package clusterapi

import (
	"archive/zip"
	"bytes"
	"embed"
	"fmt"
	"io"
	"os"
	"path"
	"path/filepath"
	"strings"

	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"k8s.io/apimachinery/pkg/util/sets"
)

const (
	zipFile = "cluster-api.zip"
)

var (
	// ClusterAPI is the core provider for cluster-api.
	ClusterAPI = Provider{
		Name:    "cluster-api",
		Sources: sets.New("cluster-api"),
	}

	// EnvTest is the provider for the local control plane.
	EnvTest = Provider{
		Name:    "envtest",
		Sources: sets.New("kube-apiserver", "etcd"),
	}

	// AWS is the provider for creating resources in AWS.
	AWS = infrastructureProvider("aws")
	// Azure is the provider for creating resources in Azure.
	Azure = infrastructureProvider("azure")
	// AzureStack is the provider for creating resources in AzureStack.
	// The AzureStack provider is maintained in an OpenShift fork of CAPZ.
	AzureStack = infrastructureProvider("azurestack")
	// AzureASO is a companion component to Azure that is used to create resources declaratively.
	AzureASO = infrastructureProvider("azureaso")
	// GCP is the provider for creating resources in GCP.
	GCP = infrastructureProvider("gcp")
	// IBMCloud is the provider for creating resources in IBM Cloud and powervs.
	IBMCloud = infrastructureProvider("ibmcloud")
	// Nutanix is the provider for creating resources in Nutanix.
	Nutanix = infrastructureProvider("nutanix")
	// OpenStack is the provider for creating resources in OpenStack.
	OpenStack = infrastructureProvider("openstack")
	// OpenStackORC is a companion component to OpenStack that is used to create resources declaratively.
	OpenStackORC = infrastructureProvider("openstackorc")
	// VSphere is the provider for creating resources in vSphere.
	VSphere = infrastructureProvider("vsphere")
)

// Provider is a Cluster API provider.
type Provider struct {
	// Name of the provider.
	Name string
	// Sources of the provider.
	Sources sets.Set[string]
}

// infrastructureProvider configures a infrastructureProvider built locally.
func infrastructureProvider(name string) Provider {
	return Provider{
		Name: name,
		Sources: sets.New(
			fmt.Sprintf("cluster-api-provider-%s", name),
		),
	}
}

// Mirror is the embedded data for the providers.
//
//go:embed mirror/*
var Mirror embed.FS

// Extract extracts the provider from the embedded data into the specified directory.
func (p Provider) Extract(dir string) error {
	f, err := Mirror.Open(path.Join("mirror", zipFile))
	if err != nil {
		return errors.Wrap(err, "failed to open cluster api zip from mirror")
	}
	defer f.Close()
	stat, err := f.Stat()
	if err != nil {
		return errors.Wrap(err, "failed to stat cluster api zip")
	}
	seek, ok := f.(io.ReaderAt)
	if !ok {
		// If the file does not support ReaderAt interface (<Go1.20)
		// we need to read the whole file into memory.
		b, err := io.ReadAll(f)
		if err != nil {
			return errors.Wrap(err, "failed to read cluster api zip")
		}
		seek = bytes.NewReader(b)
	}

	// Open a zip archive for reading.
	r, err := zip.NewReader(seek, stat.Size())
	if err != nil {
		return errors.Wrap(err, "failed to open cluster api zip")
	}

	// Ensure the directory exists.
	logrus.Debugf("Creating %s directory", dir)
	if err := os.MkdirAll(dir, 0o777); err != nil {
		return errors.Wrapf(err, "could not make directory for the %s provider", p.Name)
	}

	// Extract the files.
	for _, f := range r.File {
		name := f.Name
		nameWithoutExt := strings.TrimSuffix(name, ".exe")
		if !p.Sources.Has(name) && !p.Sources.Has(nameWithoutExt) {
			continue
		}

		path, err := sanitizeArchivePath(dir, name)
		if err != nil {
			return errors.Wrapf(err, "failed to sanitize archive file %q", name)
		}
		logrus.Debugf("Extracting %s file", path)
		if err := unpackFile(f, path); err != nil {
			return errors.Wrapf(err, "failed to extract %q", path)
		}
	}
	return nil
}

func unpackFile(f *zip.File, destPath string) error {
	src, err := f.Open()
	if err != nil {
		return errors.Wrapf(err, "failed to open file %s", f.Name)
	}
	defer src.Close()
	destFile, err := os.OpenFile(destPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o777)
	if err != nil {
		return err
	}
	defer destFile.Close()
	if _, err := io.CopyN(destFile, src, f.FileInfo().Size()); err != nil {
		return err
	}
	return nil
}

func sanitizeArchivePath(d, t string) (v string, err error) {
	v = filepath.Join(d, t)
	if strings.HasPrefix(v, filepath.Clean(d)) {
		return v, nil
	}

	return "", fmt.Errorf("%s: %s", "content filepath is tainted", t)
}

// UnpackClusterAPIBinary unpacks the cluster-api binary from the embedded data so that it can be run to create the
// infrastructure for the cluster.
func UnpackClusterAPIBinary(dir string) error {
	return ClusterAPI.Extract(dir)
}

// UnpackEnvtestBinaries unpacks the envtest binaries from the embedded data so that it can be run to create the
// infrastructure for the cluster.
func UnpackEnvtestBinaries(dir string) error {
	return EnvTest.Extract(dir)
}