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2026-10-18 19:44:38 +08:00
commit f047662129
64 changed files with 10454 additions and 0 deletions
@@ -0,0 +1,206 @@
+// Package domain 存放与存储无关的纯业务计算：日期、剩余时长、状态判定、追加换算。
+package domain
+
+import "time"
+
+const (
+	DateLayout  = "2006-01-02"
+	StampLayout = "2006-01-02 15:04:05"
+)
+
+// Today 返回本地时区当天零点。
+func Today() time.Time {
+	now := time.Now()
+	return time.Date(now.Year(), now.Month(), now.Day(), 0, 0, 0, 0, now.Location())
+}
+
+// ParseDate 解析 YYYY-MM-DD。
+func ParseDate(s string) (time.Time, error) {
+	return time.ParseInLocation(DateLayout, s, time.Local)
+}
+
+// ParseDateOr 解析失败时返回默认值。
+func ParseDateOr(s string, fallback time.Time) time.Time {
+	if t, err := ParseDate(s); err == nil {
+		return t
+	}
+	return fallback
+}
+
+// Date 格式化为 YYYY-MM-DD。
+func Date(t time.Time) string { return t.Format(DateLayout) }
+
+// DayDiff 返回 b-a 的自然日天数（不受夏令时影响）。
+func DayDiff(a, b time.Time) int {
+	ay, am, ad := a.Date()
+	by, bm, bd := b.Date()
+	ua := time.Date(ay, am, ad, 0, 0, 0, 0, time.UTC)
+	ub := time.Date(by, bm, bd, 0, 0, 0, 0, time.UTC)
+	return int(ub.Sub(ua).Hours() / 24.0)
+}
+
+// AddDays 加 n 天。
+func AddDays(t time.Time, n int) time.Time { return t.AddDate(0, 0, n) }
+
+// MonthStart 返回当月 1 日。
+func MonthStart(y int, m time.Month) time.Time {
+	return time.Date(y, m, 1, 0, 0, 0, 0, time.Local)
+}
+
+// MonthEnd 返回当月最后一天。
+func MonthEnd(y int, m time.Month) time.Time {
+	return time.Date(y, m, 1, 0, 0, 0, 0, time.Local).AddDate(0, 1, -1)
+}
+
+// WeekdayIndex 返回以周一为 0 的星期索引。
+func WeekdayIndex(t time.Time) int {
+	wd := int(t.Weekday())
+	if wd == 0 {
+		return 6
+	}
+	return wd - 1
+}
+
+// 订阅状态（存储值）
+const (
+	StatusActive = "active"
+	StatusPaused = "paused"
+	StatusClosed = "closed"
+)
+
+// 套餐类型
+const (
+	UnitDay   = "day"
+	UnitCount = "count"
+)
+
+// 派生展示状态
+const (
+	StateActive  = "active"  // 进行中
+	StatePending = "pending" // 未开始
+	StatePaused  = "paused"  // 暂停中
+	StateExpired = "expired" // 已到期
+	StateUsedUp  = "usedup"  // 次数用尽
+	StateClosed  = "closed"  // 已结束
+)
+
+// 到期预警等级
+const (
+	LevelOK      = "ok"
+	LevelWarn    = "warn"
+	LevelToday   = "today"
+	LevelExpired = "expired"
+	LevelNone    = "none" // 无期限（按次且未设有效期）
+)
+
+// Eval 是订阅的计算结果。
+type Eval struct {
+	State          string
+	DaysLeft       int // 距结束日的天数：0=今天到期，>0=未来，-1=无结束日
+	RemainingDays  int
+	RemainingCount int
+	Level          string
+}
+
+// EvalSub 计算订阅的展示状态与剩余量。
+//   - unit=day：剩余天数 = end - today + 1（含当天）
+//   - unit=count：剩余次数 = total - used；end 为可选有效期
+func EvalSub(unit, status, startDate, endDate string, total, used int, today time.Time, warnDays int) Eval {
+	e := Eval{Level: LevelNone, DaysLeft: -1}
+	if warnDays <= 0 {
+		warnDays = 3
+	}
+	start := ParseDateOr(startDate, today)
+	end, hasEnd := time.Time{}, false
+	if endDate != "" {
+		if t, err := ParseDate(endDate); err == nil {
+			end, hasEnd = t, true
+			e.DaysLeft = DayDiff(today, end)
+		}
+	}
+
+	if unit == UnitDay {
+		if hasEnd {
+			e.RemainingDays = e.DaysLeft + 1
+		}
+		if e.RemainingDays < 0 {
+			e.RemainingDays = 0
+		}
+	} else {
+		e.RemainingCount = total - used
+		if e.RemainingCount < 0 {
+			e.RemainingCount = 0
+		}
+	}
+
+	expired := false
+	if hasEnd && end.Before(today) {
+		expired = true
+	}
+	if unit == UnitCount && e.RemainingCount <= 0 {
+		expired = true
+	}
+
+	switch {
+	case status == StatusClosed:
+		e.State = StateClosed
+	case status == StatusPaused:
+		e.State = StatePaused
+	case expired:
+		if unit == UnitCount && e.RemainingCount <= 0 {
+			e.State = StateUsedUp
+		} else {
+			e.State = StateExpired
+		}
+	case start.After(today):
+		e.State = StatePending
+	default:
+		e.State = StateActive
+	}
+
+	// 预警等级只对「进行中 / 未开始」有意义
+	switch e.State {
+	case StateExpired:
+		e.Level = LevelExpired
+	case StateActive, StatePending:
+		switch {
+		case !hasEnd:
+			e.Level = LevelNone
+		case e.DaysLeft <= 0:
+			e.Level = LevelToday
+		case e.DaysLeft <= warnDays:
+			e.Level = LevelWarn
+		default:
+			e.Level = LevelOK
+		}
+	}
+	return e
+}
+
+// ExtendPlan 描述一次「按日追加」的换算结果。
+type ExtendPlan struct {
+	Base      time.Time // 计算起点
+	OldEnd    time.Time
+	NewEnd    time.Time
+	Days      int
+	SameDay   bool // 新结束日等于原结束日（未增加）
+	Backwards bool // 新结束日早于计算起点
+}
+
+// PlanExtend 根据原结束日、今天与新结束日，算出计算起点与追加天数。
+// 规则（PRD R4）：已到期从今天起算，未到期从原结束日次日起算。
+func PlanExtend(oldEnd, newEnd, today time.Time) ExtendPlan {
+	p := ExtendPlan{OldEnd: oldEnd, NewEnd: newEnd}
+	if !oldEnd.Before(today) {
+		p.Base = AddDays(oldEnd, 1)
+	} else {
+		p.Base = today
+	}
+	p.Days = DayDiff(p.Base, newEnd) + 1
+	p.SameDay = DayDiff(oldEnd, newEnd) == 0
+	p.Backwards = p.Days <= 0
+	if p.Days < 0 {
+		p.Days = 0
+	}
+	return p
+}
@@ -0,0 +1,152 @@
+package domain
+
+import (
+	"testing"
+	"time"
+)
+
+func d(y int, m time.Month, day int) time.Time {
+	return time.Date(y, m, day, 0, 0, 0, 0, time.Local)
+}
+
+func TestDayDiff(t *testing.T) {
+	cases := []struct {
+		a, b time.Time
+		want int
+	}{
+		{d(2026, 1, 1), d(2026, 1, 1), 0},
+		{d(2026, 1, 1), d(2026, 1, 31), 30},
+		{d(2026, 2, 28), d(2026, 3, 1), 1},
+		{d(2024, 2, 28), d(2024, 3, 1), 2}, // 闰年
+		{d(2026, 12, 31), d(2027, 1, 1), 1},
+		{d(2026, 1, 10), d(2026, 1, 1), -9},
+	}
+	for _, c := range cases {
+		if got := DayDiff(c.a, c.b); got != c.want {
+			t.Errorf("DayDiff(%s,%s)=%d want %d", Date(c.a), Date(c.b), got, c.want)
+		}
+	}
+}
+
+func TestEvalDay(t *testing.T) {
+	today := d(2026, 10, 18)
+	cases := []struct {
+		name      string
+		status    string
+		end       string
+		wantState string
+		wantLevel string
+		wantDays  int
+	}{
+		{"进行中", "active", "2026-11-16", StateActive, LevelOK, 30},
+		{"今天到期", "active", "2026-10-18", StateActive, LevelToday, 1},
+		{"3天内", "active", "2026-10-20", StateActive, LevelWarn, 3},
+		{"已到期", "active", "2026-10-17", StateExpired, LevelExpired, 0},
+		{"暂停中", "paused", "2026-11-16", StatePaused, LevelNone, 30},
+		{"已结束", "closed", "2026-11-16", StateClosed, LevelNone, 30},
+	}
+	for _, c := range cases {
+		e := EvalSub(UnitDay, c.status, "2026-10-01", c.end, 0, 0, today, 3)
+		if e.State != c.wantState {
+			t.Errorf("%s: state=%s want %s", c.name, e.State, c.wantState)
+		}
+		if e.Level != c.wantLevel {
+			t.Errorf("%s: level=%s want %s", c.name, e.Level, c.wantLevel)
+		}
+		if e.RemainingDays != c.wantDays {
+			t.Errorf("%s: remaining=%d want %d", c.name, e.RemainingDays, c.wantDays)
+		}
+	}
+}
+
+func TestEvalDayNotStarted(t *testing.T) {
+	today := d(2026, 10, 18)
+	e := EvalSub(UnitDay, "active", "2026-10-20", "2026-11-18", 0, 0, today, 3)
+	if e.State != StatePending {
+		t.Fatalf("state=%s want pending", e.State)
+	}
+	if e.RemainingDays != 32 {
+		t.Fatalf("remaining=%d want 32", e.RemainingDays)
+	}
+}
+
+func TestEvalCount(t *testing.T) {
+	today := d(2026, 10, 18)
+
+	// 有次数、有有效期，10 天后到期 → 正常
+	e := EvalSub(UnitCount, "active", "2026-10-01", "2026-10-28", 10, 4, today, 3)
+	if e.State != StateActive || e.Level != LevelOK || e.RemainingCount != 6 {
+		t.Fatalf("got state=%s level=%s remain=%d", e.State, e.Level, e.RemainingCount)
+	}
+
+	// 有效期就是今天 → 今天到期（而不是误判成 warn/ok）
+	e = EvalSub(UnitCount, "active", "2026-10-01", "2026-10-18", 10, 4, today, 3)
+	if e.Level != LevelToday {
+		t.Fatalf("level=%s want today", e.Level)
+	}
+
+	// 只有次数，没有有效期 → 无预警等级
+	e = EvalSub(UnitCount, "active", "2026-10-01", "", 10, 4, today, 3)
+	if e.Level != LevelNone || e.DaysLeft != -1 {
+		t.Fatalf("level=%s daysLeft=%d", e.Level, e.DaysLeft)
+	}
+
+	// 次数用尽
+	e = EvalSub(UnitCount, "active", "2026-10-01", "", 10, 10, today, 3)
+	if e.State != StateUsedUp {
+		t.Fatalf("state=%s want usedup", e.State)
+	}
+
+	// 次数还有，但有效期已过
+	e = EvalSub(UnitCount, "active", "2026-10-01", "2026-10-10", 10, 4, today, 3)
+	if e.State != StateExpired {
+		t.Fatalf("state=%s want expired", e.State)
+	}
+}
+
+func TestPlanExtend(t *testing.T) {
+	today := d(2026, 10, 18)
+
+	// 未到期：从原结束日次日顺延，追加天数 = 新旧结束日之差
+	oldEnd := d(2026, 11, 16)
+	newEnd := d(2026, 12, 2)
+	p := PlanExtend(oldEnd, newEnd, today)
+	if Date(p.Base) != "2026-11-17" {
+		t.Fatalf("base=%s", Date(p.Base))
+	}
+	if p.Days != 16 {
+		t.Fatalf("days=%d want 16", p.Days)
+	}
+
+	// 已到期：从今天起算
+	oldEnd = d(2026, 10, 5)
+	newEnd = d(2026, 11, 3)
+	p = PlanExtend(oldEnd, newEnd, today)
+	if Date(p.Base) != "2026-10-18" {
+		t.Fatalf("base=%s", Date(p.Base))
+	}
+	if p.Days != 17 {
+		t.Fatalf("days=%d want 17", p.Days)
+	}
+
+	// 选的日期早于计算起点 → 无效
+	p = PlanExtend(d(2026, 11, 16), d(2026, 11, 10), today)
+	if !p.Backwards || p.Days != 0 {
+		t.Fatalf("backwards=%v days=%d", p.Backwards, p.Days)
+	}
+}
+
+func TestMonthHelpers(t *testing.T) {
+	if got := Date(MonthEnd(2026, time.February)); got != "2026-02-28" {
+		t.Fatalf("MonthEnd=%s", got)
+	}
+	if got := Date(MonthEnd(2024, time.February)); got != "2024-02-29" {
+		t.Fatalf("MonthEnd=%s", got)
+	}
+	if got := WeekdayIndex(d(2026, 10, 18)); got != 6 { // 周日
+		t.Fatalf("WeekdayIndex=%d want 6", got)
+	}
+	if got := WeekdayIndex(d(2026, 10, 19)); got != 0 { // 周一
+		t.Fatalf("WeekdayIndex=%d want 0", got)
+	}
+}