display.go

package main

import (
	"fmt"
	"os"
	"strings"

	"github.com/jedib0t/go-pretty/v6/table"
	"github.com/jedib0t/go-pretty/v6/text"
)

func getTable(stocks []ChartResponse) {
	t := table.NewWriter()
	t.SetOutputMirror(os.Stdout)
	t.AppendHeader(table.Row{"Ticker", "Last Price", "Change", "Change %", "Prev. Close", "Currency"})

	for _, stock := range stocks {
		row := getRow(stock)
		t.AppendRow(row)
	}

	t.SetColumnConfigs([]table.ColumnConfig{
		{
			Name: "Change",
			Transformer: text.Transformer(func(val interface{}) string {
				return getColoredChangeCell(val, "")
			}),
		},
		{
			Name: "Change %",
			Transformer: text.Transformer(func(val interface{}) string {
				return getColoredChangeCell(val, "%")
			}),
		},
	})

	t.SetStyle(table.StyleColoredCyanWhiteOnBlack)
	t.Render()
}

func getRow(stock ChartResponse) table.Row {
	data := stock.Chart.Result[0].Meta
	diff := data.RegularMarketPrice - data.PreviousClose
	ticker := data.Symbol
	lastPrice := data.RegularMarketPrice
	change := appendPlus(diff)
	changePercent := appendPlus(diff / data.PreviousClose * 100)
	currency := data.Currency
	previousClose := data.PreviousClose

	return table.Row{ticker, lastPrice, change, changePercent, previousClose, currency}
}

func getColoredChangeCell(val interface{}, postfix string) string {
	strVal, ok := val.(string)
	if !ok {
		return "0.00" + postfix
	}

	var color text.Color
	if strings.Contains(strVal, "-") {
		color = text.FgRed
	} else if strings.Contains(strVal, "+") {
		color = text.FgGreen
	}

	return text.Colors{color}.Sprint(strVal + postfix)
}

func appendPlus(num float64) string {
	if num >= 0 {
		return fmt.Sprintf("+%.2f", num)
	}
	return fmt.Sprintf("%.2f", num)
}