package main

import "fmt"

/*
实例：
汤宝宝成为一国之王，手下有一个传令官和三个大臣，分别是内政大臣、外交大臣和军事大臣。
有一天，汤宝宝想要发布一个命令，传令官负责将命令传达给大臣们，大臣们根据命令的内容决定是否执行。
*/

// 接收者接口
type Receiver interface {
	perform()
	abort()
}

// 内政大臣
type HomeSecretary struct {
	isPerforming bool
}

func (h *HomeSecretary) perform() {
	h.isPerforming = true
	fmt.Println("内政大臣开始执行命令")
}

func (h *HomeSecretary) abort() {
	h.isPerforming = false
	fmt.Println("内政大臣取消执行命令")
}

// 外交大臣
type ForeignSecretary struct {
	isPerforming bool
}

func (f *ForeignSecretary) perform() {
	f.isPerforming = true
	fmt.Println("外交大臣开始执行命令")
}

func (f *ForeignSecretary) abort() {
	f.isPerforming = false
	fmt.Println("外交大臣取消执行命令")
}

// 军事大臣
type DefenseSecretary struct {
	isPerforming bool
}

func (d *DefenseSecretary) perform() {
	d.isPerforming = true
	fmt.Println("军事大臣开始执行命令")
}

func (d *DefenseSecretary) abort() {
	d.isPerforming = false
	fmt.Println("军事大臣取消执行命令")
}

// 命令接口
type Command interface {
	execute()
}

// 执行命令
type PerformCommand struct {
	receiver Receiver
}

func (c *PerformCommand) execute() {
	c.receiver.perform()
}

// 取消命令
type AbortCommand struct {
	receiver Receiver
}

func (c *AbortCommand) execute() {
	c.receiver.abort()
}

// Invoker - 传令官
type Herald struct {
	commands []Command
}

func (h *Herald) addCommand(command Command) {
	h.commands = append(h.commands, command)
}

func (h *Herald) executeCommands() {
	for _, command := range h.commands {
		command.execute()
	}
	h.commands = []Command{} // 清空命令列表
}

func main() {
	fmt.Println("========= 命令模式 =========")
	// 创建接收者
	homeSecretary := &HomeSecretary{}
	foreignSecretary := &ForeignSecretary{}
	defenseSecretary := &DefenseSecretary{}

	// 创建命令
	performHomeCommand := &PerformCommand{receiver: homeSecretary}
	abortHomeCommand := &AbortCommand{receiver: homeSecretary}
	performForeignCommand := &PerformCommand{receiver: foreignSecretary}
	abortForeignCommand := &AbortCommand{receiver: foreignSecretary}
	performDefenseCommand := &PerformCommand{receiver: defenseSecretary}
	abortDefenseCommand := &AbortCommand{receiver: defenseSecretary}

	// 创建传令官
	herald := &Herald{}

	// 添加命令
	herald.addCommand(performHomeCommand)
	herald.addCommand(performForeignCommand)
	herald.addCommand(performDefenseCommand)

	// 执行命令
	herald.executeCommands()

	// 取消命令
	herald.addCommand(abortHomeCommand)
	herald.addCommand(abortForeignCommand)
	herald.addCommand(abortDefenseCommand)

	// 执行取消命令
	herald.executeCommands()

	fmt.Println()
	fmt.Println("======= 命令模式结束 =======")
}