MORE REFACTORING!! + some improvements

Signed-off-by: ari melody <ari@arimelody.me>

music/artist.go

@@ -0,0 +1,155 @@
+package music
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/jmoiron/sqlx"
+)
+
+type Artist struct {
+    ID      string `json:"id"`
+    Name    string `json:"name"`
+    Website string `json:"website"`
+}
+
+var Artists []Artist
+
+func GetArtist(id string) *Artist {
+	for _, artist := range Artists {
+		if artist.GetID() == id {
+			return &artist
+		}
+	}
+	return nil
+}
+
+// GETTERS
+
+func (artist Artist) GetID() string {
+	return artist.ID
+}
+
+func (artist Artist) GetName() string {
+	return artist.Name
+}
+
+func (artist Artist) GetWebsite() string {
+	return artist.Website
+}
+
+// SETTERS
+
+func (artist Artist) SetID(id string) error {
+	artist.ID = id
+	return nil
+}
+
+func (artist Artist) SetName(name string) error {
+	artist.Name = name
+	return nil
+}
+
+func (artist Artist) SetWebsite(website string) error {
+	artist.Website = website
+	return nil
+}
+
+// DATABASE
+
+func (artist Artist) PushToDB(db *sqlx.DB) {
+	// fmt.Printf("Pushing artist [%s] to database...", artist.Name)
+
+	db.MustExec(
+        "INSERT INTO artists (id, name, website) "+
+        "VALUES ($1, $2, $3) "+
+        "ON CONFLICT (id) "+
+        "DO UPDATE SET name=$2, website=$3",
+		artist.ID,
+		artist.Name,
+		artist.Website,
+	)
+
+	// fmt.Printf("done!\n")
+}
+
+func PullAllArtists(db *sqlx.DB) ([]Artist, error) {
+	artists := []Artist{}
+
+	rows, err := db.Query("SELECT id, name, website FROM artists")
+	if err != nil {
+		return nil, err
+	}
+
+	for rows.Next() {
+		var artist = Artist{}
+
+		err = rows.Scan(
+            &artist.ID,
+            &artist.Name,
+            &artist.Website,
+        )
+		if err != nil {
+			return nil, err
+		}
+
+		artists = append(artists, artist)
+	}
+
+	return artists, nil
+}
+
+// HTTP HANDLERS
+
+func ServeArtist() http.Handler {
+    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+        if r.URL.Path == "/" {
+            http.NotFound(w, r)
+            return
+        }
+
+        type (
+            creditJSON struct {
+                Role    string  `json:"role"`
+                Primary bool    `json:"primary"`
+            }
+            artistJSON struct {
+                Artist
+                Credits map[string]creditJSON `json:"credits"`
+            }
+        )
+        var res = artistJSON{}
+
+        res.ID = r.URL.Path[1:]
+        var artist = GetArtist(res.ID)
+        if artist == nil {
+            http.NotFound(w, r)
+            return
+        }
+        res.Name = artist.Name
+        res.Website = artist.Website
+        res.Credits = make(map[string]creditJSON)
+
+        for _, release := range Releases {
+            for _, credit := range release.Credits {
+                if credit.Artist.ID != res.ID {
+                    continue
+                }
+                res.Credits[release.ID] = creditJSON{
+                    Role: credit.Role,
+                    Primary: credit.Primary,
+                }
+            }
+        }
+
+        jsonBytes, err := json.Marshal(res)
+        if err != nil {
+            http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+            return
+        }
+
+        w.Header().Add("Content-Type", "application/json")
+        w.WriteHeader(http.StatusOK)
+        w.Write(jsonBytes)
+    })
+}