import * as z from "zod"
import { defineAction } from "../../../automation/actions"
import { EMAIL_ORIGIN_TOKEN } from "../../../lib/email-origin"
import {
  getGmailApi,
  sendReply,
} from "@automate.ax/integration-contracts/gmail"
import { GMAIL_SEND_AND_METADATA_REQUIREMENT } from "../lib/scopes"
import {
  MESSAGE_METADATA_SCHEMA,
  REPLY_OPTIONS_SCHEMA,
} from "@automate.ax/integration-contracts/gmail"

/**
 * Replies to the latest received message in a Gmail thread.
 *
 * Sent messages are ignored, so archived conversations remain replyable.
 */
export const replyToGmailThread = defineAction("Reply to Gmail thread")
  .describe("Replies to the latest received message in a Gmail thread.")
  .account("google", GMAIL_SEND_AND_METADATA_REQUIREMENT)
  .input(
    REPLY_OPTIONS_SCHEMA.extend({
      /** Immutable Gmail thread ID receiving the reply. */
      threadId: z.string().min(1),
    }),
  )
  .output(MESSAGE_METADATA_SCHEMA)
  .retry({ replaySafety: "unsafe" })
  .handler(async ({ account, input, runtime }) => {
    const gmailApi = getGmailApi(account.secret)
    const latestReceivedMessage = [
      ...((
        await gmailApi.users.threads.get({
          format: "metadata",
          id: input.threadId,
          userId: "me",
        })
      ).data.messages ?? []),
    ]
      .filter((message) => !message.labelIds?.includes("SENT"))
      .toSorted(
        (a, b) => Number(b.internalDate ?? "0") - Number(a.internalDate ?? "0"),
      )
      .at(0)
    if (!latestReceivedMessage) {
      throw new Error("Gmail thread has no received messages to reply to.")
    }

    return await sendReply(
      gmailApi,
      latestReceivedMessage,
      input,
      runtime[EMAIL_ORIGIN_TOKEN],
    )
  })