package xrpc

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

	"github.com/bluesky-social/indigo/atproto/syntax"
	"tangled.org/core/api/org_tangled"
	"tangled.org/core/spindle/db"
	xrpcerr "tangled.org/core/xrpc/errors"
)

type OwnerBackfill interface {
	Track(dids ...syntax.DID)
	Untrack(did syntax.DID)
}

func allowListInput(w http.ResponseWriter, r *http.Request) (syntax.DID, bool) {
	var input struct {
		Did string `json:"did"`
	}
	if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
		writeError(w, invalidRequest(err), http.StatusBadRequest)
		return "", false
	}
	did, err := syntax.ParseDID(input.Did)
	if err != nil {
		writeError(w, invalidRequest(fmt.Errorf("This DID %q deosn't parse: %w", input.Did, err)), http.StatusBadRequest)
		return "", false
	}
	return did, true
}

func (x *Xrpc) allowListEntry(w http.ResponseWriter, r *http.Request) (syntax.DID, bool) {
	if _, errObj, status := x.checkSpindleOwner(r); errObj != nil {
		writeError(w, *errObj, status)
		return "", false
	}
	return allowListInput(w, r)
}

func (x *Xrpc) allowListChange(
	w http.ResponseWriter,
	r *http.Request,
	write func(q db.DBTX, did syntax.DID) error,
	declare func(b OwnerBackfill, did syntax.DID),
	change string,
) {
	did, ok := x.allowListEntry(w, r)
	if !ok {
		return
	}
	if err := write(x.Db, did); err != nil {
		writeError(w, xrpcerr.GenericError(err), http.StatusInternalServerError)
		return
	}
	if x.Backfill != nil {
		declare(x.Backfill, did)
	}
	x.Logger.InfoContext(r.Context(), "Allow-list entry "+change+".", "did", did)
	w.WriteHeader(http.StatusOK)
}

func (x *Xrpc) AllowListAdd(w http.ResponseWriter, r *http.Request) {
	x.allowListChange(w, r, db.AddToAllowlist, func(b OwnerBackfill, did syntax.DID) { b.Track(did) }, "added")
}

func (x *Xrpc) AllowListRemove(w http.ResponseWriter, r *http.Request) {
	x.allowListChange(w, r, db.RemoveFromAllowlist, OwnerBackfill.Untrack, "removed")
}

func (x *Xrpc) AllowListList(w http.ResponseWriter, r *http.Request) {
	if _, errObj, status := x.checkSpindleOwner(r); errObj != nil {
		writeError(w, *errObj, status)
		return
	}
	dids, err := db.ListAllowlist(x.Db)
	if err != nil {
		writeError(w, xrpcerr.GenericError(err), http.StatusInternalServerError)
		return
	}
	out := org_tangled.TempSpindleAllowListList_Output{Dids: make([]string, 0, len(dids))}
	for _, did := range dids {
		out.Dids = append(out.Dids, did.String())
	}
	x.writeResponse(w, r, http.StatusOK, out)
}