// Every package.json in a product repo pins each @norskvideo/ctl-* package at
// the SAME range.
//
// A repo is a workspace of packages, and a nested one (tests/, shared/) can pin
// a ctl package of its own. When the two ranges differ, the nested package runs
// a different copy from the one the root was moved to, and nothing says so:
// playout's tests/ pinned the dev-kit ^0.1.57 while the root moved to 0.2, its
// guides ran a guide proxy that built the wrong Studio prefix, and first-light
// failed every night from 2026-09-07. bump.yml now moves every pin; this keeps
// a hand edit (or a new nested package) from splitting them again.
import { lstatSync, readdirSync, readFileSync } from "node:fs";
import { join, relative } from "node:path";

const SCOPE = "@norskvideo/ctl-";
/** Directories that hold installed or generated packages, not this repo's own. */
const SKIP = new Set(["node_modules", ".git", "dist", "build", "test-temp", "generated", ".nix"]);

function manifests(root: string, dir = root, out: string[] = []): string[] {
  for (const name of readdirSync(dir)) {
    if (SKIP.has(name)) continue;
    const path = join(dir, name);
    // lstat: never follow a symlink. A repo's own packages are real
    // directories, and a link (a nix `result`, a workspace link) can lead
    // anywhere, including out of the repo entirely.
    let st: ReturnType<typeof lstatSync>;
    try {
      st = lstatSync(path);
    } catch {
      continue;
    }
    if (st.isDirectory()) manifests(root, path, out);
    else if (name === "package.json") out.push(path);
  }
  return out;
}

export function ctlPinProblems(repoRoot: string): string[] {
  const problems: string[] = [];
  /** package -> range -> the files pinning it at that range */
  const pins = new Map<string, Map<string, string[]>>();
  for (const path of manifests(repoRoot).sort()) {
    const rel = relative(repoRoot, path);
    let parsed: Record<string, Record<string, string> | undefined>;
    try {
      parsed = JSON.parse(readFileSync(path, "utf8"));
    } catch (e) {
      problems.push(`${rel} is not parseable JSON (${e instanceof Error ? e.message : String(e)}).`);
      continue;
    }
    for (const field of ["dependencies", "devDependencies", "peerDependencies", "optionalDependencies"]) {
      for (const [name, range] of Object.entries(parsed[field] ?? {})) {
        if (!name.startsWith(SCOPE) || typeof range !== "string" || range.startsWith("workspace:")) continue;
        const byRange = pins.get(name) ?? new Map<string, string[]>();
        byRange.set(range, [...(byRange.get(range) ?? []), rel]);
        pins.set(name, byRange);
      }
    }
  }
  for (const [name, byRange] of pins) {
    if (byRange.size < 2) continue;
    const where = [...byRange].flatMap(([range, files]) => files.map((f) => `${f} ${range}`)).join(", ");
    problems.push(
      `${name} is pinned at ${byRange.size} different ranges (${where}). A nested package then runs a different copy from the root's; pin it at one range everywhere (the nightly bump.yml moves every pin).`,
    );
  }
  return problems;
}