import type { FragmentsConfig, TokenConfig } from "./types.js";

const WINDOWS_DRIVE_RE = /^[a-zA-Z]:[\\/]/;

export function normalizeConfigPath(path: string): string {
  return path.trim().replace(/^\.\//, "").replace(/\/+$/, "") || ".";
}

export function portableRepoPathError(path: string): string | null {
  const normalized = path.trim();
  if (!normalized) return "Path must not be empty";
  if (normalized.startsWith("/")) return "Path must be repo-relative, not absolute";
  if (WINDOWS_DRIVE_RE.test(normalized)) {
    return "Path must be repo-relative, not absolute";
  }
  if (normalized.startsWith("~")) return "Path must not use a home directory shortcut";
  if (normalized.includes("\\")) return "Path must use POSIX / separators";

  const parts = normalized.split("/");
  if (parts.some((part) => part === "..")) {
    return "Path must not contain .. segments";
  }
  if (parts.some((part) => part.length === 0)) {
    return "Path must not contain empty segments";
  }

  return null;
}

export function isPortableRepoPath(path: string): boolean {
  return portableRepoPathError(path) === null;
}

export function resolveConfiguredAppPath(config: Pick<FragmentsConfig, "app">): string {
  return normalizeConfigPath(config.app?.path ?? ".");
}

export function topologyBase(config: Pick<FragmentsConfig, "topology">): "app" | "repo" {
  return config.topology?.base ?? "app";
}

export function tokenIncludesFromConfig(tokens: TokenConfig): string[] {
  if (tokens.sources?.length) {
    return tokens.sources.map((source) => source.path);
  }
  return tokens.include ?? [];
}