refactor(imessage): share target parsing helpers

src/imessage/target-parsing-helpers.ts

@@ -0,0 +1,132 @@
+export type ServicePrefix<TService extends string> = { prefix: string; service: TService };
+
+export type ChatTargetPrefixesParams = {
+  trimmed: string;
+  lower: string;
+  chatIdPrefixes: string[];
+  chatGuidPrefixes: string[];
+  chatIdentifierPrefixes: string[];
+};
+
+export type ParsedChatTarget =
+  | { kind: "chat_id"; chatId: number }
+  | { kind: "chat_guid"; chatGuid: string }
+  | { kind: "chat_identifier"; chatIdentifier: string };
+
+function stripPrefix(value: string, prefix: string): string {
+  return value.slice(prefix.length).trim();
+}
+
+export function resolveServicePrefixedTarget<TService extends string, TTarget>(params: {
+  trimmed: string;
+  lower: string;
+  servicePrefixes: Array<ServicePrefix<TService>>;
+  isChatTarget: (remainderLower: string) => boolean;
+  parseTarget: (remainder: string) => TTarget;
+}): ({ kind: "handle"; to: string; service: TService } | TTarget) | null {
+  for (const { prefix, service } of params.servicePrefixes) {
+    if (!params.lower.startsWith(prefix)) {
+      continue;
+    }
+    const remainder = stripPrefix(params.trimmed, prefix);
+    if (!remainder) {
+      throw new Error(`${prefix} target is required`);
+    }
+    const remainderLower = remainder.toLowerCase();
+    if (params.isChatTarget(remainderLower)) {
+      return params.parseTarget(remainder);
+    }
+    return { kind: "handle", to: remainder, service };
+  }
+  return null;
+}
+
+export function parseChatTargetPrefixesOrThrow(
+  params: ChatTargetPrefixesParams,
+): ParsedChatTarget | null {
+  for (const prefix of params.chatIdPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      const chatId = Number.parseInt(value, 10);
+      if (!Number.isFinite(chatId)) {
+        throw new Error(`Invalid chat_id: ${value}`);
+      }
+      return { kind: "chat_id", chatId };
+    }
+  }
+
+  for (const prefix of params.chatGuidPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      if (!value) {
+        throw new Error("chat_guid is required");
+      }
+      return { kind: "chat_guid", chatGuid: value };
+    }
+  }
+
+  for (const prefix of params.chatIdentifierPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      if (!value) {
+        throw new Error("chat_identifier is required");
+      }
+      return { kind: "chat_identifier", chatIdentifier: value };
+    }
+  }
+
+  return null;
+}
+
+export function resolveServicePrefixedAllowTarget<TAllowTarget>(params: {
+  trimmed: string;
+  lower: string;
+  servicePrefixes: Array<{ prefix: string }>;
+  parseAllowTarget: (remainder: string) => TAllowTarget;
+}): (TAllowTarget | { kind: "handle"; handle: string }) | null {
+  for (const { prefix } of params.servicePrefixes) {
+    if (!params.lower.startsWith(prefix)) {
+      continue;
+    }
+    const remainder = stripPrefix(params.trimmed, prefix);
+    if (!remainder) {
+      return { kind: "handle", handle: "" };
+    }
+    return params.parseAllowTarget(remainder);
+  }
+  return null;
+}
+
+export function parseChatAllowTargetPrefixes(
+  params: ChatTargetPrefixesParams,
+): ParsedChatTarget | null {
+  for (const prefix of params.chatIdPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      const chatId = Number.parseInt(value, 10);
+      if (Number.isFinite(chatId)) {
+        return { kind: "chat_id", chatId };
+      }
+    }
+  }
+
+  for (const prefix of params.chatGuidPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      if (value) {
+        return { kind: "chat_guid", chatGuid: value };
+      }
+    }
+  }
+
+  for (const prefix of params.chatIdentifierPrefixes) {
+    if (params.lower.startsWith(prefix)) {
+      const value = stripPrefix(params.trimmed, prefix);
+      if (value) {
+        return { kind: "chat_identifier", chatIdentifier: value };
+      }
+    }
+  }
+
+  return null;
+}