pingo/tui.go

// TODO(chart): dynamically render charts to fit height on not set
//
// TODO(styling): allow end user to define their own styles when hacking.
//
// Pingo defines an extensible TUI based on the bubbletea framework (v2). An
// executable entry point is defined via cmd/pingo.go. For more on this topic,
// see the Readme.
//
// The pingo TUI is a fully fledged and extensible "bubble" (read: widget) that
// can be fully implemented as an element in further terminal applications.
//
// NOTE: the bubbletea framework and subsequent "bubble" concept are beyond the
// scope of this documentation. For more, see the Readme.
//
// Pingo defines a constructor function for the Model. It takes three arguments:
//
//   - addresses([]string): the hosts to ping. The length must be greater than
//     or equal to 1
//
//   - speed(time.Duration): the polling interval
//
//   - chartHeight(int): the desired height of the resulting charts. This
//     argument is integral to ensuring desired rendering of charts, when
//     displaying multiple hosts.
//
//     NOTE: if chartHeight is 0, the chart will render to Model.Height
//
//     NOTE: chartHeight is ignored when only one address or host is provided
//
// For more, please please see InitialModel()
//
// Pingo defines two bubbletea.Cmd functions:
//
//   - Model.Tick() tea.Cmd: emits a bubbletea.TickMsg after the time.Duration
//     specified via Model.UpdateSpeed
//
//     NOTE: Model.Tick() is optional. If you choose not to use Model.Tick(),
//     it is recommended to enforce some minimum rate mechanism for calling
//     Poll(). Some servers maintain a ping rate limit, and is is possible to
//     exceed this rate trivially with the Poll() function. (Trust us, we know
//     from experience)
//
//     NOTE: Model.Tick() is automatically emit by Model.Init() - therefore,
//     you can control the timing of polling by overloading the Init function.
//
//   - Model.Poll() tea.Msg: used to asynchronously call all Model.Addresses.Poll()
//     functions.
//
//     NOTE: Model.Poll() is automatically injected into the Model.Update()
//     life cycle after Model.Tick() resolves by Model.Update(). Functionally,
//     this means you can omit either Model.Tick() or Model.Poll(), respectively.
//
// For more, see the Readme or ./examples
package pingo

import (
	"fmt"
	"slices"
	"time"

	"charm.land/bubbles/v2/viewport"
	tea "charm.land/bubbletea/v2"
	"charm.land/lipgloss/v2"
	"github.com/NimbleMarkets/ntcharts/linechart/streamlinechart"
)

// Style Definitions
var (
	// A style for chart headers
	headerStyle = lipgloss.NewStyle().
			Bold(true).
			Italic(true)

	// A style for info text
	infoStyle = lipgloss.NewStyle().
			Italic(true).
			Faint(true)

	// A style for the secondary colour
	secondaryColor = lipgloss.NewStyle().
			Foreground(lipgloss.Color("#7b2d26"))

	// A style for the primary colour
	//  primaryColor = lipgloss.NewStyle().
	// 	Foreground(lipgloss.Color("#f0f3f5"))

	// A style for handling center-aligning
	blockStyle = lipgloss.NewStyle().
			Align(lipgloss.Center)

	// borderStyle = lipgloss.NewStyle().
	// 		BorderForeground(lipgloss.Color("8")).
	// 	// Padding(1, 2).
	// 	BorderStyle(lipgloss.NormalBorder())

	// footer styles
	titleStyle = lipgloss.NewStyle().
			Align(lipgloss.Center). // implies consumer functions will apply a width
			Italic(true).
			Faint(true)

	// footer style
	footerStyle = lipgloss.NewStyle().
			Align(lipgloss.Center). // implies consumer functions will apply a width
			Italic(true).
			Faint(true)
)

type ( // tea.Msg signatures
	tickMsg       time.Time
	pollResultMsg struct {
		results []float64
		index   int
		err     error
	}
)

// Bubbletea model
type Model struct {
	Addresses   []Address      // as defined in internal/tui/types.go
	viewport    viewport.Model // mark: opinionated render
	UpdateSpeed time.Duration
	ChartHeight int
	Height      int
	Width       int
}

func InitialModel(addresses []string, speed time.Duration, chartHeight int) Model {
	var model Model
	model.viewport.MouseWheelEnabled = true // mark: opinionated render
	model.UpdateSpeed = speed
	model.ChartHeight = chartHeight

	for _, address := range addresses {
		var addr Address
		addr.MaxResults = 80
		addr.Address = address
		model.Addresses = append(model.Addresses, addr)
	}
	return model
}

func (m Model) Init() tea.Cmd {
	return m.Tick()
}

func (m Model) Tick() tea.Cmd {
	return tea.Tick(time.Millisecond*m.UpdateSpeed, func(t time.Time) tea.Msg {
		return tickMsg(t)
	})
}

func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) { // mark: opinionated render
	var cmd tea.Cmd
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	// if case is KeyMsg (keypress)
	case tea.WindowSizeMsg: // mark: opinionated render
		if m.Width == 0 && m.Height == 0 {
			m.viewport = viewport.New(
				viewport.WithHeight(10),
				viewport.WithWidth(msg.Width),
			)
		}

		m.Width = msg.Width
		m.Height = msg.Height
		for i, address := range m.Addresses {
			address.MaxResults = m.Width
			m.Addresses[i] = address
		}
		m.viewport.SetHeight(m.Height - m.getVerticalMargin())
		m.viewport.SetWidth(m.Width)
		m.viewport.YPosition = 1

	case tea.KeyPressMsg: // mark: opinionated render
		if k := msg.String(); k == "j" { // scroll down
			m.viewport.ScrollDown(1)
		} else if k == "k" { // scroll up
			m.viewport.ScrollUp(1)
		} else {
			if k == "ctrl+c" {
				cmds = append(cmds, tea.Quit)
			}
		}

	case tickMsg:
		cmds = append(cmds, m.Tick(), m.Poll())

	case pollResultMsg:
		m.Addresses[msg.index].Results = msg.results
	}

	m.viewport.SetContent(m.Render())
	m.viewport, cmd = m.viewport.Update(msg)
	cmds = append(cmds, cmd)
	// cmds = append(cmds, m.Poll)

	return m, tea.Batch(cmds...)
}

func (m Model) View() tea.View { // mark: opinionated render
	content := fmt.Sprintf("%s%s\n%s", m.header(), m.viewport.View(), m.footer())

	var v tea.View
	v.SetContent(content)
	v.AltScreen = true
	return v
}
func (m Model) Render() string { // mark: opinionated render
	var output string
	for _, address := range m.Addresses {
		if len(address.Results) == 0 {
			output = output + fmt.Sprintf("\n%s\tloading...", headerStyle.Render(address.Address))
		} else if m.Width != 0 && m.Height != 0 {
			if slices.Contains(address.Results, -1) {
				output = output + blockStyle.Width(m.Width).Render(headerStyle.Render(
					fmt.Sprintf("\n%s\t%s",
						secondaryColor.Render(address.Address),
						infoStyle.Render("(connection unstable)"),
					),
				))
			} else {
				output = output + fmt.Sprintf("\n%s",
					blockStyle.Width(m.Width).Render(headerStyle.Render(address.Address)))
			}

			// Linechart
			// set chartHeight - vertical margin
			chartHeight := m.Height - m.getVerticalMargin()

			var slc streamlinechart.Model

			if m.ChartHeight == 0 && len(m.Addresses) == 1 { // catch user specified fullscreen
				// render chart at fullscreen
				slc = streamlinechart.New(m.Width, chartHeight)
			} else if m.ChartHeight == 0 && len(m.Addresses) > 1 { // catch user specified fullscreen
				// render chart at fullscreen minus a few lines to hint at scrolling
				slc = streamlinechart.New(m.Width, chartHeight-5)
			} else {
				slc = streamlinechart.New(m.Width, m.ChartHeight)
			}

			for _, v := range address.Results {
				slc.Push(v)
			}

			slc.Draw()
			output = output + fmt.Sprintf("\n%s", slc.View())
		}
	}

	return output
}

func (m Model) header() string { return titleStyle.Width(m.Width).Render("pingo v0") } // mark: opinionated render

func (m Model) footer() string { // mark: opinionated render
	return footerStyle.Width(m.Width).Render("j/k: down/up\t|\tq/ctrl-c/esc: quit")
}

func (m Model) getVerticalMargin() int { return lipgloss.Height(m.header() + m.footer()) } // mark: opinionated render

// Returns a batched set of tea.Cmd functions for each address.
func (m Model) Poll() tea.Cmd {
	var cmds []tea.Cmd

	for i, element := range m.Addresses {
		cmds = append(cmds, func() tea.Msg {
			results, err := element.Poll()
			return pollResultMsg{results: results, err: err, index: i}
		})
	}
	return tea.Batch(cmds...)
}