package briefing

import (
	"fmt"
	"strings"

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

const (
	precipTimingChanceLowerBound = 40
	precipTimingLikelyLowerBound = 50
	precipTimingExpectLowerBound = 70
)

type PrecipTimingModule struct {
	MaxPopPercent        *int                        `json:"max_pop_percent,omitempty"`
	MaxPopTime           string                      `json:"max_pop_time,omitempty"`
	ProbabilityThreshold float64                     `json:"probability_threshold"`
	PrecipitationWindows []PrecipitationWindowModule `json:"precipitation_windows,omitempty"`
	ThunderMentioned     bool                        `json:"thunder_mentioned"`
}

type PrecipitationWindowModule struct {
	PeriodBegins          string `json:"period_begins"`
	PeriodBeginsHourLabel string `json:"period_begins_hour_label,omitempty"`
	PeriodEnds            string `json:"period_ends,omitempty"`
	PeriodEndsHourLabel   string `json:"period_ends_hour_label,omitempty"`
	MaxPopPercent         *int   `json:"max_pop_percent,omitempty"`
	MaxPopTime            string `json:"max_pop_time,omitempty"`
	MaxPopHourLabel       string `json:"max_pop_hour_label,omitempty"`
	PrecipitationType     string `json:"precipitation_type,omitempty"`
	ExpectationPhrase     string `json:"expectation_phrase,omitempty"`
}

func buildPrecipTimingModule(ctx ModuleContext, _ any) (*module.Output, error) {
	value := precipTimingValue(ctx.Derived.PrecipTiming, ctx.Timezone)
	return &module.Output{ID: module.PrecipTiming, StanzaName: "precip_timing", Value: value}, nil
}

func precipTimingValue(timing forecast.PrecipTiming, timezone string) PrecipTimingModule {
	value := PrecipTimingModule{
		ProbabilityThreshold: timing.ProbabilityThreshold,
		ThunderMentioned:     timing.ThunderMentioned,
	}
	if timing.MaxPrecipitationProbability != nil {
		value.MaxPopPercent = roundedInt(&timing.MaxPrecipitationProbability.Value)
		value.MaxPopTime = clockLabel(timing.MaxPrecipitationProbability.Time, timezone)
	}
	for _, window := range timing.PrecipitationWindows {
		item := PrecipitationWindowModule{
			PeriodBegins:          friendlyDateTimeLabel(window.Start, timezone),
			PeriodBeginsHourLabel: hourMinuteLabel(window.Start, timezone),
		}
		if window.End != nil {
			item.PeriodEnds = friendlyDateTimeLabel(*window.End, timezone)
			item.PeriodEndsHourLabel = hourMinuteLabel(*window.End, timezone)
		}
		item.MaxPopPercent = roundedInt(&window.MaxPrecipitationProbability.Value)
		item.MaxPopTime = clockLabel(window.MaxPrecipitationProbability.Time, timezone)
		item.MaxPopHourLabel = hourMinuteLabel(window.MaxPrecipitationProbability.Time, timezone)
		item.PrecipitationType = precipitationWindowType(window.TextDescriptions)
		if item.MaxPopPercent != nil {
			item.ExpectationPhrase = precipitationWindowExpectationPhrase(*item.MaxPopPercent, item.PrecipitationType)
		}
		value.PrecipitationWindows = append(value.PrecipitationWindows, item)
	}
	return value
}

func precipitationWindowType(descriptions []string) string {
	combined := strings.ToLower(strings.Join(descriptions, " "))
	switch {
	case (strings.Contains(combined, "thunderstorm") || strings.Contains(combined, "t-storm")) &&
		(strings.Contains(combined, "shower") || strings.Contains(combined, "rain")):
		return "showers and thunderstorms"
	case strings.Contains(combined, "freezing rain"):
		return "freezing rain"
	case strings.Contains(combined, "thunderstorm") || strings.Contains(combined, "t-storm"):
		return "thunderstorms"
	case strings.Contains(combined, "shower"):
		return "showers"
	case strings.Contains(combined, "snow"):
		return "snow"
	case strings.Contains(combined, "drizzle"):
		return "drizzle"
	case strings.Contains(combined, "rain"):
		return "rain"
	default:
		return "precipitation"
	}
}

func precipitationWindowExpectationPhrase(maxPopPercent int, precipitationType string) string {
	if precipitationType == "" {
		precipitationType = "precipitation"
	}
	switch {
	case maxPopPercent >= precipTimingExpectLowerBound:
		return fmt.Sprintf("Expect %s.", precipitationType)
	case maxPopPercent >= precipTimingLikelyLowerBound:
		return fmt.Sprintf("%s likely.", capitalizeFirst(strings.TrimSpace(precipitationType)))
	case maxPopPercent >= precipTimingChanceLowerBound:
		return fmt.Sprintf("Chance of %s.", precipitationType)
	default:
		return ""
	}
}