package briefing

import (
	"fmt"
	"math"
	"time"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
)

func rangeLabel(value forecast.Range) string {
	if value.Min == nil && value.Max == nil {
		return ""
	}
	if value.Min != nil && value.Max != nil {
		low := roundedInt(value.Min)
		high := roundedInt(value.Max)
		if low != nil && high != nil && *low == *high {
			return fmt.Sprintf("%d", *low)
		}
		return fmt.Sprintf("%d-%d", *low, *high)
	}
	if value.Min != nil {
		low := roundedInt(value.Min)
		return fmt.Sprintf("%d", *low)
	}
	high := roundedInt(value.Max)
	return fmt.Sprintf("%d", *high)
}

func daypartApparentRangeLabel(value forecast.Range) string {
	if value.Min == nil && value.Max == nil {
		return ""
	}
	return rangeLabel(value)
}

func roundedInt(value *float64) *int {
	if value == nil {
		return nil
	}
	rounded := int(*value + 0.5)
	if *value < 0 {
		rounded = int(*value - 0.5)
	}
	return &rounded
}

func windDirectionLabel(degrees *float64) string {
	if degrees == nil {
		return ""
	}
	labels := []string{"N", "NNE", "NE", "ENE", "E", "ESE", "SE", "SSE", "S", "SSW", "SW", "WSW", "W", "WNW", "NW", "NNW"}
	normalized := math.Mod(*degrees, 360)
	if normalized < 0 {
		normalized += 360
	}
	sector := int(math.Floor((normalized+11.25)/22.5)) % len(labels)
	return labels[sector]
}

func windDirectionTextLabel(degrees *float64) string {
	if degrees == nil {
		return ""
	}
	labels := []string{
		"north",
		"north-northeast",
		"northeast",
		"east-northeast",
		"east",
		"east-southeast",
		"southeast",
		"south-southeast",
		"south",
		"south-southwest",
		"southwest",
		"west-southwest",
		"west",
		"west-northwest",
		"northwest",
		"north-northwest",
	}
	normalized := math.Mod(*degrees, 360)
	if normalized < 0 {
		normalized += 360
	}
	sector := int(math.Floor((normalized+11.25)/22.5)) % len(labels)
	return labels[sector]
}

func timedClockLabel(value *forecast.TimedValue, timezone string) string {
	if value == nil {
		return ""
	}
	return clockLabel(value.Time, timezone)
}

func friendlyPeriodBeginsLabel(period timeutil.Period, timezone string) string {
	if !period.IsValid() {
		return ""
	}
	return friendlyDateTimeLabel(period.Start, timezone)
}

func friendlyPeriodEndsLabel(period timeutil.Period, timezone string) string {
	if !period.IsValid() {
		return ""
	}
	return friendlyDateTimeLabel(period.End, timezone)
}

func friendlyDateTimeLabel(value time.Time, timezone string) string {
	if value.IsZero() {
		return ""
	}
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	return value.In(location).Format("2006-01-02 at 3:04 PM")
}

func friendlyMonthDayTimeLabel(value time.Time, timezone string) string {
	if value.IsZero() {
		return ""
	}
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	return value.In(location).Format("January 2 at 3:04 PM")
}

func friendlyDateLabel(date string, timezone string) string {
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	parsed, err := time.ParseInLocation(timeutil.DateLayout, date, location)
	if err != nil {
		return date
	}
	return parsed.Format("Monday, January 2, 2006")
}

func localDateLabel(value time.Time, timezone string) string {
	if value.IsZero() {
		return ""
	}
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	return value.In(location).Format(timeutil.DateLayout)
}

func clockLabel(value time.Time, timezone string) string {
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	label := value.In(location).Format("3 PM")
	if label == "12 AM" && value.In(location).Minute() == 0 {
		return "12 AM"
	}
	return label
}

func hourMinuteLabel(value time.Time, timezone string) string {
	location, err := timeutil.LoadLocation(timezone)
	if err != nil {
		location = time.UTC
	}
	return value.In(location).Format("3:04 PM")
}