package activitypub

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

	webutils "git.mstar.dev/mstar/goutils/http"
	"git.mstar.dev/mstar/goutils/other"
	"git.mstar.dev/mstar/goutils/sliceutils"
	"github.com/rs/zerolog/hlog"
	"gorm.io/gorm"

	"git.mstar.dev/mstar/linstrom/activitypub"
	"git.mstar.dev/mstar/linstrom/activitypub/translators"
	"git.mstar.dev/mstar/linstrom/storage-new/dbgen"
)

func users(w http.ResponseWriter, r *http.Request) {
	log := hlog.FromRequest(r)
	userId := r.PathValue("id")

	user, err := translators.UserFromStorage(r.Context(), userId)
	if err != nil {
		log.Error().Err(err).Msg("Failed to get user from db")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	encoded, err := json.Marshal(user)
	if err != nil {
		log.Error().Err(err).Msg("Failed to marshal response")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	w.Header().Add("Content-Type", "application/activity+json")
	_, _ = fmt.Fprint(w, string(encoded))
}

func userFollowing(w http.ResponseWriter, r *http.Request) {
	log := hlog.FromRequest(r)
	userId := r.PathValue("id")
	pageNrStr := r.FormValue("page")
	exists, err := dbgen.User.DoesUserWithIdExist(userId)
	if err != nil {
		log.Error().Err(err).Str("id", userId).Msg("Failed to check if user exists")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	if !exists {
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusNotFound)
		return
	}
	apUrl := activitypub.UserIdToApUrl(userId)
	var data []byte
	followingCount, err := dbgen.UserToUserRelation.CountFollowingForId(userId)
	if err != nil {
		log.Error().Err(err).Str("id", userId).Msg("Failed to get following count")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	if pageNrStr == "" {
		col := translators.CollectionOut{
			Context:    "https://www.w3.org/ns/activitystreams",
			Type:       "OrderedCollection",
			Id:         apUrl + "/following",
			TotalItems: followingCount,
			First:      apUrl + "/following?page=0",
		}
		data, err = json.Marshal(col)
		if err != nil {
			log.Error().Err(err).Any("raw", data).Msg("Failed to marshal following collection page")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
	} else {
		pageNr, err := strconv.Atoi(pageNrStr)
		if err != nil {
			_ = webutils.ProblemDetails(
				w,
				http.StatusBadRequest,
				"/errors/bad-page",
				"bad page number",
				other.IntoPointer("page number must be an uint"),
				nil,
			)
			return
		}
		hasNextPage := followingCount-(pageNr+1)*50 > 0
		hasPreviousPage := pageNr > 0
		links, err := dbgen.UserToUserRelation.GetFollowingApLinksPagedForId(userId, pageNr)
		switch err {
		case gorm.ErrRecordNotFound:
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusNotFound)
			return
		case nil:
		default:
			log.Error().Err(err).Str("id", userId).Msg("Failed to get account via id")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
		page := translators.CollectionPageOut{
			Context: "https://www.w3.org/ns/activitystreams",
			Type:    "OrderedCollectionPage",
			Id:      fmt.Sprintf("%s/following?page=%d", apUrl, pageNr),
			PartOf:  activitypub.UserIdToApUrl(userId) + "/following",
			Items:   sliceutils.Map(links, func(t string) any { return t }),
		}
		if hasNextPage {
			page.Next = fmt.Sprintf("%s/following?page=%d", apUrl, pageNr+1)
		}
		if hasPreviousPage {
			page.Next = fmt.Sprintf("%s/following?page=%d", apUrl, pageNr-1)
		}
		data, err = json.Marshal(page)
		if err != nil {
			log.Error().Err(err).Any("raw", page).Msg("Failed to marshal following collection page")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
	}
	w.Header().Add("Content-Type", "application/activity+json")
	_, _ = fmt.Fprint(w, string(data))
}

func userFollowers(w http.ResponseWriter, r *http.Request) {
	log := hlog.FromRequest(r)
	userId := r.PathValue("id")
	pageNrStr := r.FormValue("page")
	exists, err := dbgen.User.DoesUserWithIdExist(userId)
	if err != nil {
		log.Error().Err(err).Str("id", userId).Msg("Failed to check if user exists")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	if !exists {
		log.Debug().Str("id", userId).Msg("user not found")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusNotFound)
		return
	}
	apUrl := activitypub.UserIdToApUrl(userId)
	var data []byte
	followersCount, err := dbgen.UserToUserRelation.CountFollowersForId(userId)
	if err != nil {
		log.Error().Err(err).Str("id", userId).Msg("Failed to get followers count")
		_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
		return
	}
	if pageNrStr == "" {
		col := translators.CollectionOut{
			Context:    activitypub.BaseLdContext,
			Type:       "OrderedCollection",
			Id:         apUrl + "/followers",
			TotalItems: followersCount,
			First:      apUrl + "/followers?page=0",
		}
		data, err = json.Marshal(col)
		if err != nil {
			log.Error().Err(err).Any("raw", data).Msg("Failed to marshal followers collection page")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
	} else {
		pageNr, err := strconv.Atoi(pageNrStr)
		if err != nil {
			_ = webutils.ProblemDetails(
				w,
				http.StatusBadRequest,
				"/errors/bad-page",
				"bad page number",
				other.IntoPointer("page number must be an uint"),
				nil,
			)
			return
		}
		hasNextPage := followersCount-(pageNr+1)*50 > 0
		hasPreviousPage := pageNr > 0
		links, err := dbgen.UserToUserRelation.GetFollowerApLinksPagedForId(userId, pageNr)
		switch err {
		case gorm.ErrRecordNotFound:
			log.Debug().Msg("No followers found")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusNotFound)
			return
		case nil:
		default:
			log.Error().Err(err).Str("id", userId).Msg("Failed to get account via id")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
		page := translators.CollectionPageOut{
			Context: activitypub.BaseLdContext,
			Type:    "OrderedCollectionPage",
			Id:      fmt.Sprintf("%s/followers?page=%d", apUrl, pageNr),
			PartOf:  activitypub.UserIdToApUrl(userId) + "/followers",
			Items:   sliceutils.Map(links, func(t string) any { return t }),
		}
		if hasNextPage {
			page.Next = fmt.Sprintf("%s/followers?page=%d", apUrl, pageNr+1)
		}
		if hasPreviousPage {
			page.Next = fmt.Sprintf("%s/followers?page=%d", apUrl, pageNr-1)
		}
		data, err = json.Marshal(page)
		if err != nil {
			log.Error().Err(err).Any("raw", page).Msg("Failed to marshal followers collection page")
			_ = webutils.ProblemDetailsStatusOnly(w, http.StatusInternalServerError)
			return
		}
	}
	log.Debug().Bytes("body", data).Msg("Sending collection(page) out")
	w.Header().Add("Content-Type", "application/activity+json")
	_, _ = fmt.Fprint(w, string(data))
}

/*
Fine. You win JsonLD. I can't get you to work properly. I'll just treat you like normal json then
Fuck you.

If anyone wants to get this shit working *the propper way* with JsonLD, here's the
original code
var chain goap.BaseApChain = &goap.EmptyBaseObject{}
	chain = goap.AppendUDIdData(chain, apUrl)
	chain = goap.AppendUDTypeData(chain, "Person")
	chain = goap.AppendASPreferredNameData(chain, goap.ValueValue[string]{Value: user.DisplayName})
	chain = goap.AppendW3SecurityPublicKeyData(
		chain,
		apUrl+"#main-key",
		apUrl,
		keyBytesToPem(user.PublicKey),
	)

	chainMap := chain.MarshalToMap()
	proc := ld.NewJsonLdProcessor()
	options := ld.NewJsonLdOptions("")
	tmp, tmperr := json.Marshal(chainMap)
	fmt.Println(string(tmp), tmperr)
	data, err := proc.Compact(chainMap, baseLdContext, options)
	// data, err := goap.Compact(chain, baseLdContext)
	if err != nil {
		log.Error().Err(err).Msg("Failed to marshal ap chain")
		_ = webutils.ProblemDetailsStatusOnly(w, 500)
		return
	}
*/