welcome/app/shell.go

package app

import (
	"os"
	"os/exec"
	"os/user"

	"git.sr.ht/~rockorager/vaxis"
	"git.sr.ht/~rockorager/vaxis/widgets/term"
	"git.tilde.town/nbsp/welcome/ui"
)

type Shell struct {
	loaded bool
}

func (view *Shell) Draw(state *ui.State) (row int) {
	win := state.Window().New(0, 0, 80, state.Window().Height)
	user, _ := user.Current()

	_, row = win.Wrap(vaxis.Segment{Text: `──── using the shell ────

`, Style: vaxis.Style{Foreground: vaxis.IndexColor(5)}}, vaxis.Segment{Text: `as mentioned before, interaction with stuff on tilde town is done primarily via the `},
		vaxis.Segment{Text: "terminal", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: `. good news, you've been using the terminal this whole time! it's the text application with which you've been talking to the server so far.

the method of navigation between programs inside our shared computer, however, is called a `},
		vaxis.Segment{Text: "shell", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: `. it's an interface that takes in commands, like "open a text editor" or "show me my flower", in a language that doesn't take too long to get used to. the most popular shell is called `},
		vaxis.Segment{Text: "bash", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: `, and while there are more, there's no reason to switch unless you're looking for something different.

below is a terminal session. here are some commands for you to try out:
• `},
		vaxis.Segment{Text: "ls", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " lists the contents of a folder\n• "},
		vaxis.Segment{Text: "cd", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " goes into a folder\n• "},
		vaxis.Segment{Text: "mkdir", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " makes a new folder with a given name\n• "},
		vaxis.Segment{Text: "cat", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " outputs the contents of a file (try running "},
		vaxis.Segment{Text: "cat welcome_" + user.Username + ".txt", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: "!)\n• "},
		vaxis.Segment{Text: "echo", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " makes the shell repeat what you say to it\ntype "},
		vaxis.Segment{Text: "exit", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: ` to continue the tutorial, whenever you're ready.`},
	)
	return
}

func (view *Shell) Event(state *ui.State, event vaxis.Event) (processed bool) {
	if view.loaded {
		return
	}
	view.loaded = true

	row := view.Draw(state)
	win := state.Window().New(0, row+2, 80, 80)

	vt := term.New()
	vt.TERM = os.Getenv("TERM")
	vt.Attach(state.PostEvent())
	vt.Focus()
	err := vt.Start(exec.Command("bash", "-l"))
	if err != nil {
		panic(err)
	}
	defer vt.Close()

	for ev := range state.Events() {
		switch ev.(type) {
		case term.EventClosed:
			state.HideCursor()
			vt.Detach()
			vt.Close()
			state.Window().Clear()
			ui.ViewChange <- &Editor{}
			return
		case vaxis.Redraw:
			view.Draw(state)
			vt.Draw(win)
			state.Render()
			continue
		}

		vt.Update(ev)
	}

	return
}