/**
 * Gantt Board Task CRUD Utilities
 * Full CRUD operations on gantt board tasks via Supabase
 */

const SUPABASE_URL = "https://qnatchrjlpehiijwtreh.supabase.co";
const SERVICE_KEY = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6InFuYXRjaHJqbHBlaGlpand0cmVoIiwicm9sZSI6InNlcnZpY2Vfcm9sZSIsImlhdCI6MTc3MTY0MDQzNiwiZXhwIjoyMDg3MjE2NDM2fQ.rHoc3NfL59S4lejU4-ArSzox1krQkQG-TnfXb6sslm0";

const HEADERS = {
  "apikey": SERVICE_KEY,
  "Authorization": `Bearer ${SERVICE_KEY}`,
  "Content-Type": "application/json",
};

/**
 * Generate UUID v4
 */
function generateUUID(): string {
  return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, (c) => {
    const r = (Math.random() * 16) | 0;
    const v = c === "x" ? r : (r & 0x3) | 0x8;
    return v.toString(16);
  });
}

/**
 * Get current ISO timestamp
 */
function nowISO(): string {
  return new Date().toISOString();
}

/**
 * Task interface
 */
export interface GanttTask {
  id: string;
  title: string;
  description?: string;
  status: "open" | "todo" | "blocked" | "in-progress" | "review" | "validate" | "archived" | "canceled" | "done";
  priority: "low" | "medium" | "high" | "urgent";
  type?: "idea" | "task" | "bug" | "research" | "plan";
  project_id: string;
  sprint_id?: string;
  assignee_id?: string;
  created_at: string;
  updated_at: string;
  due_date?: string;
  tags?: string[];
  comments?: unknown[];
  attachments?: unknown[];
}

/**
 * LIST all tasks (optionally filtered by status)
 */
export async function listTasks(status?: string): Promise<GanttTask[]> {
  let url = `${SUPABASE_URL}/rest/v1/tasks?select=*&order=created_at.desc`;
  if (status) {
    url = `${SUPABASE_URL}/rest/v1/tasks?select=*&status=eq.${status}&order=created_at.desc`;
  }
  
  const res = await fetch(url, { headers: HEADERS });
  if (!res.ok) throw new Error(`Failed to list tasks: ${res.status}`);
  return res.json();
}

/**
 * GET a single task by ID
 */
export async function getTask(taskId: string): Promise<GanttTask | null> {
  const url = `${SUPABASE_URL}/rest/v1/tasks?id=eq.${taskId}&select=*`;
  const res = await fetch(url, { headers: HEADERS });
  if (!res.ok) throw new Error(`Failed to get task: ${res.status}`);
  const tasks = await res.json();
  return tasks[0] || null;
}

/**
 * CREATE a new task
 */
export async function createTask(params: {
  title: string;
  description?: string;
  status?: GanttTask["status"];
  priority?: GanttTask["priority"];
  type?: GanttTask["type"];
  projectId?: string;
  assigneeId?: string;
  dueDate?: string;
  tags?: string[];
}): Promise<GanttTask> {
  const task: Partial<GanttTask> = {
    id: generateUUID(),
    title: params.title,
    description: params.description,
    status: params.status || "open",
    priority: params.priority || "medium",
    type: params.type || "task",
    project_id: params.projectId || "1",
    assignee_id: params.assigneeId || "9c29cc99-81a1-4e75-8dff-cd7cc5ceb5aa", // Max
    created_at: nowISO(),
    updated_at: nowISO(),
    due_date: params.dueDate,
    tags: params.tags || [],
    comments: [],
    attachments: [],
  };

  const res = await fetch(`${SUPABASE_URL}/rest/v1/tasks`, {
    method: "POST",
    headers: HEADERS,
    body: JSON.stringify(task),
  });
  
  if (!res.ok) throw new Error(`Failed to create task: ${res.status}`);
  return task as GanttTask;
}

/**
 * UPDATE a task (partial update)
 */
export async function updateTask(
  taskId: string,
  updates: Partial<Omit<GanttTask, "id" | "created_at">>
): Promise<void> {
  const payload = {
    ...updates,
    updated_at: nowISO(),
  };

  const res = await fetch(`${SUPABASE_URL}/rest/v1/tasks?id=eq.${taskId}`, {
    method: "PATCH",
    headers: HEADERS,
    body: JSON.stringify(payload),
  });
  
  if (!res.ok) throw new Error(`Failed to update task: ${res.status}`);
}

/**
 * DELETE a task
 */
export async function deleteTask(taskId: string): Promise<void> {
  const res = await fetch(`${SUPABASE_URL}/rest/v1/tasks?id=eq.${taskId}`, {
    method: "DELETE",
    headers: HEADERS,
  });
  
  if (!res.ok) throw new Error(`Failed to delete task: ${res.status}`);
}

/**
 * Update task status (convenience method)
 */
export async function updateTaskStatus(
  taskId: string,
  status: GanttTask["status"]
): Promise<void> {
  return updateTask(taskId, { status });
}

/**
 * Assign task to user (convenience method)
 */
export async function assignTask(
  taskId: string,
  assigneeId: string
): Promise<void> {
  return updateTask(taskId, { assignee_id: assigneeId });
}

/**
 * Mark task as done (convenience method)
 */
export async function completeTask(taskId: string): Promise<void> {
  return updateTask(taskId, { status: "done" });
}

// Example usage:
// const task = await createTask({ title: "New feature", priority: "high" });
// await updateTaskStatus(task.id, "in-progress");
// await completeTask(task.id);