// Rules for the editable project fields: name and GitHub repo links
// (R-project-repo-links). Shared by the registry, the JSON API, and the CLI.
// Keep this module free of package dependencies because the installed CLI
// imports it directly.

export const MAX_PROJECT_NAME_LENGTH = 80;

export const PROJECT_NAME_ERROR = `Project names must contain 1 to ${MAX_PROJECT_NAME_LENGTH} characters.`;
export const PROJECT_REPO_ERROR =
  "Repo links must look like https://github.com/owner/repo.";

export const projectNameError = (name: unknown): string | undefined => {
  if (typeof name !== "string") return PROJECT_NAME_ERROR;
  const length = name.trim().length;
  return length === 0 || length > MAX_PROJECT_NAME_LENGTH ? PROJECT_NAME_ERROR : undefined;
};

export type ProjectRepoParseResult = { error: string } | { url: string };

/**
 * Parse one GitHub repo link into the stored form
 * `https://github.com/<owner>/<repo>`.
 */
export const parseProjectRepoUrl = (value: unknown): ProjectRepoParseResult => {
  if (typeof value !== "string") return { error: PROJECT_REPO_ERROR };
  let parsed: URL;
  try {
    parsed = new URL(value.trim());
  } catch {
    return { error: PROJECT_REPO_ERROR };
  }
  if (parsed.protocol !== "https:") return { error: PROJECT_REPO_ERROR };
  if (parsed.hostname.toLowerCase() !== "github.com") return { error: PROJECT_REPO_ERROR };
  const segments = parsed.pathname.split("/").filter(Boolean);
  if (segments.length !== 2) return { error: PROJECT_REPO_ERROR };
  const owner = segments[0];
  const repo = segments[1].replace(/\.git$/i, "");
  if (!/^[A-Za-z0-9._-]+$/.test(owner) || !/^[A-Za-z0-9._-]+$/.test(repo)) {
    return { error: PROJECT_REPO_ERROR };
  }
  return { url: `https://github.com/${owner}/${repo}` };
};