package server

import (
	"context"
	"encoding/hex"
	"fmt"
	"strings"

	"github.com/ethereum/go-ethereum/command/server/pprof"
	"github.com/ethereum/go-ethereum/command/server/proto"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/p2p"
	"github.com/ethereum/go-ethereum/p2p/enode"
	"github.com/golang/protobuf/ptypes/empty"
)

func (s *Server) Pprof(ctx context.Context, req *proto.PprofRequest) (*proto.PprofResponse, error) {
	var payload []byte
	var headers map[string]string
	var err error

	switch req.Type {
	case proto.PprofRequest_CPU:
		payload, headers, err = pprof.CPUProfile(ctx, int(req.Seconds))
	case proto.PprofRequest_TRACE:
		payload, headers, err = pprof.Trace(ctx, int(req.Seconds))
	case proto.PprofRequest_LOOKUP:
		payload, headers, err = pprof.Profile(req.Profile, 0, 0)
	}
	if err != nil {
		return nil, err
	}

	resp := &proto.PprofResponse{
		Payload: hex.EncodeToString(payload),
		Headers: headers,
	}
	return resp, nil
}

func (s *Server) PeersAdd(ctx context.Context, req *proto.PeersAddRequest) (*proto.PeersAddResponse, error) {
	node, err := enode.Parse(enode.ValidSchemes, req.Enode)
	if err != nil {
		return nil, fmt.Errorf("invalid enode: %v", err)
	}
	srv := s.node.Server()
	if req.Trusted {
		srv.AddTrustedPeer(node)
	} else {
		srv.AddPeer(node)
	}
	return &proto.PeersAddResponse{}, nil
}

func (s *Server) PeersRemove(ctx context.Context, req *proto.PeersRemoveRequest) (*proto.PeersRemoveResponse, error) {
	node, err := enode.Parse(enode.ValidSchemes, req.Enode)
	if err != nil {
		return nil, fmt.Errorf("invalid enode: %v", err)
	}
	srv := s.node.Server()
	if req.Trusted {
		srv.RemoveTrustedPeer(node)
	} else {
		srv.RemovePeer(node)
	}
	return &proto.PeersRemoveResponse{}, nil
}

func (s *Server) PeersList(ctx context.Context, req *proto.PeersListRequest) (*proto.PeersListResponse, error) {
	resp := &proto.PeersListResponse{}

	peers := s.node.Server().PeersInfo()
	for _, p := range peers {
		resp.Peers = append(resp.Peers, peerInfoToPeer(p))
	}
	return resp, nil
}

func (s *Server) PeersStatus(ctx context.Context, req *proto.PeersStatusRequest) (*proto.PeersStatusResponse, error) {
	var peerInfo *p2p.PeerInfo
	for _, p := range s.node.Server().PeersInfo() {
		if strings.HasPrefix(p.ID, req.Enode) {
			if peerInfo != nil {
				return nil, fmt.Errorf("more than one peer with the same prefix")
			}
			peerInfo = p
		}
	}
	resp := &proto.PeersStatusResponse{}
	if peerInfo != nil {
		resp.Peer = peerInfoToPeer(peerInfo)
	}
	return resp, nil
}

func peerInfoToPeer(info *p2p.PeerInfo) *proto.Peer {
	return &proto.Peer{
		Id:      info.ID,
		Enode:   info.Enode,
		Enr:     info.ENR,
		Caps:    info.Caps,
		Name:    info.Name,
		Trusted: info.Network.Trusted,
		Static:  info.Network.Static,
	}
}

func (s *Server) ChainSetHead(ctx context.Context, req *proto.ChainSetHeadRequest) (*proto.ChainSetHeadResponse, error) {
	s.backend.APIBackend.SetHead(req.Number)
	return &proto.ChainSetHeadResponse{}, nil
}

func (s *Server) Status(ctx context.Context, _ *empty.Empty) (*proto.StatusResponse, error) {
	apiBackend := s.backend.APIBackend
	syncProgress := apiBackend.SyncProgress()

	resp := &proto.StatusResponse{
		CurrentHeader: headerToProtoHeader(apiBackend.CurrentHeader()),
		CurrentBlock:  headerToProtoHeader(apiBackend.CurrentBlock().Header()),
		NumPeers:      int64(len(s.node.Server().PeersInfo())),
		SyncMode:      s.config.SyncMode,
		Syncing: &proto.StatusResponse_Syncing{
			StartingBlock: int64(syncProgress.StartingBlock),
			HighestBlock:  int64(syncProgress.HighestBlock),
			CurrentBlock:  int64(syncProgress.CurrentBlock),
		},
	}
	return resp, nil
}

func headerToProtoHeader(h *types.Header) *proto.Header {
	return &proto.Header{
		Hash:   h.Hash().String(),
		Number: h.Number.Uint64(),
	}
}