terminal

import { createConfigSchematics, type InferParsedConfig } from "@lmstudio/sdk";

export function getAutoDetectedShellPath(): string {
  if (process.platform === "win32") {
    try {
      const { execSync } = require("child_process");
      execSync("pwsh -Command 'Write-Output \"OK\"'", { stdio: ["pipe", "pipe", "ignore"], timeout: 1000 });
      return "pwsh";
    } catch {
      try {
        const powershellPath = process.env.SystemRoot + "\\System32\\WindowsPowerShell\\v1.0\\powershell.exe";
        if (require("fs").existsSync(powershellPath)) return powershellPath;
      } catch {}
    }
  } else {
    const envShell = process.env.SHELL?.trim();
    if (envShell && require("fs").existsSync(envShell)) return envShell;
    for (const sh of ["/bin/zsh", "/bin/bash", "/bin/sh"]) {
      try {
        if (require("fs").existsSync(sh)) return sh;
      } catch {}
    }
  }
  return "";
}

export const configSchematics = createConfigSchematics()
  .field(
    "shellPath",
    "string",
    {
      displayName: "Shell Path (optional)",
      subtitle:
        "Override the default shell. Leave empty to auto-detect. " +
        "Windows: uses pwsh.exe (PowerShell 7) if available, then powershell.exe or cmd.exe. " +
        "macOS/Linux: honours $SHELL env var, then zsh > bash > sh.",
      placeholder: "Leave empty for auto-detection",
    },
    getAutoDetectedShellPath(),
  )
  .field(
    "windowsShell",
    "select",
    {
      displayName: "Windows Shell",
      subtitle:
        "Shell used for exec on Windows. " +
        "PowerShell 7 (pwsh) is recommended — it supports modern syntax, pipelines, and UTF-8 natively. " +
        "Falls back to powershell.exe if pwsh is not installed.",
      options: [
        { value: "powershell", displayName: "PowerShell 7 / pwsh (recommended)" },
        { value: "cmd", displayName: "Command Prompt (cmd.exe)" },
      ],
    },
    "powershell",
  )
  .field(
    "pythonPath",
    "string",
    {
      displayName: "Python Executable (optional)",
      subtitle:
        "Override the Python binary used by run_script. " +
        "Leave empty to auto-detect. " +
        "Windows examples: python, py, C:\\Users\\you\\AppData\\Local\\Programs\\Python\\Python312\\python.exe",
      placeholder: "Leave empty for auto-detection",
    },
    "",
  )
  .field(
    "defaultCwd",
    "string",
    {
      displayName: "Default Working Directory (optional)",
      subtitle:
        "Default directory for exec and run_script when cwd is not specified. " +
        "Leave empty to use the home directory. Supports ~ and %ENVVAR% expansion.",
      placeholder: "Leave empty for home directory",
    },
    "",
  )
  .field(
    "maxOutputSize",
    "numeric",
    {
      displayName: "Maximum Output Size (bytes)",
      subtitle:
        "Maximum size of output to return from exec commands. " +
        "Larger outputs will be truncated with an indicator.",
      hint: "Default: 10MB",
    },
    10 * 1024 * 1024,
  )
  .build();

export type ParsedConfig = InferParsedConfig<typeof configSchematics>;

// --- Validation helpers ---

/**
 * Normalise and clamp numeric config values.
 * Returns `null` when the value is out of acceptable bounds.
 */
export function clampNumeric(
  value: number | undefined,
  min: number,
  max: number,
  fallback: number,
): number {
  if (value == null || !Number.isFinite(value)) return fallback;
  if (value < min) return min;
  if (value > max) return max;
  return Math.trunc(value);
}

/**
 * Validate `defaultCwd` exists on disk (lazily, at runtime).
 */
export function validateDefaultCwd(cwd: string | undefined): string {
  if (!cwd || cwd.trim() === "") return "";
  const fs = require("fs");
  const expanded = cwd.replace(/^~/, require("os").homedir());
  if (!fs.existsSync(expanded)) return ""; // will be resolved at runtime
  return expanded;
}

/**
 * Validate `windowsShell` value.
 */
export function validateWindowsShell(value: string | undefined): "powershell" | "cmd" {
  if (value === "cmd") return "cmd";
  return "powershell";
}