package service

import "testing"

func TestParsePage_非法值当作第1页(t *testing.T) {
	cases := []string{"", "abc", "0", "-1", "-100", " "}
	for _, c := range cases {
		if got := ParsePage(c); got != 1 {
			t.Errorf("ParsePage(%q) = %d，想要 1", c, got)
		}
	}
}

func TestParsePage_合法值原样返回(t *testing.T) {
	cases := map[string]int{"1": 1, "2": 2, "9999": 9999, " 3 ": 3}
	for in, want := range cases {
		if got := ParsePage(in); got != want {
			t.Errorf("ParsePage(%q) = %d，想要 %d", in, got, want)
		}
	}
}

func TestParsePageSize_只接受白名单(t *testing.T) {
	for _, in := range []string{"20", "50", "100", " 50 "} {
		want := map[string]int{"20": 20, "50": 50, "100": 100, " 50 ": 50}[in]
		if got := ParsePageSize(in); got != want {
			t.Errorf("ParsePageSize(%q) = %d，想要 %d", in, got, want)
		}
	}
	for _, in := range []string{"", "0", "21", "200", "abc"} {
		if got := ParsePageSize(in); got != DefaultPageSize {
			t.Errorf("ParsePageSize(%q) = %d，非法值应回退 %d", in, got, DefaultPageSize)
		}
	}
}

func TestTotalPages_总数为0返回1不是0(t *testing.T) {
	if got := TotalPages(0, 100); got != 1 {
		t.Errorf("TotalPages(0) = %d，想要 1（不能出现『第 1/0 页』）", got)
	}
}

func TestTotalPages_按PageSize向上取整(t *testing.T) {
	cases := map[int]int{
		1:                   1,
		DefaultPageSize:     1,
		DefaultPageSize + 1: 2,
		DefaultPageSize * 2: 2,
		5195:                260, // 工单 #43 实测样本量：5195 条 / 20 条一页 = 260 页
	}
	for total, want := range cases {
		if got := TotalPages(total, DefaultPageSize); got != want {
			t.Errorf("TotalPages(%d) = %d，想要 %d", total, got, want)
		}
	}
}

func TestTotalPages_按选择的每页条数计算(t *testing.T) {
	if got := TotalPages(101, 50); got != 3 {
		t.Errorf("TotalPages(101, 50) = %d，想要 3", got)
	}
	if got := TotalPages(101, 100); got != 2 {
		t.Errorf("TotalPages(101, 100) = %d，想要 2", got)
	}
}

func TestClampPage_越界兜到最后一页(t *testing.T) {
	if got := ClampPage(9999, 260); got != 260 {
		t.Errorf("ClampPage(9999, 260) = %d，想要 260（兜到最后一页，不是空表格）", got)
	}
}

func TestClampPage_小于1当作第1页(t *testing.T) {
	for _, p := range []int{0, -1, -100} {
		if got := ClampPage(p, 260); got != 1 {
			t.Errorf("ClampPage(%d, 260) = %d，想要 1", p, got)
		}
	}
}

func TestClampPage_合法范围原样返回(t *testing.T) {
	if got := ClampPage(3, 260); got != 3 {
		t.Errorf("ClampPage(3, 260) = %d，想要 3", got)
	}
}

func TestNewPaginationView_首页禁用上一页和首页(t *testing.T) {
	v := NewPaginationView(1, 20, 260, "")
	if v.HasPrev {
		t.Error("第 1 页时 HasPrev 应为 false（首页/上一页要禁用）")
	}
	if !v.HasNext {
		t.Error("第 1 页且总页数 > 1 时 HasNext 应为 true")
	}
}

func TestNewPaginationView_末页禁用下一页和末页(t *testing.T) {
	v := NewPaginationView(260, 20, 260, "")
	if v.HasPrev != true {
		t.Error("最后一页时 HasPrev 应为 true（前面还有页）")
	}
	if v.HasNext {
		t.Error("最后一页时 HasNext 应为 false（下一页/末页要禁用）")
	}
}

func TestNewPaginationView_总数为0时首尾都禁用(t *testing.T) {
	v := NewPaginationView(1, 20, 1, "")
	if v.HasPrev || v.HasNext {
		t.Errorf("只有 1 页时前后都应禁用，HasPrev=%v HasNext=%v", v.HasPrev, v.HasNext)
	}
}

func TestNewPaginationView_URL带上筛选条件(t *testing.T) {
	v := NewPaginationView(2, 50, 260, "status=no_link&page_size=50")
	if v.PrevURL != "?page_size=50&status=no_link&page=1" {
		t.Errorf("PrevURL = %q，想要保留筛选和 page_size", v.PrevURL)
	}
	if v.NextURL != "?page_size=50&status=no_link&page=3" {
		t.Errorf("NextURL = %q，想要保留筛选和 page_size", v.NextURL)
	}
	if v.FirstURL != "?page_size=50&status=no_link&page=1" {
		t.Errorf("FirstURL = %q，想要保留筛选和 page_size", v.FirstURL)
	}
	if v.LastURL != "?page_size=50&status=no_link&page=260" {
		t.Errorf("LastURL = %q，想要保留筛选和 page_size", v.LastURL)
	}
	if v.PageSize != 50 || !v.PageSizeOptions[1].Selected {
		t.Fatalf("当前页容量选择不正确: %+v", v)
	}
	if len(v.FilterFields) != 1 || v.FilterFields[0].Name != "status" {
		t.Fatalf("切换容量应只保留筛选且不保留 page/page_size: %+v", v.FilterFields)
	}
}

func TestPaginationURL_无筛选条件时只有page(t *testing.T) {
	if got := PaginationURL("", 3); got != "?page=3" {
		t.Errorf("PaginationURL(\"\", 3) = %q，想要 ?page=3", got)
	}
}