package firstrechargereward

import (
	"context"
	"errors"
	"net/http"

	"chatapp3-golang/internal/model"

	"gorm.io/gorm"
)

const (
	activityStatusNotConfigured = "NOT_CONFIGURED"
	activityStatusDisabled      = "DISABLED"
	activityStatusOngoing       = "ONGOING"
	activityStatusPending       = "PENDING"
	activityStatusRewarded      = "REWARDED"
	activityStatusFailed        = "FAILED"
)

// GetHome returns app-facing first recharge reward config and the user's grant state.
func (s *Service) GetHome(ctx context.Context, user AuthUser) (*HomeResponse, error) {
	sysOrigin, err := requireUser(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
	}
	if bundle.Config == nil {
		return &HomeResponse{
			Configured:      false,
			Enabled:         false,
			ActivityStatus:  activityStatusNotConfigured,
			UserID:          user.UserID,
			SysOrigin:       sysOrigin,
			LevelConfigs:    []LevelPayload{},
			HasRewardRecord: false,
		}, nil
	}

	rewardItems := s.loadRewardItemsMap(ctx, bundle.Levels)
	resp := &HomeResponse{
		Configured:      true,
		Enabled:         bundle.Config.Enabled,
		ActivityStatus:  activityStatusOngoing,
		UserID:          user.UserID,
		SysOrigin:       bundle.Config.SysOrigin,
		LevelConfigs:    buildLevelPayloads(bundle.Levels, rewardItems, 0, 0, false),
		HasRewardRecord: false,
	}
	if !bundle.Config.Enabled {
		resp.ActivityStatus = activityStatusDisabled
	}

	record, ok, err := s.loadUserGrantRecord(ctx, bundle.Config.SysOrigin, user.UserID)
	if err != nil {
		return nil, err
	}
	if !ok {
		return resp, nil
	}

	resp.HasRewardRecord = true
	resp.RewardStatus = record.Status
	resp.Rewarded = record.Status == statusSuccess
	resp.MatchedLevel = record.Level
	resp.RechargeAmount = formatAmountCents(record.RechargeAmountCents)
	resp.RechargeAmountCents = record.RechargeAmountCents
	resp.RewardGroupID = record.RewardGroupID
	resp.RewardGroupName = record.RewardGroupName
	resp.RewardItems = rewardItems[record.RewardGroupID]
	resp.LevelConfigs = buildLevelPayloads(bundle.Levels, rewardItems, record.RechargeAmountCents, record.Level, false)

	switch record.Status {
	case statusSuccess:
		resp.ActivityStatus = activityStatusRewarded
	case statusPending:
		resp.ActivityStatus = activityStatusPending
	case statusFailed:
		resp.ActivityStatus = activityStatusFailed
	}
	return resp, nil
}

func (s *Service) loadUserGrantRecord(ctx context.Context, sysOrigin string, userID int64) (model.FirstRechargeRewardGrantRecord, bool, error) {
	if userID <= 0 {
		return model.FirstRechargeRewardGrantRecord{}, false, nil
	}
	var record model.FirstRechargeRewardGrantRecord
	err := s.db.WithContext(ctx).
		Where("sys_origin = ? AND user_id = ?", s.normalizeSysOrigin(sysOrigin), userID).
		First(&record).Error
	if errors.Is(err, gorm.ErrRecordNotFound) {
		return model.FirstRechargeRewardGrantRecord{}, false, nil
	}
	if err != nil {
		return model.FirstRechargeRewardGrantRecord{}, false, err
	}
	return record, true, nil
}