package server

import (
	"context"
	"net/http"

	"github.com/JetBrains/ij-perf-report-aggregator/pkg/data-query"
	"github.com/valyala/bytebufferpool"
	"github.com/valyala/quicktemplate"
)

func (t *StatsServer) handleLoadRequestV2(request *http.Request) (*bytebufferpool.ByteBuffer, bool, error) {
	dataQueries, wrappedAsArray, err := data_query.ReadQueryV2(request)
	if err != nil {
		return nil, false, err
	}
	return t.load(request, dataQueries, wrappedAsArray)
}

func (t *StatsServer) handleLoadRequest(request *http.Request) (*bytebufferpool.ByteBuffer, bool, error) {
	dataQueries, wrappedAsArray, err := data_query.ReadQuery(request)
	if err != nil {
		return nil, false, err
	}

	return t.load(request, dataQueries, wrappedAsArray)
}

func (t *StatsServer) load(request *http.Request, dataQueries []data_query.Query, wrappedAsArray bool) (*bytebufferpool.ByteBuffer, bool, error) {
	buffer := byteBufferPool.Get()
	isOk := false
	defer func() {
		if !isOk {
			byteBufferPool.Put(buffer)
		}
	}()

	templateWriter := quicktemplate.AcquireWriter(buffer)
	defer quicktemplate.ReleaseWriter(templateWriter)
	jsonWriter := templateWriter.N()

	if len(dataQueries) > 1 || wrappedAsArray {
		jsonWriter.S("[")
	}

	for index, dataQuery := range dataQueries {
		if index != 0 {
			jsonWriter.S(",")
		}

		err := t.computeMeasureResponse(request.Context(), dataQuery, jsonWriter)
		if err != nil {
			return nil, false, err
		}
	}

	if len(dataQueries) > 1 || wrappedAsArray {
		jsonWriter.S("]")
	}
	isOk = true
	if len(buffer.B) == 0 {
		jsonWriter.S("[]")
	}
	return buffer, true, nil
}

func (t *StatsServer) computeMeasureResponse(ctx context.Context, query data_query.Query, jsonWriter *quicktemplate.QWriter) error {
	table := query.Table
	if table == "" {
		table = "report"
	}

	err := data_query.SelectRows(ctx, query, table, t, jsonWriter)
	if err != nil {
		return err
	}
	return nil
}