package handler

import (
	"context"
	"fmt"
	"strings"
	"time"

	"github.com/go-telegram/bot/models"

	"worktimeBot/internal/domain"
)

// -- Command --

func (h *Handler) handleBurnout(ctx context.Context, msg *models.Message, user *domain.User) {
	text := h.buildBurnoutText(user)
	h.sendWithKB(ctx, msg.Chat.ID, text, backKeyboard())
}

// -- Callback --

func (h *Handler) burnoutCallback(ctx context.Context, chatID int64, msgID int, cbID string, user *domain.User) {
	defer h.answerCb(ctx, cbID)
	text := h.buildBurnoutText(user)
	kb := backKeyboard()
	h.editText(ctx, chatID, msgID, text, &kb)
}

// -- Assessment --

func (h *Handler) buildBurnoutText(user *domain.User) string {
	res, err := h.assessBurnout(user)
	if err != nil {
		return "Burnout assessment unavailable."
	}
	var b strings.Builder
	b.WriteString(fmt.Sprintf("Burnout Assessment\nLevel: %s (%d/100)\n\n", res.Level, res.Score))
	if res.ConsecutiveDays > 0 {
		b.WriteString(fmt.Sprintf("  Consecutive workdays: %d days (%d pts)\n", res.ConsecutiveDays, res.ConsecutivePts))
	}
	if res.WorkSeconds > 0 {
		wh := float64(res.WorkSeconds) / domain.SecondsPerHour
		b.WriteString(fmt.Sprintf("  Today's work: %.1f hours (%d pts)\n", wh, res.LongHoursPts))
	}
	if res.BreakSeconds > 0 {
		br := float64(res.BreakSeconds)
		total := float64(res.WorkSeconds + res.BreakSeconds)
		ratio := br / total * 100
		if ratio > 100 {
			ratio = 100
		}
		b.WriteString(fmt.Sprintf("  Break ratio: %.0f%% (%d pts)\n", ratio, res.BreakRatioPts))
	}
	if res.WeekendPts > 0 {
		b.WriteString(fmt.Sprintf("  Weekend work: yes (%d pts)\n", res.WeekendPts))
	}
	b.WriteString(fmt.Sprintf("  Work trend: %s (%d pts)\n", res.TrendDirection, res.TrendPts))
	if res.LateNightPts > 0 {
		b.WriteString(fmt.Sprintf("  Late-night work: yes (%d pts)\n", res.LateNightPts))
	}
	b.WriteString("\nRecommendations:\n")
	switch res.Level {
	case domain.BurnoutHealthy:
		b.WriteString("  Keep up the balanced routine!")
	case domain.BurnoutMild:
		b.WriteString("  Consider taking short breaks throughout the day.")
		b.WriteString("\n  Make sure to disconnect after work hours.")
	case domain.BurnoutModerate:
		b.WriteString("  Consider taking a day off soon.")
		b.WriteString("\n  Review your workload distribution.")
		b.WriteString("\n  Ensure you are taking adequate breaks.")
	case domain.BurnoutHigh:
		b.WriteString("  Strongly consider taking time off.")
		b.WriteString("\n  Your workload patterns indicate potential strain.")
		b.WriteString("\n  Please prioritize rest and recovery.")
	}
	return b.String()
}

func (h *Handler) assessBurnout(user *domain.User) (*domain.BurnoutResult, error) {
	loc := h.loadLocation(user.Timezone)
	now := time.Now().In(loc)
	today := now.Format(domain.DateLayout)
	result := &domain.BurnoutResult{}

	stats, err := h.Repo.GetOrCreateRPGStats(user.ID)
	if err == nil {
		result.ConsecutiveDays = stats.CurrentStreak
	}
	switch {
	case result.ConsecutiveDays >= 7:
		result.ConsecutivePts = 25
	case result.ConsecutiveDays >= 4:
		result.ConsecutivePts = 15
	case result.ConsecutiveDays >= 1:
		result.ConsecutivePts = 5
	}

	todayEvents, _ := h.Repo.EventsForDayByDate(user.ID, today)
	if len(todayEvents) > 0 {
		day, _ := h.Repo.GetDay(user.ID, today)
		if day != nil {
			y, m, d := now.Date()
			dayStart := time.Date(y, m, d, 0, 0, 0, 0, loc).Unix()
			totals := domain.ComputeDailyTotals(todayEvents, day.MinBreakThreshold, dayStart, now.Unix())
			result.WorkSeconds = totals.TotalSeconds
			result.BreakSeconds = totals.BreakSeconds
			workHours := float64(totals.TotalSeconds) / domain.SecondsPerHour
			switch {
			case workHours >= 12:
				result.LongHoursPts = 20
			case workHours >= 10:
				result.LongHoursPts = 15
			case workHours >= 8:
				result.LongHoursPts = 10
			}
			total := totals.TotalSeconds + totals.BreakSeconds
			if total > 0 {
				breakRatio := float64(totals.BreakSeconds) / float64(total) * 100
				switch {
				case breakRatio < 5:
					result.BreakRatioPts = 15
				case breakRatio < 10:
					result.BreakRatioPts = 10
				case breakRatio < 20:
					result.BreakRatioPts = 5
				}
			}
			if len(todayEvents) > 0 {
				lastEvent := todayEvents[len(todayEvents)-1]
				lt := time.Unix(lastEvent.OccurredAt, 0).In(loc)
				minutes := lt.Hour()*60 + lt.Minute()
				switch {
				case minutes >= 22*60:
					result.LateNightPts = 10
				case minutes >= 20*60:
					result.LateNightPts = 5
				}
			}
		}
	}

	weekday := now.Weekday()
	if weekday == time.Saturday || weekday == time.Sunday {
		if result.WorkSeconds > 0 {
			result.WeekendPts = 15
		}
	}

	result.TrendPts, result.TrendDirection = h.computeTrend(user.ID, today, loc)
	result.Score = result.ConsecutivePts + result.LongHoursPts + result.BreakRatioPts +
		result.WeekendPts + result.TrendPts + result.LateNightPts
	switch {
	case result.Score >= 61:
		result.Level = domain.BurnoutHigh
	case result.Score >= 41:
		result.Level = domain.BurnoutModerate
	case result.Score >= 21:
		result.Level = domain.BurnoutMild
	default:
		result.Level = domain.BurnoutHealthy
	}
	return result, nil
}

func (h *Handler) computeTrend(userID int64, today string, loc *time.Location) (int, string) {
	t, err := time.Parse(domain.DateLayout, today)
	if err != nil {
		return 0, "unknown"
	}
	var recent, older [3]int64
	for i := 0; i < 3; i++ {
		d := t.AddDate(0, 0, -(i + 1)).Format(domain.DateLayout)
		recent[2-i] = h.dayWorkSeconds(userID, d, loc)
	}
	for i := 0; i < 3; i++ {
		d := t.AddDate(0, 0, -(i + 4)).Format(domain.DateLayout)
		older[2-i] = h.dayWorkSeconds(userID, d, loc)
	}
	var recentAvg, olderAvg float64
	for _, v := range recent {
		recentAvg += float64(v)
	}
	for _, v := range older {
		olderAvg += float64(v)
	}
	recentAvg /= 3.0
	olderAvg /= 3.0
	return domain.ComputeTrendFromAvgs(recentAvg, olderAvg)
}

func (h *Handler) dayWorkSeconds(userID int64, date string, loc *time.Location) int64 {
	events, err := h.Repo.EventsForDayByDate(userID, date)
	if err != nil || len(events) == 0 {
		return 0
	}
	day, err := h.Repo.GetDay(userID, date)
	if err != nil || day == nil {
		return 0
	}
	y, m, d := domain.ParseGregorianDateKey(date)
	dayStart := time.Date(y, time.Month(m), d, 0, 0, 0, 0, loc).Unix()
	dayEnd := time.Date(y, time.Month(m), d, 23, 59, 59, 0, loc).Unix()
	totals := domain.ComputeDailyTotals(events, day.MinBreakThreshold, dayStart, dayEnd)
	return totals.TotalSeconds
}