import { v4 as uuidv4 } from 'uuid';
import { TaskRepository, TaskData } from '../repositories/TaskRepository.js';
import { ProjectRepository } from '../repositories/ProjectRepository.js'; // Needed to check project existence
import { logger } from '../utils/logger.js';
import { NotFoundError, ValidationError } from '../utils/errors.js'; // Using custom errors
// Define the input structure for adding a task, based on feature spec
export interface AddTaskInput {
project_id: string;
description: string;
dependencies?: string[];
priority?: 'high' | 'medium' | 'low';
status?: 'todo' | 'in-progress' | 'review' | 'done';
}
// Options for listing tasks
export interface ListTasksOptions {
project_id: string;
status?: TaskData['status'];
include_subtasks?: boolean;
}
// Type for task data potentially including nested subtasks
export interface StructuredTaskData extends TaskData {
subtasks?: StructuredTaskData[];
}
// Type for full task details including dependencies and subtasks
export interface FullTaskData extends TaskData {
dependencies: string[];
subtasks: TaskData[]; // For V1 showTask, just return direct subtasks without their own nesting/deps
}
// Input for expanding a task
export interface ExpandTaskInput {
project_id: string;
task_id: string; // Parent task ID
subtask_descriptions: string[];
force?: boolean;
}
import { Database as Db } from 'better-sqlite3'; // Import Db type
import { ConflictError } from '../utils/errors.js'; // Import ConflictError
export class TaskService {
private taskRepository: TaskRepository;
private projectRepository: ProjectRepository;
private db: Db; // Add db instance
constructor(
db: Db, // Inject Db instance
taskRepository: TaskRepository,
projectRepository: ProjectRepository
) {
this.db = db; // Store db instance
this.taskRepository = taskRepository;
this.projectRepository = projectRepository;
}
/**
* Adds a new task to a specified project.
*/
public async addTask(input: AddTaskInput): Promise<TaskData> {
logger.info(`[TaskService] Attempting to add task to project: ${input.project_id}`);
const projectExists = this.projectRepository.findById(input.project_id);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${input.project_id}`);
throw new NotFoundError(`Project with ID ${input.project_id} not found.`);
}
const taskId = uuidv4();
const now = new Date().toISOString();
const newTaskData: TaskData = {
task_id: taskId,
project_id: input.project_id,
parent_task_id: null,
description: input.description,
status: input.status ?? 'todo',
priority: input.priority ?? 'medium',
created_at: now,
updated_at: now,
};
// TODO: Validate Dependency Existence
try {
this.taskRepository.create(newTaskData, input.dependencies);
logger.info(`[TaskService] Successfully added task ${taskId} to project ${input.project_id}`);
return newTaskData;
} catch (error) {
logger.error(`[TaskService] Error adding task to project ${input.project_id}:`, error);
throw error;
}
}
/**
* Lists tasks for a project.
*/
public async listTasks(options: ListTasksOptions): Promise<TaskData[] | StructuredTaskData[]> {
logger.info(`[TaskService] Attempting to list tasks for project: ${options.project_id}`, options);
const projectExists = this.projectRepository.findById(options.project_id);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${options.project_id}`);
throw new NotFoundError(`Project with ID ${options.project_id} not found.`);
}
try {
const allTasks = this.taskRepository.findByProjectId(options.project_id, options.status);
if (!options.include_subtasks) {
const topLevelTasks = allTasks.filter(task => !task.parent_task_id);
logger.info(`[TaskService] Found ${topLevelTasks.length} top-level tasks for project ${options.project_id}`);
return topLevelTasks;
} else {
const taskMap: Map<string, StructuredTaskData> = new Map();
const rootTasks: StructuredTaskData[] = [];
for (const task of allTasks) {
taskMap.set(task.task_id, { ...task, subtasks: [] });
}
for (const task of allTasks) {
if (task.parent_task_id && taskMap.has(task.parent_task_id)) {
const parent = taskMap.get(task.parent_task_id)!;
parent.subtasks!.push(taskMap.get(task.task_id)!);
} else if (!task.parent_task_id) {
rootTasks.push(taskMap.get(task.task_id)!);
}
}
logger.info(`[TaskService] Found ${rootTasks.length} structured root tasks for project ${options.project_id}`);
return rootTasks;
}
} catch (error) {
logger.error(`[TaskService] Error listing tasks for project ${options.project_id}:`, error);
throw error;
}
}
/**
* Retrieves the full details of a single task.
*/
public async getTaskById(projectId: string, taskId: string): Promise<FullTaskData> {
logger.info(`[TaskService] Attempting to get task ${taskId} for project ${projectId}`);
const task = this.taskRepository.findById(projectId, taskId);
if (!task) {
logger.warn(`[TaskService] Task ${taskId} not found in project ${projectId}`);
throw new NotFoundError(`Task with ID ${taskId} not found in project ${projectId}.`);
}
try {
const dependencies = this.taskRepository.findDependencies(taskId);
const subtasks = this.taskRepository.findSubtasks(taskId);
const fullTaskData: FullTaskData = {
...task,
dependencies: dependencies,
subtasks: subtasks,
};
logger.info(`[TaskService] Successfully retrieved task ${taskId}`);
return fullTaskData;
} catch (error) {
logger.error(`[TaskService] Error retrieving details for task ${taskId}:`, error);
throw error;
}
}
/**
* Sets the status for one or more tasks within a project.
*/
public async setTaskStatus(projectId: string, taskIds: string[], status: TaskData['status']): Promise<number> {
logger.info(`[TaskService] Attempting to set status to '${status}' for ${taskIds.length} tasks in project ${projectId}`);
const projectExists = this.projectRepository.findById(projectId);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${projectId}`);
throw new NotFoundError(`Project with ID ${projectId} not found.`);
}
const existenceCheck = this.taskRepository.checkTasksExist(projectId, taskIds);
if (!existenceCheck.allExist) {
logger.warn(`[TaskService] One or more tasks not found in project ${projectId}:`, existenceCheck.missingIds);
throw new NotFoundError(`One or more tasks not found in project ${projectId}: ${existenceCheck.missingIds.join(', ')}`);
}
try {
const now = new Date().toISOString();
const updatedCount = this.taskRepository.updateStatus(projectId, taskIds, status, now);
if (updatedCount !== taskIds.length) {
logger.warn(`[TaskService] Expected to update ${taskIds.length} tasks, but ${updatedCount} were affected.`);
}
logger.info(`[TaskService] Successfully updated status for ${updatedCount} tasks in project ${projectId}`);
return updatedCount;
} catch (error) {
logger.error(`[TaskService] Error setting status for tasks in project ${projectId}:`, error);
throw error;
}
}
/**
* Expands a parent task by adding new subtasks.
* Optionally deletes existing subtasks first if 'force' is true.
* Uses a transaction to ensure atomicity.
* @param input - Details including parent task ID, project ID, subtask descriptions, and force flag.
* @returns The updated parent task details (including new subtasks).
* @throws {NotFoundError} If the project or parent task is not found.
* @throws {ConflictError} If subtasks exist and force is false.
* @throws {Error} If the database operation fails.
*/
public async expandTask(input: ExpandTaskInput): Promise<FullTaskData> {
const { project_id, task_id: parentTaskId, subtask_descriptions, force = false } = input;
logger.info(`[TaskService] Attempting to expand task ${parentTaskId} in project ${project_id} with ${subtask_descriptions.length} subtasks (force=${force})`);
// Use a transaction for the entire operation
const expandTransaction = this.db.transaction(() => {
// 1. Validate Parent Task Existence (within the transaction)
const parentTask = this.taskRepository.findById(project_id, parentTaskId);
if (!parentTask) {
logger.warn(`[TaskService] Parent task ${parentTaskId} not found in project ${project_id}`);
throw new NotFoundError(`Parent task with ID ${parentTaskId} not found in project ${project_id}.`);
}
// 2. Check for existing subtasks
const existingSubtasks = this.taskRepository.findSubtasks(parentTaskId);
// 3. Handle existing subtasks based on 'force' flag
if (existingSubtasks.length > 0) {
if (!force) {
logger.warn(`[TaskService] Conflict: Task ${parentTaskId} already has subtasks and force=false.`);
throw new ConflictError(`Task ${parentTaskId} already has subtasks. Use force=true to replace them.`);
} else {
logger.info(`[TaskService] Force=true: Deleting ${existingSubtasks.length} existing subtasks for parent ${parentTaskId}.`);
this.taskRepository.deleteSubtasks(parentTaskId);
// Note: Dependencies of deleted subtasks are implicitly handled by ON DELETE CASCADE in schema
}
}
// 4. Create new subtasks
const now = new Date().toISOString();
const createdSubtasks: TaskData[] = [];
for (const description of subtask_descriptions) {
const subtaskId = uuidv4();
const newSubtaskData: TaskData = {
task_id: subtaskId,
project_id: project_id,
parent_task_id: parentTaskId,
description: description, // Assuming length validation done by Zod
status: 'todo', // Default status
priority: 'medium', // Default priority
created_at: now,
updated_at: now,
};
// Use the repository's create method (which handles its own transaction part for task+deps, but is fine here)
// We pass an empty array for dependencies as expandTask doesn't set them for new subtasks
this.taskRepository.create(newSubtaskData, []);
createdSubtasks.push(newSubtaskData);
}
// 5. Fetch updated parent task details (including new subtasks and existing dependencies)
// We re-fetch to get the consistent state after the transaction commits.
// Note: This requires the transaction function to return the necessary data.
// Alternatively, construct the FullTaskData manually here. Let's construct manually.
const dependencies = this.taskRepository.findDependencies(parentTaskId); // Fetch parent's dependencies
const finalParentData: FullTaskData = {
...parentTask, // Use data fetched at the start of transaction
updated_at: now, // Update timestamp conceptually (though not saved unless status changes)
dependencies: dependencies,
subtasks: createdSubtasks, // Return the newly created subtasks
};
return finalParentData;
});
try {
// Execute the transaction
const result = expandTransaction();
logger.info(`[TaskService] Successfully expanded task ${parentTaskId} with ${subtask_descriptions.length} new subtasks.`);
return result;
} catch (error) {
logger.error(`[TaskService] Error expanding task ${parentTaskId}:`, error);
// Re-throw specific errors or generic internal error
if (error instanceof NotFoundError || error instanceof ConflictError) {
throw error;
}
throw new Error(`Failed to expand task: ${error instanceof Error ? error.message : 'Unknown error'}`);
}
}
/**
* Finds the next available task based on readiness (status 'todo', dependencies 'done')
* and prioritization (priority, creation date).
* @param projectId - The project ID.
* @returns The full details of the next task, or null if no task is ready.
* @throws {NotFoundError} If the project is not found.
* @throws {Error} If the database operation fails.
*/
public async getNextTask(projectId: string): Promise<FullTaskData | null> {
logger.info(`[TaskService] Attempting to get next task for project ${projectId}`);
// 1. Validate Project Existence
const projectExists = this.projectRepository.findById(projectId);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${projectId}`);
throw new NotFoundError(`Project with ID ${projectId} not found.`);
}
// 2. Find ready tasks using the repository method
try {
const readyTasks = this.taskRepository.findReadyTasks(projectId);
if (readyTasks.length === 0) {
logger.info(`[TaskService] No ready tasks found for project ${projectId}`);
return null; // No task is ready
}
// 3. The first task in the list is the highest priority one due to repo ordering
const nextTask = readyTasks[0];
logger.info(`[TaskService] Next task identified: ${nextTask.task_id}`);
// 4. Fetch full details (dependencies, subtasks) for the selected task
// We could potentially optimize this if findReadyTasks returned more details,
// but for separation of concerns, we call getTaskById logic (or similar).
// Re-using getTaskById logic:
return await this.getTaskById(projectId, nextTask.task_id);
} catch (error) {
logger.error(`[TaskService] Error getting next task for project ${projectId}:`, error);
throw error; // Re-throw repository or other errors
}
}
/**
* Updates specific fields of an existing task.
* @param input - Contains project ID, task ID, and optional fields to update.
* @returns The full details of the updated task.
* @throws {ValidationError} If no update fields are provided or if dependencies are invalid.
* @throws {NotFoundError} If the project, task, or any specified dependency task is not found.
* @throws {Error} If the database operation fails.
*/
public async updateTask(input: {
project_id: string;
task_id: string;
description?: string;
priority?: TaskData['priority'];
dependencies?: string[];
}): Promise<FullTaskData> {
const { project_id, task_id } = input;
logger.info(`[TaskService] Attempting to update task ${task_id} in project ${project_id}`);
// 1. Validate that at least one field is being updated
if (input.description === undefined && input.priority === undefined && input.dependencies === undefined) {
throw new ValidationError("At least one field (description, priority, or dependencies) must be provided for update.");
}
// 2. Validate Project Existence (using repo method)
const projectExists = this.projectRepository.findById(project_id);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${project_id}`);
throw new NotFoundError(`Project with ID ${project_id} not found.`);
}
// 3. Validate Task Existence (using repo method - findById also implicitly checks project scope)
// We need the task data anyway if dependencies are involved, so fetch it now.
const existingTask = this.taskRepository.findById(project_id, task_id);
if (!existingTask) {
logger.warn(`[TaskService] Task ${task_id} not found in project ${project_id}`);
throw new NotFoundError(`Task with ID ${task_id} not found in project ${project_id}.`);
}
// 4. Validate Dependency Existence if provided
if (input.dependencies !== undefined) {
if (input.dependencies.length > 0) {
const depCheck = this.taskRepository.checkTasksExist(project_id, input.dependencies);
if (!depCheck.allExist) {
logger.warn(`[TaskService] Invalid dependencies provided for task ${task_id}:`, depCheck.missingIds);
throw new ValidationError(`One or more dependency tasks not found in project ${project_id}: ${depCheck.missingIds.join(', ')}`);
}
// Also check for self-dependency
if (input.dependencies.includes(task_id)) {
throw new ValidationError(`Task ${task_id} cannot depend on itself.`);
}
}
// If input.dependencies is an empty array, it means "remove all dependencies"
}
// 5. Prepare payload for repository
const updatePayload: { description?: string; priority?: TaskData['priority']; dependencies?: string[] } = {};
if (input.description !== undefined) updatePayload.description = input.description;
if (input.priority !== undefined) updatePayload.priority = input.priority;
if (input.dependencies !== undefined) updatePayload.dependencies = input.dependencies;
// 6. Call Repository update method
try {
const now = new Date().toISOString();
// The repo method handles the transaction for task update + dependency replacement
const updatedTaskData = this.taskRepository.updateTask(project_id, task_id, updatePayload, now);
// 7. Fetch full details (including potentially updated dependencies and existing subtasks)
// Re-use logic similar to getTaskById
const finalDependencies = this.taskRepository.findDependencies(task_id);
const finalSubtasks = this.taskRepository.findSubtasks(task_id);
const fullUpdatedTask: FullTaskData = {
...updatedTaskData, // Use the data returned by the update method
dependencies: finalDependencies,
subtasks: finalSubtasks,
};
logger.info(`[TaskService] Successfully updated task ${task_id} in project ${project_id}`);
return fullUpdatedTask;
} catch (error) {
logger.error(`[TaskService] Error updating task ${task_id} in project ${project_id}:`, error);
// Re-throw specific errors if needed, otherwise let the generic error propagate
if (error instanceof Error && error.message.includes('not found')) {
// Map repo's generic error for not found back to specific NotFoundError
throw new NotFoundError(error.message);
}
throw error; // Re-throw other errors (like DB constraint errors or unexpected ones)
}
}
/**
* Deletes one or more tasks within a project.
* @param projectId - The project ID.
* @param taskIds - An array of task IDs to delete.
* @returns The number of tasks successfully deleted.
* @throws {NotFoundError} If the project or any of the specified tasks are not found.
* @throws {Error} If the database operation fails.
*/
public async deleteTasks(projectId: string, taskIds: string[]): Promise<number> {
logger.info(`[TaskService] Attempting to delete ${taskIds.length} tasks from project ${projectId}`);
// 1. Validate Project Existence
const projectExists = this.projectRepository.findById(projectId);
if (!projectExists) {
logger.warn(`[TaskService] Project not found: ${projectId}`);
throw new NotFoundError(`Project with ID ${projectId} not found.`);
}
// 2. Validate Task Existence *before* attempting delete
// This ensures we report an accurate count and catch non-existent IDs early.
const existenceCheck = this.taskRepository.checkTasksExist(projectId, taskIds);
if (!existenceCheck.allExist) {
logger.warn(`[TaskService] Cannot delete: One or more tasks not found in project ${projectId}:`, existenceCheck.missingIds);
// Throw NotFoundError here, as InvalidParams might be confusing if some IDs were valid
throw new NotFoundError(`One or more tasks to delete not found in project ${projectId}: ${existenceCheck.missingIds.join(', ')}`);
}
// 3. Call Repository delete method
try {
// The repository method handles the actual DELETE operation
const deletedCount = this.taskRepository.deleteTasks(projectId, taskIds);
// Double-check count (optional, but good sanity check)
if (deletedCount !== taskIds.length) {
logger.warn(`[TaskService] Expected to delete ${taskIds.length} tasks, but repository reported ${deletedCount} deletions.`);
// This might indicate a race condition or unexpected DB behavior, though unlikely with cascade.
// For V1, we'll trust the repo count but log the warning.
}
logger.info(`[TaskService] Successfully deleted ${deletedCount} tasks from project ${projectId}`);
return deletedCount;
} catch (error) {
logger.error(`[TaskService] Error deleting tasks from project ${projectId}:`, error);
throw error; // Re-throw database or other errors
}
}
// --- Add other task service methods later ---
}
