export interface SanitizeOptions {
  repoRoot?: string; // e.g. /home/user/.disclaw
  home?: string; // os.homedir()
  pathMappings?: Array<{ host: string; virtual: string }>;
}

/**
 * Sanitizes agent output before it is sent to a Discord channel.
 * Replaces absolute paths and sensitive tokens so they are never leaked.
 *
 * Replacement order is intentional — longest/most-specific patterns first:
 *   1. repoRoot  → <disclaw>
 *   2. home      → ~
 *   3. Discord bot token pattern → <redacted>
 *   4. Anthropic API key pattern → <redacted>
 */
/** Returns both backslash and forward-slash variants of a path (for Windows). */
function pathVariants(p: string): string[] {
  const fwd = p.replace(/\\/g, "/");
  const bwd = p.replace(/\//g, "\\");
  return fwd === bwd ? [p] : [p, fwd, bwd];
}

function replaceAll(text: string, search: string, replacement: string): string {
  return text.split(search).join(replacement);
}

export function sanitizeForDiscord(
  text: string,
  opts: SanitizeOptions = {}
): string {
  let result = text;

  // 0. Replace path mappings first (most-specific, longest host paths first)
  //    so they take precedence over generic repoRoot/home replacements.
  if (opts.pathMappings && opts.pathMappings.length > 0) {
    const sorted = [...opts.pathMappings].sort(
      (a, b) => b.host.length - a.host.length
    );
    for (const mapping of sorted) {
      for (const variant of pathVariants(mapping.host)) {
        result = replaceAll(result, variant, mapping.virtual);
      }
    }
  }

  // 1. Replace repo root before home so that sub-paths are caught by the
  //    more specific substitution first (repoRoot is usually inside home).
  if (opts.repoRoot) {
    for (const variant of pathVariants(opts.repoRoot)) {
      result = replaceAll(result, variant, "<disclaw>");
    }
  }

  // 2. Replace home directory with ~ (both slash styles for Windows)
  if (opts.home) {
    for (const variant of pathVariants(opts.home)) {
      result = replaceAll(result, variant, "~");
    }
  }

  // 3. Discord bot token  — format: [MN]<23 base64url>.<6 base64url>.<27 base64url>
  result = result.replace(
    /[MN][A-Za-z\d]{23}\.[\w-]{6}\.[\w-]{27}/g,
    "<redacted>"
  );

  // 4. Anthropic API key  — format: sk-ant-<20+ base64url chars>
  result = result.replace(/sk-ant-[A-Za-z0-9\-_]{20,}/g, "<redacted>");

  return result;
}