package zeta_global_ssp

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strconv"
	"text/template"

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

type adapter struct {
	endpoint *template.Template
}

func Builder(bidderName openrtb_ext.BidderName, config config.Adapter, server config.Server) (adapters.Bidder, error) {
	endpointTemplate, err := template.New("endpointTemplate").Parse(config.Endpoint)
	if err != nil {
		return nil, fmt.Errorf("unable to parse endpoint url template: %v", err)
	}

	bidder := &adapter{
		endpoint: endpointTemplate,
	}
	return bidder, nil
}

func (a *adapter) MakeRequests(request *openrtb2.BidRequest, requestInfo *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	zetaSspImpExt, err := a.getImpressionExt(&request.Imp[0])
	if err != nil {
		return nil, []error{err}
	}

	endpointURL, err := a.buildEndpointURL(zetaSspImpExt)
	if err != nil {
		return nil, []error{err}
	}

	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")

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

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

func (a *adapter) getImpressionExt(imp *openrtb2.Imp) (*openrtb_ext.ImpExtZetaGlobalSsp, error) {
	var bidderExt adapters.ExtImpBidder
	if err := json.Unmarshal(imp.Ext, &bidderExt); err != nil {
		return nil, &errortypes.BadInput{
			Message: "imp.ext not provided or cannot be unmarshalled",
		}
	}
	var zetaSspImpExt openrtb_ext.ImpExtZetaGlobalSsp
	if err := json.Unmarshal(bidderExt.Bidder, &zetaSspImpExt); err != nil {
		return nil, &errortypes.BadInput{
			Message: "imp.ext.bidder not provided or cannot be unmarshalled",
		}
	}
	imp.Ext = nil
	return &zetaSspImpExt, nil
}

func (a *adapter) buildEndpointURL(params *openrtb_ext.ImpExtZetaGlobalSsp) (string, error) {
	endpointParams := macros.EndpointTemplateParams{AccountID: strconv.Itoa(params.Sid)}
	return macros.ResolveMacros(a.endpoint, endpointParams)
}

func (a *adapter) MakeBids(request *openrtb2.BidRequest, requestData *adapters.RequestData, responseData *adapters.ResponseData) (*adapters.BidderResponse, []error) {
	if adapters.IsResponseStatusCodeNoContent(responseData) {
		return nil, nil
	}

	if err := adapters.CheckResponseStatusCodeForErrors(responseData); err != nil {
		return nil, []error{err}
	}

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

	bidResponse := adapters.NewBidderResponseWithBidsCapacity(len(request.Imp))
	bidResponse.Currency = response.Cur
	var errors []error
	for _, seatBid := range response.SeatBid {
		for i := range seatBid.Bid {
			bidType, err := getMediaTypeForBid(seatBid.Bid[i])
			if err != nil {
				errors = append(errors, err)
				continue
			}
			b := &adapters.TypedBid{
				Bid:     &seatBid.Bid[i],
				BidType: bidType,
			}
			bidResponse.Bids = append(bidResponse.Bids, b)
		}
	}
	return bidResponse, errors
}

func getMediaTypeForBid(bid openrtb2.Bid) (openrtb_ext.BidType, error) {
	if bid.Ext != nil {
		var bidExt openrtb_ext.ExtBid
		err := jsonutil.Unmarshal(bid.Ext, &bidExt)
		if err == nil && bidExt.Prebid != nil {
			return openrtb_ext.ParseBidType(string(bidExt.Prebid.Type))
		}
	}

	return "", &errortypes.BadServerResponse{
		Message: fmt.Sprintf("Failed to parse impression \"%s\" mediatype", bid.ImpID),
	}
}