view.go

/**
 * This file is part of tz.
 *
 * tz is free software: you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free
 * Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * tz is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
 * License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with tz.  If not, see <https://www.gnu.org/licenses/>.
 **/
package main

import (
	"fmt"
	"os"
	"strconv"
	"strings"

	"github.com/muesli/termenv"
	xterm "golang.org/x/term"
)

// Width required to display 24 hours
const UIWidth = 94
const MinimumZoneHeaderPadding = 6
const MaximumZoneHeaderColumns = UIWidth + MinimumZoneHeaderPadding

func (m model) View() string {
	s := normalTextStyle("\n  What time is it?\n\n").String()

	zoneHeaderWidth := MaximumZoneHeaderColumns
	envWidth, envErr := strconv.Atoi(os.Getenv("COLUMNS"))
	if envErr == nil {
		zoneHeaderWidth = min(envWidth, zoneHeaderWidth)
	} else {
		fd := int(os.Stdout.Fd())
		if xterm.IsTerminal(fd) {
			termWidth, _, termErr := xterm.GetSize(fd)
			if termErr == nil {
				zoneHeaderWidth = min(termWidth, zoneHeaderWidth)
			}
		}
	}

	// Show hours for each zone
	for zi, zone := range m.zones {
		hours := strings.Builder{}
		dates := strings.Builder{}
		currentTime := zone.currentTime(m.clock.t)

		startHour := 0
		if zi > 0 {
			startHour = (currentTime.Hour() - m.zones[0].currentTime(m.clock.t).Hour()) % 24
		}

		dateChanged := false
		for i := startHour; i < startHour+24; i++ {
			hour := ((i % 24) + 24) % 24 // mod 24
			out := termenv.String(fmt.Sprintf("%2d", hour))

			out = out.Foreground(term.Color(hourColorCode(hour)))
			// Cursor
			if m.clock.t.Hour() == i-startHour {
				out = out.Background(term.Color(hourColorCode(hour)))
				if hasDarkBackground {
					out = out.Foreground(term.Color("#262626")).Bold()
				} else {
					out = out.Foreground(term.Color("#f1f1f1"))
				}
			}
			hours.WriteString(out.String())
			hours.WriteString("  ")

			// Show the day under the hour, when the date changes.
			if !m.showDates {
				continue
			}
			if hour == 0 {
				dates.WriteString(formatDayChange(&m, zone))
				dateChanged = true
			}
			if !dateChanged {
				dates.WriteString("    ")
			}
		}

		var datetime string
		if m.isMilitary {
			datetime = zone.ShortMT(m.clock.t)
		} else {
			datetime = zone.ShortDT(m.clock.t)
		}

		clockString := zone.ClockEmoji(m.clock.t)
		zoneString := zone.String()
		usedZoneHeaderWidth := termenv.String(clockString + zoneString + datetime).Width()
		unusedZoneHeaderWidth := max(0, zoneHeaderWidth - usedZoneHeaderWidth - MinimumZoneHeaderPadding)
		rightAlignmentSpace := strings.Repeat(" ", unusedZoneHeaderWidth)
		zoneHeader := fmt.Sprintf("%s %s %s%s", clockString, normalTextStyle(zoneString), rightAlignmentSpace, dateTimeStyle(datetime))

		s += fmt.Sprintf("  %s\n  %s\n  %s\n", zoneHeader, hours.String(), dates.String())
	}

	if m.interactive {
		s += status(m)
	}
	return s
}

// Generate the string
func generateKeymapString(k Keymaps) string {
	return fmt.Sprintf(", %s/%s: hours, %s/%s: days, %s/%s: weeks, %s: toggle date, %s: now, %s: open in web",
		// Only use the first of each mapping
		k.PrevHour[0], k.NextHour[0],
		k.PrevDay[0], k.NextDay[0],
		k.PrevWeek[0], k.NextWeek[0],
		k.ToggleDate[0],
		k.Now[0],
		k.OpenWeb[0],
	)
}

func status(m model) string {
	var text string

	helpPrefix := "  q: quit, ?: help"

	if m.showHelp {
		text = helpPrefix + generateKeymapString(m.keymaps)
	} else {
		text = helpPrefix
	}

	for {
		text += " "
		if len(text) > UIWidth {
			text = text[0:UIWidth]
			break
		}
	}

	color := "#939183"
	if hasDarkBackground {
		color = "#605C5A"
	}

	status := termenv.String(text).Foreground(term.Color(color))

	return status.String()
}

func formatDayChange(m *model, z *Zone) string {
	zTime := z.currentTime(m.clock.t)
	if zTime.Hour() > m.clock.t.Hour() {
		zTime = zTime.AddDate(0, 0, 1)
	}

	color := "#777266"
	if hasDarkBackground {
		color = "#7B7573"
	}

	str := termenv.String(fmt.Sprintf("📆 %s", zTime.Format("Mon 02")))
	return str.Foreground(term.Color(color)).String()
}

// Return a color matching the time of the day at a given hour.
func hourColorCode(hour int) (color string) {
	switch hour {
	// Morning
	case 7, 8:
		if hasDarkBackground {
			color = "#98E1D8"
		} else {
			color = "#35B6A6"
		}

	// Day
	case 9, 10, 11, 12, 13, 14, 15, 16, 17:
		if hasDarkBackground {
			color = "#E8C64D"
		} else {
			color = "#FA8F2D"
		}

	// Evening
	case 18, 19:
		if hasDarkBackground {
			color = "#C95F48"
		} else {
			color = "#FC6442"
		}

	// Night
	default:
		if hasDarkBackground {
			color = "#5957C9"
		} else {
			color = "#664FC3"
		}
	}
	return color
}

func dateTimeStyle(str string) termenv.Style {
	color := "#777266"
	if hasDarkBackground {
		color = "#757575"
	}
	return termenv.String(str).Foreground(term.Color(color))
}

func normalTextStyle(str string) termenv.Style {
	var color = "#32312B"
	if hasDarkBackground {
		color = "#ECEAD9"
	}
	return termenv.String(str).Foreground(term.Color(color))
}