// Copyright 2026 tamakyi. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package insights

import (
	"net/http/httptest"
	"testing"
	"time"
)

func TestPct(t *testing.T) {
	cases := []struct {
		n, max int64
		want   float64
	}{
		{0, 0, 0},     // 除零：不能算出 NaN 塞进 CSS
		{5, 0, 0},     // 同上
		{10, 10, 100}, // 满格
		{1, 3, 33.3},  // 四舍五入到一位小数
		{2, 3, 66.7},
		{1, 1000, 0.1},
	}
	for _, c := range cases {
		if got := pct(c.n, c.max); got != c.want {
			t.Errorf("pct(%d, %d) = %v, want %v", c.n, c.max, got, c.want)
		}
	}
}

func TestFormatInt(t *testing.T) {
	cases := map[int64]string{
		0:       "0",
		7:       "7",
		999:     "999",
		1000:    "1,000",
		12345:   "12,345",
		1234567: "1,234,567",
		-1234:   "-1,234",
	}
	for in, want := range cases {
		if got := formatInt(in); got != want {
			t.Errorf("formatInt(%d) = %q, want %q", in, got, want)
		}
	}
}

// 窗口切分是「今日 / 近 7 天 / 近 30 天」与「本周 vs 上周」的唯一实现，
// 算错不会报错、只会安静地显示错误的数字，所以单独测。
func TestAggregateWindows(t *testing.T) {
	loc := time.Local
	today := time.Date(2026, 10, 29, 0, 0, 0, 0, loc)
	weekFrom := today.AddDate(0, 0, -(WeekDays - 1))     // 10-23
	prevFrom := today.AddDate(0, 0, -(2*WeekDays - 1))   // 10-16
	prevTo := today.AddDate(0, 0, -WeekDays)             // 10-22

	p := &Page{}
	for i := 0; i < TrendDays; i++ {
		d := today.AddDate(0, 0, -(TrendDays - 1) + i)
		p.Days = append(p.Days, Day{Key: d.Format("2006-01-02")})
	}
	set := func(offsetDays int, pv, uv, q, a int64) {
		key := today.AddDate(0, 0, offsetDays).Format("2006-01-02")
		for i := range p.Days {
			if p.Days[i].Key == key {
				p.Days[i].PV, p.Days[i].UV = pv, uv
				p.Days[i].Questions, p.Days[i].Answers = q, a
				return
			}
		}
		t.Fatalf("日期 %s 不在骨架里", key)
	}

	set(0, 5, 3, 1, 0)     // 今天：本周 + 今日
	set(-1, 2, 2, 0, 1)    // 昨天：本周
	set(-6, 4, 1, 2, 0)    // 10-23：本周起点
	set(-7, 9, 6, 0, 0)    // 10-22：上周末日
	set(-13, 6, 5, 0, 0)   // 10-16：上周起点

	p.aggregateWindows(today, weekFrom, prevFrom, prevTo)

	// 本周 = 5+2+4；上周 = 9+6
	if p.Week.PV != 11 {
		t.Errorf("Week.PV = %d, want 11", p.Week.PV)
	}
	if p.Week.PrevPV != 15 {
		t.Errorf("Week.PrevPV = %d, want 15", p.Week.PrevPV)
	}
	if !p.Week.HasDelta {
		t.Fatal("上周有数据时 HasDelta 应为 true")
	}
	if got, want := p.Week.Delta, float64(11-15)/15*100; got != want {
		t.Errorf("Week.Delta = %v, want %v", got, want)
	}
	if p.Today.PV != 5 || p.Today.UV != 3 {
		t.Errorf("Today = %+v, want PV 5 UV 3", p.Today)
	}
	if p.Month.PV != 26 {
		t.Errorf("Month.PV = %d, want 26（全部 5 天之和）", p.Month.PV)
	}
	if p.BestDay == nil || p.BestDay.PV != 9 {
		t.Errorf("BestDay = %+v, want 10-22 的 9 次", p.BestDay)
	}
}

// 上周一次访问都没有时不能给出「涨了 100%」这类结论。
func TestAggregateWindowsNoPrev(t *testing.T) {
	loc := time.Local
	today := time.Date(2026, 10, 29, 0, 0, 0, 0, loc)

	p := &Page{}
	for i := 0; i < TrendDays; i++ {
		d := today.AddDate(0, 0, -(TrendDays - 1) + i)
		p.Days = append(p.Days, Day{Key: d.Format("2006-01-02")})
	}
	p.Days[len(p.Days)-1].PV = 3

	p.aggregateWindows(today, today.AddDate(0, 0, -6), today.AddDate(0, 0, -13), today.AddDate(0, 0, -7))

	if p.Week.HasDelta {
		t.Error("上周 PV 为 0 时 HasDelta 应为 false")
	}
}

func TestSameDay(t *testing.T) {
	a := time.Date(2026, 10, 29, 0, 0, 0, 0, time.Local)
	b := time.Date(2026, 10, 29, 23, 59, 59, 0, time.Local)
	c := time.Date(2026, 10, 30, 0, 0, 1, 0, time.Local)
	if !sameDay(a, b) {
		t.Error("同一天的任意时刻应判为同一天")
	}
	if sameDay(a, c) {
		t.Error("跨天应判为不同天")
	}
}

// 访客标识必须「同日可去重、跨日不可关联」：这是面板隐私承诺的技术基础。
func TestVisitorID(t *testing.T) {
	r := NewRecorder(nil, "test-secret") // 不启动写入，仅用哈希方法
	defer r.Close()

	day1 := time.Date(2026, 10, 29, 8, 0, 0, 0, time.Local)
	day1Later := time.Date(2026, 10, 29, 22, 0, 0, 0, time.Local)
	day2 := time.Date(2026, 10, 30, 8, 0, 0, 0, time.Local)

	a := r.visitorID("1.2.3.4", day1)
	if a != r.visitorID("1.2.3.4", day1Later) {
		t.Error("同一天同一 IP 必须得到相同标识，否则 UV 去重失效")
	}
	if a == r.visitorID("1.2.3.4", day2) {
		t.Error("跨天必须得到不同标识，否则可长期追踪同一访客")
	}
	if a == r.visitorID("5.6.7.8", day1) {
		t.Error("不同 IP 同一天必须不同")
	}
	if len(a) != 32 {
		t.Errorf("标识长度 = %d, want 32", len(a))
	}
	// 换密钥后整体不可关联（运维轮换 xsrf_key 时历史哈希不会被重新对上）
	other := NewRecorder(nil, "another-secret")
	defer other.Close()
	if a == other.visitorID("1.2.3.4", day1) {
		t.Error("不同密钥应给出不同标识")
	}
}

func TestIsCrawler(t *testing.T) {
	cases := map[string]bool{
		"":                                                     true, // 空 UA 基本是脚本
		"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120.0 Safari/537.36": false,
		"Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)":                true,
		"curl/8.4.0":                    true,
		"python-requests/2.31.0":        true,
		"Mozilla/5.0 (compatible; bingbot/2.0)": true,
		"facebookexternalhit/1.1":       true,
		"Mozilla/5.0 (iPhone; CPU iPhone OS 17_0) AppleWebKit/605.1.15 Version/17.0 Mobile Safari/604.1": false,
	}
	for ua, want := range cases {
		if got := isCrawler(ua); got != want {
			t.Errorf("isCrawler(%q) = %v, want %v", ua, got, want)
		}
	}
}

func TestIsPrefetch(t *testing.T) {
	cases := []struct {
		name   string
		header string
		value  string
		want   bool
	}{
		{"普通请求", "", "", false},
		{"Chrome 预取", "Sec-Purpose", "prefetch", true},
		{"Chrome 预渲染", "Sec-Purpose", "prefetch;prerender", true},
		{"Safari 预览", "X-Purpose", "preview", true},
		{"Firefox 预取", "X-Moz", "prefetch", true},
	}
	for _, c := range cases {
		req := httptest.NewRequest("GET", "/_/someone", nil)
		if c.header != "" {
			req.Header.Set(c.header, c.value)
		}
		if got := isPrefetch(req); got != c.want {
			t.Errorf("%s: isPrefetch = %v, want %v", c.name, got, c.want)
		}
	}
}