package grpcserver

import (
	"context"
	"errors"
	"strings"

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

	pb "git.wntrmute.dev/kyle/metacrypt/gen/metacrypt/v1"
	"git.wntrmute.dev/kyle/metacrypt/internal/engine"
)

type engineServer struct {
	pb.UnimplementedEngineServiceServer
	s *GRPCServer
}

func (es *engineServer) Mount(ctx context.Context, req *pb.MountRequest) (*pb.MountResponse, error) {
	if req.Name == "" || req.Type == "" {
		return nil, status.Error(codes.InvalidArgument, "name and type are required")
	}

	var config map[string]interface{}
	if req.Config != nil {
		config = req.Config.AsMap()
	}

	if err := es.s.engines.Mount(ctx, req.Name, engine.EngineType(req.Type), config); err != nil {
		es.s.logger.Error("grpc: mount engine", "name", req.Name, "type", req.Type, "error", err)
		switch {
		case errors.Is(err, engine.ErrMountExists):
			return nil, status.Error(codes.AlreadyExists, err.Error())
		case errors.Is(err, engine.ErrUnknownType):
			return nil, status.Error(codes.InvalidArgument, err.Error())
		default:
			return nil, status.Error(codes.Internal, err.Error())
		}
	}
	return &pb.MountResponse{}, nil
}

func (es *engineServer) Unmount(ctx context.Context, req *pb.UnmountRequest) (*pb.UnmountResponse, error) {
	if req.Name == "" {
		return nil, status.Error(codes.InvalidArgument, "name is required")
	}
	if err := es.s.engines.Unmount(ctx, req.Name); err != nil {
		if errors.Is(err, engine.ErrMountNotFound) {
			return nil, status.Error(codes.NotFound, err.Error())
		}
		return nil, status.Error(codes.Internal, err.Error())
	}
	return &pb.UnmountResponse{}, nil
}

func (es *engineServer) ListMounts(_ context.Context, _ *pb.ListMountsRequest) (*pb.ListMountsResponse, error) {
	mounts := es.s.engines.ListMounts()
	pbMounts := make([]*pb.MountInfo, 0, len(mounts))
	for _, m := range mounts {
		pbMounts = append(pbMounts, &pb.MountInfo{
			Name:      m.Name,
			Type:      string(m.Type),
			MountPath: m.MountPath,
		})
	}
	return &pb.ListMountsResponse{Mounts: pbMounts}, nil
}

func (es *engineServer) Request(ctx context.Context, req *pb.EngineRequest) (*pb.EngineResponse, error) {
	if req.Mount == "" || req.Operation == "" {
		return nil, status.Error(codes.InvalidArgument, "mount and operation are required")
	}

	ti := tokenInfoFromContext(ctx)
	engReq := &engine.Request{
		Operation: req.Operation,
		Path:      req.Path,
		Data:      nil,
	}
	if req.Data != nil {
		engReq.Data = req.Data.AsMap()
	}
	if ti != nil {
		engReq.CallerInfo = &engine.CallerInfo{
			Username: ti.Username,
			Roles:    ti.Roles,
			IsAdmin:  ti.IsAdmin,
		}
	}

	resp, err := es.s.engines.HandleRequest(ctx, req.Mount, engReq)
	if err != nil {
		st := codes.Internal
		switch {
		case errors.Is(err, engine.ErrMountNotFound):
			st = codes.NotFound
		case strings.Contains(err.Error(), "forbidden"):
			st = codes.PermissionDenied
		case strings.Contains(err.Error(), "not found"):
			st = codes.NotFound
		}
		return nil, status.Error(st, err.Error())
	}

	pbData, err := structpb.NewStruct(resp.Data)
	if err != nil {
		return nil, status.Error(codes.Internal, "failed to encode response")
	}
	return &pb.EngineResponse{Data: pbData}, nil
}