moonmath/tui/asset/asset.go

package asset

import (
	"context"
	"fmt"
	"log/slog"
	"time"

	"code.humancabbage.net/sam/moonmath/coindesk"
	"code.humancabbage.net/sam/moonmath/config"
	"code.humancabbage.net/sam/moonmath/moon"
	"github.com/charmbracelet/bubbles/spinner"
	"github.com/charmbracelet/bubbles/table"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

type Model struct {
	math moon.Math

	refreshing bool
	indicator  spinner.Model

	properties  table.Model
	projections table.Model
}

type Msg struct {
	Asset coindesk.Asset
	inner tea.Msg
}

func New(cfg config.Asset) (m Model) {
	m.math = moon.NewMath(
		cfg.Asset,
		cfg.Goals,
		config.GetBases(&cfg),
	)

	tableStyle := table.DefaultStyles()
	tableStyle.Selected = tableStyle.Cell.Copy().
		Padding(0)
	tableStyle.Header = tableStyle.Header.
		Bold(true).
		Foreground(lipgloss.Color("214")).
		Border(baseStyle.GetBorderStyle(), false, false, true, false)

	// properties table

	m.properties = table.New(
		table.WithColumns([]table.Column{
			{Title: "Property", Width: 9},
			{Title: "Value", Width: 9},
		}),
		table.WithHeight(2),
		table.WithStyles(tableStyle),
	)

	// projections table

	labelsWidth := 0
	for _, l := range m.math.Labels {
		if len(l) > labelsWidth {
			labelsWidth = len(l)
		}
	}
	projectionCols := []table.Column{
		{Title: "Labels", Width: labelsWidth},
	}
	for _, c := range m.math.Columns {
		projectionCols = append(projectionCols,
			table.Column{
				Title: c.Base.Label(),
				Width: 10,
			})
	}
	m.projections = table.New(
		table.WithColumns(projectionCols),
		table.WithHeight(len(m.math.Labels)),
		table.WithStyles(tableStyle),
	)

	// indicator spinner

	m.indicator = spinner.New()
	m.indicator.Spinner = spinner.Points
	m.indicator.Style = indicatorNormalStyle

	return
}

func (m Model) Init() tea.Cmd {
	return tea.Batch(
		m.indicator.Tick,
		func() tea.Msg {
			return Msg{m.math.Asset, refresh{}}
		},
	)
}

func (m Model) Handles(a coindesk.Asset) bool {
	return m.math.Asset == a
}

func (m Model) Update(msg tea.Msg) (Model, tea.Cmd) {
	switch msg := msg.(type) {
	case Msg:
		switch msg := msg.inner.(type) {
		case refresh:
			m.refreshing = true
			m.indicator.Style = indicatorNormalStyle
			return m, tea.Batch(
				m.resumeIndicator,
				m.refresh,
				m.scheduleRefresh(),
			)
		case update:
			var cmd tea.Cmd
			if msg.err == nil {
				m.math = msg.math
				refillProperties(&m)
				refillProjections(&m)
				cmd = m.stopIndicator()
			} else {
				m.indicator.Style = indicatorErrorStyle
			}
			return m, cmd
		case stopIndicator:
			m.refreshing = false
			return m, nil
		}
	case spinner.TickMsg:
		if !m.refreshing {
			return m, nil
		}
		var cmd tea.Cmd
		m.indicator, cmd = m.indicator.Update(msg)
		return m, cmd
	}
	return m, nil
}

type refresh struct{}
type update struct {
	math moon.Math
	err  error
}
type stopIndicator struct{}

func (m Model) refresh() tea.Msg {
	ctx, cancel := context.WithDeadline(
		context.Background(),
		time.Now().Add(refreshDeadline))
	defer cancel()
	err := m.math.Refresh(ctx)
	if err != nil {
		slog.Error("refresh",
			"asset", m.math.Asset,
			"err", err,
		)
	}
	return Msg{m.math.Asset, update{m.math, err}}
}

func (m Model) resumeIndicator() tea.Msg {
	return m.indicator.Tick()
}

func (m Model) scheduleRefresh() tea.Cmd {
	return tea.Tick(refreshInterval,
		func(t time.Time) tea.Msg {
			return Msg{m.math.Asset, refresh{}}
		})
}

func (m Model) stopIndicator() tea.Cmd {
	// wait a bit to stop the indicator, so that it's more obvious
	// even when the refresh completes quickly.
	return tea.Tick(stopIndicatorDelay,
		func(t time.Time) tea.Msg {
			return Msg{m.math.Asset, stopIndicator{}}
		})
}

var refreshInterval = time.Second * 30
var refreshDeadline = time.Second * 15
var stopIndicatorDelay = time.Millisecond * 500

func refillProperties(m *Model) {
	rows := []table.Row{
		{"Asset", string(m.math.Asset)},
		{"Price", fmt.Sprintf("$%0.2f", m.math.CurrentPrice)},
	}
	m.properties.SetRows(rows)
}

func refillProjections(m *Model) {
	cols := []table.Row{m.math.Labels}
	for i := range m.math.Columns {
		entries := renderEntries(m.math.Columns[i])
		cols = append(cols, entries)
	}
	rows := transpose(cols)
	m.projections.SetRows(rows)
}

func renderEntries(c moon.Column) (entries []string) {
	entries = append(entries, fmt.Sprintf("$%.2f", c.StartingPrice))
	entries = append(entries, fmt.Sprintf("%.2f%%", (c.CDPR-1)*100))
	never := c.CDPR <= 1
	for i := range c.Projections.Dates {
		var cell string
		if never {
			cell = "NEVER!!!!!"
		} else {
			cell = c.
				Projections.
				Dates[i].
				Format("2006-01-02")
		}
		entries = append(entries, cell)
	}
	return
}

func transpose(slice []table.Row) []table.Row {
	xl := len(slice[0])
	yl := len(slice)
	result := make([]table.Row, xl)
	for i := range result {
		result[i] = make(table.Row, yl)
	}
	for i := 0; i < xl; i++ {
		for j := 0; j < yl; j++ {
			result[i][j] = slice[j][i]
		}
	}
	return result
}

func (m Model) View() string {
	var s string
	indicator := ""
	if m.refreshing {
		indicator = m.indicator.View()
	}
	right := lipgloss.JoinVertical(
		lipgloss.Center,
		baseStyle.Render(m.properties.View()),
		indicator,
	)
	s += lipgloss.JoinHorizontal(
		lipgloss.Center,
		right,
		baseStyle.Render(m.projections.View()),
	)
	return s + "\n"
}

var baseStyle = lipgloss.NewStyle().
	BorderStyle(lipgloss.RoundedBorder()).
	BorderForeground(lipgloss.Color("240"))

var indicatorNormalStyle = lipgloss.NewStyle().
	Foreground(lipgloss.Color("69"))

var indicatorErrorStyle = lipgloss.NewStyle().
	Foreground(lipgloss.Color("160"))