Add builder for adding custom sources

src/entrypoint/utils/targets.ts

@@ -0,0 +1,64 @@
+export const flags = {
+  // CORS are set to allow any origin
+  CORS_ALLOWED: 'cors-allowed',
+
+  // the stream is locked on IP, so only works if
+  // request maker is same as player (not compatible with proxies)
+  IP_LOCKED: 'ip-locked',
+} as const;
+
+export type Flags = (typeof flags)[keyof typeof flags];
+
+export const targets = {
+  // browser with CORS restrictions
+  BROWSER: 'browser',
+
+  // browser, but no CORS restrictions through a browser extension
+  BROWSER_EXTENSION: 'browser-extension',
+
+  // native app, so no restrictions in what can be played
+  NATIVE: 'native',
+
+  // any target, no target restrictions
+  ANY: 'any',
+} as const;
+
+export type Targets = (typeof targets)[keyof typeof targets];
+
+export type FeatureMap = {
+  requires: Flags[];
+  disallowed: Flags[];
+};
+
+export const targetToFeatures: Record<Targets, FeatureMap> = {
+  browser: {
+    requires: [flags.CORS_ALLOWED],
+    disallowed: [],
+  },
+  'browser-extension': {
+    requires: [],
+    disallowed: [],
+  },
+  native: {
+    requires: [],
+    disallowed: [],
+  },
+  any: {
+    requires: [],
+    disallowed: [],
+  },
+};
+
+export function getTargetFeatures(target: Targets, consistentIpForRequests: boolean): FeatureMap {
+  const features = targetToFeatures[target];
+  if (!consistentIpForRequests) features.disallowed.push(flags.IP_LOCKED);
+  return features;
+}
+
+export function flagsAllowedInFeatures(features: FeatureMap, inputFlags: Flags[]): boolean {
+  const hasAllFlags = features.requires.every((v) => inputFlags.includes(v));
+  if (!hasAllFlags) return false;
+  const hasDisallowedFlag = features.disallowed.some((v) => inputFlags.includes(v));
+  if (hasDisallowedFlag) return false;
+  return true;
+}