From 9cd5c89d08e7538a9f49a858c469348e4e4f285b Mon Sep 17 00:00:00 2001
From: Aditya Thebe <thebeaditya@gmail.com>
Date: Wed, 5 Jul 2023 11:30:33 +0545
Subject: [PATCH] calculate the window duration

---
 pkg/api.go                  |  4 ++++
 pkg/api/api.go              | 33 +++++++++++++++++++++++++++++++++
 pkg/cache/cache.go          |  1 +
 pkg/cache/postgres_query.go | 11 ++---------
 4 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/pkg/api.go b/pkg/api.go
index 2d61d7b7d..914f2f03c 100644
--- a/pkg/api.go
+++ b/pkg/api.go
@@ -91,6 +91,10 @@ type Uptime struct {
 	LastFail *time.Time `json:"last_fail,omitempty"`
 }
 
+func (u Uptime) Total() int {
+	return u.Passed + u.Failed
+}
+
 func (u Uptime) String() string {
 	if u.Passed == 0 && u.Failed == 0 {
 		return ""
diff --git a/pkg/api/api.go b/pkg/api/api.go
index 52cfccd17..8c1eb05d5 100644
--- a/pkg/api/api.go
+++ b/pkg/api/api.go
@@ -1,6 +1,7 @@
 package api
 
 import (
+	"math"
 	"net/http"
 	"time"
 
@@ -8,10 +9,14 @@ import (
 	"github.com/flanksource/canary-checker/pkg/runner"
 	"github.com/flanksource/duty/models"
 	"github.com/labstack/echo/v4"
+	"github.com/pkg/errors"
 
 	"github.com/flanksource/canary-checker/pkg"
 )
 
+// The maximum data points returned by the graph API
+const maxCheckStatuses = 100
+
 var DefaultWindow = "1h"
 
 type Response struct {
@@ -20,10 +25,13 @@ type Response struct {
 	Checks        pkg.Checks    `json:"checks"`
 	ChecksSummary models.Checks `json:"checks_summary,omitempty"`
 }
+
 type DetailResponse struct {
 	Duration   int              `json:"duration,omitempty"`
 	RunnerName string           `json:"runnerName"`
 	Status     []pkg.Timeseries `json:"status"`
+	Latency    pkg.Latency      `json:"latency"`
+	Uptime     pkg.Uptime       `json:"uptime"`
 }
 
 func About(c echo.Context) error {
@@ -41,6 +49,28 @@ func CheckDetails(c echo.Context) error {
 	}
 
 	start := time.Now()
+
+	summary, err := cache.PostgresCache.Query(*q)
+	if err != nil {
+		return errorResonse(c, err, http.StatusInternalServerError)
+	}
+	checkSummary := summary[0]
+
+	totalChecks := checkSummary.Uptime.Total()
+	if totalChecks <= maxCheckStatuses {
+		q.WindowDuration = time.Second // TODO: Maybe do not window at all
+	} else {
+		startTime := q.GetStartTime()
+		if startTime == nil {
+			return errorResonse(c, errors.New("start time must be a duration or RFC3339 timestamp"), http.StatusBadRequest)
+		}
+
+		startDuration := time.Since(*startTime)
+
+		windowsCount := int(math.Ceil(float64(totalChecks) / float64(maxCheckStatuses)))
+		q.WindowDuration = startDuration / time.Duration(windowsCount)
+	}
+
 	results, err := cache.PostgresCache.QueryStatus(c.Request().Context(), *q)
 	if err != nil {
 		return errorResonse(c, err, http.StatusInternalServerError)
@@ -50,7 +80,10 @@ func CheckDetails(c echo.Context) error {
 		RunnerName: runner.RunnerName,
 		Status:     results,
 		Duration:   int(time.Since(start).Milliseconds()),
+		Latency:    checkSummary.Latency,
+		Uptime:     checkSummary.Uptime,
 	}
+
 	return c.JSON(http.StatusOK, apiResponse)
 }
 
diff --git a/pkg/cache/cache.go b/pkg/cache/cache.go
index 1e360090e..08ac56f84 100644
--- a/pkg/cache/cache.go
+++ b/pkg/cache/cache.go
@@ -28,6 +28,7 @@ type QueryParams struct {
 	StatusCount     int
 	Labels          map[string]string
 	Trace           bool
+	WindowDuration  time.Duration
 }
 
 func (q QueryParams) Validate() error {
diff --git a/pkg/cache/postgres_query.go b/pkg/cache/postgres_query.go
index 8a0e8c157..f62099b60 100644
--- a/pkg/cache/postgres_query.go
+++ b/pkg/cache/postgres_query.go
@@ -101,17 +101,10 @@ FROM
 GROUP BY time
 `
 
-	dur, err := duration.ParseDuration(q.Start)
-	if err != nil {
-		return nil, err
-	}
-
-	start := time.Now().Add(-time.Duration(dur)).Format(time.RFC3339)
+	start := q.GetStartTime().Format(time.RFC3339)
 	end := time.Now().Format(time.RFC3339) // TODO: connect with the new date range picker
 
-	// TODO: Find the perfect window duration
-	windowDurationSeconds := (time.Minute * 15).Seconds()
-	rows, err := db.Query(ctx, query, windowDurationSeconds/2, windowDurationSeconds, start, end, q.Check)
+	rows, err := db.Query(ctx, query, q.WindowDuration.Seconds()/2, q.WindowDuration.Seconds(), start, end, q.Check)
 	if err != nil {
 		return nil, err
 	}