package rechargereward

import (
	"context"
	"net/http"
	"strings"
	"time"
)

// GetHome 返回当前登录用户的充值奖励 H5 数据。
func (s *Service) GetHome(ctx context.Context, user AuthUser) (*RechargeRewardHomeResponse, error) {
	sysOrigin, err := requireRechargeRewardUser(user)
	if err != nil {
		return nil, err
	}
	if s.java == nil {
		return nil, NewAppError(http.StatusServiceUnavailable, "java_gateway_unavailable", "java gateway is unavailable")
	}

	bundle, err := s.loadConfigBundle(ctx, sysOrigin)
	if err != nil {
		return nil, err
	}
	location := s.location
	if bundle.Config != nil {
		location = resolveLocation(bundle.Config.Timezone, s.location)
	}
	now := time.Now().In(location)
	periodStart, periodEnd := currentMonthBounds(now, location)

	currentRechargeCents, err := s.loadCurrentRechargeCents(ctx, user.UserID)
	if err != nil {
		return nil, err
	}
	accumulatedRechargeCents, err := s.loadAccumulatedRechargeCents(ctx, user.UserID)
	if err != nil {
		return nil, err
	}

	resp := &RechargeRewardHomeResponse{
		ActivityStatus:                 rechargeRewardActivityStatus(bundle.Config != nil && bundle.Config.Enabled),
		Configured:                     bundle.Config != nil,
		Enabled:                        bundle.Config != nil && bundle.Config.Enabled,
		SysOrigin:                      sysOrigin,
		Timezone:                       location.String(),
		PeriodStartAt:                  formatDateTime(periodStart),
		PeriodEndAt:                    formatDateTime(periodEnd),
		CountdownMillis:                maxInt64(0, periodEnd.UnixMilli()-now.UnixMilli()),
		UserID:                         user.UserID,
		CurrentRechargeAmount:          formatAmountCents(currentRechargeCents),
		CurrentRechargeAmountCents:     currentRechargeCents,
		AccumulatedRechargeAmount:      formatAmountCents(accumulatedRechargeCents),
		AccumulatedRechargeAmountCents: accumulatedRechargeCents,
		LevelConfigs:                   []RechargeRewardLevelPayload{},
	}
	if bundle.Config != nil {
		resp.SysOrigin = bundle.Config.SysOrigin
		resp.Timezone = normalizeRechargeRewardTimezone(bundle.Config.Timezone)
	}

	if profile, err := s.java.GetUserProfile(ctx, user.UserID); err == nil {
		resp.UserAccount = profile.Account
		resp.UserNickname = profile.UserNickname
		resp.UserAvatar = profile.UserAvatar
	} else if !isEmptyJavaProfileError(err) {
		return nil, err
	}

	if bundle.Config == nil {
		return resp, nil
	}
	matched, matchedOK := pickMatchedLevel(bundle.Levels, currentRechargeCents)
	next, nextOK := pickNextLevel(bundle.Levels, currentRechargeCents)
	if matchedOK {
		resp.MatchedLevel = matched.Level
	}
	if nextOK {
		resp.NextLevel = next.Level
		resp.NextRechargeAmount = formatAmountCents(next.RechargeAmountCents)
		resp.NextRechargeAmountCents = next.RechargeAmountCents
	}
	rewardItems := s.loadRewardItemsMap(ctx, bundle.Levels)
	matchedLevel := 0
	if matchedOK {
		matchedLevel = matched.Level
	}
	resp.LevelConfigs = buildLevelPayloads(bundle.Levels, rewardItems, currentRechargeCents, matchedLevel)
	return resp, nil
}

func (s *Service) loadCurrentRechargeCents(ctx context.Context, userID int64) (int64, error) {
	amount, err := s.java.GetThisMonthTotalPersonalRecharge(ctx, userID)
	if err != nil {
		return 0, err
	}
	return parseIntegrationAmountCents(integrationAmount(amount)), nil
}

func (s *Service) loadAccumulatedRechargeCents(ctx context.Context, userID int64) (int64, error) {
	recharges, err := s.java.MapUserTotalRecharge(ctx, []int64{userID})
	if err != nil {
		return 0, err
	}
	return totalRechargeCents(recharges[userID]), nil
}

func currentMonthBounds(now time.Time, location *time.Location) (time.Time, time.Time) {
	local := now.In(location)
	start := time.Date(local.Year(), local.Month(), 1, 0, 0, 0, 0, location)
	return start, start.AddDate(0, 1, 0)
}

func resolveLocation(timezone string, fallback *time.Location) *time.Location {
	location, err := time.LoadLocation(normalizeRechargeRewardTimezone(timezone))
	if err == nil {
		return location
	}
	if fallback != nil {
		return fallback
	}
	return time.UTC
}

func rechargeRewardActivityStatus(enabled bool) string {
	if enabled {
		return rechargeRewardActivityStatusOngoing
	}
	return rechargeRewardActivityStatusDisabled
}

func isEmptyJavaProfileError(err error) bool {
	if err == nil {
		return false
	}
	return strings.Contains(strings.ToLower(err.Error()), "empty")
}

func maxInt64(a, b int64) int64 {
	if a > b {
		return a
	}
	return b
}