import {
  fileBasename,
  formatFilePathPosition,
  splitFilePathPosition,
  stripSlashPrefixedWindowsDrive,
} from "@t3tools/client-runtime/markdown-links";
import { isWindowsAbsolutePath } from "@t3tools/shared/path";

function normalizePathSeparators(path: string): string {
  return path.replaceAll("\\", "/");
}

function trimTrailingPathSeparators(path: string): string {
  return path.replace(/[\\/]+$/, "");
}

function stripRelativePrefixes(path: string): string {
  return path.replace(/^\.\/+/, "").replace(/^\/+/, "");
}

export function formatWorkspaceRelativePath(
  pathWithPosition: string,
  workspaceRoot: string | undefined,
): string {
  const position = splitFilePathPosition(pathWithPosition);
  const normalizedPath = stripSlashPrefixedWindowsDrive(normalizePathSeparators(position.path));

  let displayPath = normalizedPath;
  if (workspaceRoot) {
    const normalizedWorkspaceRoot = stripSlashPrefixedWindowsDrive(
      normalizePathSeparators(trimTrailingPathSeparators(workspaceRoot)),
    );
    const workspaceLabel = fileBasename(normalizedWorkspaceRoot);
    const caseInsensitive = isWindowsAbsolutePath(stripSlashPrefixedWindowsDrive(workspaceRoot));
    const pathForCompare = caseInsensitive ? normalizedPath.toLowerCase() : normalizedPath;
    const workspaceForCompare = caseInsensitive
      ? normalizedWorkspaceRoot.toLowerCase()
      : normalizedWorkspaceRoot;
    const workspaceWithSeparator = `${workspaceForCompare}/`;
    const workspaceLabelWithSeparator = `${caseInsensitive ? workspaceLabel.toLowerCase() : workspaceLabel}/`;

    if (pathForCompare === workspaceForCompare) {
      displayPath = workspaceLabel;
    } else if (pathForCompare.startsWith(workspaceWithSeparator)) {
      const relativeSuffix = normalizedPath.slice(normalizedWorkspaceRoot.length + 1);
      displayPath = `${workspaceLabel}/${relativeSuffix}`;
    } else if (!normalizedPath.startsWith("/")) {
      const relativePath = stripRelativePrefixes(normalizedPath);
      displayPath = pathForCompare.startsWith(workspaceLabelWithSeparator)
        ? normalizedPath
        : `${workspaceLabel}/${relativePath}`;
    }
  }

  return formatFilePathPosition({ ...position, path: displayPath });
}