package repository

import (
	"alfred/api/request"
	"alfred/config"
	"alfred/internal/metrics"
	"alfred/model/es"
	"alfred/model/ingester"
	"alfred/pkg/es7"
	"alfred/pkg/log"
	"alfred/utils"
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"github.com/elastic/go-elasticsearch/v8/esapi"
	"go.uber.org/zap"
	"strings"
)

type WebSessionsRepository interface {
	UploadWebSession(sessionUploadRequest ingester.WebSessionUploadRequest, webSessionUploadIndex string) error
	FetchWebSessionsWithSessionId(sessionId, webSessionUploadIndex string) (*esapi.Response, error)
	FetchAllWebSession(filters request.WebSessionFilters, page *es.Page, webSessionUploadIndexList []string) (*esapi.Response, error)
	FetchWebSessionsWithDurationResponse(webSessionIds []string, webSessionUploadIndex string, filters request.WebSessionFilters, page *es.Page) (*esapi.Response, error)
}

type WebSessionsRepositoryImpl struct {
	esClient es7.ElasticSearchClient
}

func NewWebSessionsRepository(esClient es7.ElasticSearchClient) WebSessionsRepository {
	return &WebSessionsRepositoryImpl{
		esClient: esClient,
	}
}

func (r *WebSessionsRepositoryImpl) UploadWebSession(sessionUploadRequest ingester.WebSessionUploadRequest, webSessionUploadIndex string) error {
	year, month, day := utils.GetCurrentDate()

	index := webSessionUploadIndex + fmt.Sprintf("-%d-%d-%d", year, month, day)
	message, err := json.Marshal(sessionUploadRequest)
	if err != nil {
		metrics.ElasticSearchIngestionFailureCounter.WithLabelValues(webSessionUploadIndex).Inc()
		log.Error("error ingesting web session", zap.Error(err))
		return err
	}
	documentId := sessionUploadRequest.SessionAttributes.EventId
	if sessionUploadRequest.BaseAttributes.Version >= config.GetCollectorConfig().ElasticSearchConfig.MinWebVersionSupportingSingleDoc {
		documentId = sessionUploadRequest.BaseAttributes.SessionId
	}
	req := esapi.IndexRequest{
		Index:      index,
		DocumentID: documentId,
		Body:       bytes.NewReader(message),
	}

	indexResponse, err := req.Do(context.Background(), r.esClient.GetESClient())
	if err != nil {
		metrics.ElasticSearchIngestionFailureCounter.WithLabelValues(webSessionUploadIndex).Inc()
		log.Error("web session ingestion failed", zap.String("response", fmt.Sprintf("%v", indexResponse)), zap.Error(err))
		return err
	}
	defer indexResponse.Body.Close()

	metrics.ElasticSearchIngestionSuccessCounter.WithLabelValues(webSessionUploadIndex).Inc()

	return nil
}

func (r *WebSessionsRepositoryImpl) FetchWebSessionsWithSessionId(sessionId, webSessionUploadIndex string) (*esapi.Response, error) {
	content := getWebSessionFromSessionIdQuery(sessionId)
	result, err := r.esClient.FetchESData(webSessionUploadIndex, content)
	if err != nil {
		return nil, err
	}
	return result, err
}

func (r *WebSessionsRepositoryImpl) FetchAllWebSession(filters request.WebSessionFilters, page *es.Page, webSessionUploadIndexList []string) (*esapi.Response, error) {
	content := getAllPaginatedWebSessionsQuery(filters, page)
	result, err := r.esClient.FetchESDataMultipleIndex(webSessionUploadIndexList, content)
	if err != nil {
		return nil, err
	}

	return result, nil
}

func (r *WebSessionsRepositoryImpl) FetchWebSessionsWithDurationResponse(webSessionIds []string, webSessionUploadIndex string, filters request.WebSessionFilters, page *es.Page) (*esapi.Response, error) {
	content := getWebSessionWithDurationQuery(webSessionIds, filters, page)
	result, err := r.esClient.FetchESData(webSessionUploadIndex, content)
	if err != nil {
		return nil, err
	}
	return result, nil
}

func getWebSessionFromSessionIdQuery(sessionId string) string {
	termFilter := createTermSubQuery("base_attributes.session_id", sessionId)
	var sortQueryFields []string
	sortQueryFields = append(sortQueryFields, createSortQueryFields("base_attributes.client_timestamp", "asc", "strict_date_optional_time_nanos"))
	sortQueryFields = append(sortQueryFields, createSortQueryFields("session_attribute.event_id", "asc", ""))
	query := createEsQuery(
		createSearchQuery(createBoolQuery(createShouldQuery(termFilter))),
		createMultiSortQuery(sortQueryFields...),
		createSizeQuery(utils.EsUpperLimit),
	)
	return query
}

func getAllPaginatedWebSessionsQuery(filters request.WebSessionFilters, page *es.Page) string {
	projectName, agentId, ticketId, sessionId, deviceId, emailId, phoneNumber := getFilterList(filters)
	multipleShouldQuery := []string{createBoolShouldQuery(createTermSubQuery("base_attributes.project_name", projectName...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.metadata.agentId", agentId...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.metadata.ticketId", ticketId...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.metadata.emailId", emailId...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.metadata.phoneNumber", phoneNumber...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.session_id", sessionId...)),
		createBoolShouldQuery(createTermSubQuery("base_attributes.device_id", deviceId...))}
	shouldQuery := strings.Join(multipleShouldQuery, ",")
	rangeQuery := createRangeQuery("base_attributes.client_timestamp", filters.StartTimestamp, filters.EndTimestamp)

	query := createEsQuery(
		createSearchQuery(createBoolQuery(createMustQuery(shouldQuery, rangeQuery))),
		createSortQuery(filters.SortBy, string(page.SortDirection), "strict_date_optional_time_nanos"),
		createCollapseQuery("base_attributes.session_id"),
		createFromQuery(page.PageSize*page.PageNumber),
		createSizeQuery(page.PageSize),
	)
	return query
}

func getWebSessionWithDurationQuery(webSessionIds []string, filters request.WebSessionFilters, page *es.Page) string {
	boolshouldQuery := createBoolShouldQuery(createTermSubQuery("base_attributes.session_id", webSessionIds...))
	sortQuery := createSortQuery(filters.SortBy, string(page.SortDirection), "strict_date_optional_time_nanos")
	collapseQuery := createCollapseQuery("base_attributes.session_id")
	minTimestampAggregationQuery := buildAggregationQuery("min_start_timestamp", createMinAggregationQuery("session_attribute.start_timestamp"))
	maxTimestampAggregationQuery := buildAggregationQuery("max_end_timestamp", createMaxAggregationQuery("session_attribute.end_timestamp"))
	termsAggregation := createTermsAggregationQuery("base_attributes.session_id", int(page.PageSize))
	innerAggregationQuery := createAggregationQuery(minTimestampAggregationQuery, maxTimestampAggregationQuery)
	aggregationQuery := createAggregationQuery(buildAggregationQuery("buckets", termsAggregation, innerAggregationQuery))
	return createEsQuery(createSearchQuery(boolshouldQuery), sortQuery, collapseQuery, aggregationQuery, createSizeQuery(utils.EsUpperLimit))
}

func getFilterList(filters request.WebSessionFilters) (projectName, agentId, ticketId, sessionId, deviceId, emailId, phoneNumber []string) {
	if filters.ProjectName != utils.EMPTY {
		projectName = strings.Split(filters.ProjectName, utils.COMMA)
	}
	if filters.AgentId != utils.EMPTY {
		agentId = strings.Split(filters.AgentId, utils.COMMA)
	}
	if filters.TicketId != utils.EMPTY {
		ticketId = strings.Split(filters.TicketId, utils.COMMA)
	}
	if filters.SessionId != utils.EMPTY {
		sessionId = strings.Split(filters.SessionId, utils.COMMA)
	}
	if len(filters.DeviceId) != 0 {
		deviceId = filters.DeviceId
	}
	if filters.EmailId != utils.EMPTY {
		emailId = strings.Split(filters.EmailId, utils.COMMA)
	}
	return projectName, agentId, ticketId, sessionId, deviceId, emailId, phoneNumber
}