Merge pull request #4 from tstromberg/main

add projection to callout, improve log msgs

Author: tstromberg

cmd/server/main.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"os"
 	"os/signal"
+	"path/filepath"
 	"runtime"
 	"syscall"
 	"time"
@@ -36,10 +37,19 @@ func main() {
 	// Create root context
 	ctx := context.Background()
 
-	// Set up logging
+	// Set up logging with short source paths
 	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
 		AddSource: true,
 		Level:     slog.LevelInfo,
+		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+			// Shorten source file paths to show only filename:line
+			if a.Key == slog.SourceKey {
+				if src, ok := a.Value.Any().(*slog.Source); ok {
+					src.File = filepath.Base(src.File)
+				}
+			}
+			return a
+		},
 	}))
 	slog.SetDefault(logger)
 

internal/server/server.go

@@ -196,8 +196,11 @@ func New() *Server {
 		logger.InfoContext(ctx, "No fallback token available - requests must provide Authorization header")
 	}
 
-	// Start cache cleanup goroutine.
-	go server.cleanupCachesPeriodically()
+	// Note: We don't clear caches periodically because:
+	// - PR data is immutable (closed PRs don't change)
+	// - Memory usage is bounded by request patterns
+	// - Cloud Run instances are ephemeral and restart frequently anyway
+	// If needed in the future, implement LRU eviction with size limits instead of time-based clearing
 
 	return server
 }
@@ -304,36 +307,6 @@ func (s *Server) limiter(ctx context.Context, ip string) *rate.Limiter {
 	return limiter
 }
 
-// cleanupCachesPeriodically clears all caches every 30 minutes to prevent unbounded growth.
-// Cloud Run instances are ephemeral, so no complex TTL logic is needed.
-func (s *Server) cleanupCachesPeriodically() {
-	ticker := time.NewTicker(30 * time.Minute)
-	defer ticker.Stop()
-
-	for range ticker.C {
-		s.clearCache(&s.prQueryCacheMu, s.prQueryCache, "pr_query")
-		s.clearCache(&s.prDataCacheMu, s.prDataCache, "pr_data")
-	}
-}
-
-// clearCache removes all entries from a cache.
-func (s *Server) clearCache(mu *sync.RWMutex, cache map[string]*cacheEntry, name string) {
-	mu.Lock()
-	defer mu.Unlock()
-
-	count := len(cache)
-	// Clear map by creating new map
-	for key := range cache {
-		delete(cache, key)
-	}
-
-	if count > 0 {
-		s.logger.Info("Cleared cache",
-			"cache", name,
-			"cleared", count)
-	}
-}
-
 // cachedPRQuery retrieves cached PR query results.
 func (s *Server) cachedPRQuery(key string) ([]github.PRSummary, bool) {
 	s.prQueryCacheMu.RLock()

internal/server/static/index.html

@@ -1412,15 +1412,26 @@ <h3>Why calculate PR costs?</h3>
             return html;
         }
 
-        function formatR2RCallout(avgOpenHours) {
+        function formatR2RCallout(avgOpenHours, r2rSavings) {
             // Only show if average merge velocity is > 1 hour
             if (avgOpenHours <= 1) {
                 return '';
             }
 
+            // Format savings with appropriate precision
+            let savingsText;
+            if (r2rSavings >= 1000000) {
+                savingsText = '$' + (r2rSavings / 1000000).toFixed(1) + 'M';
+            } else if (r2rSavings >= 1000) {
+                savingsText = '$' + (r2rSavings / 1000).toFixed(0) + 'K';
+            } else {
+                savingsText = '$' + r2rSavings.toFixed(0);
+            }
+
             let html = '<div style="margin: 24px 0; padding: 12px 20px; background: linear-gradient(135deg, #e6f9f0 0%, #ffffff 100%); border-left: 3px solid #00c853; border-radius: 8px; font-size: 14px; color: #1d1d1f; line-height: 1.6;">';
-            html += '✓ <a href="https://codegroove.dev/" target="_blank" rel="noopener" style="color: #00c853; font-weight: 600; text-decoration: none;">Ready-to-Review</a>: <strong>$4/mo</strong> to cut merge latency to <strong>≤40 min</strong><br>';
-            html += 'Stop losing engineering hours to code review lag. Free for OSS projects. Let\'s chat: <a href="mailto:[email protected]" style="color: #00c853; text-decoration: none;">[email protected]</a>';
+            html += '✓ Based on this calculation, <a href="https://codegroove.dev/" target="_blank" rel="noopener" style="color: #00c853; font-weight: 600; text-decoration: none;">Ready-to-Review</a> would save you <strong>~' + savingsText + '/yr</strong> by cutting average merge time to ≤40 min. ';
+            html += 'Stop losing engineering hours to code review lag. Free for OSS projects. ';
+            html += 'Let\'s chat: <a href="mailto:[email protected]" style="color: #00c853; text-decoration: none;">[email protected]</a>';
             html += '</div>';
             return html;
         }
@@ -2025,7 +2036,8 @@ <h3>Why calculate PR costs?</h3>
 
                                         // Add R2R callout if enabled and merge velocity > 1 hour
                                         if (data.r2r_callout) {
-                                            html += formatR2RCallout(avgPRDurationHours);
+                                            const r2rSavings = e.r2r_savings || 0;
+                                            html += formatR2RCallout(avgPRDurationHours, r2rSavings);
                                         }
 
                                         // Calculate average PR efficiency

pkg/cost/extrapolate.go

@@ -82,6 +82,10 @@ type ExtrapolatedBreakdown struct {
 	// Grand totals
 	TotalCost  float64 `json:"total_cost"`
 	TotalHours float64 `json:"total_hours"`
+
+	// R2R cost savings calculation
+	UniqueNonBotUsers int     `json:"unique_non_bot_users"` // Count of unique non-bot users (authors + participants)
+	R2RSavings        float64 `json:"r2r_savings"`          // Annual savings if R2R cuts PR time to 40 minutes
 }
 
 // ExtrapolateFromSamples calculates extrapolated cost estimates from a sample
@@ -113,6 +117,8 @@ func ExtrapolateFromSamples(breakdowns []Breakdown, totalPRs, totalAuthors, actu
 
 	// Track unique PR authors (excluding bots)
 	uniqueAuthors := make(map[string]bool)
+	// Track unique non-bot users (authors + participants)
+	uniqueNonBotUsers := make(map[string]bool)
 
 	// Track bot vs human PR metrics
 	var humanPRCount, botPRCount int
@@ -140,6 +146,7 @@ func ExtrapolateFromSamples(breakdowns []Breakdown, totalPRs, totalAuthors, actu
 		// Track unique PR authors only (excluding bots)
 		if !breakdown.AuthorBot {
 			uniqueAuthors[breakdown.PRAuthor] = true
+			uniqueNonBotUsers[breakdown.PRAuthor] = true
 			humanPRCount++
 			sumHumanPRDuration += breakdown.PRDuration
 		} else {
@@ -150,6 +157,12 @@ func ExtrapolateFromSamples(breakdowns []Breakdown, totalPRs, totalAuthors, actu
 			sumBotModifiedLines += breakdown.Author.ModifiedLines
 		}
 
+		// Track unique participants (excluding bots)
+		for _, p := range breakdown.Participants {
+			// Participants from the Breakdown struct are already filtered to exclude bots
+			uniqueNonBotUsers[p.Actor] = true
+		}
+
 		// Accumulate PR duration (all PRs)
 		sumPRDuration += breakdown.PRDuration
 
@@ -322,6 +335,62 @@ func ExtrapolateFromSamples(breakdowns []Breakdown, totalPRs, totalAuthors, actu
 	extHumanPRs := int(float64(humanPRCount) / samples * multiplier)
 	extBotPRs := int(float64(botPRCount) / samples * multiplier)
 
+	// Calculate R2R savings
+	// Formula: baseline annual waste - (re-modeled waste with 40min PRs) - (R2R subscription cost)
+	// Baseline annual waste: preventable cost extrapolated to 52 weeks
+	uniqueUserCount := len(uniqueNonBotUsers)
+	baselineAnnualWaste := (extCodeChurnCost + extDeliveryDelayCost + extAutomatedUpdatesCost + extPRTrackingCost) * (52.0 / (float64(daysInPeriod) / 7.0))
+
+	// Re-model with 40-minute PR merge times
+	// We need to recalculate delivery delay and future costs assuming all PRs take 40 minutes (2/3 hour)
+	const targetMergeTimeHours = 40.0 / 60.0 // 40 minutes in hours
+
+	// Recalculate delivery delay cost with 40-minute PRs
+	// Delivery delay formula: hourlyRate × deliveryDelayFactor × PR duration
+	var remodelDeliveryDelayCost float64
+	for range breakdowns {
+		remodelDeliveryDelayCost += hourlyRate * cfg.DeliveryDelayFactor * targetMergeTimeHours
+	}
+	extRemodelDeliveryDelayCost := remodelDeliveryDelayCost / samples * multiplier
+
+	// Recalculate code churn with 40-minute PRs
+	// Code churn is proportional to PR duration (rework percentage increases with time)
+	// For 40 minutes, rework percentage would be minimal (< 1 day, so ~0%)
+	extRemodelCodeChurnCost := 0.0 // 40 minutes is too short for meaningful code churn
+
+	// Recalculate automated updates cost
+	// Automated updates are calculated based on PR duration
+	// With 40-minute PRs, no bot updates would be needed (happens after 1 day)
+	extRemodelAutomatedUpdatesCost := 0.0 // 40 minutes is too short for automated updates
+
+	// Recalculate PR tracking cost
+	// With faster merge times, we'd have fewer open PRs at any given time
+	// Estimate: if current avg is X hours, and we reduce to 40 min, open PRs would be (40min / X hours) of current
+	var extRemodelPRTrackingCost float64
+	var currentAvgOpenTime float64
+	if successfulSamples > 0 {
+		currentAvgOpenTime = sumPRDuration / samples
+	}
+	if currentAvgOpenTime > 0 {
+		openPRReductionRatio := targetMergeTimeHours / currentAvgOpenTime
+		extRemodelPRTrackingCost = extPRTrackingCost * openPRReductionRatio
+	} else {
+		extRemodelPRTrackingCost = 0.0
+	}
+
+	// Calculate re-modeled annual waste
+	remodelPreventablePerPeriod := extRemodelDeliveryDelayCost + extRemodelCodeChurnCost + extRemodelAutomatedUpdatesCost + extRemodelPRTrackingCost
+	remodelAnnualWaste := remodelPreventablePerPeriod * (52.0 / (float64(daysInPeriod) / 7.0))
+
+	// Subtract R2R subscription cost: $4/mo * 12 months * unique user count
+	r2rAnnualCost := 4.0 * 12.0 * float64(uniqueUserCount)
+
+	// Calculate savings
+	r2rSavings := baselineAnnualWaste - remodelAnnualWaste - r2rAnnualCost
+	if r2rSavings < 0 {
+		r2rSavings = 0 // Don't show negative savings
+	}
+
 	return ExtrapolatedBreakdown{
 		TotalPRs:                   totalPRs,
 		HumanPRs:                   extHumanPRs,
@@ -390,5 +459,8 @@ func ExtrapolateFromSamples(breakdowns []Breakdown, totalPRs, totalAuthors, actu
 
 		TotalCost:  extTotalCost,
 		TotalHours: extTotalHours,
+
+		UniqueNonBotUsers: uniqueUserCount,
+		R2RSavings:        r2rSavings,
 	}
 }