package mobilefuse

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

	"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 MobileFuseAdapter struct {
	Endpoint string
}

type ExtMf struct {
	MediaType string `json:"media_type"`
}

type BidExt struct {
	Mf ExtMf `json:"mf"`
}

type ExtSkadn struct {
	Skadn json.RawMessage `json:"skadn"`
}

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

func (adapter *MobileFuseAdapter) MakeRequests(request *openrtb2.BidRequest, reqInfo *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	var adapterRequests []*adapters.RequestData

	adapterRequest, errs := adapter.makeRequest(request)

	if errs == nil {
		adapterRequests = append(adapterRequests, adapterRequest)
	}

	return adapterRequests, errs
}

func (adapter *MobileFuseAdapter) MakeBids(incomingRequest *openrtb2.BidRequest, outgoingRequest *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.", response.StatusCode),
		}}
	}

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

	var incomingBidResponse openrtb2.BidResponse

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

	outgoingBidResponse := adapters.NewBidderResponseWithBidsCapacity(1)

	for _, seatbid := range incomingBidResponse.SeatBid {
		for i := range seatbid.Bid {
			bidType := getBidType(seatbid.Bid[i])
			seatbid.Bid[i].Ext = nil

			outgoingBidResponse.Bids = append(outgoingBidResponse.Bids, &adapters.TypedBid{
				Bid:     &seatbid.Bid[i],
				BidType: bidType,
			})
		}
	}

	return outgoingBidResponse, nil
}

func (adapter *MobileFuseAdapter) makeRequest(bidRequest *openrtb2.BidRequest) (*adapters.RequestData, []error) {
	var errs []error

	mobileFuseExtension, errs := getFirstMobileFuseExtension(bidRequest)
	if errs != nil {
		return nil, errs
	}

	validImps, err := getValidImps(bidRequest, mobileFuseExtension)
	if err != nil {
		errs = append(errs, err)
		return nil, errs
	}

	mobileFuseBidRequest := *bidRequest
	mobileFuseBidRequest.Imp = validImps
	body, err := json.Marshal(mobileFuseBidRequest)
	if err != nil {
		return nil, append(errs, err)
	}

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

	return &adapters.RequestData{
		Method:  "POST",
		Uri:     adapter.Endpoint,
		Body:    body,
		Headers: headers,
		ImpIDs:  openrtb_ext.GetImpIDs(mobileFuseBidRequest.Imp),
	}, errs
}

func getFirstMobileFuseExtension(request *openrtb2.BidRequest) (*openrtb_ext.ExtImpMobileFuse, []error) {
	var mobileFuseImpExtension openrtb_ext.ExtImpMobileFuse
	var errs []error

	for _, imp := range request.Imp {
		var bidder_imp_extension adapters.ExtImpBidder

		err := jsonutil.Unmarshal(imp.Ext, &bidder_imp_extension)

		if err != nil {
			errs = append(errs, err)
			continue
		}

		err = jsonutil.Unmarshal(bidder_imp_extension.Bidder, &mobileFuseImpExtension)

		if err != nil {
			errs = append(errs, err)
			continue
		}

		break
	}

	return &mobileFuseImpExtension, errs
}

func getMobileFuseExtensionForImp(imp *openrtb2.Imp, mobileFuseImpExtension *openrtb_ext.ExtImpMobileFuse) error {
	var bidder_imp_extension adapters.ExtImpBidder

	err := jsonutil.Unmarshal(imp.Ext, &bidder_imp_extension)
	if err != nil {
		return err
	}

	return jsonutil.Unmarshal(bidder_imp_extension.Bidder, &mobileFuseImpExtension)
}

func getValidImps(bidRequest *openrtb2.BidRequest, ext *openrtb_ext.ExtImpMobileFuse) ([]openrtb2.Imp, error) {
	var validImps []openrtb2.Imp

	for _, imp := range bidRequest.Imp {
		if imp.Banner != nil || imp.Video != nil || imp.Native != nil {
			err := getMobileFuseExtensionForImp(&imp, ext)
			if err != nil {
				return nil, err
			}

			imp.TagID = strconv.Itoa(ext.PlacementId)

			var extSkadn ExtSkadn
			err = jsonutil.Unmarshal(imp.Ext, &extSkadn)
			if err != nil {
				return nil, err
			}

			if extSkadn.Skadn != nil {
				imp.Ext, err = json.Marshal(map[string]json.RawMessage{"skadn": extSkadn.Skadn})
				if err != nil {
					return nil, err
				}
			} else {
				imp.Ext = nil
			}

			validImps = append(validImps, imp)
		}
	}

	if len(validImps) == 0 {
		return nil, fmt.Errorf("No valid imps")
	}

	return validImps, nil
}

func getBidType(bid openrtb2.Bid) openrtb_ext.BidType {
	if bid.Ext != nil {
		var bidExt BidExt
		err := jsonutil.Unmarshal(bid.Ext, &bidExt)
		if err == nil {
			if bidExt.Mf.MediaType == "video" {
				return openrtb_ext.BidTypeVideo
			} else if bidExt.Mf.MediaType == "native" {
				return openrtb_ext.BidTypeNative
			}
		}
	}

	return openrtb_ext.BidTypeBanner
}