// go:build unit

package u

import (
	"strconv"
	"testing"

	"github.com/google/go-cmp/cmp"
)

func TestFirst(t *testing.T) {
	testCases := []struct {
		name  string
		slice []int
		first int
		exist bool
	}{
		{
			name:  "multiple items slice",
			slice: []int{1, 2, 3},
			first: 1,
			exist: true,
		},
		{
			name:  "single item slice",
			slice: []int{1},
			first: 1,
			exist: true,
		},
		{
			name:  "empty slice",
			slice: []int{},
			first: 0,
			exist: false,
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {

			first, empty := First(tc.slice)

			if first != tc.first {
				t.Errorf("Error first, want %d got %d", tc.first, first)
			}

			if empty != tc.exist {
				t.Errorf("Error empty, want %t got %t", tc.exist, empty)
			}

		})
	}
}

func TestSubList(t *testing.T) {
	testCases := []struct {
		name  string
		slice []int
		size  int
		want  [][]int
	}{
		{
			name:  "sigle size sub list",
			slice: []int{1, 2, 3},
			size:  1,
			want:  [][]int{{1}, {2}, {3}},
		},
		{
			name:  "multiple size sub list",
			slice: []int{1, 2, 3, 4},
			size:  2,
			want:  [][]int{{1, 2}, {3, 4}},
		},
		{
			name:  "uneven multiple size sub list",
			slice: []int{1, 2, 3, 4, 5},
			size:  2,
			want:  [][]int{{1, 2}, {3, 4}, {5}},
		},
		{
			name:  "empty sub list",
			slice: []int{},
			size:  2,
			want:  [][]int{{}},
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {

			subList := ChunkBy(tc.slice, tc.size)

			if diff := cmp.Diff(tc.want, subList); diff != "" {
				t.Errorf("Wrong result given - wanted + got\n %s", diff)
			}
		})
	}
}

func TestFirstOrZero(t *testing.T) {
	testCases := []struct {
		name  string
		slice []int
		first int
	}{
		{
			name:  "multiple items slice",
			slice: []int{1, 2, 3},
			first: 1,
		},
		{
			name:  "single item slice",
			slice: []int{1},
			first: 1,
		},
		{
			name:  "empty slice",
			slice: []int{},
			first: 0,
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {

			first := FirstOrZero(tc.slice)

			if first != tc.first {
				t.Errorf("Error first, want %d got %d", tc.first, first)
			}

		})
	}
}

func TestMap(t *testing.T) {
	testCases := []struct {
		name string
		in   []int
		out  []string
	}{
		{
			name: "empty",
			in:   []int{},
			out:  []string{},
		},
		{
			name: "not empty",
			in:   []int{1, 2, 3},
			out:  []string{"1", "2", "3"},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			out := Map(tc.in, func(v int) string { return strconv.Itoa(v) })

			if diff := cmp.Diff(tc.out, out); diff != "" {
				t.Errorf("Map error:\n%s", diff)
			}
		})
	}
}