feat: Initial backend setup for Music Analyser

- Created FastAPI backend structure.
- Implemented Spotify Recently Played ingestion logic.
- Set up SQLite database with SQLAlchemy models.
- Added AI Service using Google Gemini.
- Created helper scripts for auth and background worker.
- Added Dockerfile and GitHub Actions workflow.

backend/scripts/get_refresh_token.py

@@ -0,0 +1,87 @@
+import os
+import sys
+import webbrowser
+import requests
+import urllib.parse
+from http.server import HTTPServer, BaseHTTPRequestHandler
+
+# Instructions for the user:
+# 1. Go to Spotify Developer Dashboard: https://developer.spotify.com/dashboard/
+# 2. Create an App.
+# 3. Edit Settings -> Redirect URIs -> Add "http://localhost:8888/callback"
+# 4. Save Settings.
+# 5. Copy Client ID and Client Secret.
+# 6. Run this script: python get_refresh_token.py
+
+# CONFIGURATION - You can hardcode these or input them when prompted
+SPOTIFY_CLIENT_ID = input("Enter your Spotify Client ID: ").strip()
+SPOTIFY_CLIENT_SECRET = input("Enter your Spotify Client Secret: ").strip()
+REDIRECT_URI = "http://localhost:8888/callback"
+SCOPE = "user-read-recently-played user-read-playback-state"
+
+class RequestHandler(BaseHTTPRequestHandler):
+    def do_GET(self):
+        query = urllib.parse.urlparse(self.path).query
+        params = urllib.parse.parse_qs(query)
+
+        if "code" in params:
+            self.send_response(200)
+            self.send_header("Content-type", "text/html")
+            self.end_headers()
+            self.wfile.write(b"<h1>Got the code! check your terminal.</h1>")
+
+            code = params["code"][0]
+            get_token(code)
+
+            # Shut down server
+            raise KeyboardInterrupt
+
+def get_token(code):
+    url = "https://accounts.spotify.com/api/token"
+    payload = {
+        "grant_type": "authorization_code",
+        "code": code,
+        "redirect_uri": REDIRECT_URI,
+        "client_id": SPOTIFY_CLIENT_ID,
+        "client_secret": SPOTIFY_CLIENT_SECRET,
+    }
+
+    response = requests.post(url, data=payload)
+    if response.status_code == 200:
+        data = response.json()
+        print("\n" + "="*50)
+        print("SUCCESS! HERE ARE YOUR CREDENTIALS")
+        print("="*50)
+        print(f"\nSPOTIFY_REFRESH_TOKEN={data['refresh_token']}")
+        print(f"SPOTIFY_CLIENT_ID={SPOTIFY_CLIENT_ID}")
+        print(f"SPOTIFY_CLIENT_SECRET={SPOTIFY_CLIENT_SECRET}")
+        print("\nSave these in your .env file or share them with the agent.")
+        print("="*50 + "\n")
+    else:
+        print("Error getting token:", response.text)
+
+def start_auth():
+    auth_url = "https://accounts.spotify.com/authorize?" + urllib.parse.urlencode({
+        "response_type": "code",
+        "client_id": SPOTIFY_CLIENT_ID,
+        "scope": SCOPE,
+        "redirect_uri": REDIRECT_URI,
+    })
+
+    print(f"Opening browser to: {auth_url}")
+    try:
+        webbrowser.open(auth_url)
+    except:
+        print(f"Could not open browser. Please manually visit: {auth_url}")
+
+    server_address = ('', 8888)
+    httpd = HTTPServer(server_address, RequestHandler)
+    print("Listening on port 8888...")
+    try:
+        httpd.serve_forever()
+    except KeyboardInterrupt:
+        pass
+    httpd.server_close()
+
+if __name__ == "__main__":
+    start_auth()