/**
* JSON File Storage
* Simple key-value storage using JSON file
*/
import { promises as fs } from 'fs'
import * as path from 'path'
export interface StorageOptions {
/** Storage file path */
storagePath: string
}
export class Storage<T = any> {
private storagePath: string
private data: Map<string, T> = new Map()
private loaded: boolean = false
constructor(options: StorageOptions) {
this.storagePath = options.storagePath
}
/**
* Load data from storage file
*/
private async load(): Promise<void> {
if (this.loaded) return
try {
const content = await fs.readFile(this.storagePath, 'utf-8')
const parsed = JSON.parse(content)
this.data = new Map(Object.entries(parsed))
} catch (error: any) {
// File doesn't exist or is invalid, start with empty data
if (error.code !== 'ENOENT') {
console.warn(`Failed to load storage from ${this.storagePath}:`, error.message)
}
this.data = new Map()
}
this.loaded = true
}
/**
* Save data to storage file
*/
private async save(): Promise<void> {
const dir = path.dirname(this.storagePath)
await fs.mkdir(dir, { recursive: true })
const obj = Object.fromEntries(this.data)
await fs.writeFile(this.storagePath, JSON.stringify(obj, null, 2), 'utf-8')
}
/**
* Get value by key
*/
async get(key: string): Promise<T | undefined> {
await this.load()
return this.data.get(key)
}
/**
* Get value by key with default value
*/
async getOrDefault(key: string, defaultValue: T): Promise<T> {
await this.load()
return this.data.get(key) ?? defaultValue
}
/**
* Set value for key
*/
async set(key: string, value: T): Promise<void> {
await this.load()
this.data.set(key, value)
await this.save()
}
/**
* Delete key
*/
async delete(key: string): Promise<boolean> {
await this.load()
const existed = this.data.delete(key)
if (existed) {
await this.save()
}
return existed
}
/**
* Check if key exists
*/
async has(key: string): Promise<boolean> {
await this.load()
return this.data.has(key)
}
/**
* Get all keys
*/
async keys(): Promise<string[]> {
await this.load()
return Array.from(this.data.keys())
}
/**
* Get all values
*/
async values(): Promise<T[]> {
await this.load()
return Array.from(this.data.values())
}
/**
* Get all entries
*/
async entries(): Promise<[string, T][]> {
await this.load()
return Array.from(this.data.entries())
}
/**
* Clear all data
*/
async clear(): Promise<void> {
this.data.clear()
await this.save()
}
/**
* Get the number of stored items
*/
async size(): Promise<number> {
await this.load()
return this.data.size
}
/**
* Reload data from file (useful for external changes)
*/
async reload(): Promise<void> {
this.loaded = false
await this.load()
}
}
/**
* Create a storage instance
*/
export function createStorage<T = any>(storagePath: string): Storage<T> {
return new Storage<T>({ storagePath })
}
