package repokit

import "errors"
import "fmt"
import "github.com/sassoftware/go-rpmutils"
import "github.com/sassoftware/go-rpmutils/cpio"
import "os"
import "strconv"
import "strings"

var rpm_dep_items []RpmDepItem = []RpmDepItem{
	{RPM_DEP_PROVIDES, rpmutils.PROVIDENAME, rpmutils.PROVIDEFLAGS, rpmutils.PROVIDEVERSION},
	{RPM_DEP_CONFLICTS, rpmutils.CONFLICTNAME, rpmutils.CONFLICTFLAGS, rpmutils.CONFLICTVERSION},
	{RPM_DEP_OBSOLETES, rpmutils.OBSOLETENAME, rpmutils.OBSOLETEFLAGS, rpmutils.OBSOLETEVERSION},
	{RPM_DEP_REQUIRES, rpmutils.REQUIRENAME, rpmutils.REQUIREFLAGS, rpmutils.REQUIREVERSION},
	{RPM_DEP_SUGGESTS, rpmutils.SUGGESTNAME, rpmutils.SUGGESTFLAGS, rpmutils.SUGGESTVERSION},
	{RPM_DEP_ENHANCES, rpmutils.ENHANCENAME, rpmutils.ENHANCEFLAGS, rpmutils.ENHANCEVERSION},
	{RPM_DEP_RECOMMENDS, rpmutils.RECOMMENDNAME, rpmutils.RECOMMENDFLAGS, rpmutils.RECOMMENDVERSION},
	{RPM_DEP_SUPPLEMENTS, rpmutils.SUPPLEMENTNAME, rpmutils.SUPPLEMENTFLAGS, rpmutils.SUPPLEMENTVERSION},
	{RPM_DEP_OLDSUGGESTS, rpmutils.OLDSUGGESTSNAME, rpmutils.OLDSUGGESTSFLAGS, rpmutils.OLDSUGGESTSVERSION},
	{RPM_DEP_OLDENHANCES, rpmutils.OLDENHANCESNAME, rpmutils.OLDENHANCESFLAGS, rpmutils.OLDENHANCESVERSION},
	{RPM_DEP_SENTINEL, 0, 0, 0},
}

func rpm_load_rpm(full_path string, checksum_type RpmChecksumType, location_href string, location_base string, change_log_limit int) (*RpmPackage, error) {
	var pkg *RpmPackage
	var err error
	var stat_mod_time int64
	var stat_size int64

	pkg, err = RpmPackageFromRpmBase(full_path, change_log_limit)
	if err != nil {
		return nil, fmt.Errorf("can not get rpm header: %v", err)
	}
	pkg.LocationHref = location_href
	pkg.LocationBase = location_base

	stat_mod_time, stat_size, err = rpm_stat_file(full_path)
	if err != nil {
		return nil, fmt.Errorf("can not stat file: %v", err)
	}

	pkg.TimeFile = stat_mod_time
	pkg.SizePackage = stat_size

	pkg.PkgId, err = rpm_get_checksum(full_path, checksum_type, "")
	if err != nil {
		return nil, fmt.Errorf("error while checksum calculation: %v", err)
	}

	// since we did calcualte the checksum with our own type,
	// we need to override the chekcsum type name
	pkg.RpmChecksumType = RpmChecksumName(checksum_type)
	return pkg, nil
}

func rpm_get_checksum(file_path string, checksum_type RpmChecksumType, cache_dir string) (string, error) {
	var checksum string
	var err error

	if cache_dir != "" {
		return "", fmt.Errorf("cache_dir is not supported")
	}

	checksum, err = rpm_checksum_file(file_path, checksum_type)
	if err != nil {
		return "", err
	}
	return checksum, nil
}

func RpmPackageFromRpmBase(full_path string, change_log_limit int) (*RpmPackage, error) {
	var f *os.File
	var err error
	var rpm *rpmutils.Rpm
	var pkg *RpmPackage
	var header_range rpmutils.HeaderRange
	var epoch_num uint64
	var time_build uint64
	var size_installed int64
	var fda uint64
	var size_archive int64
	var file_info_array []rpmutils.FileInfo
	var filenames_hashtable map[string]string
	var file_info rpmutils.FileInfo
	var pf RpmPackageFile
	var provided_hashtable map[string]string
	var ap_hashtable map[string]RpmApValueStruct
	var dep_type RpmDepType
	var libc_require_highest *RpmDependency
	var name_tag int
	var flags_tag int
	var version_tag int
	var filenames []string
	var file_flags []uint64
	var file_versions []string
	var filename_size int
	var file_flags_size int
	var file_version_size int
	var i int
	var j int
	var pre bool
	var filename string
	var num_flags uint64
	var flag_str string
	var full_version string
	var depnfv string
	var ok bool
	var ap_value RpmApValueStruct
	var cr_evr *RpmEVR
	var dependency RpmDependency
	var change_log_times []uint64
	var change_log_names []string
	var change_log_texts []string
	var log_times_size int
	var log_names_size int
	var log_texts_size int
	var last_time int64
	var time_value int64
	var changelog RpmChangelogEntry

	f, err = os.Open(full_path)
	if err != nil {
		return nil, err
	}
	defer f.Close()

	rpm, err = rpmutils.ReadRpm(f)
	if err != nil {
		return nil, err
	}

	pkg = &RpmPackage{}
	header_range = rpm.Header.GetRange()
	pkg.RpmHeaderStart = header_range.Start
	pkg.RpmHeaderEnd = header_range.End

	pkg.Name, err = rpm.Header.GetString(rpmutils.NAME)
	if err != nil {
		return nil, err
	}
	if rpm.Header.IsSource() {
		pkg.Arch = "src"
	} else {
		pkg.Arch, err = rpm.Header.GetString(rpmutils.ARCH)
		if err != nil {
			return nil, err
		}
	}
	pkg.Version, err = rpm.Header.GetString(rpmutils.VERSION)
	if err != nil {
		return nil, err
	}
	pkg.Release, err = rpm.Header.GetString(rpmutils.RELEASE)
	if err != nil {
		return nil, err
	}
	epoch_num, err = rpm.Header.GetUint64(rpmutils.EPOCH)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.Epoch = strconv.FormatUint(epoch_num, 10)

	pkg.Summary, err = rpm.Header.GetString(rpmutils.SUMMARY)
	if err != nil {
		return nil, err
	}
	pkg.Description, err = rpm.Header.GetString(rpmutils.DESCRIPTION)
	if err != nil {
		return nil, err
	}
	pkg.Url, err = rpm.Header.GetString(rpmutils.URL)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	time_build, err = rpm.Header.GetUint64(rpmutils.BUILDTIME)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.TimeBuild = int64(time_build)

	pkg.RpmLicense, err = rpm.Header.GetString(rpmutils.LICENSE)
	if err != nil {
		return nil, err
	}
	pkg.RpmVendor, err = rpm.Header.GetString(rpmutils.VENDOR)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.RpmGroup, err = rpm.Header.GetString(rpmutils.GROUP)
	if err != nil {
		return nil, err
	}
	pkg.RpmBuildHost, err = rpm.Header.GetString(rpmutils.BUILDHOST)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.RpmSourceRpm, err = rpm.Header.GetString(rpmutils.SOURCERPM)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.RpmPackager, err = rpm.Header.GetString(rpmutils.PACKAGER)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	size_installed, err = rpm.Header.InstalledSize()
	if err != nil {
		return nil, err
	}
	pkg.SizeInstalled = size_installed

	fda, err = rpm.Header.GetUint64(rpmutils.FILEDIGESTALGO)
	if err != nil {
		// default to md5. i assume the rpm file uses md5 when this field is missing
		fda = rpmutils.PGPHASHALGO_MD5
	}
	pkg.RpmChecksumType = rpmutils.GetFileAlgoName(int(fda))

	size_archive, err = rpm.Header.PayloadSize()
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	pkg.SizeArchive = size_archive

	file_info_array, err = rpm.Header.GetFiles()
	if err != nil {
		return nil, err
	}
	filenames_hashtable = make(map[string]string)
	for _, file_info = range file_info_array {
		pf = RpmPackageFile{}
		pf.FullPath = file_info.Name()
		pf.Digest = file_info.Digest()
		if file_info.Mode() & ^07777 == cpio.S_ISDIR {
			pf.Type = "dir"
		} else if file_info.Flags() & rpmutils.RPMFILE_GHOST != 0 {
			pf.Type = "ghost"
		} else {
			pf.Type = ""
		}
		filenames_hashtable[file_info.Name()] = file_info.Name()
		pkg.Files = append(pkg.Files, pf)
	}

	provided_hashtable = make(map[string]string)
	ap_hashtable = make(map[string]RpmApValueStruct)
	for dep_type = RPM_DEP_PROVIDES; rpm_dep_items[dep_type].Type != RPM_DEP_SENTINEL; dep_type++ {
		libc_require_highest = nil
		name_tag = rpm_dep_items[dep_type].NameTag
		flags_tag = rpm_dep_items[dep_type].FlagsTag
		version_tag = rpm_dep_items[dep_type].VersionTag
		if !rpm.Header.HasTag(name_tag) || !rpm.Header.HasTag(flags_tag) || !rpm.Header.HasTag(version_tag) {
			continue
		}
		filenames, err = rpm.Header.GetStrings(name_tag)
		if err != nil {
			return nil, err
		}
		file_flags, err = rpm.Header.GetUint64s(flags_tag)
		if err != nil {
			return nil, err
		}
		file_versions, err = rpm.Header.GetStrings(version_tag)
		if err != nil {
			return nil, err
		}
		filename_size = len(filenames)
		file_flags_size = len(file_flags)
		file_version_size = len(file_versions)
		for i = 0; i < file_flags_size && i < filename_size && i < file_version_size; i++ {
			pre = false
			filename = filenames[i]
			num_flags = file_flags[i]
			flag_str = rpm_flag_to_str(num_flags)
			full_version = file_versions[i]
			depnfv = filename + flag_str + full_version

			if dep_type == RPM_DEP_REQUIRES {
				if strings.HasPrefix(filename, "rpmlib(") {
					continue
				}
				if strings.HasPrefix(filename, "/") && filenames_hashtable[filename] != "" {
					if rpm_is_primary_file(filename) {
						continue
					}
				}
				_, ok = provided_hashtable[depnfv]
				if ok {
					continue
				}
				if num_flags & (rpmutils.RPMSENSE_PREREQ | rpmutils.RPMSENSE_SCRIPT_PRE | rpmutils.RPMSENSE_POSTTRANS | rpmutils.RPMSENSE_PRETRANS | rpmutils.RPMSENSE_SCRIPT_POST) != 0 {
					pre = true
				}
				ap_value, ok = ap_hashtable[filename]
				if ok {
					if ap_value.Flags == flag_str && ap_value.Version == full_version && ap_value.Pre == pre {
						continue
					}
				}
			}

			cr_evr = rpm_str_to_evr(full_version)
			if full_version != "" && cr_evr.Epoch == "" {
				continue
			}

			dependency = RpmDependency{Name: filename, Flags: flag_str, Epoch: cr_evr.Epoch, Version: cr_evr.Version, Release: cr_evr.Release}

			switch dep_type {
			case RPM_DEP_PROVIDES:
				provided_hashtable[depnfv] = ""
				pkg.Provides = append(pkg.Provides, dependency)
			case RPM_DEP_CONFLICTS:
				pkg.Conflicts = append(pkg.Conflicts, dependency)
			case RPM_DEP_OBSOLETES:
				pkg.Obsoletes = append(pkg.Obsoletes, dependency)
			case RPM_DEP_REQUIRES:
				if num_flags & RPM_SENSE_MISSINGOK != 0 {
					pkg.Recommends = append(pkg.Recommends, dependency)
					break
				}
				dependency.Pre = pre
				if strings.HasPrefix(dependency.Name, "libc.so.6") {
					if libc_require_highest == nil {
						libc_require_highest = &dependency
					} else if rpm_compare_dependency(libc_require_highest.Name, dependency.Name) == -1 {
						libc_require_highest = &dependency
					}
					break
				}
				pkg.Requires = append(pkg.Requires, dependency)
				ap_hashtable[dependency.Name] = RpmApValueStruct{Flags: flag_str, Version: full_version, Pre: dependency.Pre}
			case RPM_DEP_SUGGESTS:
				pkg.Suggests = append(pkg.Suggests, dependency)
			case RPM_DEP_ENHANCES:
				pkg.Enhances = append(pkg.Enhances, dependency)
			case RPM_DEP_RECOMMENDS:
				pkg.Recommends = append(pkg.Recommends, dependency)
			case RPM_DEP_SUPPLEMENTS:
				pkg.Supplements = append(pkg.Supplements, dependency)
			case RPM_DEP_OLDSUGGESTS:
				if num_flags & RPM_SENSE_STRONG != 0 {
					pkg.Recommends = append(pkg.Recommends, dependency)
				} else {
					pkg.Suggests = append(pkg.Suggests, dependency)
				}
			case RPM_DEP_OLDENHANCES:
				if num_flags & RPM_SENSE_STRONG != 0 {
					pkg.Supplements = append(pkg.Supplements, dependency)
				} else {
					pkg.Enhances = append(pkg.Enhances, dependency)
				}
			default:
			}
		}

		if dep_type == RPM_DEP_REQUIRES && libc_require_highest != nil {
			pkg.Requires = append(pkg.Requires, *libc_require_highest)
		}
	}

	change_log_times, err = rpm.Header.GetUint64s(rpmutils.CHANGELOGTIME)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	change_log_names, err = rpm.Header.GetStrings(rpmutils.CHANGELOGNAME)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	change_log_texts, err = rpm.Header.GetStrings(rpmutils.CHANGELOGTEXT)
	if !rpm_value_exists_or_no_such_tag(err) {
		return nil, err
	}
	log_times_size = len(change_log_times)
	log_names_size = len(change_log_names)
	log_texts_size = len(change_log_texts)
	last_time = 0
	for i = 0; i < log_times_size && i < log_names_size && i < log_texts_size && change_log_limit > 0; i++ {
		time_value = int64(change_log_times[i])
		changelog = RpmChangelogEntry{Author: strings.TrimSpace(change_log_names[i]), Date: time_value, Changelog: change_log_texts[i]}
		pkg.Changelogs = append(pkg.Changelogs, changelog)
		change_log_limit--
		if last_time == time_value {
			for j = len(pkg.Changelogs) - 2; j >= 0 && pkg.Changelogs[j].Date == time_value; j-- {
				pkg.Changelogs[j].Date--
				time_value--
			}
		} else {
			last_time = time_value
		}
	}

	rpm_reverse_array(pkg.Changelogs)
	return pkg, nil
}

func rpm_value_exists_or_no_such_tag(err error) bool {
	var target_err rpmutils.NoSuchTagError

	return err == nil || errors.As(err, &target_err)
}