package models

import (
	"bytes"
	"fmt"
	"regexp"
	"strconv"
	"strings"

	"golang.org/x/exp/slices"
	"golang.org/x/xerrors"

	"github.com/future-architect/vuls/constant"
)

// Packages is Map of Package
// { "package-name": Package }
type Packages map[string]Package

// NewPackages create Packages
func NewPackages(packs ...Package) Packages {
	m := Packages{}
	for _, pack := range packs {
		m[pack.Name] = pack
	}
	return m
}

// MergeNewVersion merges candidate version information to the receiver struct
func (ps Packages) MergeNewVersion(as Packages) {
	for name, pack := range ps {
		pack.NewVersion = pack.Version
		pack.NewRelease = pack.Release
		ps[name] = pack
	}

	for _, a := range as {
		if pack, ok := ps[a.Name]; ok {
			pack.NewVersion = a.NewVersion
			pack.NewRelease = a.NewRelease
			pack.Repository = a.Repository
			ps[a.Name] = pack
		}
	}
}

// Merge returns merged map (immutable)
func (ps Packages) Merge(other Packages) Packages {
	merged := Packages{}
	for k, v := range ps {
		merged[k] = v
	}
	for k, v := range other {
		merged[k] = v
	}
	return merged
}

// FindOne search a element
func (ps Packages) FindOne(f func(Package) bool) (string, Package, bool) {
	for key, p := range ps {
		if f(p) {
			return key, p, true
		}
	}
	return "", Package{}, false
}

// FindByFQPN search a package by Fully-Qualified-Package-Name
func (ps Packages) FindByFQPN(nameVerRel string) (*Package, error) {
	for _, p := range ps {
		if nameVerRel == p.FQPN() {
			return &p, nil
		}
	}
	return nil, xerrors.Errorf("Failed to find the package: %s", nameVerRel)
}

// Package has installed binary packages.
type Package struct {
	Name             string               `json:"name"`
	Version          string               `json:"version"`
	Release          string               `json:"release"`
	NewVersion       string               `json:"newVersion"`
	NewRelease       string               `json:"newRelease"`
	Arch             string               `json:"arch"`
	Repository       string               `json:"repository"`
	ModularityLabel  string               `json:"modularitylabel"`
	Changelog        *Changelog           `json:"changelog,omitempty"`
	AffectedProcs    []AffectedProcess    `json:",omitempty"`
	NeedRestartProcs []NeedRestartProcess `json:",omitempty"`
}

// FQPN returns Fully-Qualified-Package-Name
// name-version-release.arch
func (p Package) FQPN() string {
	fqpn := p.Name
	if p.Version != "" {
		fqpn += fmt.Sprintf("-%s", p.Version)
	}
	if p.Release != "" {
		fqpn += fmt.Sprintf("-%s", p.Release)
	}
	return fqpn
}

// FormatVer returns package version-release
func (p Package) FormatVer() string {
	ver := p.Version
	if 0 < len(p.Release) {
		ver = fmt.Sprintf("%s-%s", ver, p.Release)
	}
	return ver
}

// FormatNewVer returns package version-release
func (p Package) FormatNewVer() string {
	ver := p.NewVersion
	if 0 < len(p.NewRelease) {
		ver = fmt.Sprintf("%s-%s", ver, p.NewRelease)
	}
	return ver
}

// FormatVersionFromTo formats installed and new package version
func (p Package) FormatVersionFromTo(stat PackageFixStatus) string {
	to := p.FormatNewVer()
	if stat.NotFixedYet {
		if stat.FixState != "" {
			to = stat.FixState
		} else {
			to = "Not Fixed Yet"
		}
	} else if p.NewVersion == "" {
		to = "Unknown"
	}
	var fixedIn string
	if stat.FixedIn != "" {
		fixedIn = fmt.Sprintf(" (FixedIn: %s)", stat.FixedIn)
	}
	return fmt.Sprintf("%s-%s -> %s%s",
		p.Name, p.FormatVer(), to, fixedIn)
}

// FormatChangelog formats the changelog
func (p Package) FormatChangelog() string {
	buf := []string{}
	packVer := fmt.Sprintf("%s-%s -> %s",
		p.Name, p.FormatVer(), p.FormatNewVer())
	var delim bytes.Buffer
	for i := 0; i < len(packVer); i++ {
		delim.WriteString("-")
	}

	clog := p.Changelog.Contents
	if lines := strings.Split(clog, "\n"); len(lines) != 0 {
		clog = strings.Join(lines[0:len(lines)-1], "\n")
	}

	switch p.Changelog.Method {
	case FailedToGetChangelog:
		clog = "No changelogs"
	case FailedToFindVersionInChangelog:
		clog = "Failed to parse changelogs. For details, check yourself"
	}
	buf = append(buf, packVer, delim.String(), clog)
	return strings.Join(buf, "\n")
}

// Changelog has contents of changelog and how to get it.
// Method: models.detectionMethodStr
type Changelog struct {
	Contents string          `json:"contents"`
	Method   DetectionMethod `json:"method"`
}

// AffectedProcess keep a processes information affected by software update
type AffectedProcess struct {
	PID             string     `json:"pid,omitempty"`
	Name            string     `json:"name,omitempty"`
	ListenPorts     []string   `json:"listenPorts,omitempty"`
	ListenPortStats []PortStat `json:"listenPortStats,omitempty"`
}

// PortStat has the result of parsing the port information to the address and port.
type PortStat struct {
	BindAddress     string   `json:"bindAddress"`
	Port            string   `json:"port"`
	PortReachableTo []string `json:"portReachableTo"`
}

// NewPortStat create a PortStat from ipPort str
func NewPortStat(ipPort string) (*PortStat, error) {
	if ipPort == "" {
		return &PortStat{}, nil
	}
	sep := strings.LastIndex(ipPort, ":")
	if sep == -1 {
		return nil, xerrors.Errorf("Failed to parse IP:Port: %s", ipPort)
	}
	return &PortStat{
		BindAddress: ipPort[:sep],
		Port:        ipPort[sep+1:],
	}, nil
}

// HasReachablePort checks if Package.AffectedProcs has PortReachableTo
func (p Package) HasReachablePort() bool {
	for _, ap := range p.AffectedProcs {
		for _, lp := range ap.ListenPortStats {
			if len(lp.PortReachableTo) > 0 {
				return true
			}
		}
	}
	return false
}

// NeedRestartProcess keep a processes information affected by software update
type NeedRestartProcess struct {
	PID         string `json:"pid"`
	Path        string `json:"path"`
	ServiceName string `json:"serviceName"`
	InitSystem  string `json:"initSystem"`
	HasInit     bool   `json:"-"`
}

// SrcPackage has installed source package information.
// Debian based Linux has both of package and source information in dpkg.
// OVAL database often includes a source version (Not a binary version),
// so it is also needed to capture source version for OVAL version comparison.
// https://github.com/future-architect/vuls/issues/504
type SrcPackage struct {
	Name        string   `json:"name"`
	Version     string   `json:"version"`
	Arch        string   `json:"arch"`
	BinaryNames []string `json:"binaryNames"`
}

// AddBinaryName add the name if not exists
func (s *SrcPackage) AddBinaryName(name string) {
	if slices.Contains(s.BinaryNames, name) {
		return
	}
	s.BinaryNames = append(s.BinaryNames, name)
}

// SrcPackages is Map of SrcPackage
// { "package-name": SrcPackage }
type SrcPackages map[string]SrcPackage

// FindByBinName finds by bin-package-name
func (s SrcPackages) FindByBinName(name string) (*SrcPackage, bool) {
	for _, p := range s {
		for _, binName := range p.BinaryNames {
			if binName == name {
				return &p, true
			}
		}
	}
	return nil, false
}

// raspiPackNamePattern is a regular expression pattern to detect the Raspberry Pi specific package from the package name.
// e.g. libraspberrypi-dev, rpi-eeprom, python3-rpi.gpio, pi-bluetooth
var raspiPackNamePattern = regexp.MustCompile(`(.*raspberry.*|^rpi.*|.*-rpi.*|^pi-.*)`)

// raspiPackNamePattern is a regular expression pattern to detect the Raspberry Pi specific package from the version.
// e.g. ffmpeg 7:4.1.4-1+rpt7~deb10u1, vlc 3.0.10-0+deb10u1+rpt2
var raspiPackVersionPattern = regexp.MustCompile(`.+\+rp(t|i)\d+`)

// raspiPackNameList is a package name array of Raspberry Pi specific packages that are difficult to detect with regular expressions.
var raspiPackNameList = []string{"piclone", "pipanel", "pishutdown", "piwiz", "pixflat-icons"}

// IsRaspbianPackage judges whether it is a package related to Raspberry Pi from the package name and version
func IsRaspbianPackage(name, version string) bool {
	if raspiPackNamePattern.MatchString(name) || raspiPackVersionPattern.MatchString(version) {
		return true
	}
	for _, n := range raspiPackNameList {
		if n == name {
			return true
		}
	}

	return false
}

// RenameKernelSourcePackageName is change common kernel source package
func RenameKernelSourcePackageName(family, name string) string {
	switch family {
	case constant.Debian, constant.Raspbian:
		return strings.NewReplacer("linux-signed", "linux", "linux-latest", "linux", "-amd64", "", "-arm64", "", "-i386", "").Replace(name)
	case constant.Ubuntu:
		return strings.NewReplacer("linux-signed", "linux", "linux-meta", "linux").Replace(name)
	default:
		return name
	}
}

// IsKernelSourcePackage check whether the source package is a kernel package
func IsKernelSourcePackage(family, name string) bool {
	switch family {
	case constant.Debian, constant.Raspbian:
		switch ss := strings.Split(RenameKernelSourcePackageName(family, name), "-"); len(ss) {
		case 1:
			return ss[0] == "linux"
		case 2:
			if ss[0] != "linux" {
				return false
			}
			switch ss[1] {
			case "grsec":
				return true
			default:
				_, err := strconv.ParseFloat(ss[1], 64)
				return err == nil
			}
		default:
			return false
		}
	case constant.Ubuntu: // https://git.launchpad.net/ubuntu-cve-tracker/tree/scripts/cve_lib.py#n1219
		switch ss := strings.Split(RenameKernelSourcePackageName(family, name), "-"); len(ss) {
		case 1:
			return ss[0] == "linux"
		case 2:
			if ss[0] != "linux" {
				return false
			}
			switch ss[1] {
			case "armadaxp", "mako", "manta", "flo", "goldfish", "joule", "raspi", "raspi2", "snapdragon", "allwinner", "aws", "azure", "bluefield", "dell300x", "gcp", "gke", "gkeop", "ibm", "iot", "laptop", "lowlatency", "kvm", "nvidia", "oem", "oracle", "euclid", "hwe", "riscv", "starfive", "realtime", "mtk":
				return true
			default:
				_, err := strconv.ParseFloat(ss[1], 64)
				return err == nil
			}
		case 3:
			if ss[0] != "linux" {
				return false
			}
			switch ss[1] {
			case "ti":
				return ss[2] == "omap4"
			case "raspi", "raspi2", "allwinner", "gke", "gkeop", "ibm", "oracle", "riscv", "starfive":
				_, err := strconv.ParseFloat(ss[2], 64)
				return err == nil
			case "aws":
				switch ss[2] {
				case "hwe", "edge":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "azure":
				switch ss[2] {
				case "cvm", "fde", "edge":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "gcp":
				switch ss[2] {
				case "edge":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "intel":
				switch ss[2] {
				case "iotg", "opt":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "oem":
				switch ss[2] {
				case "osp1":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "lts":
				switch ss[2] {
				case "utopic", "vivid", "wily", "xenial":
					return true
				default:
					return false
				}
			case "hwe":
				switch ss[2] {
				case "edge":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			case "xilinx":
				return ss[2] == "zynqmp"
			case "nvidia":
				switch ss[2] {
				case "tegra":
					return true
				default:
					_, err := strconv.ParseFloat(ss[2], 64)
					return err == nil
				}
			default:
				return false
			}
		case 4:
			if ss[0] != "linux" {
				return false
			}
			switch ss[1] {
			case "azure":
				if ss[2] != "fde" {
					return false
				}
				_, err := strconv.ParseFloat(ss[3], 64)
				return err == nil
			case "intel":
				if ss[2] != "iotg" {
					return false
				}
				_, err := strconv.ParseFloat(ss[3], 64)
				return err == nil
			case "lowlatency":
				if ss[2] != "hwe" {
					return false
				}
				_, err := strconv.ParseFloat(ss[3], 64)
				return err == nil
			case "nvidia":
				if ss[2] != "tegra" {
					return false
				}
				switch ss[3] {
				case "igx":
					return true
				default:
					_, err := strconv.ParseFloat(ss[3], 64)
					return err == nil
				}
			default:
				return false
			}
		default:
			return false
		}
	default:
		return false
	}
}