feat: 增强日月食搜索、沙罗周期与内行星凌日

- 使用压缩表加速查找日月食沙罗周期信息 - 优化日月食搜索跳步，减少非食季朔望月扫描 - 新增本地日全食、日环食、月全食搜索接口，返回 ok 区分未找到结果 - 新增水星、金星地心凌日查询及测试
2026-05-03 19:00:08 +08:00
parent 3ffdbe0034
commit bec7b8a0d8
20 changed files with 1987 additions and 408 deletions
@@ -0,0 +1,73 @@
+package mercury
+
+import (
+	"time"
+
+	"b612.me/astro/basic"
+)
+
+// TransitInfo 地心水星凌日信息 / geocentric Mercury transit information.
+//
+// Start、Greatest、End、InternalStart、InternalEnd 都保持调用者输入的时区。
+// 内切接触不存在时 InternalStart / InternalEnd 为零值。
+// Start, Greatest, End, InternalStart, and InternalEnd preserve the caller's timezone.
+// InternalStart and InternalEnd are zero values when internal contacts do not exist.
+type TransitInfo struct {
+	Valid bool
+
+	Start         time.Time
+	InternalStart time.Time
+	Greatest      time.Time
+	InternalEnd   time.Time
+	End           time.Time
+
+	Duration         time.Duration
+	InternalDuration time.Duration
+
+	MinimumSeparationArcsec  float64
+	SunSemidiameterArcsec    float64
+	PlanetSemidiameterArcsec float64
+
+	HasInternal bool
+}
+
+// NextTransit 下一次地心水星凌日 / next geocentric Mercury transit.
+func NextTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.NextMercuryTransit(basic.Date2JDE(date.UTC())), date.Location())
+}
+
+// LastTransit 上一次地心水星凌日 / previous geocentric Mercury transit.
+func LastTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.LastMercuryTransit(basic.Date2JDE(date.UTC())), date.Location())
+}
+
+// ClosestTransit 最近一次地心水星凌日 / closest geocentric Mercury transit.
+func ClosestTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.ClosestMercuryTransit(basic.Date2JDE(date.UTC())), date.Location())
+}
+
+func transitInfoFromBasic(result basic.PlanetTransitResult, loc *time.Location) TransitInfo {
+	if !result.Valid {
+		return TransitInfo{}
+	}
+	start := basic.JDE2DateByZone(result.ExternalIngress, loc, false)
+	greatest := basic.JDE2DateByZone(result.Greatest, loc, false)
+	end := basic.JDE2DateByZone(result.ExternalEgress, loc, false)
+	info := TransitInfo{
+		Valid:                    true,
+		Start:                    start,
+		Greatest:                 greatest,
+		End:                      end,
+		Duration:                 end.Sub(start),
+		MinimumSeparationArcsec:  result.MinimumSeparationArcsec,
+		SunSemidiameterArcsec:    result.SunSemidiameterArcsec,
+		PlanetSemidiameterArcsec: result.PlanetSemidiameterArcsec,
+		HasInternal:              result.HasInternal,
+	}
+	if result.HasInternal {
+		info.InternalStart = basic.JDE2DateByZone(result.InternalIngress, loc, false)
+		info.InternalEnd = basic.JDE2DateByZone(result.InternalEgress, loc, false)
+		info.InternalDuration = info.InternalEnd.Sub(info.InternalStart)
+	}
+	return info
+}