package logic

import (
	"context"
	"errors"
	"time"

	"spark-server/internal/module/energy/entity"
	"spark-server/internal/pkg/errs"
)

// CheckInResult is returned after a successful daily sign-in.
type CheckInResult struct {
	Day          int   `json:"day"`
	RewardPoint  int   `json:"reward_point"`
	ContinueDays int   `json:"continue_days"`
	NeedDays     int   `json:"need_days"`
	Energy       int64 `json:"energy"`
	Kind         int16 `json:"kind"`
}

// CheckIn signs the current local day and credits energy.
func (s *Service) CheckIn(ctx context.Context, userID int64) (*CheckInResult, error) {
	if !s.ready() || userID <= 0 {
		return nil, errs.ErrUnauthorized
	}
	today := dayKeyOf(s.now())
	return s.signDay(ctx, userID, today, entity.KindSign, "签到奖励")
}

func (s *Service) signDay(ctx context.Context, userID int64, day int, kind int16, source string) (*CheckInResult, error) {
	if _, ok := parseDayKey(day); !ok {
		return nil, errs.ErrInvalidArgument
	}
	if _, err := s.repo.GetSign(ctx, userID, day); err == nil {
		return nil, errs.ErrDuplicate
	} else if err != nil && !errors.Is(err, errs.ErrNotFound) {
		return nil, err
	}

	streak, _ := s.computeStreak(ctx, userID, dayKeyOf(s.now()))
	rewardDay := streak + 1
	if kind == entity.KindMakeup {
		rewardDay = 1
	}
	reward := entity.CycleRewards(rewardDay)
	reason := "sign"
	if kind == entity.KindMakeup {
		reason = "makeup"
	}

	rec := &entity.SignRecord{
		UserID: userID, DayKey: day, Kind: kind, Reward: reward,
		CreatedMS: time.Now().UnixMilli(),
	}
	if err := s.repo.CreateSign(ctx, rec); err != nil {
		return nil, err
	}
	wallet, _, err := s.repo.AddEnergy(ctx, userID, int64(reward), reason, day, source)
	if err != nil {
		return nil, err
	}
	newStreak, _ := s.computeStreak(ctx, userID, dayKeyOf(s.now()))
	need := entity.DefaultNeedDays - (newStreak % entity.DefaultNeedDays)
	if need <= 0 {
		need = entity.DefaultNeedDays
	}
	return &CheckInResult{
		Day: day, RewardPoint: reward, ContinueDays: newStreak,
		NeedDays: need, Energy: wallet.Energy, Kind: kind,
	}, nil
}