package triplelift_native

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 TripleliftNativeAdapter struct {
	endpoint string
	extInfo  TripleliftNativeExtInfo
}

type TripleliftInnerExt struct {
	Format int `json:"format"`
}

type TripleliftRespExt struct {
	Triplelift TripleliftInnerExt `json:"triplelift_pb"`
}

type TripleliftNativeExtInfo struct {
	// Array is used for deserialization.
	PublisherWhitelist []string `json:"publisher_whitelist"`

	// Map is used for optimized memory access and should be constructed after deserialization.
	PublisherWhitelistMap map[string]struct{}
}

type ExtImpData struct {
	TagCode string `json:"tag_code"`
}

type ExtImp struct {
	*adapters.ExtImpBidder
	Data *ExtImpData `json:"data,omitempty"`
}

func getBidType(ext TripleliftRespExt) openrtb_ext.BidType {
	return openrtb_ext.BidTypeNative
}

func processImp(imp *openrtb2.Imp, request *openrtb2.BidRequest) error {
	// get the triplelift extension
	var ext ExtImp
	var tlext openrtb_ext.ExtImpTriplelift

	if err := jsonutil.Unmarshal(imp.Ext, &ext); err != nil {
		return err
	}
	if err := jsonutil.Unmarshal(ext.Bidder, &tlext); err != nil {
		return err
	}
	if imp.Native == nil {
		return fmt.Errorf("no native object specified")
	}

	if ext.Data != nil && len(ext.Data.TagCode) > 0 && (msnInSite(request) || msnInApp(request)) {
		imp.TagID = ext.Data.TagCode
	} else {
		imp.TagID = tlext.InvCode
	}

	// floor is optional
	if tlext.Floor == nil {
		return nil
	}
	imp.BidFloor = *tlext.Floor

	return nil
}

// msnInApp returns whether msn.com is in request.app.publisher.domain
func msnInApp(request *openrtb2.BidRequest) bool {
	return request.App != nil && request.App.Publisher != nil && request.App.Publisher.Domain == "msn.com"
}

// msnInSite returns whether msn.com is in request.site.publisher.domain
func msnInSite(request *openrtb2.BidRequest) bool {
	return request.Site != nil && request.Site.Publisher != nil && request.Site.Publisher.Domain == "msn.com"
}

// Returns the effective publisher ID
func effectivePubID(pub *openrtb2.Publisher) string {
	if pub != nil {
		if pub.Ext != nil {
			var pubExt openrtb_ext.ExtPublisher
			err := jsonutil.Unmarshal(pub.Ext, &pubExt)
			if err == nil && pubExt.Prebid != nil && pubExt.Prebid.ParentAccount != nil && *pubExt.Prebid.ParentAccount != "" {
				return *pubExt.Prebid.ParentAccount
			}
		}
		if pub.ID != "" {
			return pub.ID
		}
	}
	return "unknown"
}

func (a *TripleliftNativeAdapter) MakeRequests(request *openrtb2.BidRequest, extra *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	errs := make([]error, 0, len(request.Imp)+1)
	reqs := make([]*adapters.RequestData, 0, 1)
	// copy the request, because we are going to mutate it
	tlRequest := *request
	// this will contain all the valid impressions
	var validImps []openrtb2.Imp
	// pre-process the imps
	for _, imp := range tlRequest.Imp {
		if err := processImp(&imp, request); err == nil {
			validImps = append(validImps, imp)
		} else {
			errs = append(errs, err)
		}
	}
	publisher := getPublisher(request)
	publisherID := effectivePubID(publisher)
	if _, exists := a.extInfo.PublisherWhitelistMap[publisherID]; !exists {
		err := fmt.Errorf("Unsupported publisher for triplelift_native")
		return nil, []error{err}
	}
	if len(validImps) == 0 {
		err := fmt.Errorf("No valid impressions for triplelift")
		errs = append(errs, err)
		return nil, errs
	}
	tlRequest.Imp = validImps
	reqJSON, err := json.Marshal(tlRequest)
	if err != nil {
		errs = append(errs, err)
		return nil, errs
	}
	headers := http.Header{}
	headers.Add("Content-Type", "application/json;charset=utf-8")
	headers.Add("Accept", "application/json")
	ad := a.endpoint
	reqs = append(reqs, &adapters.RequestData{
		Method:  "POST",
		Uri:     ad,
		Body:    reqJSON,
		Headers: headers,
		ImpIDs:  openrtb_ext.GetImpIDs(tlRequest.Imp)})
	return reqs, errs
}

func getPublisher(request *openrtb2.BidRequest) *openrtb2.Publisher {
	if request.App != nil {
		return request.App.Publisher
	}
	return request.Site.Publisher
}

func getBidCount(bidResponse openrtb2.BidResponse) int {
	c := 0
	for _, sb := range bidResponse.SeatBid {
		c = c + len(sb.Bid)
	}
	return c
}

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

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

	if response.StatusCode != http.StatusOK {
		return nil, []error{&errortypes.BadServerResponse{Message: fmt.Sprintf("Unexpected status code: %d. Run with request.debug = 1 for more info", response.StatusCode)}}
	}
	var bidResp openrtb2.BidResponse
	if err := jsonutil.Unmarshal(response.Body, &bidResp); err != nil {
		return nil, []error{err}
	}
	var errs []error
	count := getBidCount(bidResp)
	bidResponse := adapters.NewBidderResponseWithBidsCapacity(count)

	for _, sb := range bidResp.SeatBid {
		for i := 0; i < len(sb.Bid); i++ {
			bid := sb.Bid[i]
			var bidExt TripleliftRespExt
			bidType := getBidType(bidExt)
			bidResponse.Bids = append(bidResponse.Bids, &adapters.TypedBid{
				Bid:     &bid,
				BidType: bidType,
			})
		}
	}
	return bidResponse, errs
}

// Builder builds a new instance of the TripleliftNative adapter for the given bidder with the given config.
func Builder(bidderName openrtb_ext.BidderName, config config.Adapter, server config.Server) (adapters.Bidder, error) {
	extraInfo, err := getExtraInfo(config.ExtraAdapterInfo)
	if err != nil {
		return nil, err
	}

	// Populate map for faster memory access
	extraInfo.PublisherWhitelistMap = make(map[string]struct{}, len(extraInfo.PublisherWhitelist))
	for _, v := range extraInfo.PublisherWhitelist {
		extraInfo.PublisherWhitelistMap[v] = struct{}{}
	}

	bidder := &TripleliftNativeAdapter{
		endpoint: config.Endpoint,
		extInfo:  extraInfo,
	}
	return bidder, nil
}

func getExtraInfo(v string) (TripleliftNativeExtInfo, error) {
	if len(v) == 0 {
		return getDefaultExtraInfo(), nil
	}

	var extraInfo TripleliftNativeExtInfo
	if err := jsonutil.Unmarshal([]byte(v), &extraInfo); err != nil {
		return extraInfo, fmt.Errorf("invalid extra info: %v", err)
	}

	return extraInfo, nil
}

func getDefaultExtraInfo() TripleliftNativeExtInfo {
	return TripleliftNativeExtInfo{
		PublisherWhitelist: []string{},
	}
}