package agent

import (
	"github.com/gliderlabs/ssh"
	"io"
	"log"
	"strconv"
	"time"
)

// global configuration

type AgentState struct {

	// Advance warning time to notify the user of something important happening
	advanceWarningTime time.Duration

	// session expiry time
	sessionExpiryTime time.Duration

	// ticker
	tickerInterval time.Duration
	ticker         *time.Ticker

	// map of unique session id to a session
	sessions map[int]*AgentSession
}

type AgentSession struct {
	startTime time.Time

	// For sending messages to the user
	sshSession ssh.Session
}

var state AgentState

func ConfigureAgent(advanceWarningTime, sessionExpiryTime, tickerInterval time.Duration) {
	state = AgentState{
		advanceWarningTime: advanceWarningTime,
		sessionExpiryTime:  sessionExpiryTime,
		tickerInterval:     tickerInterval,
		ticker:             time.NewTicker(tickerInterval),
		sessions:           make(map[int]*AgentSession),
	}

	go func() {
		for {
			<-state.ticker.C
			check()
		}
	}()
}

func Login(sessionId int, sshSession ssh.Session) {
	log.Println("New login")
	agentSession := AgentSession{
		startTime:  time.Now(),
		sshSession: sshSession,
	}
	state.sessions[sessionId] = &agentSession
	LogStatus()
}

func LogOut(sessionId int) {
	log.Println("User logged out")
	delete(state.sessions, sessionId)
	LogStatus()
	check()
}

func LogStatus() {
	fmt := "%-20s %-20s"
	log.Println()
	log.Printf(fmt, "UID", "START_TIME")
	for uid, session := range state.sessions {
		log.Printf(fmt, strconv.Itoa(uid), session.startTime.Format("2006-01-02 15:04:05"))
	}
	log.Println()
}

func check() {
	log.Println("Timer is firing!")
	for _, session := range state.sessions {
		io.WriteString(session.sshSession.Stderr(), "\n\nThe clock is ticking for you!\n\n")
	}
}