album: extend struct for /api/album/%d/data

This also includes tests against a sample response from the
https://monster-siren.hypergryph.com/api/album/1030/data endpoint.

Signed-off-by: Yonah <contrib@gensokyo.uk>

cmd/msrfetch/enrich.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"flag"
 	"log"
+	"slices"
 
 	"git.gensokyo.uk/yonah/monstersirenfetch"
 )
@@ -36,8 +37,28 @@ func mustEnrich(ctx context.Context) {
 	} else {
 		n := new(netDirect)
 		for _, ca := range c {
-			log.Printf("enriching album %s (%s)", ca.Name, ca.CID.String())
+			if ca.Album == nil {
+				log.Fatal("albums contains nil")
+			}
+
+			if !ca.Album.IsFull() {
+				if err = ca.Album.Enrich(ctx, n); err != nil {
+					log.Fatal(err)
+				}
+				log.Printf("enriched album %s (%s) with %d songs", ca.Album.CID.String(), ca.Album.Name, len(ca.Songs))
+			} else {
+				log.Printf("skipped album %s (%s)", ca.Album.CID.String(), ca.Album.Name)
+			}
+
+			// consistency check: for later validating enriched songs against flatten
+			flattenSongs := make([]monstersirenfetch.AlbumSong, 0, len(ca.Songs))
+
 			for _, cs := range ca.Songs {
+				if cs == nil {
+					log.Fatal("songs contains nil")
+				}
+				flattenSongs = append(flattenSongs, monstersirenfetch.AlbumSong{CID: cs.CID, Name: cs.Name, Artists: cs.Artists})
+
 				if !cs.IsFull() {
 					if err = cs.Enrich(ctx, n); err != nil {
 						log.Fatal(err)
@@ -47,6 +68,19 @@ func mustEnrich(ctx context.Context) {
 					log.Printf("skipped song %s: %s (%s)", cs.CID.String(), cs.SourceURL, cs.Name)
 				}
 			}
+
+			// consistency check: enriched songs match flattened songs
+			slices.SortFunc(flattenSongs, func(a, b monstersirenfetch.AlbumSong) int { return int(a.CID - b.CID) })
+			enrichSongs := make([]monstersirenfetch.AlbumSong, len(ca.Album.Songs))
+			copy(enrichSongs, ca.Album.Songs)
+			slices.SortFunc(enrichSongs, func(a, b monstersirenfetch.AlbumSong) int { return int(a.CID - b.CID) })
+			if !slices.EqualFunc(flattenSongs, enrichSongs, func(a monstersirenfetch.AlbumSong, b monstersirenfetch.AlbumSong) bool {
+				return a.CID == b.CID && a.Name == b.Name && slices.Equal(a.Artists, b.Artists)
+			}) {
+				log.Fatalf("album %s enrichment inconsistent with flatten state", ca.Album.Name)
+			} else {
+				log.Printf("validated %d songs associated with album %s", len(enrichSongs), ca.Album.CID.String())
+			}
 		}
 		mustWriteJSON(flagOutputPath, c)
 		log.Println("composite data written to", flagOutputPath)

cmd/msrfetch/fetch.go

@@ -32,6 +32,7 @@ func mustFetch(ctx context.Context) {
 
 	const (
 		invalidContainsNil = "invalid composite data"
+		invalidNotEnriched = "this composite is not enriched"
 	)
 
 	var urls []string
@@ -39,17 +40,23 @@ func mustFetch(ctx context.Context) {
 		if ca.Album == nil {
 			log.Fatal(invalidContainsNil)
 		}
-		if ca.CoverURL == "" {
-			log.Fatalf("album %s missing coverUrl", ca.CID.String())
+		if !ca.Album.IsFull() {
+			log.Fatal(invalidNotEnriched)
+		}
+		if ca.Album.CoverURL == "" {
+			log.Fatalf("album %s missing coverUrl", ca.Album.CID.String())
+		}
+		urls = append(urls, ca.Album.CoverURL)
+		if ca.Album.CoverDeURL != "" {
+			urls = append(urls, ca.Album.CoverDeURL)
 		}
-		urls = append(urls, ca.CoverURL)
 
 		for _, cs := range ca.Songs {
 			if cs == nil {
 				log.Fatal(invalidContainsNil)
 			}
 			if !cs.IsFull() {
-				log.Fatal("this composite is not enriched")
+				log.Fatal(invalidNotEnriched)
 			}
 
 			urls = append(urls, cs.SourceURL)