So many changes. Some tests

Gemfile

@@ -10,3 +10,5 @@ gem "rake", "~> 13.0"
 gem "minitest", "~> 5.16"
 
 gem "rubocop", "~> 1.21"
+
+gem "standard", "~> 1.44"

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    picopackage (0.2.0)
+    picopackage (0.2.1)
       digest
       open-uri (~> 0.5)
       yaml (~> 0.4)
@@ -14,22 +14,27 @@ GEM
     debug (1.10.0)
       irb (~> 1.10)
       reline (>= 0.3.8)
-    digest (3.1.1)
+    digest (3.2.0)
     io-console (0.8.0)
-    irb (1.14.3)
+    irb (1.15.1)
+      pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     json (2.9.1)
     language_server-protocol (3.17.0.3)
+    lint_roller (1.1.0)
     minitest (5.25.4)
     open-uri (0.5.0)
       stringio
       time
       uri
     parallel (1.26.3)
-    parser (3.3.6.0)
+    parser (3.3.7.0)
       ast (~> 2.4.1)
       racc
+    pp (0.6.2)
+      prettyprint
+    prettyprint (0.2.0)
     psych (5.2.3)
       date
       stringio
@@ -53,7 +58,22 @@ GEM
       unicode-display_width (>= 2.4.0, < 4.0)
     rubocop-ast (1.37.0)
       parser (>= 3.3.1.0)
+    rubocop-performance (1.23.1)
+      rubocop (>= 1.48.1, < 2.0)
+      rubocop-ast (>= 1.31.1, < 2.0)
     ruby-progressbar (1.13.0)
+    standard (1.44.0)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.70.0)
+      standard-custom (~> 1.0.0)
+      standard-performance (~> 1.6)
+    standard-custom (1.0.2)
+      lint_roller (~> 1.0)
+      rubocop (~> 1.50)
+    standard-performance (1.6.0)
+      lint_roller (~> 1.1)
+      rubocop-performance (~> 1.23.0)
     stringio (3.1.2)
     time (0.4.1)
       date
@@ -73,6 +93,7 @@ DEPENDENCIES
   picopackage!
   rake (~> 13.0)
   rubocop (~> 1.21)
+  standard (~> 1.44)
 
 BUNDLED WITH
    2.6.2

README.md

@@ -1,28 +1,16 @@
 # Picopackage
 
-TODO: Delete this and the text below, and describe your gem
-
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/picopackge`. To experiment with that code, run `bin/console` for an interactive prompt.
+A command line tool for installing and managing [Picopackages](https://picopackage.org).
 
 ## Installation
 
-TODO: Replace `UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG` with your gem name right after releasing it to RubyGems.org. Please do not do it earlier due to security reasons. Alternatively, replace this section with instructions to install your gem from git if you don't plan to release to RubyGems.org.
-
-Install the gem and add to the application's Gemfile by executing:
-
 ```bash
-bundle add UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
-```
-
-If bundler is not being used to manage dependencies, install the gem by executing:
-
-```bash
-gem install UPDATE_WITH_YOUR_GEM_NAME_IMMEDIATELY_AFTER_RELEASE_TO_RUBYGEMS_ORG
+gem install picopackage
 ```
 
 ## Usage
 
-TODO: Write usage instructions here
+`picopackage install <url|filepath>`
 
 ## Development
 

Rakefile

@@ -5,8 +5,9 @@ require "minitest/test_task"
 
 Minitest::TestTask.create
 
-require "rubocop/rake_task"
+# require "rubocop/rake_task"
+# RuboCop::RakeTask.new
 
-RuboCop::RakeTask.new
+require "standard/rake"
 
-task default: %i[test rubocop]
+task default: %i[test standard]

bin/console

@@ -2,7 +2,7 @@
 # frozen_string_literal: true
 
 require "bundler/setup"
-require "picop"
+require "picopackage"
 
 # You can add fixtures and/or initialization code here to make experimenting
 # with your gem easier. You can also use a different console, if you like.

exe/ppkg

@@ -1,15 +1,15 @@
 #!/usr/bin/env ruby
 
 # Add lib directory to load path
-lib_path = File.expand_path('../lib', __dir__)
+lib_path = File.expand_path("../lib", __dir__)
 $LOAD_PATH.unshift(lib_path) unless $LOAD_PATH.include?(lib_path)
 
-require 'picopackage'
+require "picopackage"
 
 begin
   Picopackage::CLI.run(ARGV)
 rescue => e
   warn "Error: #{e.message}"
-  warn e.backtrace if ENV['DEBUG']
+  warn e.backtrace if ENV["DEBUG"]
   exit 1
 end

lib/picopackage.rb

@@ -1,16 +1,18 @@
 # frozen_string_literal: true
 
 require_relative "picopackage/version"
-require_relative "picopackage/http_fetcher"
-require_relative "picopackage/provider"
-require_relative "picopackage/source_file"
-require_relative "picopackage/scanner"
 require_relative "picopackage/fetch"
+require_relative "picopackage/provider"
+require_relative "picopackage/package"
+require_relative "picopackage/scanner"
 require_relative "picopackage/cli"
 
 module Picopackage
   class Error < StandardError; end
+
   class FileTooLargeError < StandardError; end
+
   class FetchError < StandardError; end
+
   class LocalModificationError < StandardError; end
 end

lib/picopackage/cli.rb

@@ -5,71 +5,71 @@ module Picopackage
     def self.run(argv = ARGV)
       command = argv.shift
       case command
-      when 'scan'
+      when "scan"
         options = {}
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg scan [options] DIRECTORY"
           # opts.on('-v', '--verbose', 'Run verbosely') { |v| options[:verbose] = v }
         end.parse!(argv)
 
-        dir = argv.first || '.'
+        dir = argv.first || "."
         Picopackage::Scanner.scan(dir).each { |f| puts f.file_path }
 
-      when 'digest'
+      when "init"
         OptionParser.new do |opts|
-          opts.banner = "Usage: ppkg digest FILE"
+          opts.banner = "Usage: ppkg init FILE"
         end.parse!(argv)
 
         file = argv.first
-        Picopackage::SourceFile.from_file(file).digest!
+        Picopackage::Package.from_file(file).init_metadata
 
-      when 'checksum'
+      when "checksum"
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg checksum FILE"
         end.parse!(argv)
         file = argv.first
-        puts Picopackage::SourceFile.from_file(file).checksum
+        puts Picopackage::Package.from_file(file).checksum
 
-      when 'verify'
+      when "verify"
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg sign FILE"
         end.parse!(argv)
 
         path = argv.first
-        source = SourceFile.from_file(path)
+        source = Package.from_file(path)
 
-        if source.metadata['content_checksum'].nil?
+        if source.metadata["content_checksum"].nil?
           puts "⚠️  No checksum found in #{path}"
           puts "Run 'ppkg sign #{path}' to add one"
           exit 1
         end
 
-        unless source.verify
+        unless source.verify_payload
           puts "❌ Checksum verification failed for #{path}"
-          puts "Expected: #{source.metadata['content_checksum']}"
+          puts "Expected: #{source.metadata["content_checksum"]}"
           puts "Got:      #{source.checksum}"
           exit 1
         end
 
         puts "✅ #{path} verified successfully"
 
-      when 'inspect'
+      when "inspect"
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg inspect FILE|DIRECTORY"
         end.parse!(argv)
 
         path = argv.first
-        Picopackage::SourceFile.from_file(path).inspect
+        Picopackage::Package.from_file(path).inspect_metadata
 
-      when 'fetch'
+      when "fetch"
         options = {force: false}
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg fetch [options] URI [PATH]"
-          opts.on('-f', '--force', 'Force fetch') { |f| options[:force] = f }
+          opts.on("-f", "--force", "Force fetch") { |f| options[:force] = f }
         end.parse!(argv)
 
         url = argv.shift
-        path = argv.shift || '.'  # use '.' if no path provided
+        path = argv.shift || "."  # use '.' if no path provided
 
         if url.nil?
           puts "Error: URI is required"
@@ -85,17 +85,17 @@ module Picopackage
           exit 1
         end
 
-      when 'update'
+      when "update"
         options = {force: false}
         OptionParser.new do |opts|
           opts.banner = "Usage: ppkg update [options] FILE"
-          opts.on('-f', '--force', 'Force update') { |f| options[:force] = f }
+          opts.on("-f", "--force", "Force update") { |f| options[:force] = f }
         end.parse!(argv)
 
         file = argv.first
-        source_file = SourceFile.from_file(file)
+        package = Package.from_file(file)
         begin
-          Fetch.fetch(source_file.url, File.dirname(file), force: options[:force])
+          Fetch.fetch(package.url, File.dirname(file), force: options[:force])
         rescue LocalModificationError => e
           puts "Error: #{e.message}"
         rescue => e
@@ -105,7 +105,7 @@ module Picopackage
 
       else
         puts "Unknown command: #{command}"
-        puts "Available commands: scan, sign, inspect, update"
+        puts "Available commands: fetch, update, scan, sign, inspect"
         exit 1
       end
     rescue OptionParser::InvalidOption => e
@@ -113,8 +113,28 @@ module Picopackage
       exit 1
     rescue => e
       puts "Error: #{e.message}"
-      puts e.backtrace if ENV['DEBUG']
+      puts e.backtrace if ENV["DEBUG"]
       exit 1
     end
+
+    def self.determine_script_source
+      # Get the full path of the currently executing script
+      current_path = File.expand_path($0)
+
+      # Check if script is in GEM_PATH
+      gem_paths = Gem.path.map { |p| File.expand_path(p) }
+
+      is_gem = gem_paths.any? { |path| current_path.start_with?(path) }
+
+      if is_gem
+        # Running from gem installation
+        gem_name = File.basename(File.dirname(File.dirname(current_path)))
+        version = File.basename(File.dirname(current_path))
+        {source: :gem, path: current_path, gem_name: gem_name, version: version}
+      else
+        # Running from local installation
+        {source: :local, path: current_path}
+      end
+    end
   end
 end

lib/picopackage/fetch.rb

@@ -1,104 +1,167 @@
-require 'net/http'
-require 'fileutils'
-require 'tempfile'
-require 'json'
-require 'debug'
+require "net/http"
+require "fileutils"
+require "tempfile"
+require "json"
+require "debug"
 
 module Picopackage
   class Fetch
+    class Error < StandardError; end
+    class HTTPError < Error; end
+    class FileTooLargeError < Error; end
+    class NotModifiedError < Error; end  # Add this
+    class TooManyRedirectsError < Error; end  # Add this
+
+    MAX_REDIRECTS = 5 # This constant is used but not defined
+
+    def initialize(max_size: 1024 * 1024, timeout: 10)
+      @max_size = max_size
+      @timeout = timeout
+    end
+
+    def fetch(uri)
+      case uri.scheme
+      when "http", "https" then fetch_http(uri)
+      when "file" then fetch_file(uri)
+      else
+        raise Error, "Unsupported scheme: #{uri.scheme}"
+      end
+    end
+
     def self.fetch(url, destination, force: false)
       raise ArgumentError, "Destination directory does not exist: #{destination}" unless Dir.exist?(destination)
-
       provider = Provider.for(url)
-      source_file = provider.source_file
+      package = provider.package
+      file_path = File.join(destination, package.filename)
 
-      file_path = File.join(destination, source_file.filename)
+      local_package = File.exist?(file_path) ? FileProvider.new(file_path).package : nil
 
-      if File.exist?(file_path) && force
-        source_file.save(destination)
-      elsif File.exist?(file_path)
-        local_source_file = SourceFile.from_file(file_path)
-        status = Status.compare(local_source_file, source_file)
+      resolver = Resolver.new(package, local_package, file_path, force: force).resolve
 
-        if force
-          source_file.save(destination)
-        elsif status.modified?
-          raise LocalModificationError, "#{status.message}. Use -f or --force to overwrite local version"
-        elsif status.outdated?
-          puts "Updated from #{local_source_file.version} to #{source_file.version}"
-          source_file.save(destination)
-        elsif status.up_to_date?
-          puts status.message
+      case resolver[:state]
+      when :kept, :updated
+        puts resolver[:message]
+      when :conflict
+        raise LocalModificationError, resolver[:message]
+      end
+      provider.package
     end
 
+    private
+
+    def fetch_http(uri, etag = nil)
+      Net::HTTP.start(uri.host, uri.port, connection_options(uri)) do |http|
+        request = Net::HTTP::Get.new(uri.request_uri)
+        request["If-None-Match"] = etag if etag
+
+        response = http.request(request)
+        handle_response(response, uri)
+      end
+    end
+
+    def fetch_file(uri)
+      File.read(uri.path)
+    end
+
+    def connection_options(uri)
+      {
+        use_ssl: uri.scheme == "https",
+        read_timeout: @timeout,
+        open_timeout: @timeout
+      }
+    end
+
+    def handle_response(response, uri)
+      case response
+      when Net::HTTPSuccess
+        {
+          body: read_body(response),
+          etag: response["ETag"]
+        }
+      when Net::HTTPNotModified
+        raise NotModifiedError.new("Resource not modified", etag: response["ETag"])
+      when Net::HTTPRedirection
+        handle_redirect(response, uri)
       else
-        source_file.save(destination)
-        if source_file.imported?
-          source_file.digest!
-          puts "Picopackage created for #{source_file.filename}"
+        raise HTTPError, "HTTP #{response.code}: #{response.message}"
+      end
+    end
+
+    def handle_redirect(response, uri, redirect_count = 0)
+      raise TooManyRedirectsError if redirect_count >= MAX_REDIRECTS
+      location = response["location"]
+      new_uri = URI(location)
+      # Handle both relative paths and full URLs
+      new_uri = uri.merge(location) if new_uri.relative?
+      fetch(new_uri, redirect_count: redirect_count + 1)
+    end
+
+    def read_body(response)
+      buffer = String.new(capacity: @max_size)
+      response.read_body do |chunk|
+        raise FileTooLargeError, "Response would exceed #{@max_size} bytes" if buffer.bytesize + chunk.bytesize > @max_size
+        buffer << chunk
+      end
+      buffer
+    end
+  end
+
+  ##
+  # States:
+  # - kept: local file was converted to a picopackage and kept
+  # - updated: local file was updated with remote picopackage
+  # - conflict: local and remote files differ - manually resolve or use -f to force
+  class Resolver
+    attr_reader :remote, :local, :local_path, :force
+    def initialize(remote_package, local_package, local_path, force: false)
+      @remote = remote_package
+      @local = local_package
+      @local_path = local_path
+      @force = force
+      @same_checksum = @remote.payload_checksum == @local&.payload_checksum
+    end
+
+    STATES = %i[kept updated conflict].freeze
+
+    def resolve
+      validate_state_hash(
+        if @force
+          @remote.save(local_path)
+          {state: :updated, message: "Force mode: overwrote local file with remote package"}
+        elsif @local.nil?
+          @remote.save(local_path)
+          {state: :kept, message: "Saved Package as new file"}
+        elsif @remote.payload_version != @local.payload_version
+          {state: :conflict, message: "Version conflict. Local: #{@local.payload_version}, Remote: #{@remote.payload_version}"}
+        elsif @remote.payload_timestamp_as_time > @local.payload_timestamp_as_time
+          @remote.save(local_path)
+          {state: :updated, message: "Updated to newer version"}
+        elsif !@same_checksum
+          handle_checksum_mismatch
+        elsif @local.was_bare_file
+          debugger
+          @local.save(local_path)
+          {state: :kept, message: "Packaged existing file as Picopackage"}
         else
-          puts "Picopackage downloaded to #{file_path}"
+          {state: :kept, message: "Local file is up to date"}
         end
-      end
-      provider.source_file
-    end
-  end
-
-  class Status
-    attr_reader :state, :local_version, :remote_version
-
-    def self.compare(local_source_file, remote_source_file)
-      return new(:outdated) if local_source_file.metadata.nil? || remote_source_file.metadata.nil?
-
-      local_version = local_source_file.metadata["version"]
-      remote_version = remote_source_file.metadata["version"]
-
-      if local_version == remote_version
-        if local_source_file.modified?
-          new(:modified, local_version:)
-        else
-          new(:up_to_date, local_version:)
-        end
-      else
-        new(:outdated, 
-          local_version:, 
-          remote_version:,
-          modified: local_source_file.modified?
       )
     end
+
+    private
+
+    def validate_state_hash(hash)
+      raise "Invalid state" unless STATES.include?(hash[:state])
+      raise "Missing message" unless hash[:message].is_a?(String)
+      hash
     end
 
-    def initialize(state, local_version: nil, remote_version: nil, modified: false)
-      @state = state
-      @local_version = local_version
-      @remote_version = remote_version
-      @modified = modified
-    end
-
-    def modified?
-      @modified || @state == :modified
-    end
-
-    def up_to_date?
-      @state == :up_to_date
-    end
-
-    def outdated?
-      @state == :outdated
-    end
-
-    def message
-      case state
-      when :up_to_date
-        "Picopackage is up to date"
-      when :outdated
-        if modified?
-          "Local Picopackage (v#{local_version}) has modifications but remote version (v#{remote_version}) is available"
+    def handle_checksum_mismatch
+      if @force
+        @remote.save(local_path)  # In force mode, remote wins
+        {state: :updated, message: "Overwrote local file with remote package"}
       else
-          "Local Picopackage (v#{local_version}) is outdated. Remote version: v#{remote_version}"
-        end
-      when :modified
-        "Local Picopackage has been modified from original version (v#{local_version})"
+        {state: :conflict, message: "Files differ. Use --force to convert both to packages"}
       end
     end
   end

lib/picopackage/package.rb

@@ -0,0 +1,128 @@
+require "yaml"
+require "digest"
+require "forwardable"
+
+module Picopackage
+  METADATA_PATTERN = /^\n*#\s*@PICOPACKAGE_START\n(.*?)^\s*#\s*@PICOPACKAGE_END\s*$/m
+
+  class Metadata < Struct.new(:url, :filename, :payload_version, :payload_timestamp, :payload_checksum, :etag, keyword_init: true)
+    # the #from_file method will create a new instance of Metadata from a file path, rather than read a package's metadata
+    def self.from_file(file_path, content: nil)
+      new(content: File.read(file_path))
+    end
+
+    def self.from_url_response(url, response)
+    end
+
+    def self.from_content(content)
+      return new unless content =~ METADATA_PATTERN
+
+      yaml_content = $1.each_line.map { |line| line.sub(/^\s*#\s?/, "").rstrip }.join("\n")
+
+      # Load and transform in one chain
+      @metadata = new(**YAML.safe_load(yaml_content)
+                                    .slice(*Metadata.members.map(&:to_s))
+                                    .transform_keys(&:to_sym))
+    rescue
+      new # Return empty hash on any YAML/transformation errors
+    end
+
+    def empty? = to_h.values.all?(&:nil?)
+  end
+
+  class Payload
+    def self.from_content(content) = content.sub(METADATA_PATTERN, "")
+
+    def self.normalize(payload) = payload.rstrip + "\n\n"
+
+    def self.normalized_from_content(content) = Payload.from_content(content).then { Payload.normalize(_1) }
+
+    def self.from_file(file_path) = normalized_from_content(File.read(file_path))
+
+    def self.checksum(payload) = "sha256:#{Digest::SHA256.hexdigest(payload)}"
+
+    def self.checksum_from_content(content) = checksum(from_content(content))
+  end
+
+  class Package
+    extend Forwardable
+    attr_reader :content, :payload, :metadata, :was_bare_file
+
+    def_delegators :@metadata,
+      :url, :url=,
+      :filename, :filename=,
+      :payload_version, :payload_version=,
+      :payload_timestamp, :payload_timestamp=,
+      :payload_checksum, :payload_checksum=
+
+    def self.from_file(file_path)
+      if File.exist?(file_path)
+        new(content: File.read(file_path))
+      end
+    end
+
+    def initialize(content:)
+      @content = content
+      @payload = Payload.normalized_from_content(@content)
+      @metadata = Metadata.from_content(@content)
+
+      if is_bare_file?
+        @was_bare_file = true
+        init_metadata
+      else
+        @was_bare_file = false
+      end
+    end
+
+    def is_bare_file? = @metadata.empty?
+
+    def init_metadata
+      @metadata.url ||= url
+      @metadata.filename ||= filename
+      @metadata.payload_checksum ||= Payload.checksum_from_content(content)
+      @metadata.payload_timestamp ||= payload_timestamp
+    end
+
+    def save(path, filename = nil)
+      path = File.join(path, filename || @metadata.filename) if File.directory?(path)
+
+      File.write(path, generate_package)
+    end
+
+    def verify_payload
+      return false if metadata.payload_checksum.nil? || metadata.payload_checksum&.empty?
+      Payload.checksum(payload) == metadata.payload_checksum
+    end
+
+    def payload_timestamp_as_time
+      @metadata&.payload_timestamp ? Time.parse(@metadata.payload_timestamp) : nil
+    end
+
+    def modified? = !verify_payload
+
+    def inspect_metadata = puts JSON.pretty_generate(@metadata.to_h)
+
+    private
+
+    def generate_package
+      @metadata.url = url.to_s
+      metadata_block = generate_metadata
+      if METADATA_PATTERN.match?(content)
+        content.sub(METADATA_PATTERN, "\n#{metadata_block}")
+      else
+        [content.rstrip, "\n#{metadata_block}"].join("\n")
+      end
+    end
+
+    # This will need a comment style one day, to work with other languages
+    def generate_metadata
+      yaml_content = @metadata.to_h.transform_keys(&:to_s).to_yaml.strip
+      [
+        "# @PICOPACKAGE_START",
+        yaml_content.lines.map { |line| "# #{line}" }.join,
+        "# @PICOPACKAGE_END",
+        ""
+      ].join("\n")
+    end
+  end
+end

lib/picopackage/provider.rb

@@ -1,3 +1,6 @@
+require "time"
+require "pathname"
+
 module Picopackage
   class Provider
     def self.for(url)
@@ -17,94 +20,119 @@ module Picopackage
   end
 
   # Base class for fetching content from a URL
-  # The variable `body` will contain the content retrieved from the URL
-  # The variable `content` will contain both and code + metadata - this would be writen to a file.
-  # The variable `code` will contain the code extracted from `content`
-  # The variable `metadata` will contain the metadata extracted from `content`
+  # The variable `body` will contain the package_data retrieved from the URL
+  # The variable `package_data` will contain both and payload + metadata - this would be writen to a file.
+  # The variable `payload` will contain the payload extracted from `package_data`
+  # The variable `metadata` will contain the metadata extracted from `package_data`
 
-  # Job of the Provider class is to fetch the body from the URL, and then extract the content and the filename from the body
-  # The SourceFile class will then take the body and split it into code and metadata
+  # Job of the Provider class is to fetch the body from the URL, and then extract the package_data
+  # and the filename from the body. The Package class will then take the body and split it into payload and metadata
 
   class DefaultProvider
     MAX_SIZE = 1024 * 1024
     TIMEOUT = 10
-    attr_reader :url, :source_file
+    attr_reader :url, :package
 
     def self.handles_url?(url) = :maybe
 
-    def initialize(url)
+    def initialize(url, fetcher: Fetch.new(max_size: MAX_SIZE, timeout: TIMEOUT))
       @url = transform_url(url)
-      @uri = URI(@url)
-      @body = nil
-      @content = nil
+      @fetcher = fetcher
+      @package = Package.new(content: content)
+      populate_metadata
     end
 
-    def body = @body ||= fetch
-    def json_body = @json_body ||= JSON.parse(body)
-    def transform_url(url) = url
+    def transform_url(url) = URI(url)
 
-    def fetch
-      begin
-        Net::HTTP.start(@uri.host, @uri.port, use_ssl: @uri.scheme == 'https', read_timeout: TIMEOUT, open_timeout: TIMEOUT) do |http|
-          http.request_get(@uri.path) do |response|
-            raise "Unexpected response: #{response.code}" unless response.is_a?(Net::HTTPSuccess)
+    def body
+      @body ||= @fetcher.fetch(@url)
+    rescue Fetch::Error => e
+      raise FetchError, e.message
+    end
 
-            @body = String.new(capacity: MAX_SIZE)
-            response.read_body do |chunk|
-              if @body.bytesize + chunk.bytesize > MAX_SIZE
-                raise FileTooLargeError, "Response would exceed #{MAX_SIZE} bytes"
-              end
-              @body << chunk
-            end
-            @body
-          end
-        end
-      end
-      @body
+    def json_body
+      @json_body ||= JSON.parse(body)
+    rescue JSON::ParserError
+      raise FetchError, "Failed to parse JSON response"
     end
 
+    def payload_timestamp = Time.now.httpdate
+
     def handles_body?
       true
-    rescue FileTooLargeError, Net::HTTPError, RuntimeError => e
+    rescue FileTooLargeError, Net::HTTPError, RuntimeError
       false
     end
 
     # Implement in subclass - this come from the `body`.
-    # Spliting content into code and metadata is the job of the SourceFile class
+    # Spliting content into payload and metadata is the job of the Package class
     def content = body
 
     # Implement in subclass - this should return the filename extracted from the body - if it exists, but not from the metadata
     def filename = File.basename @url
 
-    def source_file
-      @source_file ||= SourceFile.from_content(content, metadata: {'filename' => filename, 'url' => url, 'version' => '0.0.1'})
+    def populate_metadata
+      @package.filename ||= filename
+      @package.url ||= @url
+      @package.payload_timestamp ||= payload_timestamp
+      @package.payload_checksum ||= Payload.checksum(content)
     end
   end
 
   class GithubGistProvider < DefaultProvider
     def self.handles_url?(url) = url.match?(%r{gist\.github\.com})
+
     def content = json_body["files"].values.first["content"]
+
     def filename = json_body["files"].values.first["filename"]
+
     def transform_url(url)
       gist_id = url[/gist\.github\.com\/[^\/]+\/([a-f0-9]+)/, 1]
       "https://api.github.com/gists/#{gist_id}"
     end
+
+    def payload_timestamp
+      Time.parse(json_body["created_at"])
+    rescue ArgumentError
+      nil
+    end
   end
 
   class OpenGistProvider < DefaultProvider
     def handles_url?(url) = :maybe
+
     def transform_url(url) = "#{url}.json"
+
     def content = json_body.dig("files", 0, "content")
+
     def filename = json_body.dig("files", 0, "filename")
+
     def handles_body?
       content && filename
-    rescue FileTooLargeError, Net::HTTPError, RuntimeError => e
+    rescue FileTooLargeError, Net::HTTPError, RuntimeError
       false
     end
     # If we successfully fetch the body, and the body contains content and a filename, then we can handle the body
   end
 
+  class FileProvider < DefaultProvider
+    def self.handles_url?(url) = File.exist?(url)
+
+    def transform_url(url) = Pathname(url)
+
+    def content = url.read
+
+    def filename = url.basename.to_s
+
+    def payload_timestamp
+      url.mtime.httpdate
+    rescue Errno::ENOENT
+      nil
+    end
+  end
+
   PROVIDERS = [
+    FileProvider,
     GithubGistProvider,
     OpenGistProvider,
     DefaultProvider

lib/picopackage/scanner.rb

@@ -4,8 +4,8 @@ module Picopackage
       Dir.glob(File.join(directory, pattern)).select do |file|
         next unless File.file?(file)
         content = File.read(file)
-        content.match?(SourceFile::METADATA_PATTERN)
-      end.map { |file| SourceFile.new(file) }
+        content.match?(Package::METADATA_PATTERN)
+      end.map { |file| Package.new(file) }
     end
   end
 end

lib/picopackage/source_file.rb

@@ -1,120 +0,0 @@
-require "yaml"
-require "digest"
-
-module Picopackage
-  class SourceFile
-    attr_reader :content, :metadata, :code, :original_path
-
-    METADATA_PATTERN = /^\n*#\s*@PICOPACKAGE_START\n(.*?)^\s*#\s*@PICOPACKAGE_END\s*$/m
-
-    def self.from_file(file_path) = new(content: File.read(file_path), original_path: file_path)
-  
-    def self.from_content(content, metadata: {})
-      instance = new(content: content)
-      instance.imported! if instance.metadata.empty?
-
-      updated_metadata = metadata.merge(instance.metadata)
-
-      ## For new Picopackages, we should add metadata and checksum
-      instance.update_metadata(updated_metadata)
-
-      instance
-    end
-
-    def initialize(content:, original_path: nil)
-      @original_path = original_path
-
-      @content = content
-      @metadata = extract_metadata
-      @code = extract_code
-    end
-
-    def imported! = @imported = true
-
-    def imported? = @imported ||= false
-
-    def content = @content
-    
-    def url = @metadata['url']
-
-    def filename = @metadata['filename']
-
-    def version = @metadata['version'] || '0.0.1'
-
-    def checksum = "sha256:#{Digest::SHA256.hexdigest(code)}"
-
-    def inspect_metadata = puts JSON.pretty_generate(@metadata)
-
-    def save(destination = nil)
-      path = determine_save_path(destination)
-      File.write(path, content)
-      path
-    end
-
-    def extract_code = content.sub(METADATA_PATTERN, '')
-
-    def extract_metadata
-      return {} unless content =~ METADATA_PATTERN
-  
-      yaml_content = $1.lines.map do |line|
-        line.sub(/^\s*#\s?/, '').rstrip
-      end.join("\n")
-  
-      YAML.safe_load(yaml_content)
-    end
-
-    def update_metadata(metadata_hash)
-      @metadata = metadata_hash
-      @content = generate_content
-    end
-    
-    def digest!
-      hash = checksum
-      return puts "File already has a checksum" if metadata['content_checksum'] == hash
-  
-      new_metadata = metadata.merge('content_checksum' => hash)
-      update_metadata(new_metadata)
-      save
-    end
-
-    def verify
-      return false unless metadata.key? 'content_checksum'
-      checksum == metadata['content_checksum']
-    end
-
-    def modified? = !verify
-
-    private
-
-    def generate_content
-      metadata_block = generate_metadata
-      if content =~ METADATA_PATTERN
-        content.sub(METADATA_PATTERN, "\n#{metadata_block}")
-      else
-        [content.rstrip, "\n#{metadata_block}"].join("\n")
-      end
-    end
-    
-    # This will need a comment style one day, to work with other languages
-    def generate_metadata
-      yaml_content = @metadata.to_yaml.strip
-      [
-        "# @PICOPACKAGE_START",
-        yaml_content.lines.map { |line| "# #{line}" }.join,
-        "# @PICOPACKAGE_END",
-        ""
-      ].join("\n")
-    end
-
-    def determine_save_path(destination)
-      if destination.nil?
-        @original_path || filename || raise("No filename available")
-      elsif File.directory?(destination)
-        File.join(destination, filename || File.basename(@original_path))
-      else
-        destination
-      end
-    end
-
-  end
-end

lib/picopackage/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Picopackage
-  VERSION = "0.2.0"
+  VERSION = "0.2.1"
 end

notes.md

@@ -0,0 +1,25 @@
+## Package Installation Flow
+
+1. **Fetch URL**
+   └─> Download content
+   └─> Build Package Instance (Metadata & Payload)
+   └─> Check local file status
+
+2. **Local File Check**
+   ├─> If file doesn't exist:
+   │   └─> Save file
+   │
+   └─> If file exists:
+       └─> Compare versions
+           ├─> If older/same:
+           │   └─> "Package already installed"
+           │
+           └─> If newer:
+               └─> Check local modifications
+                   ├─> If modified:
+                   │   └─> "Local modifications detected"
+                   │   └─> "Use 'update <file_path>'"
+                   │
+                   └─> If unmodified:
+                       └─> "Update available"
+                       └─> "Use 'update <file_path> -f' to force update"

picopackage.gemspec

@@ -37,6 +37,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "yaml", "~> 0.4"
   spec.add_dependency "digest"
   spec.add_development_dependency "debug"
+  spec.add_development_dependency "standard"
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html

test/test_picopackage.rb

@@ -7,7 +7,13 @@ class TestPicopackage < Minitest::Test
     refute_nil ::Picopackage::VERSION
   end
 
-  def test_it_does_something_useful
-    assert false
+  def test_it_can_load_a_picopackage_file
+    sf = Picopackage::FileProvider.new(File.read("test/files/uniquify_array_packaged.rb"))
+    assert_equal "uniquify_array_packaged.rb", sf.metadata.filename
+  end
+
+  def test_it_can_create_a_picopackage_from_bare_file
+    sf = Picopackage::FileProvider.new(File.read("test/files/uniquify_array_bare.rb"))
+    assert_equal "uniquify_array_bare.rb", sf.metadata.filename
   end
 end