import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";

/** Error whose message is safe to surface to the model or user. */
export class WorkspaceError extends Error {}

/** OS-appropriate example path shown to the model in tool descriptions and reminders. */
export const EXAMPLE_PATH =
  process.platform === "win32" ? "D:/AI stuff/MyProject" : "/home/me/my-project";

let root: string | null = null;

/**
 * LM Studio may run tool calls and prompt hooks in a fresh plugin process (or reload the
 * plugin between turns), which would wipe in-memory state. Mirror the workspace to a small
 * file so any process can pick it back up. Shared across chats; set_workspace overwrites it.
 */
const STATE_FILE = path.join(os.tmpdir(), "lmstudio-code-agent-workspace.txt");

function persistRoot(abs: string): void {
  try {
    fs.writeFileSync(STATE_FILE, abs, "utf8");
  } catch {
    // Best effort; in-memory state still works within this process.
  }
}

/** Current root: in-memory if set, otherwise restored from the state file if still valid. */
function currentRoot(): string | null {
  if (root !== null) return root;
  try {
    const saved = fs.readFileSync(STATE_FILE, "utf8").trim();
    if (saved && fs.statSync(saved).isDirectory()) {
      root = saved;
      return root;
    }
  } catch {
    // No saved state, or the folder no longer exists.
  }
  return null;
}

function norm(p: string): string {
  return process.platform === "win32" ? p.toLowerCase() : p;
}

export function hasWorkspace(): boolean {
  return currentRoot() !== null;
}

/** Returns the workspace root, or throws if none is set yet. */
export function getWorkspace(): string {
  const r = currentRoot();
  if (r === null) {
    throw new WorkspaceError(
      "No working folder set yet. Ask the user for their project folder and call set_workspace first."
    );
  }
  return r;
}

/**
 * Strip surrounding whitespace and matching quotes/backticks models often add.
 * On Windows, also repair escape damage: when a model sends "D:\temp" with single
 * backslashes, JSON parsing turns "\t" into a tab, "\b" into a backspace, etc.
 */
export function cleanPathInput(p: string): string {
  let s = p.trim();
  for (let i = 0; i < 2; i++) {
    const n = s.length;
    if (n >= 2) {
      const a = s[0];
      const b = s[n - 1];
      if ((a === '"' && b === '"') || (a === "'" && b === "'") || (a === "`" && b === "`")) {
        s = s.slice(1, n - 1).trim();
      } else break;
    }
  }
  if (process.platform === "win32") {
    s = s
      .replace(/\t/g, "\\t")
      .replace(/\n/g, "\\n")
      .replace(/\r/g, "\\r")
      .replace(/\f/g, "\\f")
      .replace(/\x08/g, "\\b");
  }
  return s;
}

/** Suggestion hint: nearest existing ancestor folder plus up to 10 of its subfolders. */
export function suggestFolders(abs: string): string {
  let dir = path.dirname(abs);
  for (let i = 0; i < 8; i++) {
    if (!fs.existsSync(dir)) {
      const parent = path.dirname(dir);
      if (parent === dir) break;
      dir = parent;
      continue;
    }
    try {
      const names = fs
        .readdirSync(dir, { withFileTypes: true })
        .filter((e) => e.isDirectory())
        .map((e) => e.name)
        .sort()
        .slice(0, 10);
      if (names.length === 0) return `\nClosest existing folder is ${dir} (no subfolders).`;
      return `\nClosest existing folder is ${dir}. Subfolders:\n${names.join("\n")}`;
    } catch {
      return "";
    }
  }
  return "";
}

/** Validates, canonicalizes, and stores the workspace root. Returns the absolute path. */
export function setWorkspace(p: string): string {
  const clean = cleanPathInput(p);
  if (clean === "" || clean.includes("\0")) {
    throw new WorkspaceError("Invalid folder path.");
  }
  const abs = path.resolve(clean);
  let st: fs.Stats;
  try {
    st = fs.statSync(abs);
  } catch {
    throw new WorkspaceError(
      `Folder not found: ${abs}. Check the exact spelling and case.${suggestFolders(abs)}`
    );
  }
  if (!st.isDirectory()) {
    throw new WorkspaceError(`Not a folder: ${abs}`);
  }
  root = abs;
  persistRoot(abs);
  return abs;
}

/**
 * Resolves `rel` against the workspace root and guarantees it stays inside.
 * Accepts relative paths (joined under root) or absolute paths (checked for containment).
 */
export function resolveSafe(rel: string): string {
  const r = getWorkspace();
  rel = cleanPathInput(rel);
  if (rel === "" || rel.includes("\0")) {
    throw new WorkspaceError("Invalid path.");
  }
  // Models often use "/" or "\" to mean "the project root".
  if (rel === "/" || rel === "\\") return r;

  const resolved = path.resolve(r, rel);
  const relToRoot = path.relative(norm(r), norm(resolved));
  const escapes =
    relToRoot === ".." || relToRoot.startsWith(".." + path.sep) || path.isAbsolute(relToRoot);

  if (escapes) {
    // Recovery: the model gave a path beside the workspace, e.g. "D:\AI stuff\Foo.csproj"
    // when the root is "D:\AI stuff\Foo". Use the file inside the workspace if it exists.
    if (path.isAbsolute(rel) && norm(path.dirname(resolved)) === norm(path.dirname(r))) {
      const candidate = path.join(r, path.basename(resolved));
      if (fs.existsSync(candidate)) return candidate;
    }
    throw new WorkspaceError(
      `Path escapes the working folder: ${rel}. The working folder is ${r}. ` +
        `Use paths relative to it, e.g. "src/app.ts" or just the file name.`
    );
  }
  return resolved;
}

import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";

/** Error whose message is safe to surface to the model or user. */
export class WorkspaceError extends Error {}

/** OS-appropriate example path shown to the model in tool descriptions and reminders. */
export const EXAMPLE_PATH =
  process.platform === "win32" ? "D:/AI stuff/MyProject" : "/home/me/my-project";

let root: string | null = null;

/**
 * LM Studio may run tool calls and prompt hooks in a fresh plugin process (or reload the
 * plugin between turns), which would wipe in-memory state. Mirror the workspace to a small
 * file so any process can pick it back up. Shared across chats; set_workspace overwrites it.
 */
const STATE_FILE = path.join(os.tmpdir(), "lmstudio-code-agent-workspace.txt");

function persistRoot(abs: string): void {
  try {
    fs.writeFileSync(STATE_FILE, abs, "utf8");
  } catch {
    // Best effort; in-memory state still works within this process.
  }
}

/** Current root: in-memory if set, otherwise restored from the state file if still valid. */
function currentRoot(): string | null {
  if (root !== null) return root;
  try {
    const saved = fs.readFileSync(STATE_FILE, "utf8").trim();
    if (saved && fs.statSync(saved).isDirectory()) {
      root = saved;
      return root;
    }
  } catch {
    // No saved state, or the folder no longer exists.
  }
  return null;
}

function norm(p: string): string {
  return process.platform === "win32" ? p.toLowerCase() : p;
}

export function hasWorkspace(): boolean {
  return currentRoot() !== null;
}

/** Returns the workspace root, or throws if none is set yet. */
export function getWorkspace(): string {
  const r = currentRoot();
  if (r === null) {
    throw new WorkspaceError(
      "No working folder set yet. Ask the user for their project folder and call set_workspace first."
    );
  }
  return r;
}

/**
 * Strip surrounding whitespace and matching quotes/backticks models often add.
 * On Windows, also repair escape damage: when a model sends "D:\temp" with single
 * backslashes, JSON parsing turns "\t" into a tab, "\b" into a backspace, etc.
 */
export function cleanPathInput(p: string): string {
  let s = p.trim();
  for (let i = 0; i < 2; i++) {
    const n = s.length;
    if (n >= 2) {
      const a = s[0];
      const b = s[n - 1];
      if ((a === '"' && b === '"') || (a === "'" && b === "'") || (a === "`" && b === "`")) {
        s = s.slice(1, n - 1).trim();
      } else break;
    }
  }
  if (process.platform === "win32") {
    s = s
      .replace(/\t/g, "\\t")
      .replace(/\n/g, "\\n")
      .replace(/\r/g, "\\r")
      .replace(/\f/g, "\\f")
      .replace(/\x08/g, "\\b");
  }
  return s;
}

/** Suggestion hint: nearest existing ancestor folder plus up to 10 of its subfolders. */
export function suggestFolders(abs: string): string {
  let dir = path.dirname(abs);
  for (let i = 0; i < 8; i++) {
    if (!fs.existsSync(dir)) {
      const parent = path.dirname(dir);
      if (parent === dir) break;
      dir = parent;
      continue;
    }
    try {
      const names = fs
        .readdirSync(dir, { withFileTypes: true })
        .filter((e) => e.isDirectory())
        .map((e) => e.name)
        .sort()
        .slice(0, 10);
      if (names.length === 0) return `\nClosest existing folder is ${dir} (no subfolders).`;
      return `\nClosest existing folder is ${dir}. Subfolders:\n${names.join("\n")}`;
    } catch {
      return "";
    }
  }
  return "";
}

/** Validates, canonicalizes, and stores the workspace root. Returns the absolute path. */
export function setWorkspace(p: string): string {
  const clean = cleanPathInput(p);
  if (clean === "" || clean.includes("\0")) {
    throw new WorkspaceError("Invalid folder path.");
  }
  const abs = path.resolve(clean);
  let st: fs.Stats;
  try {
    st = fs.statSync(abs);
  } catch {
    throw new WorkspaceError(
      `Folder not found: ${abs}. Check the exact spelling and case.${suggestFolders(abs)}`
    );
  }
  if (!st.isDirectory()) {
    throw new WorkspaceError(`Not a folder: ${abs}`);
  }
  root = abs;
  persistRoot(abs);
  return abs;
}

/**
 * Resolves `rel` against the workspace root and guarantees it stays inside.
 * Accepts relative paths (joined under root) or absolute paths (checked for containment).
 */
export function resolveSafe(rel: string): string {
  const r = getWorkspace();
  rel = cleanPathInput(rel);
  if (rel === "" || rel.includes("\0")) {
    throw new WorkspaceError("Invalid path.");
  }
  // Models often use "/" or "\" to mean "the project root".
  if (rel === "/" || rel === "\\") return r;

  const resolved = path.resolve(r, rel);
  const relToRoot = path.relative(norm(r), norm(resolved));
  const escapes =
    relToRoot === ".." || relToRoot.startsWith(".." + path.sep) || path.isAbsolute(relToRoot);

  if (escapes) {
    // Recovery: the model gave a path beside the workspace, e.g. "D:\AI stuff\Foo.csproj"
    // when the root is "D:\AI stuff\Foo". Use the file inside the workspace if it exists.
    if (path.isAbsolute(rel) && norm(path.dirname(resolved)) === norm(path.dirname(r))) {
      const candidate = path.join(r, path.basename(resolved));
      if (fs.existsSync(candidate)) return candidate;
    }
    throw new WorkspaceError(
      `Path escapes the working folder: ${rel}. The working folder is ${r}. ` +
        `Use paths relative to it, e.g. "src/app.ts" or just the file name.`
    );
  }
  return resolved;
}