package server

import (
	"context"
	"fmt"
	"time"

	"git.t-juice.club/torjus/ezshare/pb"
	"git.t-juice.club/torjus/ezshare/server/interceptors"
	"git.t-juice.club/torjus/ezshare/store"
	"github.com/dustin/go-humanize"
	"github.com/google/uuid"
	"go.uber.org/zap"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

type GRPCFileServiceServer struct {
	Logger   *zap.SugaredLogger
	Hostname string
	store    store.FileStore
	pb.UnimplementedFileServiceServer
}

func NewGRPCFileServiceServer(store store.FileStore) *GRPCFileServiceServer {
	return &GRPCFileServiceServer{Hostname: "localhost:8051", store: store, Logger: zap.NewNop().Sugar()}
}

func (s *GRPCFileServiceServer) UploadFile(ctx context.Context, req *pb.UploadFileRequest) (*pb.UploadFileResponse, error) {
	// Check if authorized
	if !interceptors.RoleAtLeast(ctx, pb.User_USER) {
		return nil, status.Error(codes.PermissionDenied, "permission denied")
	}
	var f pb.File
	f.Data = req.GetData()
	f.Metadata = &pb.File_Metadata{}
	f.Metadata.OriginalFilename = req.OriginalFilename
	if req.WithPasscode {
		f.Metadata.Passcode = uuid.Must(uuid.NewRandom()).String()
	}

	f.Metadata.ExpiresOn = req.ExpiresOn

	f.Metadata.MaxViews = req.MaxViews

	id, err := s.store.StoreFile(&f)
	if err != nil {
		s.Logger.Warnw("Error storing file.", "error", err)
		return nil, err
	}
	fileUrl := fmt.Sprintf("%s/files/%s", s.Hostname, id)
	if req.WithPasscode {
		fileUrl = fmt.Sprintf("%s?passcode=%s", fileUrl, f.Metadata.Passcode)
	}
	s.Logger.Infow("Received file.", "id", id, "size", humanize.Bytes(uint64(len(f.Data))))
	return &pb.UploadFileResponse{Id: id, FileUrl: fileUrl}, nil
}

func (s *GRPCFileServiceServer) GetFile(ctx context.Context, req *pb.GetFileRequest) (*pb.GetFileResponse, error) {
	f, err := s.store.GetFile(req.Id)
	if err != nil {
		return nil, err
	}

	// Check if expired, viewed too many times, or needs passcode
	if f.Metadata.ExpiresOn != nil {
		if f.Metadata.ExpiresOn.AsTime().Before(time.Now()) {
			if err := s.store.DeleteFile(f.FileId); err != nil {
				s.Logger.Warnw("Error deleting expired file.", "error", err)
			}
			return nil, status.Error(codes.NotFound, "no such file")
		}
	}

	// Check if requires passcode
	if f.Metadata.Passcode != "" {
		if f.Metadata.Passcode != req.Passcode {
			return nil, status.Error(codes.PermissionDenied, "needs passcode")
		}
	}

	// Too many views
	if f.Metadata.MaxViews != 0 {
		if f.Metadata.CurrentViews >= f.Metadata.MaxViews {
			if err := s.store.DeleteFile(f.FileId); err != nil {
				s.Logger.Warnw("Error deleting expired file.", "error", err)
			}
			return nil, status.Error(codes.NotFound, "no such file")
		}
	}

	f.Metadata.CurrentViews++
	if _, err := s.store.StoreFile(f); err != nil {
		s.Logger.Warnw("Error storing updated file.", "error", err)
	}

	s.Logger.Infow("Sending file to client.", "id", f.FileId, "size", humanize.Bytes(uint64(len(f.Data))))
	return &pb.GetFileResponse{File: f}, nil
}

func (s *GRPCFileServiceServer) DeleteFile(ctx context.Context, req *pb.DeleteFileRequest) (*pb.DeleteFileResponse, error) {
	// Check if authorized
	if !interceptors.RoleAtLeast(ctx, pb.User_USER) {
		return nil, status.Error(codes.PermissionDenied, "permission denied")
	}
	// Ensure owner of file or admin
	f, err := s.store.GetFile(req.Id)
	if err != nil {
		if err == store.ErrNoSuchItem {
			return nil, status.Error(codes.NotFound, "no such file")
		}
		s.Logger.Warnw("Error getting file.", "error", err)
		return nil, status.Errorf(codes.Internal, "error getting file: %s", err)
	}
	if !(f.Metadata.Owner == interceptors.UserIDFromContext(ctx) || interceptors.RoleFromContext(ctx) == pb.User_ADMIN) {
		return nil, status.Error(codes.PermissionDenied, "permission denied")
	}

	if err := s.store.DeleteFile(req.Id); err != nil {
		s.Logger.Warnw("Error deleting file.", "error", err)
		return nil, err
	}
	s.Logger.Infow("Deleted file.", "id", req.Id)
	return &pb.DeleteFileResponse{}, nil
}

func (s *GRPCFileServiceServer) ListFiles(ctx context.Context, req *pb.ListFilesRequest) (*pb.ListFilesResponse, error) {
	var infos []*pb.ListFilesResponse_ListFileInfo
	allInfos, err := s.store.ListFiles()
	if err != nil {
		return nil, err
	}
	if interceptors.RoleFromContext(ctx) == pb.User_ADMIN {
		return &pb.ListFilesResponse{Files: allInfos}, nil
	}

	ownerID := interceptors.UserIDFromContext(ctx)
	for _, info := range allInfos {
		if info.Metadata.Owner == ownerID {
			infos = append(infos, info)
		}
	}

	return &pb.ListFilesResponse{
		Files: infos,
	}, nil
}