package paginator

import (
	"testing"

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

func TestCut(t *testing.T) {
	items := []int{1, 2, 3}
	page := 2
	limit := 1
	pageCount := 1
	pag := New(items, page, limit, pageCount)
	t.Logf("pag: %s", pag)
}

func TestNilItems(t *testing.T) {
	pag := New[int](nil, 1, 10, 0)

	assert.Equal(t, 0, pag.TotalCount())
	assert.Equal(t, 0, pag.TotalPage())
	assert.Empty(t, pag.Items())
	assert.Equal(t, 0, pag.CurPage())
	assert.Equal(t, 0, pag.PreviewPage())
	assert.Equal(t, 0, pag.NextPage())
	assert.Equal(t, 0, pag.FirstPage())
	assert.Equal(t, 0, pag.LastPage())
	assert.Empty(t, pag.PageRange())
}

func TestEmptyItems(t *testing.T) {
	pag := New([]int{}, 1, 10, 0)

	assert.Equal(t, 0, pag.TotalCount())
	assert.Equal(t, 0, pag.TotalPage())
	assert.Empty(t, pag.Items())
	assert.Equal(t, 0, pag.CurPage())
	assert.Equal(t, 0, pag.PreviewPage())
	assert.Equal(t, 0, pag.NextPage())
	assert.Equal(t, 0, pag.FirstPage())
	assert.Equal(t, 0, pag.LastPage())
	assert.Empty(t, pag.PageRange())
}

func TestNilItemsWithDifferentPages(t *testing.T) {
	tests := []struct {
		name      string
		page      int
		limit     int
		pageCount int
	}{
		{name: "page=0,limit=1", page: 0, limit: 1, pageCount: 0},
		{name: "page=1,limit=1", page: 1, limit: 1, pageCount: 0},
		{name: "page=5,limit=10", page: 5, limit: 10, pageCount: 0},
		{name: "page=1,limit=1,pageCount=3", page: 1, limit: 1, pageCount: 3},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			pag := New[string](nil, tt.page, tt.limit, tt.pageCount)

			assert.Equal(t, 0, pag.TotalCount())
			assert.Equal(t, 0, pag.TotalPage())
			assert.Empty(t, pag.Items())
		})
	}
}