package sspBC

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"

	"github.com/prebid/openrtb/v20/openrtb2"
	"github.com/prebid/prebid-server/v4/adapters"
	"github.com/prebid/prebid-server/v4/config"
	"github.com/prebid/prebid-server/v4/errortypes"
	"github.com/prebid/prebid-server/v4/metrics"
	"github.com/prebid/prebid-server/v4/openrtb_ext"
	"github.com/prebid/prebid-server/v4/util/jsonutil"
)

const (
	adapterVersion = "6.0"
)

type (
	adapter struct {
		endpoint string
	}
	requestInfo struct {
		PbsEntryPoint metrics.RequestType
	}
	requestData struct {
		Request     *openrtb2.BidRequest `json:"bidRequest"`
		RequestInfo *requestInfo         `json:"requestInfo"`
	}
)

// ---------------ADAPTER INTERFACE------------------
// Builder builds a new instance of the sspBC adapter
func Builder(_ openrtb_ext.BidderName, config config.Adapter, _ config.Server) (adapters.Bidder, error) {
	endpoint, err := buildAdapterEndpoint(config.Endpoint, adapterVersion)
	if err != nil {
		return nil, fmt.Errorf("unable to build sspbc adapter endpoint: %w", err)
	}

	bidder := &adapter{
		endpoint: endpoint,
	}

	return bidder, nil
}

func (a *adapter) MakeRequests(request *openrtb2.BidRequest, extraRequestInfo *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	sspBcRequest := &requestData{
		Request: request,
		RequestInfo: &requestInfo{
			PbsEntryPoint: extraRequestInfo.PbsEntryPoint,
		},
	}

	requestJSON, err := json.Marshal(sspBcRequest)
	if err != nil {
		return nil, []error{err}
	}

	requestData := &adapters.RequestData{
		Method: http.MethodPost,
		Uri:    a.endpoint,
		Body:   requestJSON,
		ImpIDs: openrtb_ext.GetImpIDs(request.Imp),
	}

	return []*adapters.RequestData{requestData}, nil
}

func (a *adapter) MakeBids(internalRequest *openrtb2.BidRequest, externalRequest *adapters.RequestData, externalResponse *adapters.ResponseData) (*adapters.BidderResponse, []error) {
	if externalResponse.StatusCode == http.StatusNoContent {
		return nil, nil
	}

	if externalResponse.StatusCode != http.StatusOK {
		err := &errortypes.BadServerResponse{
			Message: fmt.Sprintf("unexpected status code: %d.", externalResponse.StatusCode),
		}
		return nil, []error{err}
	}

	var response openrtb2.BidResponse
	if err := jsonutil.Unmarshal(externalResponse.Body, &response); err != nil {
		return nil, []error{err}
	}

	bidResponse := adapters.NewBidderResponseWithBidsCapacity(len(internalRequest.Imp))
	bidResponse.Currency = response.Cur

	var errors []error
	for _, seatBid := range response.SeatBid {
		for i := range seatBid.Bid {
			bid := seatBid.Bid[i]
			bidType, err := getBidType(bid)
			if err != nil {
				return nil, []error{err}
			}

			bidResponse.Bids = append(bidResponse.Bids, &adapters.TypedBid{
				Bid:     &bid,
				BidType: bidType,
			})
		}
	}

	return bidResponse, errors
}

func getBidType(bid openrtb2.Bid) (openrtb_ext.BidType, error) {
	switch bid.MType {
	case openrtb2.MarkupBanner:
		return openrtb_ext.BidTypeBanner, nil
	case openrtb2.MarkupVideo:
		return openrtb_ext.BidTypeVideo, nil
	case openrtb2.MarkupAudio:
		return openrtb_ext.BidTypeAudio, nil
	case openrtb2.MarkupNative:
		return openrtb_ext.BidTypeNative, nil
	default:
		return "", &errortypes.BadServerResponse{
			Message: fmt.Sprintf("unsupported MType: %d.", bid.MType),
		}
	}
}

func buildAdapterEndpoint(endpoint string, adapterVersion string) (string, error) {
	endpointURL, err := url.Parse(endpoint)
	if err != nil {
		return "", fmt.Errorf("unable to parse endpoint URL: %w", err)
	}

	params := endpointURL.Query()
	params.Add("bdver", adapterVersion)
	endpointURL.RawQuery = params.Encode()

	return endpointURL.String(), nil
}