package service

import (
	"context"
	"errors"
	"time"

	"gorm.io/gorm"

	smokemodel "wx_service/internal/smoke/model"
)

type SmokeMotivation struct {
	Message string `json:"message"`
	Type    string `json:"type"`
}

func (s *SmokeLogService) Motivation(ctx context.Context, uid int, asOf time.Time, profile *smokemodel.SmokeUserProfile) (SmokeMotivation, error) {
	home, err := s.HomeSummary(ctx, uid, asOf)
	if err != nil {
		return SmokeMotivation{}, err
	}

	minutesSinceLast := -1
	if home.LastSmokeAt != nil {
		diff := int(asOf.Sub(*home.LastSmokeAt).Minutes())
		if diff < 0 {
			diff = 0
		}
		minutesSinceLast = diff
	}

	dailyTarget := 0
	if profile != nil && profile.BaselineCigsPerDay > 0 {
		dailyTarget = profile.BaselineCigsPerDay
	}

	quitMotivation := ""
	if profile != nil && len(profile.QuitMotivations) > 0 {
		quitMotivation = profile.QuitMotivations[0]
	}

	scene, fallback := buildMotivationScene(home, minutesSinceLast, dailyTarget, quitMotivation)
	if quote, ok, err := s.loadMotivationQuote(ctx, scene); err != nil {
		return fallback, err
	} else if ok {
		return SmokeMotivation{Message: quote.Message, Type: quote.Type}, nil
	}

	if scene != "default" {
		if quote, ok, err := s.loadMotivationQuote(ctx, "default"); err != nil {
			return fallback, err
		} else if ok {
			return SmokeMotivation{Message: quote.Message, Type: quote.Type}, nil
		}
	}

	return fallback, nil
}

func buildMotivationScene(home SmokeHomeSummary, minutesSinceLast int, dailyTarget int, quitMotivation string) (string, SmokeMotivation) {
	if home.ResistedCount > 0 && minutesSinceLast >= 0 && minutesSinceLast < 30 {
		return "recent_resist", SmokeMotivation{
			Message: "太棒了！你刚刚成功抵抗了一次烟瘾",
			Type:    "praise",
		}
	}

	if dailyTarget > 0 && home.TodayCount < int(float64(dailyTarget)*0.5) {
		return "below_half_target", SmokeMotivation{
			Message: "今天的表现非常出色，继续保持！",
			Type:    "encourage",
		}
	}

	if dailyTarget > 0 && home.TodayCount == dailyTarget-1 {
		return "near_limit", SmokeMotivation{
			Message: "还剩最后一支配额，考虑把它留到睡前？",
			Type:    "hint",
		}
	}

	if dailyTarget > 0 && home.TodayCount > dailyTarget {
		msg := "没关系，明天是新的一天。"
		if quitMotivation != "" {
			msg = msg + "记住你为什么要戒烟：" + quitMotivation
		}
		return "over_target", SmokeMotivation{
			Message: msg,
			Type:    "comfort",
		}
	}

	return "default", SmokeMotivation{
		Message: "保持连胜纪录！",
		Type:    "encourage",
	}
}

func (s *SmokeLogService) loadMotivationQuote(ctx context.Context, scene string) (smokemodel.SmokeMotivationQuote, bool, error) {
	var quote smokemodel.SmokeMotivationQuote
	if err := s.db.WithContext(ctx).
		Where("scene = ? AND enabled = 1", scene).
		Order("weight DESC, id ASC").
		First(&quote).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return smokemodel.SmokeMotivationQuote{}, false, nil
		}
		return smokemodel.SmokeMotivationQuote{}, false, err
	}
	if quote.Message == "" || quote.Type == "" {
		return smokemodel.SmokeMotivationQuote{}, false, nil
	}
	return quote, true, nil
}