import { promises as fs } from "node:fs";
import os from "node:os";
import path from "node:path";
import { FileHandle, type FilesNamespace, type PromptPreprocessorController } from "@lmstudio/sdk";

export interface RegistryVideo {
  originalName: string;
  frames: string[];
  createdAt: string;
}

export interface VideoRegistry {
  userFilesDir?: string;
  identifierPrefix?: string;
  videos: Record<string, RegistryVideo>;
}

export interface UserFilesTarget {
  dir: string;
  prefix: string;
}

const REGISTRY_FILE = "video-registry.json";

// 1x1 transparent PNG, used to probe where LM Studio stores uploaded files.
const TINY_PNG_BASE64 =
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==";

export async function loadRegistry(workDir: string): Promise<VideoRegistry> {
  try {
    const raw = await fs.readFile(path.join(workDir, REGISTRY_FILE), "utf8");
    const parsed = JSON.parse(raw) as Partial<VideoRegistry>;
    return { userFilesDir: parsed.userFilesDir, identifierPrefix: parsed.identifierPrefix, videos: parsed.videos ?? {} };
  } catch {
    return { videos: {} };
  }
}

export async function saveRegistry(workDir: string, registry: VideoRegistry): Promise<void> {
  await fs.mkdir(workDir, { recursive: true });
  const tmp = path.join(workDir, `${REGISTRY_FILE}.tmp`);
  await fs.writeFile(tmp, JSON.stringify(registry, null, 2), "utf8");
  await fs.rename(tmp, path.join(workDir, REGISTRY_FILE));
}

/**
 * Uploads a tiny probe image through the SDK and asks where LM Studio stored it, which reveals
 * the user-files directory. The probe itself is a temporary upload that LM Studio cleans up on its own.
 */
export async function discoverUserFilesDir(ctl: PromptPreprocessorController): Promise<UserFilesTarget | null> {
  const workDir = ctl.getWorkingDirectory();
  await fs.mkdir(workDir, { recursive: true });
  const probePath = path.join(workDir, ".plugin-video-probe.png");
  try {
    await fs.writeFile(probePath, Buffer.from(TINY_PNG_BASE64, "base64"));
    const handle = await ctl.client.files.prepareImage(probePath);
    const filePath = await handle.getFilePath();
    return { dir: path.dirname(filePath), prefix: handle.identifier.startsWith("local:") ? "local:" : "" };
  } catch (err) {
    ctl.debug("Could not discover LM Studio user-files directory:", err instanceof Error ? err.message : String(err));
    return null;
  } finally {
    await fs.rm(probePath, { force: true }).catch(() => {});
  }
}

export async function fallbackUserFilesDir(): Promise<string | null> {
  const dir = path.join(os.homedir(), ".cache", "lm-studio", "user-files");
  try {
    await fs.access(dir);
    return dir;
  } catch {
    return null;
  }
}

export function frameFileName(videoKey: string, index: number): string {
  return `plugin-video__${videoKey}__frame_${String(index).padStart(4, "0")}.jpg`;
}

export async function findFramesOnDisk(dir: string, videoKey: string): Promise<string[]> {
  const all = await fs.readdir(dir).catch(() => [] as string[]);
  return all.filter(f => f.startsWith(`plugin-video__${videoKey}__frame_`) && f.endsWith(".jpg")).sort();
}

/**
 * Builds a FileHandle that points at a file we manage on disk ourselves (inside LM Studio's
 * user-files directory). Direct construction is deprecated by the SDK, but it is exactly what is
 * needed here: the reference stays valid across turns and restarts because the file persists.
 */
export function makePersistentHandle(
  files: FilesNamespace,
  prefix: string,
  fileName: string,
  sizeBytes: number,
): FileHandle {
  return new FileHandle(files, `${prefix}${fileName}`, "image", sizeBytes, fileName);
}

import { promises as fs } from "node:fs";
import os from "node:os";
import path from "node:path";
import { FileHandle, type FilesNamespace, type PromptPreprocessorController } from "@lmstudio/sdk";

export interface RegistryVideo {
  originalName: string;
  frames: string[];
  createdAt: string;
}

export interface VideoRegistry {
  userFilesDir?: string;
  identifierPrefix?: string;
  videos: Record<string, RegistryVideo>;
}

export interface UserFilesTarget {
  dir: string;
  prefix: string;
}

const REGISTRY_FILE = "video-registry.json";

// 1x1 transparent PNG, used to probe where LM Studio stores uploaded files.
const TINY_PNG_BASE64 =
  "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg==";

export async function loadRegistry(workDir: string): Promise<VideoRegistry> {
  try {
    const raw = await fs.readFile(path.join(workDir, REGISTRY_FILE), "utf8");
    const parsed = JSON.parse(raw) as Partial<VideoRegistry>;
    return { userFilesDir: parsed.userFilesDir, identifierPrefix: parsed.identifierPrefix, videos: parsed.videos ?? {} };
  } catch {
    return { videos: {} };
  }
}

export async function saveRegistry(workDir: string, registry: VideoRegistry): Promise<void> {
  await fs.mkdir(workDir, { recursive: true });
  const tmp = path.join(workDir, `${REGISTRY_FILE}.tmp`);
  await fs.writeFile(tmp, JSON.stringify(registry, null, 2), "utf8");
  await fs.rename(tmp, path.join(workDir, REGISTRY_FILE));
}

/**
 * Uploads a tiny probe image through the SDK and asks where LM Studio stored it, which reveals
 * the user-files directory. The probe itself is a temporary upload that LM Studio cleans up on its own.
 */
export async function discoverUserFilesDir(ctl: PromptPreprocessorController): Promise<UserFilesTarget | null> {
  const workDir = ctl.getWorkingDirectory();
  await fs.mkdir(workDir, { recursive: true });
  const probePath = path.join(workDir, ".plugin-video-probe.png");
  try {
    await fs.writeFile(probePath, Buffer.from(TINY_PNG_BASE64, "base64"));
    const handle = await ctl.client.files.prepareImage(probePath);
    const filePath = await handle.getFilePath();
    return { dir: path.dirname(filePath), prefix: handle.identifier.startsWith("local:") ? "local:" : "" };
  } catch (err) {
    ctl.debug("Could not discover LM Studio user-files directory:", err instanceof Error ? err.message : String(err));
    return null;
  } finally {
    await fs.rm(probePath, { force: true }).catch(() => {});
  }
}

export async function fallbackUserFilesDir(): Promise<string | null> {
  const dir = path.join(os.homedir(), ".cache", "lm-studio", "user-files");
  try {
    await fs.access(dir);
    return dir;
  } catch {
    return null;
  }
}

export function frameFileName(videoKey: string, index: number): string {
  return `plugin-video__${videoKey}__frame_${String(index).padStart(4, "0")}.jpg`;
}

export async function findFramesOnDisk(dir: string, videoKey: string): Promise<string[]> {
  const all = await fs.readdir(dir).catch(() => [] as string[]);
  return all.filter(f => f.startsWith(`plugin-video__${videoKey}__frame_`) && f.endsWith(".jpg")).sort();
}

/**
 * Builds a FileHandle that points at a file we manage on disk ourselves (inside LM Studio's
 * user-files directory). Direct construction is deprecated by the SDK, but it is exactly what is
 * needed here: the reference stays valid across turns and restarts because the file persists.
 */
export function makePersistentHandle(
  files: FilesNamespace,
  prefix: string,
  fileName: string,
  sizeBytes: number,
): FileHandle {
  return new FileHandle(files, `${prefix}${fileName}`, "image", sizeBytes, fileName);
}