package service_event

import (
	"context"
	"nixcn-cms/data"
	"nixcn-cms/internal/exception"
	"nixcn-cms/service/shared"
	"strconv"
	"time"

	"github.com/google/uuid"
)

type JoinedEventListData struct {
	Limit  *string `json:"limit"`
	Offset *string `json:"offset"`
}

type JoinedEventListPayload struct {
	Context context.Context
	UserId  uuid.UUID
	Data    *JoinedEventListData
}

type JoinedEventListResult struct {
	Common shared.CommonResult
	Data   *[]data.EventIndexDoc `json:"event_list"`
}

func (self *EventServiceImpl) GetJoinedEvent(payload *JoinedEventListPayload) (result *JoinedEventListResult) {
	var limit string
	if payload.Data.Limit == nil || *payload.Data.Limit == "" {
		limit = "20"
	} else {
		limit = *payload.Data.Limit
	}

	var offset string
	if payload.Data.Offset == nil || *payload.Data.Offset == "" {
		exc := new(exception.Builder).
			SetStatus(exception.StatusUser).
			SetService(exception.ServiceEvent).
			SetEndpoint(exception.EndpointEventServiceList).
			SetType(exception.TypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			SetError(nil).
			Throw(payload.Context)

		return &JoinedEventListResult{
			Common: shared.CommonResult{
				HttpCode:  400,
				Exception: exc,
			},
		}
	} else {
		offset = *payload.Data.Offset
	}

	limitNum, err := strconv.Atoi(limit)
	if err != nil {
		exc := new(exception.Builder).
			SetStatus(exception.StatusUser).
			SetService(exception.ServiceEvent).
			SetEndpoint(exception.EndpointEventServiceList).
			SetType(exception.TypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			SetError(err).
			Throw(payload.Context)

		return &JoinedEventListResult{
			Common: shared.CommonResult{HttpCode: 400, Exception: exc},
		}
	}

	offsetNum, err := strconv.Atoi(offset)
	if err != nil {
		exc := new(exception.Builder).
			SetStatus(exception.StatusUser).
			SetService(exception.ServiceEvent).
			SetEndpoint(exception.EndpointEventServiceList).
			SetType(exception.TypeCommon).
			SetOriginal(exception.CommonErrorInvalidInput).
			SetError(err).
			Throw(payload.Context)

		return &JoinedEventListResult{
			Common: shared.CommonResult{HttpCode: 400, Exception: exc},
		}
	}

	eventList, err := new(data.Event).
		GetEventsByUserId(payload.Context, payload.UserId, int64(limitNum), int64(offsetNum))

	if err != nil {
		exc := new(exception.Builder).
			SetStatus(exception.StatusServer).
			SetService(exception.ServiceEvent).
			SetEndpoint(exception.EndpointEventServiceList).
			SetType(exception.TypeSpecific).
			SetOriginal(exception.EventListDatabaseFailed).
			SetError(err).
			Throw(payload.Context)

		return &JoinedEventListResult{
			Common: shared.CommonResult{
				HttpCode:  500,
				Exception: exc,
			},
		}
	}

	if eventList != nil && len(*eventList) > 0 {
		attendances, err := new(data.Attendance).GetEventsByUserID(payload.Context, payload.UserId)

		checkinMap := make(map[uuid.UUID]time.Time)
		if err == nil && attendances != nil {
			for _, att := range *attendances {
				checkinMap[att.EventId] = att.CheckinAt
			}
		}

		for i := range *eventList {
			item := &(*eventList)[i]

			item.IsJoined = true

			eID, _ := uuid.Parse(item.EventId)

			if checkinTime, signedUp := checkinMap[eID]; signedUp {
				if !checkinTime.IsZero() && checkinTime.After(time.Unix(0, 0)) {
					item.IsCheckedIn = true
				}
			}

			cCount, _ := new(data.Attendance).CountCheckedInUsersByEventID(payload.Context, eID)
			item.CheckinCount = cCount
		}
	}

	if eventList != nil {
		for i := range *eventList {
			(*eventList)[i].IsJoined = true
		}
	}

	successExc := new(exception.Builder).
		SetStatus(exception.StatusSuccess).
		SetService(exception.ServiceEvent).
		SetEndpoint(exception.EndpointEventServiceList).
		SetType(exception.TypeCommon).
		SetOriginal(exception.CommonSuccess).
		Throw(payload.Context)

	return &JoinedEventListResult{
		Common: shared.CommonResult{
			HttpCode:  200,
			Exception: successExc,
		},
		Data: eventList,
	}
}