package bliink

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

	"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/openrtb_ext"
	"github.com/prebid/prebid-server/v4/util/jsonutil"
)

type adapter struct {
	endpoint string
}

// Builder builds a new instance of the Bliink adapter for the given bidder with the given config.
func Builder(_ openrtb_ext.BidderName, config config.Adapter, server config.Server) (adapters.Bidder, error) {
	bidder := &adapter{
		endpoint: config.Endpoint,
	}

	return bidder, nil
}

func (a *adapter) MakeRequests(request *openrtb2.BidRequest, _ *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	requestJSON, err := json.Marshal(request)
	if err != nil {
		return nil, []error{err}
	}

	headers := http.Header{}
	headers.Add("Content-Type", "application/json;charset=utf-8")
	headers.Add("Accept", "application/json")
	headers.Add("x-openrtb-version", "2.5")

	requestData := &adapters.RequestData{
		Method:  "POST",
		Uri:     a.endpoint,
		Body:    requestJSON,
		Headers: headers,
		ImpIDs:  openrtb_ext.GetImpIDs(request.Imp),
	}

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

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

	if responseData.StatusCode == http.StatusBadRequest {
		err := &errortypes.BadInput{
			Message: "Unexpected status code: 400. Bad request from publisher. Run with request.debug = 1 for more info.",
		}
		return nil, []error{err}
	}

	if responseData.StatusCode != http.StatusOK {
		err := &errortypes.BadServerResponse{
			Message: fmt.Sprintf("Unexpected status code: %d. Run with request.debug = 1 for more info.", responseData.StatusCode),
		}
		return nil, []error{err}
	}

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

	if len(response.SeatBid) == 0 {
		return nil, []error{&errortypes.BadServerResponse{
			Message: "Empty SeatBid array",
		}}
	}

	bidResponse := adapters.NewBidderResponseWithBidsCapacity(len(request.Imp))
	bidResponse.Currency = response.Cur
	var errs []error
	for _, seatBid := range response.SeatBid {
		for i, bid := range seatBid.Bid {
			mediaType, err := getMediaTypeForImp(bid.ImpID, request.Imp)
			if err != nil {
				errs = append(errs, err)
				continue
			}
			bidResponse.Bids = append(bidResponse.Bids, &adapters.TypedBid{
				Bid:     &seatBid.Bid[i],
				BidType: mediaType,
			})
		}
	}

	return bidResponse, errs
}

func getMediaTypeForImp(impId string, imps []openrtb2.Imp) (openrtb_ext.BidType, error) {
	var mediaType openrtb_ext.BidType
	var typeCnt = 0
	for _, imp := range imps {
		if imp.ID == impId {
			if imp.Banner != nil {
				typeCnt += 1
				mediaType = openrtb_ext.BidTypeBanner
			}
			if imp.Native != nil {
				typeCnt += 1
				mediaType = openrtb_ext.BidTypeNative
			}
			if imp.Video != nil {
				typeCnt += 1
				mediaType = openrtb_ext.BidTypeVideo
			}
		}
	}
	if typeCnt == 1 {
		return mediaType, nil
	}
	return mediaType, fmt.Errorf("unable to fetch mediaType in multi-format: %s", impId)
}