package v4

import (
	"fmt"
	"strings"
	"time"

	metricsV3 "go.signoz.io/signoz/pkg/query-service/app/metrics/v3"
	"go.signoz.io/signoz/pkg/query-service/constants"
	"go.signoz.io/signoz/pkg/query-service/model"
	v3 "go.signoz.io/signoz/pkg/query-service/model/v3"
	"go.signoz.io/signoz/pkg/query-service/utils"
)

// PrepareTimeseriesFilterQuery builds the sub-query to be used for filtering timeseries based on the search criteria
func PrepareTimeseriesFilterQuery(mq *v3.BuilderQuery) (string, error) {
	var conditions []string
	var fs *v3.FilterSet = mq.Filters
	var groupTags []v3.AttributeKey = mq.GroupBy

	conditions = append(conditions, fmt.Sprintf("metric_name = %s", utils.ClickHouseFormattedValue(mq.AggregateAttribute.Key)))
	conditions = append(conditions, fmt.Sprintf("temporality = '%s'", mq.Temporality))

	if fs != nil && len(fs.Items) != 0 {
		for _, item := range fs.Items {
			toFormat := item.Value
			op := v3.FilterOperator(strings.ToLower(strings.TrimSpace(string(item.Operator))))
			if op == v3.FilterOperatorContains || op == v3.FilterOperatorNotContains {
				toFormat = fmt.Sprintf("%%%s%%", toFormat)
			}
			fmtVal := utils.ClickHouseFormattedValue(toFormat)
			switch op {
			case v3.FilterOperatorEqual:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') = %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorNotEqual:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') != %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorIn:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') IN %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorNotIn:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') NOT IN %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorLike:
				conditions = append(conditions, fmt.Sprintf("like(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorNotLike:
				conditions = append(conditions, fmt.Sprintf("notLike(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorRegex:
				conditions = append(conditions, fmt.Sprintf("match(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorNotRegex:
				conditions = append(conditions, fmt.Sprintf("not match(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorGreaterThan:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') > %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorGreaterThanOrEq:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') >= %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorLessThan:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') < %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorLessThanOrEq:
				conditions = append(conditions, fmt.Sprintf("JSONExtractString(labels, '%s') <= %s", item.Key.Key, fmtVal))
			case v3.FilterOperatorContains:
				conditions = append(conditions, fmt.Sprintf("like(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorNotContains:
				conditions = append(conditions, fmt.Sprintf("notLike(JSONExtractString(labels, '%s'), %s)", item.Key.Key, fmtVal))
			case v3.FilterOperatorExists:
				conditions = append(conditions, fmt.Sprintf("has(JSONExtractKeys(labels), '%s')", item.Key.Key))
			case v3.FilterOperatorNotExists:
				conditions = append(conditions, fmt.Sprintf("not has(JSONExtractKeys(labels), '%s')", item.Key.Key))
			default:
				return "", fmt.Errorf("unsupported filter operator")
			}
		}
	}
	whereClause := strings.Join(conditions, " AND ")

	var selectLabels string
	for _, tag := range groupTags {
		selectLabels += fmt.Sprintf("JSONExtractString(labels, '%s') as %s, ", tag.Key, tag.Key)
	}

	// The table JOIN key always exists
	selectLabels += "fingerprint"

	filterSubQuery := fmt.Sprintf(
		"SELECT DISTINCT %s FROM %s.%s WHERE %s",
		selectLabels,
		constants.SIGNOZ_METRIC_DBNAME,
		constants.SIGNOZ_TIMESERIES_LOCAL_TABLENAME,
		whereClause,
	)

	return filterSubQuery, nil
}

// PrepareMetricQuery prepares the query to be used for fetching metrics
// from the database
// start and end are in milliseconds
// step is in seconds
func PrepareMetricQuery(start, end int64, queryType v3.QueryType, panelType v3.PanelType, mq *v3.BuilderQuery, options metricsV3.Options) (string, error) {

	// TODO(srikanthcc): implement
	return "", nil
}

func BuildPromQuery(promQuery *v3.PromQuery, step, start, end int64) *model.QueryRangeParams {
	return &model.QueryRangeParams{
		Query: promQuery.Query,
		Start: time.UnixMilli(start),
		End:   time.UnixMilli(end),
		Step:  time.Duration(step * int64(time.Second)),
	}
}