// clickup/get_task.ts
interface TaskResponse {
  id: string;
  name: string;
  description?: string;
  text_content?: string;
  status?: {
    status: string;
    color: string;
    orderindex: number;
    type: "open" | "closed" | "custom";
  };
  orderindex?: string;
  date_created?: string;
  date_updated?: string;
  date_closed?: string | null;
  date_done?: string | null;
  archived?: boolean;
  creator?: {
    id: number;
    username: string;
    email: string;
    color: string;
    profilePicture?: string;
  };
  assignees?: Array<{
    id: number;
    username: string;
    email: string;
    color: string;
    initials: string;
    profilePicture?: string;
  }>;
  watchers?: Array<{
    id: number;
    username: string;
    email: string;
    color: string;
    initials: string;
    profilePicture?: string;
  }>;
  checklists?: Array<{
    id: string;
    name: string;
    orderindex: number;
    resolved: number;
    unresolved: number;
    items: Array<{
      id: string;
      name: string;
      orderindex: number;
      assignee?: number;
      resolved: boolean;
      parent?: string;
      date_created: string;
      children?: string[];
    }>;
  }>;
  tags?: Array<{
    name: string;
    tag_fg: string;
    tag_bg: string;
    creator?: number;
  }>;
  parent?: string | null;
  priority?: {
    id: string;
    priority: "urgent" | "high" | "normal" | "low";
    color: string;
  };
  due_date?: string | null;
  start_date?: string | null;
  time_estimate?: number | null;
  time_spent?: number | null;
  custom_fields?: Array<{
    id: string;
    name: string;
    type: string;
    type_config: Record<string, any>;
    value: any;
  }>;
  list?: {
    id: string;
    name: string;
    access: boolean;
  };
  project?: {
    id: string;
    name: string;
    hidden: boolean;
    access: boolean;
  };
  folder?: {
    id: string;
    name: string;
    hidden: boolean;
    access: boolean;
  };
  space?: {
    id: string;
    name: string;
  };
  url?: string;
  permission_level?: string;
  custom_item_id?: number | null;
  custom_task_ids?: Array<{
    custom_task_id: string;
    team_id: string;
  }>;
  dependencies?: Array<{
    task_id: string;
    depends_on: string;
    type: number;
    date_created: string;
    userid: string;
  }>;
  linked_tasks?: Array<{
    task_id: string;
    link_id: string;
    date_created: string;
    userid: string;
  }>;
  team_id?: string;
  custom_id?: string | null;
  attachments?: Array<{
    id: string;
    version: string;
    date: string;
    title: string;
    extension: string;
    thumbnail_small: string;
    thumbnail_large: string;
    size: number;
  }>;
  shared?: Array<{
    id: string;
    name: string;
    type: string;
    access_level: string;
    team_id: string;
  }>;
  followers?: Array<{
    id: number;
    username: string;
    email: string;
    color: string;
    initials: string;
    profilePicture?: string;
  }>;
  [key: string]: any; // For future API additions
}

type FieldSelector = Array<keyof TaskResponse | string>;

// All we need here is the access token.
type ClickupCredentials = {
  access_token: string;
};

export async function main(
  task_id: string,
  fields: FieldSelector = ["id", "name", "status", "date_created"],
  credentials: ClickupCredentials,
) {
  // Input validation
  if (!task_id?.trim()) throw new Error("Task ID is required");

  // API call
  const response = await fetch(
    `https://api.clickup.com/api/v2/task/${task_id}`,
    {
      headers: {
        "Authorization": credentials.access_token,
      },
    },
  );

  if (!response.ok) {
    const error = await response.text();
    throw new Error(`ClickUp Error ${response.status}: ${error}`);
  }

  // Full response parsing
  const fullTask = await response.json();

  // Field filtering
  return fields.length > 0 ? filterFields(fullTask, fields) : fullTask;
}

// Recursive field filtering function
function filterFields(obj: any, fields: FieldSelector): any {
  return fields.reduce((acc, field) => {
    const [root, ...nested] = (field as string).split(".");

    if (obj[root] !== undefined) {
      if (nested.length > 0 && typeof obj[root] === "object") {
        acc[root] = filterFields(obj[root], [nested.join(".")]);
      } else {
        acc[root] = obj[root];
      }
    }

    return acc;
  }, {} as Record<string, any>);
}