#!/usr/bin/env ruby
require 'find'
require 'net/http'
require 'uri'
require 'digest/sha1'
require 'json'
require 'fileutils'

@command = ARGV[0]
@pkgName = ARGV[1]

@device = JSON.parse(File.read('./device.json'), symbolize_names: true)
@device.each do |key, elem| #symbolize also values
  @device[key] = @device[key].to_sym rescue @device[key]
end

def setPkg
  require './packages/' + @pkgName
  @pkg = Object.const_get(@pkgName.capitalize)
  puts "Found #{@pkgName}, version #{@pkg.version}"
end

def search (pkgName)
  Find.find ('packages') do |filename|
    return setPkg if filename == 'packages/' + pkgName + '.rb'
  end
  puts "package #{pkgName} not found :("
end

def download
  if @pkg.binary_url && @pkg.binary_url.has_key?(@device[:architecture])
    url = @pkg.binary_url[@device[:architecture]]
    source = false
    puts "Precompiled binary available, downloading..."
  else
    url = @pkg.source_url
    source = true
    puts "No precompiled binary available for your platform, downloading source..."
  end
  uri = URI.parse url
  filename = File.basename(uri.path)
  system('wget', '--content-disposition', url)
  abort 'Checksum mismatch, try again' unless Digest::SHA1.hexdigest( File.read("./#{filename}") ) == @pkg.binary_sha1[@device[:architecture]]
  puts "Archive downloaded"
  return {source: source, filename: filename}
end

def install
  meta = download
  if meta[:source] == true
    puts "Building from source, this may take a while..."
    @pkg.build
    puts "Installing..."
    @pkg.install
  else
    puts "Unpacking archive, this may take a while..."
    system "tar", "zxf", meta[:filename]
    puts "Installing..."
    FileUtils.mv './usr', './xd'
    FileUtils.mv './dlist', "./meta/#{@pkgName}.directorylist"
    FileUtils.mv './filelist', "./meta/#{@pkgName}.filelist"
  end
 
  #add to installed packages
  @device[:installed_packages].push(name: @pkgName, version: @pkg.version)
  File.open('./device.json', 'w') do |file|
    output = JSON.parse @device.to_json
    file.write JSON.pretty_generate(output)
  end
  puts "#{@pkgName.capitalize} installed!"
end

def remove
  File.open("./meta/#{@pkgName}.filelist").each_line do |line|
    File.unlink '.' + line.chomp
  end
  
  File.readlines("./meta/#{@pkgName}.directorylist").reverse.each do |line|
    begin
      Dir.rmdir '.' + line.chomp
    rescue => exception #swallow exception
    end
  end

  File.unlink "./meta/#{@pkgName}.filelist"
  File.unlink "./meta/#{@pkgName}.directorylist"
  
  #remove from installed packages
  @device[:installed_packages].each do |elem|
    @device[:installed_packages].delete elem if elem[:name] == @pkgName
  end
  File.open('./device.json', 'w') do |file|
    out = JSON.parse @device.to_json
    file.write JSON.pretty_generate(out)
  end
  puts "#{@pkgName.capitalize} removed!"
end

case @command
when "search"
  search @pkgName
when "download"
  search @pkgName
  download
when "install"
  search @pkgName
  install
when "remove"
  search @pkgName
  remove
when nil
  puts "Chromebrew, version 0.1"
  puts "Usage: cbrew [command] [package]"
  puts "Available commands: search, download, install, remove"
else
  puts "I have no idea how to do #{@command} :("
  puts "Available commands: search, download, install, remove"
end