feat(server-go): 和风天气接入与高发病天气预警规则（#12）

server-go/internal/handler/weather.go

@@ -0,0 +1,52 @@
+package handler
+
+import (
+	"net/http"
+	"strconv"
+
+	"silk-server-go/internal/middleware"
+	"silk-server-go/internal/model"
+	"silk-server-go/internal/service"
+
+	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
+)
+
+// RegisterWeatherRoutes 注册天气与天气预警路由
+func RegisterWeatherRoutes(rg *gin.RouterGroup, db *gorm.DB, weather *service.WeatherService) {
+	read := middleware.RequirePermission(db, "weather:read")
+	rg.GET("/weather/now", read, weatherNow(weather))
+	rg.GET("/weather/alerts", read, listWeatherAlerts(db))
+}
+
+// weatherNow 实时天气 + 规则评估（实时触发；stage 可选：late5 等）
+func weatherNow(weather *service.WeatherService) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		now, err := weather.FetchNow(c.Request.Context())
+		if err != nil {
+			c.JSON(http.StatusBadGateway, gin.H{"error": err.Error()})
+			return
+		}
+		daily, err := weather.FetchDaily(c.Request.Context())
+		if err != nil {
+			c.JSON(http.StatusBadGateway, gin.H{"error": err.Error()})
+			return
+		}
+		stage := c.Query("stage")
+		alerts := service.EvaluateWeatherRules(*now, daily, stage)
+		c.JSON(http.StatusOK, gin.H{"weather": now, "alerts": alerts})
+	}
+}
+
+// listWeatherAlerts 最近天气预警
+func listWeatherAlerts(db *gorm.DB) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		limit := 20
+		if l, err := strconv.Atoi(c.Query("limit")); err == nil && l > 0 && l <= 100 {
+			limit = l
+		}
+		var list []model.WeatherAlert
+		db.Order("created_at DESC").Limit(limit).Find(&list)
+		c.JSON(http.StatusOK, list)
+	}
+}