import os from "node:os";

// Regex patterns to find the SSH port from Remote SSH extension logs.

// `ms-vscode-remote.remote-ssh`: `-> socksPort <port> ->` or `between local port <port>`

// `codeium.windsurf-remote-openssh`, `jeanp413.open-remote-ssh`, `google.antigravity-remote-openssh`: `=> <port>(socks) =>`

// `anysphere.remote-ssh`: `Socks port: <port>`

export const RemoteSSHLogPortRegex =

/(?:-> socksPort (\d+) ->|between local port (\d+)|=> (\d+)\(socks\) =>|Socks port: (\d+))/g;

/**

* Given the contents of a Remote - SSH log file, find the most recent port

* number used by the SSH process. This is typically the socks port, but the

* local port works too.

*

* Returns null if no port is found.

*/

export function findPort(text: string): number | null {

const allMatches = [...text.matchAll(RemoteSSHLogPortRegex)];

if (allMatches.length === 0) {

return null;

}

// Get the last match, which is the most recent port.

const lastMatch = allMatches[allMatches.length - 1];

// Each capture group corresponds to a different Remote SSH extension log format:

// [0] full match, [1] and [2] ms-vscode-remote.remote-ssh,

// [3] devin/windsurf/open-remote-ssh/antigravity, [4] anysphere.remote-ssh

const portStr = lastMatch[1] || lastMatch[2] || lastMatch[3] || lastMatch[4];

if (!portStr) {

return null;

}

return Number.parseInt(portStr);

}

/**

* Substitute `${env:VAR}` with `process.env.VAR` (unset → empty string),

* `${userHome}` (anywhere) with `os.homedir()`, and a leading `~` with

* `os.homedir()`. Env substitution runs first so env values can themselves

* contain `~` or `${userHome}`.

*/

export function expandPath(input: string): string {

const expanded = input.replace(

/\$\{env:([A-Za-z_][A-Za-z0-9_]*)\}/g,

(_, name: string) => process.env[name] ?? "",

);

const userHome = os.homedir();

const tildeExpanded = expanded.startsWith("~")

? userHome + expanded.substring("~".length)

: expanded;

return tildeExpanded.replaceAll("${userHome}", userHome);

}

/** `toLowerCase` typed for indexing `Lowercase`-keyed records without a cast. */

export function lowercase<T extends string>(value: T): Lowercase<T> {

return value.toLowerCase() as Lowercase<T>;

}

/**

* Return the number of times a substring appears in a string.

*/

export function countSubstring(needle: string, haystack: string): number {

if (needle.length < 1 || haystack.length < 1) {

return 0;

}

let count = 0;

let pos = haystack.indexOf(needle);

while (pos !== -1) {

count++;

pos = haystack.indexOf(needle, pos + needle.length);

}

return count;

}

/**

* Wraps `arg` in `"..."` unless every character is in the shell-safe

* whitelist (matching Python `shlex.quote`'s set: alphanumerics plus

* `@%+,=:./-`). Anything else (whitespace, `"`, `&|;()<>*?[~#!^\` `$`)

* forces quoting so the output is a single token in POSIX `sh`, cmd.exe,

* and PowerShell.

*

* Not a universal shell-escape: `$VAR` / `$(...)` / `%VAR%` still expand

* inside `"..."`. For untrusted values use {@link escapeShellArg}.

*

* @see https://docs.python.org/3/library/shlex.html#shlex.quote

* @see https://learn.microsoft.com/en-us/archive/blogs/twistylittlepassagesallalike/everyone-quotes-command-line-arguments-the-wrong-way

*/

export function escapeCommandArg(arg: string): string {

if (arg !== "" && /^[\w@%+,=:./-]+$/.test(arg)) {

return arg;

}

return `"${arg.replaceAll('"', String.raw`\"`)}"`;

}

/**

* Cross-platform shell quoting that blocks variable expansion. Use for

* values from outside the user's local settings (e.g. server-controlled).

*/

export function escapeShellArg(arg: string): string {

if (os.platform() === "win32") {

const escaped = arg.replace(/"/g, '""').replace(/%/g, "%%");

return `"${escaped}"`;

}

return `'${arg.replace(/'/g, "'\\''")}'`;

}