commit 24edb0a159ffb206c207c885aab455e3afb8f02e
Author: Luka Vandervelden <lukc@upyum.com>
Date:   Thu Oct 31 21:57:58 2019 +0100

    Initial commit.

diff --git a/shard.yml b/shard.yml
new file mode 100644
index 0000000..9726238
--- /dev/null
+++ b/shard.yml
@@ -0,0 +1,14 @@
+name: package
+version: 0.1.0
+
+authors:
+  - Luka Vandervelden <lukc@upyum.com>
+
+# description: |
+#   Short description of package
+
+dependencies:
+    specparser:
+        git: https://git.karchnu.fr/WeirdOS/recipes-parser
+
+license: MIT
diff --git a/src/io.cr b/src/io.cr
new file mode 100644
index 0000000..bac30fb
--- /dev/null
+++ b/src/io.cr
@@ -0,0 +1,34 @@
+require "colorize"
+
+class Weird::Context
+	# FIXME: Use log files.
+	# FIXME: def log(), that puts stuff as-is in the logs.
+
+	def debug(text)
+		STDERR.puts ":: #{text}".colorize(:cyan)
+		STDERR.flush
+	end
+	def info(text)
+		STDOUT
+			.<<(":: ".colorize(:blue))
+			.<<(text.colorize(:white))
+			.<<("\n")
+		STDOUT.flush
+	end
+	def title(text)
+		STDOUT
+			.<<("|> ".colorize(:blue).bright)
+			.<<(text.colorize(:white).bright)
+			.<<("\n")
+		STDOUT.flush
+	end
+	def warning(text)
+		STDERR.puts ":: #{text}".colorize(:yellow)
+		STDERR.flush
+	end
+	def error(text)
+		STDERR.puts "!! #{text}".colorize(:red)
+		STDERR.flush
+	end
+end
+
diff --git a/src/package.cr b/src/package.cr
new file mode 100644
index 0000000..88ef9d7
--- /dev/null
+++ b/src/package.cr
@@ -0,0 +1,39 @@
+require "option_parser"
+
+require "./package/*"
+
+root : String? = nil
+args = [] of String
+
+OptionParser.parse do |parser|
+	parser.banner = "usage: package [options] <command> [arguments]"
+
+	parser.unknown_args do |unknown_args|
+		args = unknown_args
+	end
+end
+
+context = Package::Context.new
+
+context.root = root unless root.nil?
+
+command = args[0]
+args.shift
+
+begin
+	case command
+	when "add"
+		context.install args
+	when "remove"
+		context.remove args.map { |s| Package::Atom.from_string s }
+	end
+rescue e : Package::CollisionException
+	context.error e
+
+	e.collisions.each do |file|
+		context.error "  - #{file}"
+	end
+rescue e : Package::Exception
+	context.error e
+end
+
diff --git a/src/package/atom.cr b/src/package/atom.cr
new file mode 100644
index 0000000..169f10a
--- /dev/null
+++ b/src/package/atom.cr
@@ -0,0 +1,31 @@
+
+class Package::Atom
+	# 'name', 'name >= 3.1', 'name:slot', 'name:slot < 3.3.3.3', …
+	getter name : String
+
+	# FIXME: Group these together.
+	getter operator : String?
+	getter version : String?
+
+	getter release : Int32?
+
+	getter slot : String?
+
+	def initialize(@name, @slot = nil)
+	end
+
+	def sanitized_slot
+		slot.try &.gsub /\//, ":"
+	end
+
+	# FIXME: What if other data are provided?
+	def to_s
+		"#{name} :#{slot}"
+	end
+
+	# FIXME: Parse slot syntax, parse operators.
+	def self.from_string(s : String)
+		Atom.new s
+	end
+end
+
diff --git a/src/package/context.cr b/src/package/context.cr
new file mode 100644
index 0000000..11d30d3
--- /dev/null
+++ b/src/package/context.cr
@@ -0,0 +1,176 @@
+require "colorize"
+require "uuid"
+require "file_utils"
+
+require "../io.cr"
+
+require "./weird.cr"
+
+class Package::Context < Weird::Context
+	property root = "/"
+
+	# Stores informations about already installed packages, their
+	# manifests, and so on.
+	@database = Database.new
+
+	def initialize()
+	end
+
+	def root=(@root)
+		@database.root = "#{@root}#{Database::PATH_FROM_ROOT}"
+	end
+
+	def install(package : Package, data_directory : String)
+	end
+
+	# FIXME: Should atomic upgrades be handled here?
+	def install(files : Array(String))
+		work_dirs = Hash(String, String).new
+		manifests = Hash(String, Manifest).new
+		packages = Hash(String, Package).new
+
+		files.each do |file|
+			work_dir = get_work_directory
+			data_dir = "#{work_dir}/data"
+
+			work_dirs[file] = work_dir
+
+			Weird.extract file, work_dir, data_dir
+
+			package = Package.new "#{work_dir}/control.spec"
+			packages[file] = package
+
+			if is_installed? package.to_atom
+				raise ::Package::Exception.new "Package '#{package.to_atom.to_s}' is already installed."
+			end
+
+			Manifest.new("#{work_dir}/manifest").tap do |manifest|
+				manifest.no_collisions! self
+
+				manifests[file] = manifest
+			end
+
+			# FIXME: Check signatures (not implemented in packages ATM).
+		end
+
+
+		files.each do |file|
+			info "Installing '#{file}'"
+
+			work_dir = work_dirs[file]
+			data_dir = "#{work_dir}/data"
+
+			package = packages[file]
+			manifest = manifests[file]
+
+			manifest.each do |entry|
+				if entry.type == "directory" && Dir.exists? entry.file
+					next
+				end
+
+				debug "++ #{entry.file}"
+				entry.install data_dir, @root
+			end
+
+			@database << {package, manifest}
+
+			FileUtils.rm_r work_dir
+		end
+	end
+	def install(file : String)
+		install [file]
+	end
+	def install(atoms : Array(Atom))
+	end
+	def install(atom : Atom)
+		install [atom]
+	end
+	def upgrade(atom : Atom)
+	end
+
+	def remove(packages : Array(Package))
+		# First part of this function is about extracting
+		# reverse-dependencies. Once we have them all, we remove
+		# everything one by one.
+		all_packages = @database.get_all_packages
+		packages_to_remove = [] of Package
+		unchecked_packages = Deque(Package).new
+
+		packages.each do |package|
+			unchecked_packages << package
+		end
+
+		while unchecked_packages.size > 0
+			package = unchecked_packages.pop
+
+			packages_to_remove << package
+
+			all_packages
+				.select do |p|
+					p.dependencies.any? do |dependency|
+						# FIXME: Check full atoms and not just names.
+
+						# FIXME: Checking there’s no collision with world files is probably done around here.
+						packages_to_remove.find &.name.==(dependency)
+					end
+				end
+				.each do |p|
+					if unchecked_packages.find &.==(p)
+						next
+					end
+
+					if packages_to_remove.find &.==(p)
+						next
+					end
+
+					unchecked_packages << p
+				end
+		end
+
+		packages_to_remove.reverse.each do |package|
+			manifest = @database.get_manifest package
+
+			manifest.reverse.each do |entry|
+				if entry.type == "directory" && (!Dir.exists?(entry.file) || !Dir.empty?(entry.file))
+					next
+				end
+
+				debug "-- #{entry.file}"
+				entry.remove @root
+			end
+
+			@database.remove package
+		end
+	end
+	def remove(package : Package)
+		remove [package]
+	end
+	def remove(atoms : Array(Atom))
+		remove atoms.map { |atom| @database.get_package atom }
+	end
+	def remove(atom : Atom)
+		remove [atom]
+	end
+
+	def installed_packages : Array(Package)
+	end
+
+	def is_installed?(atom : Atom)
+		@database.is_installed? atom
+	end
+
+	def update_repository_cache
+	end
+	def download_to_cache(atom : Atom, url : String)
+	end
+
+	def database_directory
+	end
+
+	def get_work_directory
+		directory = "/tmp/package-#{UUID.random}"
+		FileUtils.mkdir_p directory
+		directory
+	end
+end
+
diff --git a/src/package/database.cr b/src/package/database.cr
new file mode 100644
index 0000000..cba6330
--- /dev/null
+++ b/src/package/database.cr
@@ -0,0 +1,78 @@
+require "file_utils"
+
+require "./package.cr"
+require "./manifest.cr"
+
+class Package::Database
+	PATH_FROM_ROOT = "/var/lib/package"
+
+	property root : String
+
+	def initialize
+		@root = Database::PATH_FROM_ROOT
+	end
+
+	def <<(tuple : Tuple(Package, Manifest))
+		package, manifest = tuple
+
+		entry_path = get_entry_path(package)
+
+		FileUtils.mkdir_p entry_path
+
+		FileUtils.cp package.file_path, "#{entry_path}/package.spec"
+		FileUtils.cp manifest.file_path, "#{entry_path}/manifest"
+	end
+
+	def remove(package : Package)
+		FileUtils.rm_r get_entry_path package.to_atom
+	end
+
+	def is_installed?(atom : Atom)
+		Dir.exists? get_entry_path(atom)
+	end
+
+	def get_package(atom : Atom)
+		if atom.slot.nil?
+			atom = Atom.new atom.name,
+				slot: get_sanitized_slots(atom.name)[0]
+		end
+
+		entry_path = get_entry_path(atom)
+
+		Package.new "#{entry_path}/package.spec"
+	end
+
+	def get_all_packages
+		packages = [] of Package
+
+		Dir.children(@root).each do |name|
+			path = "#{@root}/#{name}"
+
+			Dir.children(path).each do |slot|
+				packages << Package.new "#{path}/#{slot}/package.spec"
+			end
+		end
+
+		packages
+	end
+
+	def get_manifest(package : Package)
+		Manifest.new "#{get_entry_path(package)}/manifest"
+	end
+
+	private def get_sanitized_slots(name : String)
+		Dir.children "#{@root}/#{name}"
+	end
+
+	private def get_entry_path(package : Package)
+		get_entry_path package.to_atom
+	end
+
+	private def get_entry_path(atom : Atom)
+		name = atom.name
+		slot = atom.sanitized_slot
+
+		"#{@root}/#{name}/#{slot}"
+	end
+end
+
diff --git a/src/package/exception.cr b/src/package/exception.cr
new file mode 100644
index 0000000..60f7df5
--- /dev/null
+++ b/src/package/exception.cr
@@ -0,0 +1,4 @@
+
+class Package::Exception < Exception
+end
+
diff --git a/src/package/manifest.cr b/src/package/manifest.cr
new file mode 100644
index 0000000..f252f3c
--- /dev/null
+++ b/src/package/manifest.cr
@@ -0,0 +1,101 @@
+require "./exception.cr"
+
+class ::Package::InvalidManifest < ::Package::Exception
+	def initialize(@message)
+	end
+end
+
+class ::Package::CollisionException < ::Package::Exception
+	getter collisions
+	def initialize(@message, @collisions : Array(String))
+	end
+end
+
+# FIXME: split Entry into File, Symlink and Directory
+record Package::ManifestEntry, file : String, type : String, data : String? do
+	def install(origin_root, destination_root)
+		origin      = "#{origin_root}/#{@file}"
+		destination = "#{destination_root}/#{@file}"
+
+		destination = destination.gsub /\/\.\//, "/"
+		destination = destination.gsub /\/\/*/, "/"
+
+		case @type
+		when "directory"
+			FileUtils.mkdir destination unless Dir.exists? destination
+		when "symlink"
+			link = File.readlink origin
+			File.symlink link, destination
+		when "file", "other"
+			FileUtils.cp origin, destination
+		end
+	end
+
+	def remove(root)
+		path = "#{root}/#{@file}"
+
+		path = path.gsub /\/\.\//, "/"
+		path = path.gsub /\/\/*/, "/"
+
+		case @type
+		when "file", "symlink", "other"
+			FileUtils.rm path
+		when "directory"
+			if Dir.children(path).size == 0
+				FileUtils.rmdir path
+			end
+		end
+	end
+end
+
+class Package::Manifest < Array(Package::ManifestEntry)
+	getter file_path : String
+
+	def initialize(size : Int32, @file_path)
+		initialize size
+	end
+
+	def self.new(file_path) : self
+		lines = File.read(file_path).lines
+		instance = self.new lines.size, file_path
+
+		lines.each do |line|
+			line = line.split ':'
+
+			file, type = line
+			data = line[2]?
+
+			instance << ManifestEntry.new file, type, data
+		end
+
+		instance
+	rescue e : Errno
+		raise e
+	rescue e
+		raise InvalidManifest.new "Could not parse Manifest: invalid entries"
+	end
+
+	def list_collisions(root : String)
+		collisions = [] of ManifestEntry
+
+		each do |entry|
+			case entry.type
+			when "file", "symlink", "other"
+				if File.exists? "#{root}/#{entry.file}"
+					collisions << entry
+				end
+			end
+		end
+
+		collisions
+	end
+
+	def no_collisions!(context)
+		collisions = list_collisions context.root
+
+		if collisions.size > 0
+			raise CollisionException.new "Collisions detected.", collisions.map &.file
+		end
+	end
+end
+
diff --git a/src/package/package.cr b/src/package/package.cr
new file mode 100644
index 0000000..7141bfb
--- /dev/null
+++ b/src/package/package.cr
@@ -0,0 +1,49 @@
+require "specparser"
+
+require "./exception.cr"
+
+class Package::Package
+	getter name    : String
+	getter version : String
+	getter release : Int32
+	getter slot    : String
+
+	getter dependencies = Array(String).new
+
+	getter file_path : String
+
+	def initialize(@file_path)
+		specs = SpecParser.parse File.read file_path
+
+		name    : String? = nil
+		version : String? = nil
+		release : Int32?  = nil
+		slot    : String? = nil
+
+		specs.assignments.each do |key, value|
+			case key
+			when "name"
+				name = value.as_s
+			when "version"
+				version = value.as_s
+			when "release"
+				release = value.as_s.to_i
+			when "slot"
+				slot = value.as_s
+			when "dependencies"
+				@dependencies = value.as_a_or_s
+			end
+		end
+
+		@name    = name.not_nil!
+		@version = version.not_nil!
+		@release = release.not_nil!
+		@slot    = slot.not_nil!
+	end
+
+	def to_atom
+		Atom.new @name, slot: @slot
+	end
+end
+
+
diff --git a/src/package/weird.cr b/src/package/weird.cr
new file mode 100644
index 0000000..7743d99
--- /dev/null
+++ b/src/package/weird.cr
@@ -0,0 +1,20 @@
+require "file_utils"
+
+class Package::Weird
+	def self.extract(file, metadata_destination, data_destination)
+		FileUtils.mkdir_p "#{metadata_destination}"
+		r = Process.run "tar", ["xf", file, "-C", metadata_destination],
+			output: STDOUT, error: STDERR
+
+		raise Exception.new "Invalid package: extraction failed" unless r.success?
+
+		FileUtils.mkdir_p "#{data_destination}"
+		r = Process.run "tar", [
+			"xf", "#{metadata_destination}/data.tar.xz",
+			"-C", data_destination],
+			output: STDOUT, error: STDERR
+
+		raise Exception.new "Invalid package: data.tar.xz extraction failed" unless r.success?
+	end
+end
+