0.3.06

server/internal/recommend/profile.go

@@ -109,6 +109,11 @@ type Profile struct {
 	// good reason to *tell* someone about a title and a poor reason to rank by it: two
 	// films sharing an actor are often nothing alike.
 	PersonWeights map[string]float64
+	// DecadeWeights and ReasonEvidence retain just enough of the source history for the
+	// explanation layer to say why a particular title fits. They do not participate in
+	// ranking: ordering and wording remain deliberately separate concerns.
+	DecadeWeights  map[int]float64
+	ReasonEvidence []ReasonEvidence
 	// Seen holds item ids *and* series ids already watched or in progress, so a
 	// recommendation never suggests something the user is already partway through.
 	Seen       map[string]bool
@@ -116,6 +121,11 @@ type Profile struct {
 	Seeds      []Seed
 }
 
+type ReasonEvidence struct {
+	Item      Item
+	Favourite bool
+}
+
 func (p Profile) IsEmpty() bool { return len(p.GenreWeights) == 0 && len(p.Seeds) == 0 }
 
 // Decode parses raw Emby items, keeping the original payload attached.
@@ -141,14 +151,26 @@ func BuildProfile(history, favorites []Item) Profile {
 		GenreWeights:  map[string]float64{},
 		StudioWeights: map[string]float64{},
 		PersonWeights: map[string]float64{},
+		DecadeWeights: map[int]float64{},
 		Seen:          map[string]bool{},
 		SeenTitles:    map[string]bool{},
 	}
 
 	seedSeen := map[string]bool{}
 	tasteSeen := map[string]bool{}
+	reasonSeen := map[string]bool{}
 	for i, item := range history {
 		profile.markSeen(item)
+		reasonItem := item
+		reasonItem.Raw = nil
+		reasonID := item.ID
+		if item.SeriesID != "" {
+			reasonID = item.SeriesID
+		}
+		if reasonID != "" && !reasonSeen[reasonID] {
+			reasonSeen[reasonID] = true
+			profile.ReasonEvidence = append(profile.ReasonEvidence, ReasonEvidence{Item: reasonItem})
+		}
 
 		// Several episodes of one series are evidence for one taste, not several
 		// independent tastes. Keep the newest occurrence's recency weight and still
@@ -176,6 +198,15 @@ func BuildProfile(history, favorites []Item) Profile {
 
 	for _, item := range favorites {
 		profile.absorb(item, favoriteWeight)
+		reasonItem := item
+		reasonItem.Raw = nil
+		reasonID := item.ID
+		if reasonID != "" && !reasonSeen[reasonID] {
+			reasonSeen[reasonID] = true
+			profile.ReasonEvidence = append(profile.ReasonEvidence, ReasonEvidence{
+				Item: reasonItem, Favourite: true,
+			})
+		}
 	}
 	return profile
 }
@@ -223,6 +254,12 @@ func (p *Profile) absorbTaste(item Item, weight float64) {
 			p.PersonWeights[name] += weight
 		}
 	}
+	if item.ProductionYear > 0 {
+		if p.DecadeWeights == nil {
+			p.DecadeWeights = map[int]float64{}
+		}
+		p.DecadeWeights[item.ProductionYear/10*10] += weight
+	}
 }
 
 // isExplainablePerson keeps the cast list down to the roles a viewer would recognise as