/**
* Base DAO interface providing common CRUD operations
*/
export interface BaseDao<T, K = string> {
/**
* Find all entities
*/
findAll(): Promise<T[]>;
/**
* Find entity by ID
*/
findById(id: K): Promise<T | null>;
/**
* Create new entity
*/
create(entity: Omit<T, 'id'>): Promise<T>;
/**
* Update existing entity
*/
update(id: K, entity: Partial<T>): Promise<T | null>;
/**
* Delete entity by ID
*/
delete(id: K): Promise<boolean>;
/**
* Check if entity exists
*/
exists(id: K): Promise<boolean>;
/**
* Count total entities
*/
count(): Promise<number>;
}
/**
* Base DAO implementation with common functionality
*/
export abstract class BaseDaoImpl<T, K = string> implements BaseDao<T, K> {
protected abstract getAll(): Promise<T[]>;
protected abstract saveAll(entities: T[]): Promise<void>;
protected abstract getEntityId(entity: T): K;
protected abstract createEntity(data: Omit<T, 'id'>): T;
protected abstract updateEntity(existing: T, updates: Partial<T>): T;
async findAll(): Promise<T[]> {
return this.getAll();
}
async findById(id: K): Promise<T | null> {
const entities = await this.getAll();
return entities.find((entity) => this.getEntityId(entity) === id) || null;
}
async create(data: Omit<T, 'id'>): Promise<T> {
const entities = await this.getAll();
const newEntity = this.createEntity(data);
entities.push(newEntity);
await this.saveAll(entities);
return newEntity;
}
async update(id: K, updates: Partial<T>): Promise<T | null> {
const entities = await this.getAll();
const index = entities.findIndex((entity) => this.getEntityId(entity) === id);
if (index === -1) {
return null;
}
const updatedEntity = this.updateEntity(entities[index], updates);
entities[index] = updatedEntity;
await this.saveAll(entities);
return updatedEntity;
}
async delete(id: K): Promise<boolean> {
const entities = await this.getAll();
const index = entities.findIndex((entity) => this.getEntityId(entity) === id);
if (index === -1) {
return false;
}
entities.splice(index, 1);
await this.saveAll(entities);
return true;
}
async exists(id: K): Promise<boolean> {
const entity = await this.findById(id);
return entity !== null;
}
async count(): Promise<number> {
const entities = await this.getAll();
return entities.length;
}
}
