// repo-keys.ts — the SHARED config-key derivation for a repo (KEY: AUTOPILOT-110).
//
// A repo is keyed in the CONFIG by a CANDIDATE list, most specific
// first: the origin slug `owner/repo` (exact) → the slug's bare repo name → the
// local basename. Both per-repo maps use it — `shipping.repos`
// (AUTO-SHIP-ON-DONE, autopilot.config.json) and `models.repos`
// (AUTOPILOT-110/111, ACTUATOR-owned — actuator.config.json, with this repo's
// own autopilot.config.json `models` only a fallback; see config.ts) — so one
// repo cannot be "acme/thing" to the shipping lane and "thing" to the model map.
//
// Extracted from shipping.ts at AUTOPILOT-110 so the model resolution
// (spawn-model.ts) can match a repo WITHOUT importing shipping.ts: shipping.ts
// → config.ts → spawn-model.ts already exists, so a spawn-model → shipping
// import would be a cycle. This module imports only ./framework/git.ts (itself
// node-builtins-only) — still a leaf, safe for both to depend on.

import { basename } from "node:path";
import { git } from "./framework/git.ts";

/** The repo's origin slug `owner/repo` (structural parse of `git remote get-url
 *  origin`), or null. Solely for config-key matching — never a web guess. */
export function originSlug(repo: string): string | null {
  const url = git(repo, ["remote", "get-url", "origin"]);
  if (!url) return null;
  let path = "";
  try {
    const u = new URL(url);
    if (u.protocol !== "https:" && u.protocol !== "http:" && u.protocol !== "ssh:") return null;
    path = u.pathname.replace(/^\/+/, "");
  } catch {
    // scp-style git@host:owner/repo.git — the explicit fallback shape
    const scp = url.replace(/^[^@]+@/, "");
    const i = scp.indexOf(":");
    if (i <= 0) return null;
    path = scp.slice(i + 1);
  }
  const clean = path.replace(/\.git$/, "").replace(/\/+$/, "");
  const parts = clean.split("/").filter(Boolean);
  if (parts.length < 2) return null; // a bare repo path has no forge slug
  return parts.slice(-2).join("/");
}

/** The config-key candidates for a repo, most specific first: the origin slug
 *  (exact) → the slug's bare repo name → the local basename. */
export function repoPolicyKeys(repo: string): string[] {
  const keys: string[] = [];
  const slug = originSlug(repo);
  if (slug) {
    keys.push(slug);
    const bare = slug.split("/").pop();
    if (bare && !keys.includes(bare)) keys.push(bare);
  }
  const base = basename(repo);
  if (base && !keys.includes(base)) keys.push(base);
  return keys;
}

/** The display/config key suggested for a repo (slug when derivable, else the
 *  repo basename). */
export function suggestedPolicyKey(repo: string): string {
  return originSlug(repo) ?? basename(repo);
}