package smartadserver

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"path"
	"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 SmartAdserverAdapter struct {
	defaultHost   string
	secondaryHost string
	Server        config.Server
}

type PendingImpAndExt struct {
	imp openrtb2.Imp
	ext openrtb_ext.ExtImpSmartadserverOut
}

// Builder builds a new instance of the SmartAdserver 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 := &SmartAdserverAdapter{
		defaultHost:   config.Endpoint,
		secondaryHost: "https://prebid-global.smartadserver.com",
	}
	return bidder, nil
}

// MakeRequests makes the HTTP requests which should be made to fetch bids.
func (a *SmartAdserverAdapter) MakeRequests(request *openrtb2.BidRequest, reqInfo *adapters.ExtraRequestInfo) ([]*adapters.RequestData, []error) {
	if len(request.Imp) == 0 {
		return nil, []error{&errortypes.BadInput{
			Message: "No impression in the bid request",
		}}
	}

	var adapterRequests []*adapters.RequestData
	var errs []error

	// We copy the original request.
	smartRequest := *request

	// We create or copy the Site object.
	if smartRequest.Site == nil {
		smartRequest.Site = &openrtb2.Site{}
	} else {
		site := *smartRequest.Site
		smartRequest.Site = &site
	}

	// We create or copy the Publisher object.
	if smartRequest.Site.Publisher == nil {
		smartRequest.Site.Publisher = &openrtb2.Publisher{}
	} else {
		publisher := *smartRequest.Site.Publisher
		smartRequest.Site.Publisher = &publisher
	}

	var pendingImpsAndExts []PendingImpAndExt
	var imps []openrtb2.Imp
	isProgrammaticGuaranteed := false
	impExtKey := "bidder"

	// Filter out impressions that do not have the proper bidder extensions
	for _, imp := range request.Imp {
		var bidderExt adapters.ExtImpBidder
		if err := jsonutil.Unmarshal(imp.Ext, &bidderExt); err != nil {
			errs = append(errs, &errortypes.BadInput{
				Message: "Error parsing bidderExt object",
			})
			continue
		}

		var smartadserverExtIn openrtb_ext.ExtImpSmartadserverIn
		if err := jsonutil.Unmarshal(bidderExt.Bidder, &smartadserverExtIn); err != nil {
			errs = append(errs, &errortypes.BadInput{
				Message: "Error parsing smartadserverExt parameters",
			})
			continue
		}

		if !isProgrammaticGuaranteed && smartadserverExtIn.ProgrammaticGuaranteed {
			isProgrammaticGuaranteed = true
			impExtKey = "smartadserver"
		}

		pendingImpsAndExts = append(pendingImpsAndExts, PendingImpAndExt{imp, openrtb_ext.ExtImpSmartadserverOut(smartadserverExtIn)})

		// Properly set publisher id from extentions for coming request
		smartRequest.Site.Publisher.ID = strconv.Itoa(smartadserverExtIn.NetworkID)
	}

	// Loop again to serialize extension properly
	for _, pendingImpAndExt := range pendingImpsAndExts {
		var completeExt map[string]any
		if err := json.Unmarshal(pendingImpAndExt.imp.Ext, &completeExt); err != nil {
			errs = append(errs, &errortypes.BadInput{
				Message: "Error parsing imp.Ext object",
			})
			continue
		}

		// Delete `bidder` extensions, then write it again with either `bidder` or `smartadserver` key, without unwanted elements.
		delete(completeExt, "bidder")
		completeExt[impExtKey] = pendingImpAndExt.ext

		var errMarshal error
		if pendingImpAndExt.imp.Ext, errMarshal = json.Marshal(completeExt); errMarshal != nil {
			errs = append(errs, &errortypes.BadInput{
				Message: errMarshal.Error(),
			})
			continue
		}

		imps = append(imps, pendingImpAndExt.imp)
	}

	// Only create the request if it has at least one correctly formatted impression
	if len(imps) != 0 {
		smartRequest.Imp = imps

		reqJSON, err := json.Marshal(smartRequest)
		if err != nil {
			errs = append(errs, &errortypes.BadInput{
				Message: "Error parsing reqJSON object",
			})
			return nil, errs
		}

		url, err := a.BuildEndpointURL(isProgrammaticGuaranteed)
		if url == "" {
			errs = append(errs, err)
			return nil, errs
		}

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

		adapterRequests = append(adapterRequests, &adapters.RequestData{
			Method:  "POST",
			Uri:     url,
			Body:    reqJSON,
			Headers: headers,
			ImpIDs:  openrtb_ext.GetImpIDs(smartRequest.Imp),
		})
	}

	return adapterRequests, errs
}

// MakeBids unpacks the server's response into Bids.
func (a *SmartAdserverAdapter) 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: "Unexpected status code: " + strconv.Itoa(response.StatusCode) + ". Run with request.debug = 1 for more info",
		}}
	}

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

	bidResponse := adapters.NewBidderResponseWithBidsCapacity(5)

	for _, sb := range bidResp.SeatBid {
		for i := 0; i < len(sb.Bid); i++ {
			bid := sb.Bid[i]
			bidResponse.Bids = append(bidResponse.Bids, &adapters.TypedBid{
				Bid:     &bid,
				BidType: getBidTypeFromMarkupType(bid.MType),
			})

		}
	}
	return bidResponse, []error{}
}

// BuildEndpointURL : Builds endpoint url
func (a *SmartAdserverAdapter) BuildEndpointURL(isProgrammaticGuaranteed bool) (string, error) {
	host := a.defaultHost

	if isProgrammaticGuaranteed {
		host = a.secondaryHost
	}

	uri, err := url.Parse(host)
	if err != nil || uri.Scheme == "" || uri.Host == "" {
		return "", &errortypes.BadInput{
			Message: "Malformed URL: " + host + ".",
		}
	}

	if isProgrammaticGuaranteed {
		uri.Path = path.Join(uri.Path, "ortb")
	} else {
		uri.Path = path.Join(uri.Path, "api/bid")
		uri.RawQuery = "callerId=5"
	}

	return uri.String(), nil
}

func getBidTypeFromMarkupType(mtype openrtb2.MarkupType) openrtb_ext.BidType {
	switch mtype {
	case openrtb2.MarkupVideo:
		return openrtb_ext.BidTypeVideo
	case openrtb2.MarkupAudio:
		return openrtb_ext.BidTypeAudio
	case openrtb2.MarkupBanner:
		return openrtb_ext.BidTypeBanner
	case openrtb2.MarkupNative:
		return openrtb_ext.BidTypeNative
	default:
		return openrtb_ext.BidTypeBanner
	}
}