admin_import_network.go

package api

import (
	"context"
	"errors"
	"fmt"
	"regexp"
	"strings"

	vgfs "github.com/elysiumstation/fury/libs/fs"
	"github.com/elysiumstation/fury/libs/jsonrpc"
	"github.com/elysiumstation/fury/paths"
	"github.com/elysiumstation/fury/wallet/network"

	"github.com/mitchellh/mapstructure"
)

var (
	ErrInvalidNetworkSource = errors.New("invalid network source")

	githubToml = regexp.MustCompile(`(http[s]?://)(github\.com).*(.toml)$`)
)

type AdminImportNetworkParams struct {
	Name      string `json:"name"`
	URL       string `json:"url"`
	Overwrite bool   `json:"overwrite"`
}

type AdminImportNetworkResult struct {
	Name string `json:"name"`
}

type AdminImportNetwork struct {
	networkStore NetworkStore
}

type Reader func(uri string, net interface{}) error

type Readers struct {
	ReadFromFile Reader
	ReadFromURL  Reader
}

func NewReaders() Readers {
	return Readers{
		ReadFromFile: paths.ReadStructuredFile,
		ReadFromURL:  paths.FetchStructuredFile,
	}
}

func (h *AdminImportNetwork) Handle(_ context.Context, rawParams jsonrpc.Params) (jsonrpc.Result, *jsonrpc.ErrorDetails) {
	params, err := validateImportNetworkParams(rawParams)
	if err != nil {
		return nil, InvalidParams(err)
	}

	net, err := readImportNetworkSource(params)
	if errors.Is(err, ErrInvalidNetworkSource) {
		return nil, InvalidParams(err)
	}
	if err != nil {
		return nil, InternalError(err)
	}

	if len(params.Name) != 0 {
		net.Name = params.Name
	}

	if len(net.Name) == 0 {
		return nil, InvalidParams(ErrNetworkNameIsRequired)
	}

	if exist, err := h.networkStore.NetworkExists(net.Name); err != nil {
		return nil, InternalError(fmt.Errorf("could not verify the network existence: %w", err))
	} else if exist && !params.Overwrite {
		return nil, InvalidParams(ErrNetworkAlreadyExists)
	}

	if err := h.networkStore.SaveNetwork(net); err != nil {
		return nil, InternalError(err)
	}

	return AdminImportNetworkResult{
		Name: net.Name,
	}, nil
}

// urlPreCheck looks for basic user errors in the given URL. For example if a github
// URL is supplied instead of a link to the raw-file-contents.
func urlPreCheck(url string) error {
	m := githubToml.FindString(url)
	if len(m) == 0 {
		return nil
	}

	// make a suggestion
	suggestion := strings.Replace(url, "github.com", "raw.githubusercontent.com", 1)
	suggestion = strings.Replace(suggestion, "/blob/", "/", 1)
	return fmt.Errorf("this URL leads to a Github page and not the network configuration, did you mean %s", suggestion)
}

func validateImportNetworkParams(rawParams jsonrpc.Params) (AdminImportNetworkParams, error) {
	if rawParams == nil {
		return AdminImportNetworkParams{}, ErrParamsRequired
	}

	params := AdminImportNetworkParams{}
	if err := mapstructure.Decode(rawParams, &params); err != nil {
		return AdminImportNetworkParams{}, ErrParamsDoNotMatch
	}

	if params.URL == "" {
		return AdminImportNetworkParams{}, ErrNetworkSourceIsRequired
	}

	if err := urlPreCheck(params.URL); err != nil {
		return AdminImportNetworkParams{}, err
	}
	return params, nil
}

// readImportNetworkSource parse the network file given by the source in the params
// into a `Network` which can then be saved to disk.
func readImportNetworkSource(params AdminImportNetworkParams) (*network.Network, error) {
	net := &network.Network{}
	rs := NewReaders()

	s, filePath, isFile := strings.Cut(params.URL, FileSchemePrefix)
	if isFile && len(s) == 0 {
		exists, err := vgfs.FileExists(filePath)
		if err != nil {
			return nil, fmt.Errorf("could not check file's existence at %q: %w", filePath, err)
		}
		if !exists {
			return nil, fmt.Errorf("the network source file does not exist: %w", ErrInvalidNetworkSource)
		}

		err = rs.ReadFromFile(filePath, net)
		if err == paths.ErrEmptyFile {
			return nil, fmt.Errorf("network source file is empty: %w", ErrInvalidNetworkSource)
		}
		if err != nil {
			return nil, fmt.Errorf("could not read the network configuration at %q: %w", filePath, err)
		}
		return net, nil
	}

	if len(params.URL) != 0 {
		err := rs.ReadFromURL(params.URL, net)
		if err == paths.ErrEmptyResponse {
			return nil, fmt.Errorf("network source url points to an empty file: %w", ErrInvalidNetworkSource)
		}
		if err != nil {
			return nil, fmt.Errorf("could not fetch the network configuration from %q: %w", params.URL, err)
		}
		return net, nil
	}

	return net, nil
}

func NewAdminImportNetwork(
	networkStore NetworkStore,
) *AdminImportNetwork {
	return &AdminImportNetwork{
		networkStore: networkStore,
	}
}