feat(dashboard): add traffic flow sankey chart (#5465)

* feat(dashboard): add traffic flow sankey chart

Add dashboard flow APIs and a Sankey-based flow view with user, optional API key, model, and channel layers.\n\nReuse the dashboard VChart palette, add precise link/node tooltips and interactions, and cover filtering, layer ordering, color stability, and error states with tests.

* feat: build flow chart from quota data

---------

Co-authored-by: CaIon <i@caion.me>

controller/usedata.go

@@ -10,6 +10,24 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+func parseFlowQuotaTimeRange(c *gin.Context) (int64, int64, bool) {
+	startTimestamp, err := strconv.ParseInt(c.Query("start_timestamp"), 10, 64)
+	if err != nil || startTimestamp <= 0 {
+		common.ApiErrorMsg(c, "invalid start_timestamp")
+		return 0, 0, false
+	}
+	endTimestamp, err := strconv.ParseInt(c.Query("end_timestamp"), 10, 64)
+	if err != nil || endTimestamp <= 0 {
+		common.ApiErrorMsg(c, "invalid end_timestamp")
+		return 0, 0, false
+	}
+	if endTimestamp < startTimestamp {
+		common.ApiErrorMsg(c, "invalid time range")
+		return 0, 0, false
+	}
+	return startTimestamp, endTimestamp, true
+}
+
 func GetAllQuotaDates(c *gin.Context) {
 	startTimestamp, _ := strconv.ParseInt(c.Query("start_timestamp"), 10, 64)
 	endTimestamp, _ := strconv.ParseInt(c.Query("end_timestamp"), 10, 64)
@@ -66,3 +84,48 @@ func GetUserQuotaDates(c *gin.Context) {
 	})
 	return
 }
+
+func GetAllFlowQuotaDates(c *gin.Context) {
+	startTimestamp, endTimestamp, ok := parseFlowQuotaTimeRange(c)
+	if !ok {
+		return
+	}
+	username := c.Query("username")
+	dates, err := model.GetFlowQuotaData(startTimestamp, endTimestamp, username, 0, c.GetInt("role"))
+	if err != nil {
+		common.ApiError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"message": "",
+		"data":    dates,
+	})
+	return
+}
+
+func GetUserFlowQuotaDates(c *gin.Context) {
+	userId := c.GetInt("id")
+	startTimestamp, endTimestamp, ok := parseFlowQuotaTimeRange(c)
+	if !ok {
+		return
+	}
+	if endTimestamp-startTimestamp > 2592000 {
+		c.JSON(http.StatusOK, gin.H{
+			"success": false,
+			"message": "时间跨度不能超过 1 个月",
+		})
+		return
+	}
+	dates, err := model.GetFlowQuotaData(startTimestamp, endTimestamp, "", userId, common.RoleCommonUser)
+	if err != nil {
+		common.ApiError(c, err)
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"success": true,
+		"message": "",
+		"data":    dates,
+	})
+	return
+}