package main

import (
	"fmt"
	"slices"
)

/*
实例：
汤宝宝一时想不开，当了房产中介。
他负责把房东和租客撮合在一起，帮他们达成租房协议。
*/

// 抽象中介者
type Mediator interface {
	register(colleague Colleague)
	Notify(sender Colleague, event string)
}

// 具体中介者 - 房产中介
type HousingMediator struct {
	colleagues []Colleague
}

func (m *HousingMediator) register(colleague Colleague) {
	if slices.Contains(m.colleagues, colleague) {
		return // 已注册
	}
	m.colleagues = append(m.colleagues, colleague)
}

func (m *HousingMediator) Notify(sender Colleague, event string) {
	for _, colleague := range m.colleagues {
		if colleague != sender {
			colleague.Receive(event)
		}
	}
}

// 抽象同事类
type Colleague interface {
	Send(event string)
	Receive(event string)
}

// 具体同事类 - 房东
type Landlord struct {
	mediator Mediator
	name     string
}

func (l *Landlord) Send(event string) {
	fmt.Printf("房东%s发布信息: %s\n", l.name, event)
	l.mediator.Notify(l, event)
}

func (l *Landlord) Receive(event string) {
	fmt.Printf("房东%s收到通知: %s\n", l.name, event)
}

// 具体同事类 - 租客
type Tenant struct {
	mediator Mediator
	name     string
}

func (t *Tenant) Send(event string) {
	fmt.Printf("租客%s发布需求: %s\n", t.name, event)
	t.mediator.Notify(t, event)
}

func (t *Tenant) Receive(event string) {
	fmt.Printf("租客%s收到通知: %s\n", t.name, event)
}

func main() {
	fmt.Println("============= 中介者模式 =============")

	mediator := &HousingMediator{}

	landlord1 := &Landlord{mediator: mediator, name: "张三"}
	landlord2 := &Landlord{mediator: mediator, name: "李四"}
	tenant1 := &Tenant{mediator: mediator, name: "王五"}
	tenant2 := &Tenant{mediator: mediator, name: "赵六"}

	mediator.register(landlord1)
	mediator.register(landlord2)
	mediator.register(tenant1)
	mediator.register(tenant2)

	landlord1.Send("张三有一套两室一厅的房子出租，月租2000元。")
	fmt.Println("-----")
	tenant1.Send("王五需要一套三室的房子，预算3000元/月。")

	fmt.Println()
	fmt.Println("=========== 中介者模式结束 ===========")
}