package util

import (
	"testing"

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

// TC-0234: page=2, pageSize=10
func TestNormalizePage(t *testing.T) {
	tests := []struct {
		name             string
		page, pageSize   int64
		wantP, wantSize  int64
	}{
		{"normal values", 2, 10, 2, 10},
		{"page=0", 0, 10, 1, 10},
		{"page=-1", -1, 10, 1, 10},
		{"pageSize=0", 1, 0, 1, 20},
		{"pageSize=-5", 1, -5, 1, 20},
		{"pageSize>100", 1, 500, 1, 100},
		{"pageSize=100 boundary", 1, 100, 1, 100},
		{"pageSize=101 boundary", 1, 101, 1, 100},
		{"both zero", 0, 0, 1, 20},
		{"both negative", -3, -10, 1, 20},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			p, s := NormalizePage(tt.page, tt.pageSize)
			assert.Equal(t, tt.wantP, p)
			assert.Equal(t, tt.wantSize, s)
		})
	}
}

// TC-0242: `user@example.com`
func TestIsValidEmail(t *testing.T) {
	tests := []struct {
		name  string
		email string
		want  bool
	}{
		{"standard email", "user@example.com", true},
		{"with dots", "user.name@example.com", true},
		{"with plus", "user+tag@example.com", true},
		{"with hyphen domain", "user@my-domain.com", true},
		{"missing @", "userexample.com", false},
		{"missing domain", "user@", false},
		{"missing TLD", "user@example", false},
		{"empty string", "", false},
		{"double @", "user@@example.com", false},
		{"space in email", "user @example.com", false},
		{"short TLD", "user@example.c", false},
		{"subdomain", "user@sub.example.com", true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			assert.Equal(t, tt.want, IsValidEmail(tt.email))
		})
	}
}

// TC-0249: `13800138000`
func TestIsValidPhone(t *testing.T) {
	tests := []struct {
		name  string
		phone string
		want  bool
	}{
		{"chinese mobile", "13800138000", true},
		{"with country code", "+8613800138000", true},
		{"too short 6 digits", "123456", false},
		{"min 7 digits", "1234567", true},
		{"max 15 digits", "+123456789012345", true},
		{"over 16 digits", "1234567890123456", false},
		{"contains letters", "1380013abc", false},
		{"empty string", "", false},
		{"only plus", "+", false},
		{"plus with short", "+123456", false},
		{"leading zero not first", "01234567890", false},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			assert.Equal(t, tt.want, IsValidPhone(tt.phone))
		})
	}
}