import { isWindows } from "./os";

/**
 * Normalize user-provided executable path for the current OS.
 * - Expands ~ on macOS/Linux via PathUtils (when available)
 * - Ensures .exe suffix on Windows when missing
 */
export function normalizeExecutablePath(input: string): string {
  const trimmed = (input || "").trim();
  if (!trimmed) return "";

  const path = trimmed;

  if (isWindows() && !/\.(exe|cmd|bat)$/i.test(path)) {
    return `${path}.exe`;
  }
  return path;
}

/** Join path segments using Zotero PathUtils (cross-platform). */
export function joinPath(...parts: string[]): string {
  const filtered = parts.filter(Boolean);
  if (!filtered.length) return "";
  try {
    return PathUtils.join(...filtered);
  } catch (e) {
    ztoolkit.log("[ChatPapers] PathUtils.join failed", filtered, e);
    throw e;
  }
}

/** Normalize user-provided storage directory paths (prefs). */
export function normalizeStoragePath(input: string): string {
  const trimmed = (input || "").trim();
  if (!trimmed) return "";

  const unified = trimmed.replace(/\\/g, "/").replace(/\/+/g, "/");

  const winMatch = unified.match(/^([A-Za-z]:)(\/.*)?$/);
  if (winMatch) {
    const drive = winMatch[1];
    const rest = (winMatch[2] || "")
      .split("/")
      .filter((part) => part && part !== ".")
      .join("\\");
    return rest ? `${drive}\\${rest}` : drive;
  }

  const absolute = unified.startsWith("/");
  const parts = unified.split("/").filter((part) => part && part !== ".");
  let result = parts.join("/");
  if (absolute) result = `/${result}`;
  return result.replace(/\/+$/, "") || (absolute ? "/" : "");
}

/** Safe single path segment for file or directory names (cross-platform). */
export function sanitizePathSegment(input: string, maxLen = 120): string {
  const cleaned = String(input || "")
    .replace(/[<>:"/\\|?*\x00-\x1f]/g, "_")
    .replace(/[.\s]+$/, "")
    .trim();
  if (!cleaned) return "_";
  if (cleaned.length <= maxLen) return cleaned;
  let hash = 0;
  for (let i = 0; i < input.length; i++) {
    hash = (hash * 31 + input.charCodeAt(i)) | 0;
  }
  const tail = Math.abs(hash).toString(36);
  return `${cleaned.slice(0, Math.max(1, maxLen - tail.length - 1))}_${tail}`;
}

/** Convert local file path to file:// URL for <audio src>. */
export function pathToFileUrl(filePath: string): string {
  const normalized = filePath.replace(/\\/g, "/");
  if (normalized.startsWith("file://")) return normalized;
  if (/^[A-Za-z]:\//.test(normalized)) {
    return `file:///${encodeURI(normalized)}`;
  }
  return `file://${encodeURI(normalized)}`;
}