feat: add pure ssh2 remote operations

pi-ssh/src/import.ts

@@ -0,0 +1,53 @@
+import { execFileSync } from "node:child_process";
+import { existsSync, readFileSync } from "node:fs";
+import { homedir } from "node:os";
+import { join } from "node:path";
+
+export type EffectiveSshConfig = Map<string, string[]>;
+
+export function parseSshG(text: string): EffectiveSshConfig {
+  const values: EffectiveSshConfig = new Map();
+  for (const line of text.split(/\r?\n/)) {
+    const separator = line.indexOf(" ");
+    if (separator < 1) continue;
+    const key = line.slice(0, separator).trim().toLowerCase();
+    const value = line.slice(separator + 1).trim();
+    if (!key || !value) continue;
+    const current = values.get(key) ?? [];
+    current.push(value);
+    values.set(key, current);
+  }
+  return values;
+}
+
+export function resolveOpenSshAlias(alias: string): EffectiveSshConfig {
+  if (!/^[A-Za-z0-9][A-Za-z0-9._-]*$/.test(alias)) throw new Error(`invalid SSH alias: ${alias}`);
+  const output = execFileSync("ssh", ["-G", "--", alias], {
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+  return parseSshG(output);
+}
+
+export function effectiveValue(config: EffectiveSshConfig, key: string): string | undefined {
+  return config.get(key.toLowerCase())?.at(-1);
+}
+
+export function effectiveValues(config: EffectiveSshConfig, key: string): string[] {
+  return config.get(key.toLowerCase()) ?? [];
+}
+
+export function listDirectSshAliases(configPath = join(homedir(), ".ssh", "config")): string[] {
+  if (!existsSync(configPath)) return [];
+  const aliases: string[] = [];
+  const text = readFileSync(configPath, "utf8");
+  for (const line of text.split(/\r?\n/)) {
+    const match = /^\s*Host\s+(.+?)\s*$/i.exec(line);
+    if (!match) continue;
+    for (const alias of match[1].split(/\s+/)) {
+      if (!alias || alias.includes("*") || alias.includes("?") || alias.startsWith("!")) continue;
+      if (!aliases.includes(alias)) aliases.push(alias);
+    }
+  }
+  return aliases;
+}