package shell

import (
	"io"
	"os/exec"
	"sync"
	"time"
)

// Status represents the status of a shell for a workspace.
type Status struct {
	WorkspaceID string `json:"workspaceId"`
	ShellID     string `json:"shellId,omitempty"`
	Running     bool   `json:"running"`
	PID         int    `json:"pid,omitempty"`
}

// ExitInfo holds the exit reason of a shell.
type ExitInfo struct {
	Code   int
	Signal string
}

// Session holds the runtime state of a started shell.
type Session struct {
	ShellID     string
	WorkspaceID string
	Root        string
	Cmd         *exec.Cmd
	Stdin       io.WriteCloser
	Subscribers map[Subscription]struct{}
	Exit        ExitInfo
	CreatedAt   time.Time
	mu          sync.Mutex
}

// removeSubscription removes sub from s.Subscribers. It is safe to call when
// the subscription is no longer present.
func (s *Session) removeSubscription(sub *subscription) {
	s.mu.Lock()
	defer s.mu.Unlock()
	delete(s.Subscribers, sub)
}