import type { AxiosInstance } from 'axios'
import type { AuthEventMap, AuthState } from './types'
import axios from 'axios'

export function createAxiosInstance(baseURL: string): AxiosInstance {
	return axios.create({
		baseURL,
		withCredentials: true,
		headers: {
			'Content-Type': 'application/json',
		},
	})
}

export class EventEmitter {
	private listeners: Map<string, Set<() => void>> = new Map()

	on<K extends AuthState>(event: K, handler: AuthEventMap[K]): void {
		if (!this.listeners.has(event)) {
			this.listeners.set(event, new Set())
		}
		const listeners = this.listeners.get(event)
		if (listeners !== undefined) {
			listeners.add(handler)
		}
	}

	off<K extends AuthState>(event: K, handler: AuthEventMap[K]): void {
		const eventListeners = this.listeners.get(event)
		if (eventListeners) {
			eventListeners.delete(handler)
		}
	}

	emit<K extends AuthState>(event: K): void {
		const eventListeners = this.listeners.get(event)
		if (eventListeners) {
			eventListeners.forEach((handler) => { handler() })
		}
	}

	removeAllListeners<K extends AuthState>(event?: K): void {
		if (event !== undefined) {
			this.listeners.delete(event)
		} else {
			this.listeners.clear()
		}
	}
}

export function queryParams(): Record<string, string> {
	if (typeof window === 'undefined' || !window.location.search) {
		return {}
	}
	const params = new URLSearchParams(window.location.search)
	const result: Record<string, string> = {}
	params.forEach((value, key) => {
		result[key] = value
	})
	return result
}