package repository

import (
	"testing"

	"github.com/user-management-system/internal/pkg/pagination"
)

func TestPaginationResultFromTotal(t *testing.T) {
	tests := []struct {
		name        string
		total       int64
		params      pagination.PaginationParams
		wantPages   int
		wantTotal   int64
		wantPage    int
		wantPageSize int
	}{
		{
			name:         "exact division",
			total:        100,
			params:       pagination.PaginationParams{Page: 1, PageSize: 20},
			wantPages:    5,
			wantTotal:    100,
			wantPage:     1,
			wantPageSize: 20,
		},
		{
			name:         "with remainder",
			total:        105,
			params:       pagination.PaginationParams{Page: 1, PageSize: 20},
			wantPages:    6,
			wantTotal:    105,
			wantPage:     1,
			wantPageSize: 20,
		},
		{
			name:         "zero total",
			total:        0,
			params:       pagination.PaginationParams{Page: 1, PageSize: 20},
			wantPages:    0,
			wantTotal:    0,
			wantPage:     1,
			wantPageSize: 20,
		},
		{
			name:         "single page",
			total:        5,
			params:       pagination.PaginationParams{Page: 1, PageSize: 20},
			wantPages:    1,
			wantTotal:    5,
			wantPage:     1,
			wantPageSize: 20,
		},
		{
			name:         "page 2",
			total:        50,
			params:       pagination.PaginationParams{Page: 2, PageSize: 20},
			wantPages:    3,
			wantTotal:    50,
			wantPage:     2,
			wantPageSize: 20,
		},
		{
			name:         "small page size",
			total:        10,
			params:       pagination.PaginationParams{Page: 1, PageSize: 3},
			wantPages:    4,
			wantTotal:    10,
			wantPage:     1,
			wantPageSize: 3,
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			result := paginationResultFromTotal(tc.total, tc.params)
			if result == nil {
				t.Fatal("expected non-nil result")
			}
			if result.Total != tc.wantTotal {
				t.Errorf("expected total %d, got %d", tc.wantTotal, result.Total)
			}
			if result.Page != tc.wantPage {
				t.Errorf("expected page %d, got %d", tc.wantPage, result.Page)
			}
			if result.PageSize != tc.wantPageSize {
				t.Errorf("expected page_size %d, got %d", tc.wantPageSize, result.PageSize)
			}
			if result.Pages != tc.wantPages {
				t.Errorf("expected pages %d, got %d", tc.wantPages, result.Pages)
			}
		})
	}
}