import { existsSync } from "fs";
import { readFile, writeFile } from "fs/promises";
import { join } from "path";

export type TaskStatus = "pending" | "in_progress" | "done" | "blocked";

export interface Task {
  text: string;
  status: TaskStatus;
  note: string;
}

export const TASK_FILE_NAME = ".lmstudio-tasks.json";

/**
 * Fallback store used when file writes are disabled. Keyed by workspace root so
 * two chats pointed at different folders do not share a checklist.
 */
const memoryStore = new Map<string, Task[]>();

export class TaskStore {
  private readonly filePath: string;

  /**
   * @param persist when false the checklist lives only in the plugin process,
   *   so the "allow writing files" toggle is never quietly bypassed.
   */
  constructor(
    private readonly root: string,
    private readonly persist: boolean,
  ) {
    this.filePath = join(root, TASK_FILE_NAME);
  }

  get storageDescription(): string {
    return this.persist ? TASK_FILE_NAME : "plugin memory (not saved to disk)";
  }

  async load(): Promise<Task[]> {
    if (!this.persist) {
      return memoryStore.get(this.root) ?? [];
    }
    if (!existsSync(this.filePath)) return [];
    try {
      const parsed: unknown = JSON.parse(await readFile(this.filePath, "utf-8"));
      if (!Array.isArray(parsed)) return [];
      return parsed.filter(isTask);
    } catch {
      return [];
    }
  }

  async save(tasks: Task[]): Promise<void> {
    if (!this.persist) {
      memoryStore.set(this.root, tasks);
      return;
    }
    await writeFile(this.filePath, JSON.stringify(tasks, null, 2), "utf-8");
  }
}

function isTask(value: unknown): value is Task {
  if (typeof value !== "object" || value === null) return false;
  const candidate = value as Record<string, unknown>;
  return (
    typeof candidate.text === "string" &&
    typeof candidate.status === "string" &&
    ["pending", "in_progress", "done", "blocked"].includes(candidate.status)
  );
}

const STATUS_MARK: Record<TaskStatus, string> = {
  pending: "[ ]",
  in_progress: "[~]",
  done: "[x]",
  blocked: "[!]",
};

export function renderTasks(tasks: Task[]): string {
  if (tasks.length === 0) {
    return "The checklist is empty. Use set_tasks to create one.";
  }
  const lines = tasks.map((task, index) => {
    const note = task.note.trim() === "" ? "" : `  -- ${task.note.trim()}`;
    return `${index + 1}. ${STATUS_MARK[task.status]} ${task.text}${note}`;
  });
  const remaining = tasks.filter((task) => task.status !== "done").length;
  lines.push("", `${tasks.length - remaining}/${tasks.length} done, ${remaining} remaining.`);
  return lines.join("\n");
}

import { existsSync } from "fs";
import { readFile, writeFile } from "fs/promises";
import { join } from "path";

export type TaskStatus = "pending" | "in_progress" | "done" | "blocked";

export interface Task {
  text: string;
  status: TaskStatus;
  note: string;
}

export const TASK_FILE_NAME = ".lmstudio-tasks.json";

/**
 * Fallback store used when file writes are disabled. Keyed by workspace root so
 * two chats pointed at different folders do not share a checklist.
 */
const memoryStore = new Map<string, Task[]>();

export class TaskStore {
  private readonly filePath: string;

  /**
   * @param persist when false the checklist lives only in the plugin process,
   *   so the "allow writing files" toggle is never quietly bypassed.
   */
  constructor(
    private readonly root: string,
    private readonly persist: boolean,
  ) {
    this.filePath = join(root, TASK_FILE_NAME);
  }

  get storageDescription(): string {
    return this.persist ? TASK_FILE_NAME : "plugin memory (not saved to disk)";
  }

  async load(): Promise<Task[]> {
    if (!this.persist) {
      return memoryStore.get(this.root) ?? [];
    }
    if (!existsSync(this.filePath)) return [];
    try {
      const parsed: unknown = JSON.parse(await readFile(this.filePath, "utf-8"));
      if (!Array.isArray(parsed)) return [];
      return parsed.filter(isTask);
    } catch {
      return [];
    }
  }

  async save(tasks: Task[]): Promise<void> {
    if (!this.persist) {
      memoryStore.set(this.root, tasks);
      return;
    }
    await writeFile(this.filePath, JSON.stringify(tasks, null, 2), "utf-8");
  }
}

function isTask(value: unknown): value is Task {
  if (typeof value !== "object" || value === null) return false;
  const candidate = value as Record<string, unknown>;
  return (
    typeof candidate.text === "string" &&
    typeof candidate.status === "string" &&
    ["pending", "in_progress", "done", "blocked"].includes(candidate.status)
  );
}

const STATUS_MARK: Record<TaskStatus, string> = {
  pending: "[ ]",
  in_progress: "[~]",
  done: "[x]",
  blocked: "[!]",
};

export function renderTasks(tasks: Task[]): string {
  if (tasks.length === 0) {
    return "The checklist is empty. Use set_tasks to create one.";
  }
  const lines = tasks.map((task, index) => {
    const note = task.note.trim() === "" ? "" : `  -- ${task.note.trim()}`;
    return `${index + 1}. ${STATUS_MARK[task.status]} ${task.text}${note}`;
  });
  const remaining = tasks.filter((task) => task.status !== "done").length;
  lines.push("", `${tasks.length - remaining}/${tasks.length} done, ${remaining} remaining.`);
  return lines.join("\n");
}