import type { Role, RoleResult, StartStep } from "@uncaged/nerve-core";

export type IntakeMeta = {
  issueUrl: string;
  host: string | null;
  owner: string | null;
  repo: string | null;
  issueNumber: number | null;
  valid: boolean;
  failureKind: "none" | "invalid_input";
  failureReason: string | null;
};

function parseIssueUrl(raw: string): IntakeMeta {
  const issueUrl = raw.trim();
  const match = issueUrl.match(/^https?:\/\/([^/\s]+)\/([^/\s]+)\/([^/\s]+)\/issues\/(\d+)(?:[/?#].*)?$/i);
  if (match === null) {
    return {
      issueUrl,
      host: null,
      owner: null,
      repo: null,
      issueNumber: null,
      valid: false,
      failureKind: "invalid_input",
      failureReason: `invalid issue URL: ${issueUrl}`,
    };
  }

  const issueNumber = Number(match[4]);
  if (!Number.isInteger(issueNumber) || issueNumber <= 0) {
    return {
      issueUrl,
      host: null,
      owner: null,
      repo: null,
      issueNumber: null,
      valid: false,
      failureKind: "invalid_input",
      failureReason: `invalid issue number: ${match[4]}`,
    };
  }

  return {
    issueUrl,
    host: match[1],
    owner: match[2],
    repo: match[3],
    issueNumber,
    valid: true,
    failureKind: "none",
    failureReason: null,
  };
}

export function buildIntakeRole(): Role<IntakeMeta> {
  return async (start: StartStep): Promise<RoleResult<IntakeMeta>> => {
    const parsed = parseIssueUrl(start.content);
    if (!parsed.valid) {
      return { content: parsed.failureReason ?? "invalid issue URL", meta: parsed };
    }
    return {
      content: `parsed issue URL: ${parsed.owner}/${parsed.repo}#${parsed.issueNumber} @ ${parsed.host}`,
      meta: parsed,
    };
  };
}