eon/cmd/main.go

package main

import (
	"bufio"
	"bytes"
	"eon/common"
	"eon/lib"
	"fmt"
	"io"
	"os"
	"regexp"
	"sort"
	"strings"

	"math/big"
	"net/http"
	"net/url"

	"golang.org/x/sys/unix"
	"golang.org/x/term"

	"github.com/dustin/go-humanize"
	"github.com/fatih/color"
)

func main() {
	if len(os.Args) < 2 {
		fmt.Println("Usage: eon <list/info/install/remove/clean/repo/help> [args]")
		os.Exit(1)
	}

	logger := &common.DefaultLogger

	for i, arg := range os.Args {
		if arg == "--help" || arg == "-h" || (i != 1 && arg == "help") {
			logger.LogFunc(lib.Log{
				Level:   "FATAL",
				Content: "To ask for help, use 'eon help <list/info/install/remove/clean/repo/help>', not --help, -h, or eon <command> help.",
			})
		}
	}
	switch os.Args[1] {
	case "help":
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon help (list/info/install/remove/clean/repo/help) [args]")
			os.Exit(1)
		} else {
			switch os.Args[2] {
			case "list":
				fmt.Println("Usage: eon list (repo/local)")
				fmt.Println("- repo: lists packages available in repositories.")
				fmt.Println("- local: lists installed packages.")
			case "info":
				fmt.Println("Usage: eon info <package> [(repo/local)] [<repository>]")
				fmt.Println("Shows information about a package.")
			case "install":
				fmt.Println("Usage: eon install <package> [<repository>]")
				fmt.Println("Installs a package.")
			case "remove":
				fmt.Println("Usage: eon remove <package>")
				fmt.Println("Removes a package.")
			case "clean":
				fmt.Println("Usage: eon clean")
				fmt.Println("Removes unused dependencies.")
			case "repo":
				fmt.Println("Usage: eon repo (add/del/list)")
				fmt.Println("- add <packageUrl>: adds a repository.")
				fmt.Println("- del <name>: removes a repository.")
				fmt.Println("- list: lists repositories.")
			case "help":
				fmt.Println("Usage: eon help (list/info/install/remove/clean/repo/help) [args]")
				fmt.Println("Shows help.")
			default:
				fmt.Println(color.RedString("Unknown command: " + os.Args[2]))
				os.Exit(1)
			}
		}
	case "install":
		var forceMode bool
		var yesMode bool
		var inMemoryMode bool
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon install <package>")
			os.Exit(1)
		}
		var localPackageList []string
		fileInfos := make(map[string]os.FileInfo)
		var repoPackageList []string
		for _, pkg := range os.Args[2:] {
			if !strings.HasPrefix(pkg, "-") {
				fileInfo, err := os.Stat(pkg)
				if err != nil || fileInfo.IsDir() {
					if os.IsNotExist(err) || fileInfo.IsDir() {
						// This unholy regex is a package name validator. It validates repository-name/package-name/1.0.0-prerelease.1+meta.1
						// The regex is so unholy it breaks JetBrains' regex parser, so I had to disable it.
						//goland:noinspection RegExpUnnecessaryNonCapturingGroup
						match, err := regexp.Match(`^(?:([a-z0-9_-]+)/)?([a-z0-9_-]+)(?:/(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?)?$`, []byte(pkg))
						if err != nil {
							fmt.Println(color.RedString("Failed to validate package name: " + err.Error()))
							os.Exit(1)
						}
						if !match {
							fmt.Println(color.RedString("Invalid package name: " + pkg))
							os.Exit(1)
						} else {
							repoPackageList = append(repoPackageList, pkg)
						}
					} else {
						fmt.Println(color.RedString("Failed to get file information: " + err.Error()))
						os.Exit(1)
					}
				} else {
					localPackageList = append(localPackageList, pkg)
					fileInfos[pkg] = fileInfo
				}
			} else {
				switch pkg {
				case "--force", "-f":
					forceMode = true
				case "--optimizeForSpeed", "-O":
					inMemoryMode = true
				case "--yes", "-y":
					yesMode = true
				}
			}
		}
		// We contact the database before we print anything as to not break the formatting.
		err := common.EstablishDBConnection(logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
			os.Exit(1)
		}
		// We refresh the package list. This takes a lot of arguments, haha.
		err = common.RefreshPackageList(common.DefaultListRepositoriesInDB, common.DefaultAddRemotePackageToDB,
			common.DefaultGetFingerprintFromDB, common.DefaultAddFingerprintToDB, common.DefaultCheckRepositoryInDB,
			common.DefaultAddRepositoryToDB, common.DefaultListRemotePackagesInDB, common.DefaultRemoveRemotePackageFromDB,
			logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to refresh package list: " + err.Error()))
			os.Exit(1)
		}
		// Let's start printing things.
		if len(localPackageList) > 0 || len(repoPackageList) > 0 {
			var epkList []common.InstallPackage
			var skipEpkList [][]string
			var dependencies int

		localPackageListIteration:
			for _, pkg := range localPackageList {
				// Check if the package is already in epkList.
				for _, epk := range epkList {
					if epk.EPKPreMap.DisplayData.Name == pkg {
						continue localPackageListIteration
					}
				}

				epkFile, err := os.Open(pkg)
				if err != nil {
					fmt.Println(color.RedString("Failed to open package: " + err.Error()))
					os.Exit(1)
				}

				var preMap lib.EPKPreMap
				var vagueErr error
				var epkBytes bytes.Buffer
				if !inMemoryMode {
					preMap, err, vagueErr = lib.PreMapEPK(lib.StreamOrBytes{FileStream: epkFile, IsFileStream: true}, fileInfos[pkg].Size())
				} else {
					_, err = io.Copy(bufio.NewWriter(&epkBytes), epkFile)
					if err != nil {
						fmt.Println(color.RedString("Failed to read package into memory: " + err.Error() +
							", have you tried disabling in-memory mode?"))
						os.Exit(1)
					}
					err := epkFile.Close()
					if err != nil {
						fmt.Println(color.HiYellowString("Failed to close package file: " + err.Error() + ", memory leak possible."))
					}
					preMap, err, vagueErr = lib.PreMapEPK(lib.StreamOrBytes{Bytes: epkBytes.Bytes()}, fileInfos[pkg].Size())
				}
				if err != nil || vagueErr != nil {
					common.PreMapEPKHandleError(err, vagueErr, logger)
					os.Exit(1)
				}

				// Check if the architecture is supported.
				var uts unix.Utsname
				err = unix.Uname(&uts)
				if err != nil {
					fmt.Println(color.RedString("Failed to get system architecture: " + err.Error()))
					os.Exit(1)
				}

				// Check if the architecture is supported.
				if preMap.DisplayData.Architecture != "noarch" || preMap.DisplayData.Architecture != string(uts.Machine[:]) {
					fmt.Println(color.RedString("Package architecture not supported: " + preMap.DisplayData.Architecture))
					os.Exit(1)
				}

				preMap.DisplayData.IsDependency = false

				var installPackage common.InstallPackage
				installPackage.EPKPreMap = &preMap
				installPackage.Url = ""
				installPackage.Priority = 0
				installPackage.IsRemote = false
				installPackage.IsForced = false
				if !inMemoryMode {
					installPackage.StreamOrBytes = lib.StreamOrBytes{
						FileStream:   epkFile,
						IsFileStream: true,
					}
				} else {
					installPackage.StreamOrBytes = lib.StreamOrBytes{
						Bytes: epkBytes.Bytes(),
					}
				}

				installPackage.Repository = lib.Repository{Name: "Local file"}
				preMap.IsUpgrade = true

				version, exists, err := common.DefaultCheckEPKInDB(preMap.DisplayData.Name)
				if err != nil {
					fmt.Println(color.RedString("Failed to check for package in database: " + err.Error()))
				}

				if exists {
					if version.Compare(&preMap.DisplayData.Version) != -1 {
						if !forceMode {
							skipEpk := []string{preMap.DisplayData.Name, preMap.DisplayData.Architecture, preMap.DisplayData.Version.String(), "Local file", humanize.BigIBytes(preMap.DisplayData.DecompressedSize), "Skip"}
							skipEpkList = append(skipEpkList, skipEpk)
						} else {
							installPackage.IsForced = true
							var emptyList []string
							var addedDeps int
							epkList, addedDeps, err = common.HandleDependencies(dependencies, installPackage, 0, []lib.RemoteEPK{}, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
							if err != nil {
								fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
								os.Exit(1)
							} else {
								dependencies += addedDeps
							}
							epkList = append(epkList, installPackage)
						}
					} else {
						var emptyList []string
						var addedDeps int
						epkList, addedDeps, err = common.HandleDependencies(dependencies, installPackage, 0, []lib.RemoteEPK{}, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
						if err != nil {
							fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
							os.Exit(1)
						} else {
							dependencies += addedDeps
						}
						epkList = append(epkList, installPackage)
					}
				} else {
					preMap.IsUpgrade = false
					var emptyList []string
					var addedDeps int
					epkList, addedDeps, err = common.HandleDependencies(dependencies, installPackage, 0, []lib.RemoteEPK{}, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
					if err != nil {
						fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
						os.Exit(1)
					} else {
						dependencies += addedDeps
					}
					epkList = append(epkList, installPackage)
				}
			}

		repoPackageListIteration:
			for _, pkg := range repoPackageList {
				// Check if the package is already in epkList.
				for _, epk := range epkList {
					if epk.EPKPreMap.DisplayData.Name == pkg {
						continue repoPackageListIteration
					}
				}

				// Check if the package is already installed.
				version, exists, err := common.DefaultCheckEPKInDB(pkg)
				if err != nil {
					fmt.Println(color.RedString("Failed to check for package in database: " + err.Error()))
					os.Exit(1)
				}

				var remoteEPK lib.RemoteEPK
				var epkEntry common.InstallPackage

				remoteEpkList, err := common.DefaultListRemotePackagesInDB()
				if err != nil {
					fmt.Println(color.RedString("Failed to list remote packages: " + err.Error()))
					os.Exit(1)
				}

				epkExists := false
				for _, epk := range remoteEpkList {
					if epk.Name == pkg {
						remoteEPK = epk
						epkExists = true
						break
					}
				}

				if !epkExists {
					fmt.Println(color.RedString("Package not found: " + pkg))
					os.Exit(1)
				}

				// Calculate the download URL
				epkDownloadUrl, err := url.JoinPath(remoteEPK.Repository.URL, remoteEPK.Path)
				if err != nil {
					fmt.Println(color.RedString("Failed to join URL: " + err.Error()))
					os.Exit(1)

				}

				// Pre-map the EPK
				preMap, err, vagueErr := lib.PreMapRemoteEPK(remoteEPK, logger)
				if err != nil || vagueErr != nil {
					common.PreMapRemoteEPKHandleError(err, vagueErr, logger)
					os.Exit(1)
				}

				preMap.DisplayData.IsDependency = false

				// Map the data we have
				epkEntry.Priority = 0
				epkEntry.EPKPreMap = &preMap
				epkEntry.Url = epkDownloadUrl
				epkEntry.IsRemote = true
				epkEntry.Repository = remoteEPK.Repository
				if !inMemoryMode {
					epkEntry.StreamOrBytes.IsURL = true
					epkEntry.StreamOrBytes.URL = epkDownloadUrl
					epkEntry.StreamOrBytes.RepositoryName = remoteEPK.Repository.Name
				} else {
					// Download the entire EPK into memory
					epkBytes, err := http.Get(epkDownloadUrl)
					if err != nil {
						fmt.Println(color.RedString("Failed to download package: " + err.Error()))
						os.Exit(1)
					}

					if epkBytes.StatusCode != 200 {
						fmt.Println(color.RedString("Failed to download package: " + epkBytes.Status))
						os.Exit(1)
					}

					// Calculate the total size of the package
					contentLength := new(big.Int)
					contentLength.SetString(epkBytes.Header.Get("Content-Length"), 10)

					// Print that we are downloading the package
					fmt.Println("\nDownloading package: " + preMap.DisplayData.Name + " (" + humanize.BigIBytes(contentLength) + ")")

					// Hide the cursor for reasons explained below.
					fmt.Print("\033[?25l")

					// Copy the stream into a buffer
					var buffer bytes.Buffer
					_, err = io.Copy(&lib.ProgressWriter{
						Logger: logger,
						Total:  contentLength,
						Writer: &buffer,
					}, epkBytes.Body)
					if err != nil {
						fmt.Println(color.RedString("Failed to read package into memory: " + err.Error()))
						os.Exit(1)
					}

					// Set the progress to 100%
					logger.LogFunc(lib.Log{
						Level:    "PROGRESS",
						Progress: big.NewInt(1),
						Total:    big.NewInt(1),
					})

					// Show the cursor again because we're done with the progress bar.
					fmt.Print("\033[?25h")

					// Close the response body
					err = epkBytes.Body.Close()
					if err != nil {
						fmt.Println(color.HiYellowString("Failed to close response body: " + err.Error() + ", memory leak possible."))
					}

					// Set the buffer as the bytes
					epkEntry.StreamOrBytes.Bytes = buffer.Bytes()
					epkEntry.StreamOrBytes.IsURL = false
					epkEntry.StreamOrBytes.IsFileStream = false

					// Reset the buffer
					buffer.Reset()
				}

				// Make decisions on what happens if the package is already installed.
				if exists {
					if version.Compare(&preMap.DisplayData.Version) != -1 {
						// If the version is the same or newer, skip the package.
						if !forceMode {
							skipEpkList = append(skipEpkList, []string{preMap.DisplayData.Name, preMap.DisplayData.Architecture, preMap.DisplayData.Version.String(), remoteEPK.Repository.Name, humanize.BigIBytes(preMap.DisplayData.DecompressedSize), "Skip"})
						} else {
							// If the version is the same or newer, but the user wants to force the installation, install it.
							epkEntry.IsForced = true
							// We can let it use our remoteEPKList to save a SQL query.
							var emptyList []string
							var addedDeps int
							epkList, addedDeps, err = common.HandleDependencies(dependencies, epkEntry, 0, remoteEpkList, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
							if err != nil {
								fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
								os.Exit(1)
							} else {
								// We add the dependencies to the total count.
								dependencies += addedDeps
							}
							epkList = append(epkList, epkEntry)
						}
					} else {
						// If the version is older, install it.
						var emptyList []string
						var addedDeps int
						epkList, addedDeps, err = common.HandleDependencies(dependencies, epkEntry, 0, remoteEpkList, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
						if err != nil {
							fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
							os.Exit(1)
						} else {
							dependencies += addedDeps
						}
						epkList = append(epkList, epkEntry)
					}
				} else {
					// If the package is not installed, install it.
					var emptyList []string
					var addedDeps int
					epkList, addedDeps, err = common.HandleDependencies(dependencies, epkEntry, 0, remoteEpkList, common.DefaultListRemotePackagesInDB, epkList, &emptyList, logger)
					if err != nil {
						fmt.Println(color.RedString("Failed to handle dependencies: " + err.Error()))
						os.Exit(1)
					} else {
						dependencies += addedDeps
					}
					epkList = append(epkList, epkEntry)
				}
			}

			// Sort the list of packages to install by priority, then alphabetically.
			sort.Slice(epkList, func(i, j int) bool {
				if epkList[i].Priority == epkList[j].Priority {
					return epkList[i].EPKPreMap.DisplayData.Name < epkList[j].EPKPreMap.DisplayData.Name
				}
				return epkList[i].Priority > epkList[j].Priority
			})

			// Give the summary of the installation.
			fmt.Println("\nThe following packages will be installed:")
			width, _, err := term.GetSize(int(os.Stdout.Fd()))
			if err != nil {
				fmt.Println(color.RedString("Failed to get terminal width: " + err.Error()))
				os.Exit(1)
			}
			if width < 42 {
				fmt.Println(color.RedString("Terminal too small. Minimum required width: 42 characters."))
				os.Exit(1)
			}
			for range width {
				fmt.Print("=")
			}
			fmt.Println()
			tableList := []string{"Package", "Architecture", "Version", "Repository", "Installed Size", "Action"}
			maxSize := width / 6
			for _, item := range tableList {
				common.PrintWithEvenPadding(item, maxSize)
			}
			fmt.Println()
			for range width {
				fmt.Print("=")
			}
			fmt.Println()

			for _, pkg := range skipEpkList {
				for _, item := range pkg {
					common.PrintWithEvenPadding(color.GreenString(item), maxSize)
				}
			}

			for _, pkg := range epkList {
				finalisedList := make([]string, 6)
				finalisedList[0] = pkg.EPKPreMap.DisplayData.Name
				finalisedList[1] = pkg.EPKPreMap.DisplayData.Architecture
				finalisedList[2] = pkg.EPKPreMap.DisplayData.Version.String()
				if !pkg.IsRemote {
					finalisedList[3] = "Local file"
				} else {
					finalisedList[3] = pkg.Repository.Name
				}
				finalisedList[4] = humanize.BigIBytes(pkg.EPKPreMap.DisplayData.DecompressedSize)
				if pkg.IsForced {
					finalisedList[5] = "Forced installation"
				} else if pkg.EPKPreMap.IsUpgrade {
					finalisedList[5] = "Upgrade"
				} else {
					finalisedList[5] = "Install"
				}
				for _, item := range finalisedList {
					common.PrintWithEvenPadding(item, maxSize)
				}
			}

			if len(epkList) > 0 {
				for range width {
					fmt.Print("=")
				}
				fmt.Println("Transaction Summary")
				fmt.Println("\nInstalling " + humanize.Comma(int64(len(epkList))) + " packages, of which " + humanize.Comma(int64(dependencies)) + " are dependencies.")
				fmt.Println("Total download size: " + humanize.BigIBytes(common.GetTotalSize(epkList)))
				fmt.Println("Total installed size: " + humanize.BigIBytes(common.GetTotalInstalledSize(epkList)) + "\n")
				var response string
				if !yesMode {
					response = logger.LogFunc(lib.Log{
						Level:     "INFO",
						Content:   "Proceed with installation (y/n)?",
						Prompt:    true,
						PlaySound: true,
					})
				}
				if strings.ToLower(response) == "y" || yesMode {
					// We hide the cursor because it makes the progress bar look weird and other package managers hide
					// it during installation. For some reason, it builds suspense. Or it does with me anyway, when
					// a program hides the cursor, it makes me think twice than to Ctrl+C it :P
					// - Arzumify
					fmt.Print("\033[?25l")
					// Time to install things.
					for _, installPackage := range epkList {
						if installPackage.IsRemote {
							if !inMemoryMode {
								// Set the package stream to the URL.
								installPackage.StreamOrBytes.IsURL = true
								installPackage.StreamOrBytes.IsRemote = true
								installPackage.StreamOrBytes.RepositoryName = installPackage.Repository.Name
								installPackage.StreamOrBytes.IsFileStream = false
								installPackage.StreamOrBytes.URL = installPackage.Url
							} else {
								// Download the entire EPK into memory
								epkBytes, err := http.Get(installPackage.Url)
								if err != nil {
									fmt.Println(color.RedString("Failed to download package: " + err.Error()))
									os.Exit(1)
								}

								if epkBytes.StatusCode != 200 {
									fmt.Println(color.RedString("Failed to download package: " + epkBytes.Status))
									os.Exit(1)
								}

								// Start streaming the package into a buffer
								contentLength := new(big.Int).SetBytes([]byte(epkBytes.Header.Get("Content-Length")))
								fmt.Println("\nDownloading package: " + installPackage.EPKPreMap.DisplayData.Name + " (" + humanize.BigIBytes(contentLength) + ")")
								var buffer bytes.Buffer
								_, err = io.Copy(&lib.ProgressWriter{
									Logger: logger,
									Total:  contentLength,
									Writer: &buffer,
								}, epkBytes.Body)
								if err != nil {
									fmt.Println(color.RedString("Failed to read package into memory: " + err.Error()))
									os.Exit(1)
								}

								// Set the progress to 100%
								logger.LogFunc(lib.Log{
									Level:    "PROGRESS",
									Progress: big.NewInt(1),
									Total:    big.NewInt(1),
								})

								// Close the response body
								err = epkBytes.Body.Close()
								if err != nil {
									fmt.Println(color.HiYellowString("Failed to close response body: " + err.Error() + ", memory leak possible."))
								}

								fmt.Println("Package downloaded")

								// Set the buffer as the bytes
								installPackage.StreamOrBytes.Bytes = buffer.Bytes()
								installPackage.StreamOrBytes.IsURL = false
								installPackage.StreamOrBytes.IsRemote = true
								installPackage.StreamOrBytes.RepositoryName = installPackage.Repository.Name
								installPackage.StreamOrBytes.IsFileStream = false
							}
						}
						// Map the EPK metadata.
						metadata, err, vagueErr := lib.FullyMapMetadata(installPackage.StreamOrBytes,
							installPackage.EPKPreMap, common.DefaultGetFingerprintFromDB,
							common.DefaultAddFingerprintToDB, func(*lib.Logger) {
								logger.LogFunc(lib.Log{
									Level: "WARN",
									Content: "This server does not support range requests. Please use the -O flag to " +
										"enable in memory mode, or contact the server administrator to use a web server " +
										"that supports range requests, such as Apache or Nginx. The speed of download " +
										"is considerably slowed, as we need to discard bytes since we can only read " +
										"sequentially.",
									Prompt: false,
								})
							}, logger)
						if err != nil || vagueErr != nil {
							common.FullyMapMetadataHandleError(err, vagueErr, logger)
						}
						// Install the package.
						tempDir, err, vagueErr := lib.InstallEPK(installPackage.StreamOrBytes,
							metadata, installPackage.EPKPreMap, common.DefaultAddEPKToDB, logger)
						if err != nil || vagueErr != nil {
							common.InstallEPKHandleError(tempDir, err, vagueErr, logger)
						}
						// Done!
						fmt.Println("Installed package: " + installPackage.EPKPreMap.DisplayData.Name)
					}
					// We show the cursor again because we're done with the progress bar.
					fmt.Print("\033[?25h")
				} else {
					fmt.Println("Installation cancelled.")
					os.Exit(1)
				}
			} else {
				for range width {
					fmt.Print("=")
				}
				fmt.Println("No packages left to install. To force re-install / downgrade, use the --force flag, " +
					"though this may result in breakage.")
				os.Exit(0)
			}
		} else {
			fmt.Println("No packages to install.")
			os.Exit(0)
		}
	case "repo":
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon repo (add/del/list)")
			os.Exit(1)
		}

		switch os.Args[2] {
		case "add":
			if len(os.Args) < 4 {
				fmt.Println("Usage: eon repo add <packageUrl>")
				os.Exit(1)
			} else {
				err := common.EstablishDBConnection(logger)
				if err != nil {
					fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
					os.Exit(1)
				}
				repoName, err, vagueErr := lib.AddRepository(os.Args[3], common.DefaultAddRepositoryToDB, common.DefaultGetFingerprintFromDB, common.DefaultAddFingerprintToDB, common.DefaultAddRemotePackageToDB, common.DefaultCheckRepositoryInDB, false, logger)
				if err != nil || vagueErr != nil {
					common.AddRepositoryHandleError(err, vagueErr, logger)
				} else {
					fmt.Println("Added repository " + repoName + " to the database.")
				}
			}
		case "del":
			if len(os.Args) < 4 {
				fmt.Println("Usage: eon repo del <name>")
				os.Exit(1)
			} else {
				err := common.EstablishDBConnection(logger)
				if err != nil {
					fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
					os.Exit(1)
				}
				err, vagueErr := lib.RemoveRepository(os.Args[3], common.DefaultRemoveRepositoryFromDB, common.DefaultCheckRepositoryInDB, logger)
				if err != nil || vagueErr != nil {
					common.RemoveRepositoryHandleError(err, vagueErr, logger)
				}
			}
		case "list":
			err := common.EstablishDBConnection(logger)
			if err != nil {
				fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
				os.Exit(1)
			}
			repos, err := common.DefaultListRepositoriesInDB()
			if err != nil {
				fmt.Println(color.RedString("Failed to get repositories: " + err.Error()))
				os.Exit(1)
			}
			if len(repos) == 0 {
				fmt.Println("No repositories.")
			} else {
				fmt.Println("Repositories:")
				for _, repo := range repos {
					fmt.Println("\n" + repo.Name + ":\n" + "- " + repo.Description + "\n- URL: " + repo.URL + "\n- Owner: " + repo.Owner)
				}
				fmt.Println()
			}
		}
	case "remove":
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon remove <package>")
			os.Exit(1)
		}
		err := common.EstablishDBConnection(logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
			os.Exit(1)
		}
		// Create a map of all installed packages, to minimise the database queries later.
		epkMap, decompressedSizeMap, repositoryMap, _, err := common.DefaultListEPKsInDB()
		if err != nil {
			fmt.Println(color.RedString("Failed to list installed packages: " + err.Error()))
			os.Exit(1)
		}
		// Create a list of packages to remove.
		var packageRemoveList []common.RemovePackage
		for _, pkg := range os.Args[2:] {
			var removePackage common.RemovePackage
			_, exists, err := common.DefaultCheckEPKInDB(pkg)
			if err != nil {
				fmt.Println(color.RedString("Failed to check for package in database: " + err.Error()))
				os.Exit(1)
			}
			if !exists {
				fmt.Println(color.RedString("Package not found: " + pkg))
				os.Exit(1)
			}
			// Search to see if it's parent is still installed.
			for _, epk := range epkMap {
				for _, dep := range epk.Dependencies {
					if dep == os.Args[2] {
						// First, check if it's in the list of packages to remove.
						var found bool
						for _, epkName := range os.Args[2:] {
							if epkName == epk.Name {
								found = true
								break
							}
						}
						if !found {
							fmt.Println(color.RedString("Package " + pkg + " is a dependency of another package (" + epk.Name + ") and cannot be removed."))
							os.Exit(1)
						} else {
							// It is in the list of packages to remove, we need to set this package's priority higher.
							removePackage.Priority++
						}
					}
				}
			}
			// Add it to the list of packages to remove.
			removePackage.Name = pkg
			removePackage.DisplayData = epkMap[pkg]
			packageRemoveList = append(packageRemoveList, removePackage)
		}

		if len(packageRemoveList) > 0 {
			// First, re-order the packageRemoveList by priority, then alphabetically.
			sort.Slice(packageRemoveList, func(i, j int) bool {
				if packageRemoveList[i].Priority == packageRemoveList[j].Priority {
					return packageRemoveList[i].Name < packageRemoveList[j].Name
				}
				return packageRemoveList[i].Priority > packageRemoveList[j].Priority
			})

			// Print the packages that will be removed.
			fmt.Println("The following packages will be removed:")
			width, _, err := term.GetSize(int(os.Stdout.Fd()))
			if err != nil {
				fmt.Println(color.RedString("Failed to get terminal width: " + err.Error()))
				os.Exit(1)
			}
			if width < 42 {
				fmt.Println(color.RedString("Terminal too small. Minimum required width: 42 characters."))
				os.Exit(1)
			}
			for range width {
				fmt.Print("=")
			}
			fmt.Println()
			tableList := []string{"Package", "Architecture", "Version", "Repository", "Installed Size", "Action"}
			maxSize := width / 6
			for _, item := range tableList {
				common.PrintWithEvenPadding(item, maxSize)
			}
			fmt.Println()
			for range width {
				fmt.Print("=")
			}
			fmt.Println()
			for _, pkg := range packageRemoveList {
				finalisedList := make([]string, 6)
				finalisedList[0] = pkg.Name
				finalisedList[1] = pkg.DisplayData.Architecture
				finalisedList[2] = pkg.DisplayData.Version.String()
				finalisedList[3] = repositoryMap[pkg.Name].Name
				finalisedList[4] = humanize.BigIBytes(decompressedSizeMap[pkg.Name])
				finalisedList[5] = "Remove"
				for _, item := range finalisedList {
					common.PrintWithEvenPadding(item, maxSize)
				}
			}
			for range width {
				fmt.Print("=")
			}
			fmt.Println("Transaction Summary")
			fmt.Println("\nRemoving " + humanize.Comma(int64(len(packageRemoveList))) + " packages.")
			space := new(big.Int)
			for _, pkg := range packageRemoveList {
				space = new(big.Int).Add(space, decompressedSizeMap[pkg.Name])
			}
			fmt.Println("Total reclaimed space: " + humanize.BigIBytes(space) + "\n")
			response := logger.LogFunc(lib.Log{
				Level:   "INFO",
				Content: "Proceed with removal (y/n)?",
				Prompt:  true,
			})
			if strings.ToLower(response) == "y" {
				for _, pkg := range packageRemoveList {
					err, vagueErr := lib.RemoveEPK(pkg.Name, common.DefaultRemoveEPKFromDB, common.DefaultGetEPKRemoveInfoFromDB, logger)
					if err != nil || vagueErr != nil {
						common.RemoveEPKHandleError(err, vagueErr, logger)
						fmt.Println(color.RedString("Failed to remove package: " + vagueErr.Error() + err.Error()))
					}
					fmt.Println("Removed package: " + pkg.Name)
				}
			} else {
				fmt.Println("Removal cancelled.")
				os.Exit(1)
			}
		}
	case "list":
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon list (remote/local)")
			os.Exit(1)
		}

		err := common.EstablishDBConnection(logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
			os.Exit(1)
		}

		width, _, err := term.GetSize(int(os.Stdout.Fd()))
		if err != nil {
			fmt.Println(color.RedString("Failed to get terminal width: " + err.Error()))
			os.Exit(1)
		}

		if width < 15 {
			fmt.Println(color.RedString("Terminal too small. Minimum required width: 15 characters."))
			os.Exit(1)
		}

		maxWidth := width / 3

		switch os.Args[2] {
		case "remote":
			// Refresh the package list.
			err = common.RefreshPackageList(common.DefaultListRepositoriesInDB, common.DefaultAddRemotePackageToDB,
				common.DefaultGetFingerprintFromDB, common.DefaultAddFingerprintToDB, common.DefaultCheckRepositoryInDB,
				common.DefaultAddRepositoryToDB, common.DefaultListRemotePackagesInDB, common.DefaultRemoveRemotePackageFromDB,
				logger)
			if err != nil {
				fmt.Println(color.RedString("Failed to refresh package list: " + err.Error()))
				os.Exit(1)
			}

			remoteEpkList, err := common.DefaultListRemotePackagesInDB()
			if err != nil {
				fmt.Println(color.RedString("Failed to list remote packages: " + err.Error()))
				os.Exit(1)
			}
			if len(remoteEpkList) == 0 {
				fmt.Println("No remote packages.")
			} else {
				fmt.Println("\nRemote packages:")
				for range width {
					fmt.Print("=")
				}
				for _, item := range []string{"Name", "Version", "Repository"} {
					common.PrintWithEvenPadding(item, maxWidth)
				}
				for range width {
					fmt.Print("=")
				}
				for _, epk := range remoteEpkList {
					var printMap []string
					printMap = append(printMap, epk.Name, epk.Version.String(), epk.Repository.Name)
					for _, item := range printMap {
						common.PrintWithEvenPadding(item, maxWidth)
					}
					fmt.Println()
				}
				for range width {
					fmt.Print("=")
				}
			}
		case "local":
			epkMap, _, repositoryMap, _, err := common.DefaultListEPKsInDB()
			if err != nil {
				fmt.Println(color.RedString("Failed to list installed packages: " + err.Error()))
				os.Exit(1)
			}

			if len(epkMap) == 0 {
				fmt.Println("No local packages.")
			} else {
				// Sort the map by name.
				var epkList []string
				for epk := range epkMap {
					epkList = append(epkList, epk)
				}
				sort.Strings(epkList)
				fmt.Println("Local packages:")
				for range width {
					fmt.Print("=")
				}
				for _, item := range []string{"Name", "Version", "Repository"} {
					common.PrintWithEvenPadding(item, maxWidth)
				}
				for range width {
					fmt.Print("=")
				}
				for _, epk := range epkList {
					version := epkMap[epk].Version
					var printMap []string
					printMap = append(printMap, epk, version.String(), repositoryMap[epk].Name)
					for _, item := range printMap {
						common.PrintWithEvenPadding(item, maxWidth)
					}
					fmt.Println()
				}
				for range width {
					fmt.Print("=")
				}
			}
		}
	case "info":
		if len(os.Args) < 3 {
			fmt.Println("Usage: eon info <package>")
			os.Exit(1)
		}

		err := common.EstablishDBConnection(logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
			os.Exit(1)
		}

		err = common.RefreshPackageList(common.DefaultListRepositoriesInDB, common.DefaultAddRemotePackageToDB,
			common.DefaultGetFingerprintFromDB, common.DefaultAddFingerprintToDB, common.DefaultCheckRepositoryInDB,
			common.DefaultAddRepositoryToDB, common.DefaultListRemotePackagesInDB, common.DefaultRemoveRemotePackageFromDB,
			logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to refresh package list: " + err.Error()))
		}

		remoteEpks, err := common.DefaultListRemotePackagesInDB()
		if err != nil {
			fmt.Println(color.RedString("Failed to list installed packages: " + err.Error()))
			os.Exit(1)
		}

		var remoteEpk lib.RemoteEPK
		for _, epk := range remoteEpks {
			if epk.Name == os.Args[2] {
				remoteEpk = epk
				break
			}
		}

		if remoteEpk.Name == "" {
			fmt.Println(color.RedString("Package not found: " + os.Args[2]))
			os.Exit(1)
		}

		epkPreMap, err, vagueErr := lib.PreMapRemoteEPK(remoteEpk, logger)
		if err != nil || vagueErr != nil {
			common.PreMapRemoteEPKHandleError(err, vagueErr, logger)
		}

		packageUrl, err := url.JoinPath(remoteEpk.Repository.URL, remoteEpk.Path)
		if err != nil {
			fmt.Println(color.RedString("Failed to join URL: " + err.Error()))
			os.Exit(1)
		}

		metadata, err, vagueErr := lib.FullyMapMetadata(lib.StreamOrBytes{
			IsURL: true,
			URL:   packageUrl,
		}, &epkPreMap, common.DefaultGetFingerprintFromDB, common.DefaultAddFingerprintToDB, func(*lib.Logger) {
			logger.LogFunc(lib.Log{
				Level: "WARN",
				Content: "This server does not support range requests. Please use the -O flag to " +
					"enable in memory mode, or contact the server administrator to use a web server " +
					"that supports range requests, such as Apache or Nginx. The speed of download " +
					"is considerably slowed, as we need to discard bytes since we can only read " +
					"sequentially.",
				Prompt: false,
			})
		}, logger)
		if err != nil || vagueErr != nil {
			common.FullyMapMetadataHandleError(err, vagueErr, logger)
		}

		width, _, err := term.GetSize(int(os.Stdout.Fd()))
		if err != nil {
			fmt.Println(color.RedString("Failed to get terminal width: " + err.Error()))
			os.Exit(1)
		}

		if width < 11 {
			fmt.Println(color.RedString("Terminal too small. Minimum required width: 11 characters."))
			os.Exit(1)
		}

		fmt.Println()

		for range width {
			fmt.Print("=")
		}

		common.PrintWithEvenPadding("Information", width/2)
		common.PrintWithEvenPadding("Content", width/2)

		for range width {
			fmt.Print("=")
		}

		common.PrintWithEvenPadding("Name", width/2)
		common.PrintWithEvenPadding(epkPreMap.DisplayData.Name, width/2)

		common.PrintWithEvenPadding("Version", width/2)
		common.PrintWithEvenPadding(metadata.Version.String(), width/2)

		common.PrintWithEvenPadding("Description", width/2)
		common.PrintWithEvenPadding(metadata.Description, width/2)

		common.PrintWithEvenPadding("License", width/2)
		common.PrintWithEvenPadding(metadata.License, width/2)

		common.PrintWithEvenPadding("Architecture", width/2)
		common.PrintWithEvenPadding(metadata.Architecture, width/2)

		common.PrintWithEvenPadding("Installed Size", width/2)
		common.PrintWithEvenPadding(humanize.BigIBytes(metadata.DecompressedSize), width/2)

		common.PrintWithEvenPadding("Download Size", width/2)
		common.PrintWithEvenPadding(humanize.Bytes(uint64(metadata.Size)), width/2)

		common.PrintWithEvenPadding("Repository", width/2)
		common.PrintWithEvenPadding(remoteEpk.Repository.Name, width/2)

		common.PrintWithEvenPadding("Dependencies", width/2)
		if len(metadata.Dependencies) == 0 {
			common.PrintWithEvenPadding("None", width/2)
		} else {
			common.PrintWithEvenPadding(strings.Join(metadata.Dependencies, ", "), width/2)
		}

		// We don't print the long description - it's meant for GUIs.

		for range width {
			fmt.Print("=")
		}
	case "clean":
		err := common.EstablishDBConnection(logger)
		if err != nil {
			fmt.Println(color.RedString("Failed to establish a connection to the database: " + err.Error()))
			os.Exit(1)
		}

		packages, _, repositoryMap, _, err := common.DefaultListEPKsInDB()
		if err != nil {
			fmt.Println(color.RedString("Failed to list installed packages: " + err.Error()))
			os.Exit(1)
		}

		if len(packages) == 0 {
			fmt.Println("No packages to clean.")
			os.Exit(0)
		} else {
			var removeList []common.RemovePackage
			for _, pkg := range packages {
				// Check if it's a dependency of another package.
				if pkg.IsDependency {
					// Add it to list of candidates for removal.
					var removePackage common.RemovePackage
					removePackage.Name = pkg.Name
					removePackage.DisplayData = pkg
					removeList = append(removeList, removePackage)
				}
			}

			for _, pkg := range removeList {
				// Check if it's parent is still installed.
				for _, epk := range packages {
					for _, dep := range epk.Dependencies {
						if dep == pkg.Name {
							// First, check if it's in the list of packages to remove.
							var found bool
							for _, epkName := range removeList {
								if epkName.Name == epk.Name {
									found = true
									break
								}
							}
							if !found {
								fmt.Println(color.RedString("Package " + pkg.Name + " is a dependency of another package (" + epk.Name + ") and cannot be removed."))
								os.Exit(1)
							} else {
								// It is in the list of packages to remove, we need to set this package's priority higher.
								pkg.Priority++
							}
						}
					}
				}
			}

			if len(removeList) > 0 {
				// First, re-order the packageRemoveList by priority, then alphabetically.
				sort.Slice(removeList, func(i, j int) bool {
					if removeList[i].Priority == removeList[j].Priority {
						return removeList[i].Name < removeList[j].Name
					}
					return removeList[i].Priority > removeList[j].Priority
				})

				// Print the packages that will be removed.
				fmt.Println("The following packages will be removed:")
				width, _, err := term.GetSize(int(os.Stdout.Fd()))
				if err != nil {
					fmt.Println(color.RedString("Failed to get terminal width: " + err.Error()))
					os.Exit(1)
				}

				if width < 42 {
					fmt.Println(color.RedString("Terminal too small. Minimum required width: 42 characters."))
					os.Exit(1)
				}

				for range width {
					fmt.Print("=")
				}

				tableList := []string{"Package", "Architecture", "Version", "Repository", "Installed Size", "Action"}
				maxSize := width / 6
				for _, item := range tableList {
					common.PrintWithEvenPadding(item, maxSize)
				}

				fmt.Println()

				for range width {
					fmt.Print("=")
				}

				for _, pkg := range removeList {
					finalisedList := make([]string, 6)
					finalisedList[0] = pkg.Name
					finalisedList[1] = pkg.DisplayData.Architecture
					finalisedList[2] = pkg.DisplayData.Version.String()
					finalisedList[3] = repositoryMap[pkg.Name].Name
					finalisedList[4] = humanize.BigIBytes(pkg.DisplayData.DecompressedSize)
					finalisedList[5] = "Remove"
					for _, item := range finalisedList {
						common.PrintWithEvenPadding(item, maxSize)
					}
					fmt.Println()
				}

				for range width {
					fmt.Print("=")
				}

				fmt.Println("Transaction Summary")
				fmt.Println("\nRemoving " + humanize.Comma(int64(len(removeList))) + " packages.")
				space := new(big.Int)
				for _, pkg := range removeList {
					space = new(big.Int).Add(space, pkg.DisplayData.DecompressedSize)
				}
				fmt.Println("Total reclaimed space: " + humanize.BigIBytes(space) + "\n")

				response := logger.LogFunc(lib.Log{
					Level:   "INFO",
					Content: "Proceed with removal (y/n)?",
					Prompt:  true,
				})

				if strings.ToLower(response) == "y" {
					for _, pkg := range removeList {
						err, vagueErr := lib.RemoveEPK(pkg.Name, common.DefaultRemoveEPKFromDB, common.DefaultGetEPKRemoveInfoFromDB, logger)
						if err != nil || vagueErr != nil {
							common.RemoveEPKHandleError(err, vagueErr, logger)
							fmt.Println(color.RedString("Failed to remove package: " + vagueErr.Error() + err.Error()))
						}
						fmt.Println("Removed package: " + pkg.Name)
					}
				} else {
					fmt.Println("Removal cancelled.")
					os.Exit(1)
				}
			} else {
				fmt.Println("No packages to clean.")
				os.Exit(0)
			}
		}
	default:
		fmt.Println(color.RedString("Unknown or unimplemented command: " + os.Args[1]))
		os.Exit(1)
	}
}