package generics

import (
	"testing"

	"github.com/stretchr/testify/require"
)

func TestMapPairs(t *testing.T) {
	tests := map[string]struct {
		src map[string]int
		dst []Pair[string, int]
	}{
		"nil map": {
			src: nil,
			dst: Pairs[string, int]{},
		},
		"empty map": {
			src: map[string]int{},
			dst: Pairs[string, int]{},
		},
		"filled map": {
			src: map[string]int{
				"foo": 1,
				"bar": 2,
				"baz": 3,
			},
			dst: Pairs[string, int]{
				{
					Key:   "foo",
					Value: 1,
				},
				{
					Key:   "bar",
					Value: 2,
				},
				{
					Key:   "baz",
					Value: 3,
				},
			},
		},
	}

	for name, tc := range tests {
		name, tc := name, tc
		t.Run(name, func(t *testing.T) {
			dst := MapPairs(tc.src)
			require.ElementsMatch(t, tc.dst, dst)
		})
	}
}

func TestMapKeys(t *testing.T) {
	tests := map[string]struct {
		src map[string]int
		dst []string
	}{
		"nil map": {
			src: nil,
			dst: []string{},
		},
		"empty map": {
			src: map[string]int{},
			dst: []string{},
		},
		"filled map": {
			src: map[string]int{
				"foo": 1,
				"bar": 2,
				"baz": 3,
			},
			dst: []string{
				"foo",
				"bar",
				"baz",
			},
		},
	}

	for name, tc := range tests {
		name, tc := name, tc
		t.Run(name, func(t *testing.T) {
			dst := MapKeys(tc.src)
			require.ElementsMatch(t, tc.dst, dst)
		})
	}
}

func TestMapValues(t *testing.T) {
	tests := map[string]struct {
		src map[string]int
		dst []int
	}{
		"nil map": {
			src: nil,
			dst: []int{},
		},
		"empty map": {
			src: map[string]int{},
			dst: []int{},
		},
		"filled map": {
			src: map[string]int{
				"foo": 1,
				"bar": 2,
				"baz": 3,
			},
			dst: []int{1, 2, 3},
		},
	}

	for name, tc := range tests {
		name, tc := name, tc
		t.Run(name, func(t *testing.T) {
			dst := MapValues(tc.src)
			require.ElementsMatch(t, tc.dst, dst)
		})
	}
}

func TestInvertMap(t *testing.T) {
	tests := map[string]struct {
		src map[string]int
		dst map[int]string
	}{
		"nil map": {
			src: nil,
			dst: nil,
		},
		"empty map": {
			src: map[string]int{},
			dst: map[int]string{},
		},
		"filled map": {
			src: map[string]int{
				"foo": 1,
				"bar": 2,
				"baz": 3,
			},
			dst: map[int]string{
				1: "foo",
				2: "bar",
				3: "baz",
			},
		},
	}

	for name, tc := range tests {
		name, tc := name, tc
		t.Run(name, func(t *testing.T) {
			dst := InvertMap(tc.src)

			if tc.dst == nil {
				require.Nil(t, dst)
				return
			}
			require.NotNil(t, dst)
			require.EqualValues(t, tc.dst, dst)
		})
	}
}