package rpmmd

import (

	"encoding/json"

	"fmt"

	"io/ioutil"

	"os"

	"os/exec"

	"path/filepath"

	"sort"

	"strconv"

	"strings"

	"time"

	"github.com/gobwas/glob"

)

type repository struct {

	Name           string `json:"name"`

	BaseURL        string `json:"baseurl,omitempty"`

	Metalink       string `json:"metalink,omitempty"`

	MirrorList     string `json:"mirrorlist,omitempty"`

	GPGKey         string `json:"gpgkey,omitempty"`

	CheckGPG       bool   `json:"check_gpg,omitempty"`

	RHSM           bool   `json:"rhsm,omitempty"`

	MetadataExpire string `json:"metadata_expire,omitempty"`

}

type dnfRepoConfig struct {

	ID             string `json:"id"`

	BaseURL        string `json:"baseurl,omitempty"`

	Metalink       string `json:"metalink,omitempty"`

	MirrorList     string `json:"mirrorlist,omitempty"`

	GPGKey         string `json:"gpgkey,omitempty"`

	IgnoreSSL      bool   `json:"ignoressl"`

	SSLCACert      string `json:"sslcacert,omitempty"`

	SSLClientKey   string `json:"sslclientkey,omitempty"`

	SSLClientCert  string `json:"sslclientcert,omitempty"`

	MetadataExpire string `json:"metadata_expire,omitempty"`

}

type RepoConfig struct {

	Name           string

	BaseURL        string

	Metalink       string

	MirrorList     string

	GPGKey         string

	CheckGPG       bool

	IgnoreSSL      bool

	MetadataExpire string

	RHSM           bool

}

type PackageList []Package

type Package struct {

	Name        string

	Summary     string

	Description string

	URL         string

	Epoch       uint

	Version     string

	Release     string

	Arch        string

	BuildTime   time.Time

	License     string

}

func (pkg Package) ToPackageBuild() PackageBuild {

	// Convert the time to the API time format

	return PackageBuild{

		Arch:           pkg.Arch,

		BuildTime:      pkg.BuildTime.Format("2006-01-02T15:04:05"),

		Epoch:          pkg.Epoch,

		Release:        pkg.Release,

		Changelog:      "CHANGELOG_NEEDED", // the same value as lorax-composer puts here

		BuildConfigRef: "BUILD_CONFIG_REF", // the same value as lorax-composer puts here

		BuildEnvRef:    "BUILD_ENV_REF",    // the same value as lorax-composer puts here

		Source: PackageSource{

			License:   pkg.License,

			Version:   pkg.Version,

			SourceRef: "SOURCE_REF", // the same value as lorax-composer puts here

		},

	}

}

func (pkg Package) ToPackageInfo() PackageInfo {

	return PackageInfo{

		Name:         pkg.Name,

		Summary:      pkg.Summary,

		Description:  pkg.Description,

		Homepage:     pkg.URL,

		UpstreamVCS:  "UPSTREAM_VCS", // the same value as lorax-composer puts here

		Builds:       []PackageBuild{pkg.ToPackageBuild()},

		Dependencies: nil,

	}

}

// TODO: the public API of this package should not be reused for serialization.

type PackageSpec struct {

	Name           string `json:"name"`

	Epoch          uint   `json:"epoch"`

	Version        string `json:"version,omitempty"`

	Release        string `json:"release,omitempty"`

	Arch           string `json:"arch,omitempty"`

	RemoteLocation string `json:"remote_location,omitempty"`

	Checksum       string `json:"checksum,omitempty"`

	Secrets        string `json:"secrets,omitempty"`

	CheckGPG       bool   `json:"check_gpg,omitempty"`

}

type dnfPackageSpec struct {

	Name           string `json:"name"`

	Epoch          uint   `json:"epoch"`

	Version        string `json:"version,omitempty"`

	Release        string `json:"release,omitempty"`

	Arch           string `json:"arch,omitempty"`

	RepoID         string `json:"repo_id,omitempty"`

	Path           string `json:"path,omitempty"`

	RemoteLocation string `json:"remote_location,omitempty"`

	Checksum       string `json:"checksum,omitempty"`

	Secrets        string `json:"secrets,omitempty"`

}

type PackageSource struct {

	License   string   `json:"license"`

	Version   string   `json:"version"`

	SourceRef string   `json:"source_ref"`

	Metadata  struct{} `json:"metadata"` // it's just an empty struct in lorax-composer

}

type PackageBuild struct {

	Arch           string        `json:"arch"`

	BuildTime      string        `json:"build_time"`

	Epoch          uint          `json:"epoch"`

	Release        string        `json:"release"`

	Source         PackageSource `json:"source"`

	Changelog      string        `json:"changelog"`

	BuildConfigRef string        `json:"build_config_ref"`

	BuildEnvRef    string        `json:"build_env_ref"`

	Metadata       struct{}      `json:"metadata"` // it's just an empty struct in lorax-composer

}

type PackageInfo struct {

	Name         string         `json:"name"`

	Summary      string         `json:"summary"`

	Description  string         `json:"description"`

	Homepage     string         `json:"homepage"`

	UpstreamVCS  string         `json:"upstream_vcs"`

	Builds       []PackageBuild `json:"builds"`

	Dependencies []PackageSpec  `json:"dependencies,omitempty"`

}

type RPMMD interface {

	// FetchMetadata returns all metadata about the repositories we use in the code. Specifically it is a

	// list of packages and dictionary of checksums of the repositories.

	FetchMetadata(repos []RepoConfig, modulePlatformID string, arch string) (PackageList, map[string]string, error)

	// Depsolve takes a list of required content (specs), explicitly unwanted content (excludeSpecs), list

	// or repositories, and platform ID for modularity. It returns a list of all packages (with solved

	// dependencies) that will be installed into the system.

	Depsolve(specs, excludeSpecs []string, repos []RepoConfig, modulePlatformID, arch string) ([]PackageSpec, map[string]string, error)

}

type DNFError struct {

	Kind   string `json:"kind"`

	Reason string `json:"reason"`

}

func (err *DNFError) Error() string {

	return fmt.Sprintf("DNF error occured: %s: %s", err.Kind, err.Reason)

}

type RepositoryError struct {

	msg string

}

func (re *RepositoryError) Error() string {

	return re.msg

}

type RHSMSecrets struct {

	SSLCACert     string `json:"sslcacert,omitempty"`

	SSLClientKey  string `json:"sslclientkey,omitempty"`

	SSLClientCert string `json:"sslclientcert,omitempty"`

}

func getRHSMSecrets() *RHSMSecrets {

	keys, err := filepath.Glob("/etc/pki/entitlement/*-key.pem")

	if err != nil {

		return nil

	}

	for _, key := range keys {

		cert := strings.TrimSuffix(key, "-key.pem") + ".pem"

		if _, err := os.Stat(cert); err == nil {

			return &RHSMSecrets{

				SSLCACert:     "/etc/rhsm/ca/redhat-uep.pem",

				SSLClientKey:  key,

				SSLClientCert: cert,

			}

		}

	}

	return nil

}

func LoadRepositories(confPaths []string, distro string) (map[string][]RepoConfig, error) {

	var f *os.File

	var err error

	path := "/repositories/" + distro + ".json"

	for _, confPath := range confPaths {

		f, err = os.Open(confPath + path)

		if err == nil {

			break

		} else if !os.IsNotExist(err) {

			return nil, err

		}

	}

	if err != nil {

		return nil, &RepositoryError{"LoadRepositories failed: none of the provided paths contain distro configuration"}

	}

	defer f.Close()

	var reposMap map[string][]repository

	repoConfigs := make(map[string][]RepoConfig)

	err = json.NewDecoder(f).Decode(&reposMap)

	if err != nil {

		return nil, err

	}

	for arch, repos := range reposMap {

		for _, repo := range repos {

			config := RepoConfig{

				Name:           repo.Name,

				BaseURL:        repo.BaseURL,

				Metalink:       repo.Metalink,

				MirrorList:     repo.MirrorList,

				GPGKey:         repo.GPGKey,

				CheckGPG:       repo.CheckGPG,

				RHSM:           repo.RHSM,

				MetadataExpire: repo.MetadataExpire,

			}

			repoConfigs[arch] = append(repoConfigs[arch], config)

		}

	}

	return repoConfigs, nil

}

func runDNF(dnfJsonPath string, command string, arguments interface{}, result interface{}) error {

	var call = struct {

		Command   string      `json:"command"`

		Arguments interface{} `json:"arguments,omitempty"`

	}{

		command,

		arguments,

	}

	cmd := exec.Command(dnfJsonPath)

	stdin, err := cmd.StdinPipe()

	if err != nil {

		return err

	}

	cmd.Stderr = os.Stderr

	stdout, err := cmd.StdoutPipe()

	if err != nil {

		return err

	}

	err = cmd.Start()

	if err != nil {

		return err

	}

	err = json.NewEncoder(stdin).Encode(call)

	if err != nil {

		return err

	}

	stdin.Close()

	output, err := ioutil.ReadAll(stdout)

	if err != nil {

		return err

	}

	err = cmd.Wait()

	const DnfErrorExitCode = 10

	if runError, ok := err.(*exec.ExitError); ok && runError.ExitCode() == DnfErrorExitCode {

		var dnfError DNFError

		err = json.Unmarshal(output, &dnfError)

		if err != nil {

			return err

		}

		return &dnfError

	}

	err = json.Unmarshal(output, result)

	if err != nil {

		return err

	}

	return nil

}

type rpmmdImpl struct {

	CacheDir    string

	RHSM        *RHSMSecrets

	dnfJsonPath string

}

func NewRPMMD(cacheDir, dnfJsonPath string) RPMMD {

	return &rpmmdImpl{

		CacheDir:    cacheDir,

		RHSM:        getRHSMSecrets(),

		dnfJsonPath: dnfJsonPath,

	}

}

func (repo RepoConfig) toDNFRepoConfig(rpmmd *rpmmdImpl, i int) (dnfRepoConfig, error) {

	id := strconv.Itoa(i)

	dnfRepo := dnfRepoConfig{

		ID:             id,

		BaseURL:        repo.BaseURL,

		Metalink:       repo.Metalink,

		MirrorList:     repo.MirrorList,

		GPGKey:         repo.GPGKey,

		IgnoreSSL:      repo.IgnoreSSL,

		MetadataExpire: repo.MetadataExpire,

	}

	if repo.RHSM {

		if rpmmd.RHSM == nil {

			return dnfRepoConfig{}, fmt.Errorf("RHSM secrets not found on host")

		}

		dnfRepo.SSLCACert = rpmmd.RHSM.SSLCACert

		dnfRepo.SSLClientKey = rpmmd.RHSM.SSLClientKey

		dnfRepo.SSLClientCert = rpmmd.RHSM.SSLClientCert

	}

	return dnfRepo, nil

}

func (r *rpmmdImpl) FetchMetadata(repos []RepoConfig, modulePlatformID string, arch string) (PackageList, map[string]string, error) {

	var dnfRepoConfigs []dnfRepoConfig

	for i, repo := range repos {

		dnfRepo, err := repo.toDNFRepoConfig(r, i)

		if err != nil {

			return nil, nil, err

		}

		dnfRepoConfigs = append(dnfRepoConfigs, dnfRepo)

	}

	var arguments = struct {

		Repos            []dnfRepoConfig `json:"repos"`

		CacheDir         string          `json:"cachedir"`

		ModulePlatformID string          `json:"module_platform_id"`

		Arch             string          `json:"arch"`

	}{dnfRepoConfigs, r.CacheDir, modulePlatformID, arch}

	var reply struct {

		Checksums map[string]string `json:"checksums"`

		Packages  PackageList       `json:"packages"`

	}

	err := runDNF(r.dnfJsonPath, "dump", arguments, &reply)

	sort.Slice(reply.Packages, func(i, j int) bool {

		return reply.Packages[i].Name < reply.Packages[j].Name

	})

	checksums := make(map[string]string)

	for i, repo := range repos {

		checksums[repo.Name] = reply.Checksums[strconv.Itoa(i)]

	}

	return reply.Packages, checksums, err

}

func (r *rpmmdImpl) Depsolve(specs, excludeSpecs []string, repos []RepoConfig, modulePlatformID, arch string) ([]PackageSpec, map[string]string, error) {

	var dnfRepoConfigs []dnfRepoConfig

	for i, repo := range repos {

		dnfRepo, err := repo.toDNFRepoConfig(r, i)

		if err != nil {

			return nil, nil, err

		}

		dnfRepoConfigs = append(dnfRepoConfigs, dnfRepo)

	}

	var arguments = struct {

		PackageSpecs     []string        `json:"package-specs"`

		ExcludSpecs      []string        `json:"exclude-specs"`

		Repos            []dnfRepoConfig `json:"repos"`

		CacheDir         string          `json:"cachedir"`

		ModulePlatformID string          `json:"module_platform_id"`

		Arch             string          `json:"arch"`

	}{specs, excludeSpecs, dnfRepoConfigs, r.CacheDir, modulePlatformID, arch}

	var reply struct {

		Checksums    map[string]string `json:"checksums"`

		Dependencies []dnfPackageSpec  `json:"dependencies"`

	}

	err := runDNF(r.dnfJsonPath, "depsolve", arguments, &reply)

	dependencies := make([]PackageSpec, len(reply.Dependencies))

	for i, pack := range reply.Dependencies {

		id, err := strconv.Atoi(pack.RepoID)

		if err != nil {

			panic(err)

		}

		repo := repos[id]

		dep := reply.Dependencies[i]

		dependencies[i].Name = dep.Name

		dependencies[i].Epoch = dep.Epoch

		dependencies[i].Version = dep.Version

		dependencies[i].Release = dep.Release

		dependencies[i].Arch = dep.Arch

		dependencies[i].RemoteLocation = dep.RemoteLocation

		dependencies[i].Checksum = dep.Checksum

		dependencies[i].CheckGPG = repo.CheckGPG

		if repo.RHSM {

			dependencies[i].Secrets = "org.osbuild.rhsm"

		}

	}

	return dependencies, reply.Checksums, err

}

func (packages PackageList) Search(globPatterns ...string) (PackageList, error) {

	var globs []glob.Glob

	for _, globPattern := range globPatterns {

		g, err := glob.Compile(globPattern)

		if err != nil {

			return nil, err

		}

		globs = append(globs, g)

	}

	var foundPackages PackageList

	for _, pkg := range packages {

		for _, g := range globs {

			if g.Match(pkg.Name) {

				foundPackages = append(foundPackages, pkg)

				break

			}

		}

	}

	sort.Slice(packages, func(i, j int) bool {

		return packages[i].Name < packages[j].Name

	})

	return foundPackages, nil

}

func (packages PackageList) ToPackageInfos() []PackageInfo {

	resultsNames := make(map[string]int)

	var results []PackageInfo

	for _, pkg := range packages {

		if index, ok := resultsNames[pkg.Name]; ok {

			foundPkg := &results[index]

			foundPkg.Builds = append(foundPkg.Builds, pkg.ToPackageBuild())

		} else {

			newIndex := len(results)

			resultsNames[pkg.Name] = newIndex

			packageInfo := pkg.ToPackageInfo()

			results = append(results, packageInfo)

		}

	}

	return results

}

func (pkg *PackageInfo) FillDependencies(rpmmd RPMMD, repos []RepoConfig, modulePlatformID string, arch string) (err error) {

	pkg.Dependencies, _, err = rpmmd.Depsolve([]string{pkg.Name}, nil, repos, modulePlatformID, arch)

	return

}