feat: integrate Pi backend and Pi Web

pi-web/lib/file-paths.ts

@@ -0,0 +1,43 @@
+export function normalizeFilePathSlashes(filePath: string): string {
+  if (/^[a-zA-Z]:[\\/]/.test(filePath) || filePath.startsWith("\\\\")) {
+    return filePath.replace(/\\/g, "/");
+  }
+  return filePath;
+}
+
+export function encodeFilePathForApi(filePath: string): string {
+  return normalizeFilePathSlashes(filePath)
+    .split("/")
+    .filter(Boolean)
+    .map(encodeURIComponent)
+    .join("/");
+}
+
+export function getFileName(filePath: string): string {
+  const normalized = normalizeFilePathSlashes(filePath).replace(/\/+$/, "");
+  return normalized.split("/").pop() ?? normalized;
+}
+
+export function getFileDirectory(filePath: string): string {
+  const normalized = normalizeFilePathSlashes(filePath).replace(/\/+$/, "");
+  const lastSlash = normalized.lastIndexOf("/");
+  if (lastSlash < 0) return "";
+  if (lastSlash === 0) return "/";
+  if (lastSlash === 2 && /^[a-zA-Z]:\//.test(normalized)) return normalized.slice(0, 3);
+  return normalized.slice(0, lastSlash);
+}
+
+export function getRelativeFilePath(filePath: string, cwd?: string): string {
+  if (!cwd) return filePath;
+
+  const normalizedFile = normalizeFilePathSlashes(filePath);
+  const normalizedCwd = normalizeFilePathSlashes(cwd).replace(/\/$/, "");
+  if (normalizedFile.startsWith(normalizedCwd + "/")) {
+    return normalizedFile.slice(normalizedCwd.length + 1);
+  }
+  return filePath;
+}
+
+export function joinFilePath(parent: string, child: string): string {
+  return `${normalizeFilePathSlashes(parent).replace(/\/$/, "")}/${child}`;
+}