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: `Interaction with 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!

The tool we use to navigate between programs *within* the terminal, however, is called a `},
		vaxis.Segment{Text: "shell", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: `. It's an interface that accepts commands, like "open a text editor" or "show me my flower", in a special language. 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 adventure.

below is a shell prompt. Here are some shell commands for you to try out; type them and hit Enter to run them:
• `},
		vaxis.Segment{Text: "ls", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " list the contents of a folder\n• "},
		vaxis.Segment{Text: "cd", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " change (move) into a directory (folder)\n• "},
		vaxis.Segment{Text: "mkdir", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " make a new directory (folder) with a given name\n• "},
		vaxis.Segment{Text: "cat", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: " output 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: " make the shell repeat what you say to it\ntype "},
		vaxis.Segment{Text: "exit", Style: vaxis.Style{Foreground: vaxis.IndexColor(3)}},
		vaxis.Segment{Text: ` and hit Enter 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
}