist plugin",
			initialPlugins:  []string{"p1", "p2", "p3"},
			removingPlugin:  "p1",
			wantErr:         false,
			expectedPlugins: []string{"p2", "p3"},
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			var r = make(Registry)
			for _, name := range tt.initialPlugins {
				_ = r.Register(name, mockPluginFactory)
			}

			err := r.Unregister(tt.removingPlugin)

			if (err != nil) != tt.wantErr {
				t.Errorf("Register() error = %v, wantErr %v", err, tt.wantErr)
				return
			}

			if !reflect.DeepEqual(r.FactoryNames(), tt.expectedPlugins) {
				t.Errorf("FactoryNames() = %v, want %v", r.FactoryNames(), tt.expectedPlugins)
			}
		})
	}
}

func TestRegistry_Merge(t *testing.T) {
	var r1 = make(Registry)
	_ = r1.Register("p1", mockPluginFactory)
	_ = r1.Register("p2", mockPluginFactory)
	_ = r1.Register("p3", mockPluginFactory)

	var r2 = make(Registry)
	_ = r2.Register("p4", mockPluginFactory)
	_ = r2.Register("p5", mockPluginFactory)

	expectedPlugins := []string{
		"p1", "p2", "p3", "p4", "p5",
	}

	err := r1.Merge(r2)
	if err != nil {
		t.Errorf("Merge() returned error: %v", err)
	}

	if !reflect.DeepEqual(r1.FactoryNames(), expectedPlugins) {
		t.Errorf("FactoryNames() = %v, want %v", r1.FactoryNames(), expectedPlugins)
	}
}