import {
  answersByTemplateIndex,
  submissionUpdateText,
  type NormalizedSubmissionAnswer,
  type OldAnswersByQuestionId,
  type SubmissionQuestion,
} from "@/lib/form/submission-intake";

const NEW_SUBMISSION_TEMPLATE = "New submission from {username} ({id}).";
const UPDATED_SUBMISSION_TEMPLATE = "Submission updated by {username} ({id}).\n{update}";

type SubmissionWebhookMessageOptions = {
  template: string | null;
  isUpdate: boolean;
  userName: string | null | undefined;
  discordId: string;
  submissionLink: string;
  questions: SubmissionQuestion[];
  answers: NormalizedSubmissionAnswer[];
  oldAnswersByQuestionId: OldAnswersByQuestionId;
};

export function submissionWebhookMessage({
  template,
  isUpdate,
  userName,
  discordId,
  submissionLink,
  questions,
  answers,
  oldAnswersByQuestionId,
}: SubmissionWebhookMessageOptions) {
  const answersByIndex = answersByTemplateIndex(questions, answers);
  const updatesText = isUpdate
    ? submissionUpdateText(questions, answers, oldAnswersByQuestionId)
    : "";
  const messageTemplate = template?.trim()
    || (isUpdate ? UPDATED_SUBMISSION_TEMPLATE : NEW_SUBMISSION_TEMPLATE);

  return messageTemplate.replace(/\{([^}]+)\}/g, (_match, variable: string) => {
    const key = variable.toLowerCase();
    if (key === "username" || key === "displayname") {
      return userName || "Unknown User";
    }
    if (key === "id") {
      return discordId;
    }
    if (key === "link") {
      return submissionLink;
    }
    if (key === "update") {
      return updatesText;
    }
    return answersByIndex[variable] || "Not Provided";
  });
}