package cliui

import (

"context"

"fmt"

"io"

"os"

"os/signal"

"sync"

"time"

"github.com/briandowns/spinner"

"golang.org/x/xerrors"

"github.com/coder/coder/codersdk"

)

type AgentOptions struct {

WorkspaceName string

Fetch func(context.Context) (codersdk.WorkspaceAgent, error)

FetchInterval time.Duration

WarnInterval time.Duration

}

// Agent displays a spinning indicator that waits for a workspace agent to connect.

func Agent(ctx context.Context, writer io.Writer, opts AgentOptions) error {

if opts.FetchInterval == 0 {

opts.FetchInterval = 500 * time.Millisecond

}

if opts.WarnInterval == 0 {

opts.WarnInterval = 30 * time.Second

}

var resourceMutex sync.Mutex

agent, err := opts.Fetch(ctx)

if err != nil {

return xerrors.Errorf("fetch: %w", err)

}

if agent.Status == codersdk.WorkspaceAgentConnected {

return nil

}

if agent.Status == codersdk.WorkspaceAgentDisconnected {

opts.WarnInterval = 0

}

spin := spinner.New(spinner.CharSets[78], 100*time.Millisecond, spinner.WithColor("fgHiGreen"))

spin.Writer = writer

spin.ForceOutput = true

spin.Suffix = " Waiting for connection from " + Styles.Field.Render(agent.Name) + "..."

spin.Start()

defer spin.Stop()

ctx, cancelFunc := context.WithCancel(ctx)

defer cancelFunc()

stopSpin := make(chan os.Signal, 1)

signal.Notify(stopSpin, os.Interrupt)

defer signal.Stop(stopSpin)

go func() {

select {

case <-ctx.Done():

return

case <-stopSpin:

}

signal.Stop(stopSpin)

spin.Stop()

// nolint:revive

os.Exit(1)

}()

ticker := time.NewTicker(opts.FetchInterval)

defer ticker.Stop()

timer := time.NewTimer(opts.WarnInterval)

defer timer.Stop()

go func() {

select {

case <-ctx.Done():

return

case <-timer.C:

}

resourceMutex.Lock()

defer resourceMutex.Unlock()

message := "Don't panic, your workspace is booting up!"

if agent.Status == codersdk.WorkspaceAgentDisconnected {

message = "The workspace agent lost connection! Wait for it to reconnect or restart your workspace."

}

// This saves the cursor position, then defers clearing from the cursor

// position to the end of the screen.

_, _ = fmt.Fprintf(writer, "\033[s\r\033[2K%s\n\n", Styles.Paragraph.Render(Styles.Prompt.String()+message))

defer fmt.Fprintf(writer, "\033[u\033[J")

}()

for {

select {

case <-ctx.Done():

return ctx.Err()

case <-ticker.C:

}

resourceMutex.Lock()

agent, err = opts.Fetch(ctx)

if err != nil {

return xerrors.Errorf("fetch: %w", err)

}

if agent.Status != codersdk.WorkspaceAgentConnected {

resourceMutex.Unlock()

continue

}

resourceMutex.Unlock()

return nil

}

}