feat: add percentages to custom event data (#130)

* feat(core): add events percentage to properties endpoint

* fix(dashboard): error page styles relying on mantine preset

* fix(core): return percentages with materialised table

* feat(dashboard): show percentage on home and expanded page

core/db/duckdb/properties.go

@@ -9,6 +9,11 @@ import (
 	"github.com/medama-io/medama/model"
 )
 
+const (
+	EventsCountStmt      = "COUNT(*) AS events"
+	EventsPercentageStmt = "ifnull(ROUND(COUNT(*) / (SELECT total_events FROM total), 4), 0) AS events_percentage"
+)
+
 // GetWebsiteReferrersSummary returns a summary of the referrers for the given filters.
 func (c *Client) GetWebsiteCustomProperties(ctx context.Context, filter *db.Filters) ([]*model.StatsCustomProperties, error) {
 	var properties []*model.StatsCustomProperties
@@ -21,16 +26,22 @@ func (c *Client) GetWebsiteCustomProperties(ctx context.Context, filter *db.Filt
 	//
 	// Events is the number of events for the custom property
 	//
-	// Visitors is the number of unique visitors for the custom property.
-	query := qb.New()
+	// Events percentage is the percentage of events for the custom property
+	query := qb.New().WithMaterialized(
+		qb.NewCTE("total", qb.New().
+			Select("COUNT(*) FILTER (WHERE name IS NOT NULL) AS total_events").
+			From("views").
+			LeftJoin(EventsJoinStmt).
+			Where(filter.WhereString())))
 
 	// If the property name is empty, return only the property names with their
 	// aggregated events and visitors. No values.
 	if filter.PropertyName == nil || filter.PropertyName.Value == "" {
 		query = query.Select(
 			"name",
 			"'' AS value",
-			"COUNT(*) AS events",
+			EventsCountStmt,
+			EventsPercentageStmt,
 		).
 			From("views").
 			LeftJoin(EventsJoinStmt).
@@ -44,7 +55,8 @@ func (c *Client) GetWebsiteCustomProperties(ctx context.Context, filter *db.Filt
 		query = query.Select(
 			"'' AS name",
 			"value",
-			"COUNT(*) AS events",
+			EventsCountStmt,
+			EventsPercentageStmt,
 		).
 			From("views").
 			LeftJoin(EventsJoinStmt).

core/db/duckdb/query/qb.go

@@ -13,6 +13,7 @@ type QueryBuilder struct {
 	cteClauses       []CTE
 	selectClauses    []string
 	fromClause       []string
+	joinClause       string
 	leftJoinClause   string
 	whereClause      string
 	groupByClause    []string
@@ -47,6 +48,11 @@ func (qb *QueryBuilder) From(tables ...string) *QueryBuilder {
 	return qb
 }
 
+func (qb *QueryBuilder) Join(query string) *QueryBuilder {
+	qb.joinClause = query
+	return qb
+}
+
 func (qb *QueryBuilder) LeftJoin(query string) *QueryBuilder {
 	qb.leftJoinClause = query
 	return qb
@@ -100,6 +106,11 @@ func (qb *QueryBuilder) Build() string {
 	query.WriteString(" FROM ")
 	query.WriteString(strings.Join(qb.fromClause, ", "))
 
+	if qb.joinClause != "" {
+		query.WriteString(" JOIN ")
+		query.WriteString(qb.joinClause)
+	}
+
 	if qb.leftJoinClause != "" {
 		query.WriteString(" LEFT JOIN ")
 		query.WriteString(qb.leftJoinClause)

core/model/stats.go

@@ -168,7 +168,8 @@ type StatsLanguages struct {
 }
 
 type StatsCustomProperties struct {
-	Name   string `db:"name"`
-	Value  string `db:"value"`
-	Events int    `db:"events"`
+	Name             string  `db:"name"`
+	Value            string  `db:"value"`
+	Events           int     `db:"events"`
+	EventsPercentage float32 `db:"events_percentage"`
 }