Completed backend code

src/services/recentlyPlayedService.tsx

@@ -0,0 +1,102 @@
+import type { GetRecentlyPlayedTracksResponse, GetRecentlyPlayedTracksInput, AudioFeaturesResponse } from "../types/spotify-web-api";
+import getMultiTrackAudioFeatures from "./multiTrackAudioFeaturesService";
+import type { HistoricalMetrics } from "../types/enhancify";
+
+async function getRecentlyPlayedTracksMetrics(apiOptions: GetRecentlyPlayedTracksInput) : Promise<HistoricalMetrics | {}> {
+    let url = "https://api.spotify.com/v1/me/player/recently-played";
+
+    // Extract the query parameters from the API options input
+    // to create a request string
+    let queryParams: string[] = [];
+    for (const [key, value] of Object.entries(apiOptions.data)) {
+        if (!value) {
+            continue;
+        }
+        queryParams.push(key + "=" + value);
+    }
+    url += queryParams.join("&");
+
+    var accessToken = Spicetify.Platform.Session.accessToken;
+
+    // Make the API request to get the recently
+    // played songs
+    let RecentlyPlayedTracksResponse = await fetch(url, 
+        {
+            headers: {
+                Authorization: "Bearer " + accessToken,
+            },
+
+        }
+    );
+
+    // If the respone was not successfully retrieved,
+    // then return an empty object
+    if (RecentlyPlayedTracksResponse.status != 200) {
+        return {};
+    }
+
+    // Get the musical characteristics of each song
+    // Get all the song ids
+    let songIDs: string[] = [];
+    let RecentlyPlayedTracksResponseJSON = await RecentlyPlayedTracksResponse.json();
+    for (let item of RecentlyPlayedTracksResponseJSON.items) {
+        songIDs.push(item.track.id);
+    }
+    let audioFeatures = await getMultiTrackAudioFeatures(songIDs);
+
+    // Process the audio features
+    let relevantMetrics = ["acousticness", "danceability", "energy", "instrumentalness",
+                           "liveness", "speechiness", "valence"];
+    let metricsData: { [metric: string]: {total: number, count: number} } = {};
+    for (let metric of relevantMetrics) {
+        metricsData[metric] = {total: 0, count: 0};
+    }
+    for (let audioFeature of audioFeatures) {
+        for (let feature of Object.keys(audioFeature)) {
+            if (feature in relevantMetrics) {
+                if (audioFeature[feature as keyof AudioFeaturesResponse]) {
+                    metricsData[feature].total += parseInt(audioFeature[feature as keyof AudioFeaturesResponse]);
+                    metricsData[feature].count += 1;
+                }
+            }
+        }
+    }
+
+    // Average out the song metrics
+    let result: HistoricalMetrics = {
+        acousticness: {
+            average: 0,
+            count: 0
+        },
+        danceability: {
+            average: 0,
+            count: 0
+        },
+        energy: {
+            average: 0,
+            count: 0
+        },
+        instrumentalness: {
+            average: 0,
+            count: 0
+        },
+        liveness: {
+            average: 0,
+            count: 0
+        },
+        speechiness: {
+            average: 0,
+            count: 0
+        },
+        valence: {
+            average: 0,
+            count: 0
+        }
+    };
+    for (let metric in Object.keys(metricsData)) {
+        result[metric as keyof HistoricalMetrics].average = metricsData[metric].total / metricsData[metric].count;
+        result[metric as keyof HistoricalMetrics].count = metricsData[metric].count;
+    }
+
+    return result;
+}

src/types/enhancify.d.ts

@@ -21,3 +21,34 @@ export type MetricFeatures = {
 export type SelectedMetrics = {
   [metric: string]: string
 };
+
+export type HistoricalMetrics = {
+  acousticness: {
+    average: number, 
+    count: number
+  }, 
+  danceability: {
+    average: number, 
+    count: number
+  }, 
+  energy: {
+    average: number, 
+    count: number
+  }, 
+  instrumentalness: {
+    average: number, 
+    count: number
+  }, 
+  liveness: {
+    average: number, 
+    count: number
+  }, 
+  speechiness: {
+    average: number, 
+    count: number
+  }, 
+  valence: {
+    average: number, 
+    count: number
+  }
+}

src/types/spotify-web-api.d.ts

@@ -161,7 +161,7 @@ export type GetRecommendationsResponse = {
     }[]
 };
 
-export class GetRecentlyPlayedTracks {
+export class GetRecentlyPlayedTracksInput {
   data = new RecentlyPlayedTracks();
 }