package grpcserver

import (
	"context"
	"encoding/json"

	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/types/known/timestamppb"

	pb "git.wntrmute.dev/kyle/metacrypt/gen/metacrypt/v2"
	internacme "git.wntrmute.dev/kyle/metacrypt/internal/acme"
	"git.wntrmute.dev/kyle/metacrypt/internal/engine"
)

type acmeServer struct {
	pb.UnimplementedACMEServiceServer
	s *GRPCServer
}

func (as *acmeServer) CreateEAB(ctx context.Context, req *pb.CreateEABRequest) (*pb.CreateEABResponse, error) {
	ti := tokenInfoFromContext(ctx)
	h, err := as.getOrCreateHandler(req.Mount)
	if err != nil {
		return nil, status.Error(codes.NotFound, "mount not found")
	}
	cred, err := h.CreateEAB(ctx, ti.Username)
	if err != nil {
		as.s.logger.Error("grpc: acme create EAB", "error", err)
		return nil, status.Error(codes.Internal, "failed to create EAB credentials")
	}
	return &pb.CreateEABResponse{Kid: cred.KID, HmacKey: cred.HMACKey}, nil
}

func (as *acmeServer) SetConfig(ctx context.Context, req *pb.SetConfigRequest) (*pb.SetConfigResponse, error) {
	if req.DefaultIssuer == "" {
		return nil, status.Error(codes.InvalidArgument, "default_issuer is required")
	}
	// Verify mount exists.
	if _, err := as.getOrCreateHandler(req.Mount); err != nil {
		return nil, status.Error(codes.NotFound, "mount not found")
	}
	cfg := &internacme.ACMEConfig{DefaultIssuer: req.DefaultIssuer}
	data, _ := json.Marshal(cfg)
	barrierPath := "acme/" + req.Mount + "/config.json"
	if err := as.s.sealMgr.Barrier().Put(ctx, barrierPath, data); err != nil {
		as.s.logger.Error("grpc: acme set config", "error", err)
		return nil, status.Error(codes.Internal, "failed to save config")
	}
	return &pb.SetConfigResponse{}, nil
}

func (as *acmeServer) ListAccounts(ctx context.Context, req *pb.ListAccountsRequest) (*pb.ListAccountsResponse, error) {
	h, err := as.getOrCreateHandler(req.Mount)
	if err != nil {
		return nil, status.Error(codes.NotFound, "mount not found")
	}
	accounts, err := h.ListAccounts(ctx)
	if err != nil {
		as.s.logger.Error("grpc: acme list accounts", "error", err)
		return nil, status.Error(codes.Internal, "internal error")
	}
	pbAccounts := make([]*pb.ACMEAccount, 0, len(accounts))
	for _, a := range accounts {
		contacts := make([]string, len(a.Contact))
		copy(contacts, a.Contact)
		pbAccounts = append(pbAccounts, &pb.ACMEAccount{
			Id:            a.ID,
			Status:        a.Status,
			Contact:       contacts,
			MciasUsername: a.MCIASUsername,
			CreatedAt:     timestamppb.New(a.CreatedAt),
		})
	}
	return &pb.ListAccountsResponse{Accounts: pbAccounts}, nil
}

func (as *acmeServer) ListOrders(ctx context.Context, req *pb.ListOrdersRequest) (*pb.ListOrdersResponse, error) {
	h, err := as.getOrCreateHandler(req.Mount)
	if err != nil {
		return nil, status.Error(codes.NotFound, "mount not found")
	}
	orders, err := h.ListOrders(ctx)
	if err != nil {
		as.s.logger.Error("grpc: acme list orders", "error", err)
		return nil, status.Error(codes.Internal, "internal error")
	}
	pbOrders := make([]*pb.ACMEOrder, 0, len(orders))
	for _, o := range orders {
		identifiers := make([]string, 0, len(o.Identifiers))
		for _, id := range o.Identifiers {
			identifiers = append(identifiers, id.Type+":"+id.Value)
		}
		pbOrders = append(pbOrders, &pb.ACMEOrder{
			Id:          o.ID,
			AccountId:   o.AccountID,
			Status:      o.Status,
			Identifiers: identifiers,
			CreatedAt:   timestamppb.New(o.CreatedAt),
			ExpiresAt:   timestamppb.New(o.ExpiresAt),
		})
	}
	return &pb.ListOrdersResponse{Orders: pbOrders}, nil
}

func (as *acmeServer) getOrCreateHandler(mountName string) (*internacme.Handler, error) {
	as.s.mu.Lock()
	defer as.s.mu.Unlock()

	// Verify mount is a CA engine.
	mount, err := as.s.engines.GetMount(mountName)
	if err != nil {
		return nil, err
	}
	if mount.Type != engine.EngineTypeCA {
		return nil, engine.ErrMountNotFound
	}

	// Check handler cache on GRPCServer.
	if h, ok := as.s.acmeHandlers[mountName]; ok {
		return h, nil
	}

	baseURL := as.s.cfg.Server.ExternalURL
	if baseURL == "" {
		baseURL = "https://" + as.s.cfg.Server.ListenAddr
	}
	h := internacme.NewHandler(mountName, as.s.sealMgr.Barrier(), as.s.engines, baseURL, as.s.logger)
	as.s.acmeHandlers[mountName] = h
	return h, nil
}