class Fanforce::AppFactory::CLI::ScaffoldingFile
  include Fanforce::AppFactory::CLI::Utils

  require 'digest'
  require 'multi_json'
  require_gem 'diffy', 'diffy'

  attr_reader :scaffold_filepath, :app

  def initialize(scaffold_filepath, app=nil)
    @scaffold_filepath = scaffold_filepath
    @app = app
    if app
      @filepath = "#{app.dir}/" + scaffold_filepath.gsub("#{Fanforce::AppFactory::CLI::Scaffolding.dir}/", '')
      @relativepath = extract_relativepath(@filepath)
    end
  end

  def create
    if File.directory?(scaffold_filepath)
      mkdir
      return nil
    end

    return update if File.exists?(filepath)

    contents = File.open(scaffold_filepath).read
    File.open(filepath, 'w') {|f| f.write(cleanse_content(contents)) }
    log "#{'Created'.format(:green,:bold)} #{relativepath}"
    return true
  end

  def update
    if File.directory?(scaffold_filepath)
      mkdir
      return nil
    end

    is_missing = is_missing?
    if !is_missing
      return if is_corrupted?
      return if is_forked?
      return if is_current_version?
    end

    content = updated_content
    File.open(filepath, 'w') {|f| f.write(content) }

    log "#{(is_missing ? 'Created' : 'Updated').format(:green,:bold)} #{relativepath}"
    return true
  end

  def status
    return @status unless @status.nil?
    if is_missing?
      @status = :missing
    elsif is_corrupted?
      @status = :corrupted
    elsif is_forked?
      @status = :forked
    elsif is_previous_version?
      @status = :previous
    elsif is_diverged?
      @status = :diverged
    elsif is_current_version?
      @status = :current
    else
      error "Unknown status for #{relativepath}"
    end
  end

  def diff_changes
    return nil if scaffold_filepath =~ /\/Routes\.rb$/
    return nil if is_missing?
    return nil if is_image_file?

    original_contents = File.open(filepath).read
    Diffy::Diff.new(original_contents, updated_content).to_s(:text)
  end

  ######################################################################################################################

  def mkdir
    Dir.mkdir(filepath) if !File.directory?(filepath)
  end

  def extension
    @extension ||= scaffold_filepath.match(/([^\/\.]+)$/)[1].to_s.downcase
  end

  def extension_type
    @extension_type ||= extension.downcase.to_sym
  end

  ######################################################################################################################

  def scaffold_type(filepath=scaffold_filepath)
    # :file, :image, :partial, :items, :json, :skipped
    @scaffold_types ||= {}
    return @scaffold_types[filepath] unless @scaffold_types[filepath].nil?
    return if !File.exists?(filepath)

    if is_image_file?
      type = :image
    elsif filepath =~ /\/.+\.json$/
      type = :json
    else
      first_line = File.open(filepath).read.split("\n").first
      if first_line
        matches = first_line.match(/\s*\S+\s*AppFactoryScaffolding\s*:\s*(FILE|PARTIAL|ITEMS|SKIPPED)/)
        type = matches[1].downcase.to_sym if matches and matches[1]
      end
    end
    raise "scaffold_type could not be read from file: #{filepath}" if !type
    raise "scaffold_type (#{type}) is unknown: #{lines.first}" if ![:file, :image, :partial, :items, :json, :skipped].include?(type)
    @scaffold_types[filepath] = type
  end

  ######################################################################################################################

  def is_missing?
    return @is_missing unless @is_missing.nil?
    @is_missing = !File.exists?(filepath)
  end

  def is_corrupted?
    return @is_corrupted unless @is_corrupted.nil?
    scaffold_type = scaffold_type(filepath)
    if !scaffold_type
      error "The first line of #{relativepath} should specify an AppFactoryScaffolding type"
    elsif scaffold_type == :json
      begin MultiJson.load(File.open(filepath).read)
      rescue Exception => e; error "Corrupted #{relativepath}: #{e.message}"; end
    elsif scaffold_type == :partial
      File.open(filepath).read.match(/^\s*\S+\s*END PARTIAL/)
    end
    @is_corrupted = false
  end

  def is_previous_version?
    return @is_previous_version unless @is_previous_version.nil?
    return @is_previous_version = false if is_current_version?

    # :file, :image, :partial, :items, :json, :skipped
    if [:file,:image,:partial].include?(scaffold_type)
      @is_previous_version = digest_exists_in_registry?(current_digest)
    elsif [:items].include?(scaffold_type)
      list_exists_in_registry?(File.open(filepath).read)
    elsif [:json].include?(scaffold_type)
      json_exists_in_registry?(File.open(filepath).read)
    elsif [:skipped].include?(scaffold_type)
      return @is_previous_version = false
    else
      raise 'unknown scaffold_type'
    end
  end

  def is_forkable?
    return @is_forkable unless @is_forkable.nil?
    @is_forkable = !(scaffold_filepath =~ /\/(Routes\.rb|config\.json|.gitignore)$/)
  end

  def is_image_file?
    return @is_image_file unless @is_image_file.nil?
    @is_image_file = scaffold_filepath =~ /\.(png|jpg|gif|ico)$/
  end

  def is_forked?
    return @is_forked unless @is_forked.nil?
    return @is_forked = true if is_image_file? and !is_current_version? and !is_previous_version?
    return @is_forked = false if !is_forkable?
    @is_forked = File.open(filepath, &:readline).include?('FORKED')
  end

  def is_diverged?
    return @is_diverged unless @is_diverged.nil?
    @is_diverged = !is_current_version?
  end

  def is_current_version?
    return @is_current unless @is_current.nil?

    # :file, :image, :partial, :items, :json, :skipped
    if [:file,:image].include?(scaffold_type)
      @is_current = (current_digest == scaffold_digest)
    elsif [:partial].include?(scaffold_type)
      @is_current = (current_digest == updated_digest)
    elsif [:items].include?(scaffold_type)
      @is_current = list_matches_latest_registry?(File.open(filepath).read)
    elsif [:json].include?(scaffold_type)
      @is_current = json_matches_latest_registry?(File.open(filepath).read)
    elsif [:skipped].include?(scaffold_type)
      @is_current = true
    else
      raise 'unknown scaffold_type'
    end
  end

  ######################################################################################################################

  def registry_filepath
    scaffold_fileparts = scaffold_filepath.split('/')
    "#{scaffold_fileparts[0...-1].join('/')}/._#{scaffold_fileparts[-1]}.registry"
  end

  def digest_exists_in_registry?(digest)
    return false if !File.exists?(registry_filepath)

    File.open(registry_filepath, 'r').each do |line|
      version, previous_digest = line.strip.split(/:\s?/)
      return true if digest == previous_digest
    end
    return false
  end

  def list_registry_rules(&block)
    return @list_registry_rules unless @list_registry_rules.nil? or block
    rules = {ADD: [], REM: [], OPT: []}
    File.open(registry_filepath).each_line do |line|
      rule_changes = MultiJson.load(line.split(':', 2)[1], symbolize_keys: true)

      rule_changes[:ADD].each do |item|
        item = item.strip
        rules[:ADD] << item unless rules[:ADD].include?(item)
        rules[:REM].delete(item)
        rules[:OPT].delete(item)
      end if rule_changes[:ADD]

      rule_changes[:REM].each do |item|
        item = item.strip
        rules[:ADD].delete(item)
        rules[:REM] << item unless rules[:REM].include?(item)
        rules[:OPT].delete(item)
      end if rule_changes[:REM]

      rule_changes[:OPT].each do |item|
        item = item.strip
        rules[:ADD].delete(item)
        rules[:REM].delete(item)
        rules[:OPT] << item unless rules[:OPT].include?(item)
      end if rule_changes[:OPT]

      block.call(rules) if block
    end
    @list_registry_rules = rules
  end

  def list_matches_latest_registry?(contents)
    raise if scaffold_type != :items
    list = []
    contents = contents.is_a?(Array) ? contents : contents.split("\n")
    contents.each do |line|
      line = line.strip
      list << line if line.present? and line !~ /^\s*#/
    end
    list_registry_rules[:ADD].each do |item|
      return false if !list.include?(item)
    end
    list_registry_rules[:REM].each do |item|
      return false if list.include?(item)
    end
    return true
  end

  def list_exists_in_registry?(contents)
    raise if scaffold_type != :items
    list = []
    contents = contents.is_a?(Array) ? contents : contents.split("\n")
    contents.each do |line|
      line = line.strip
      list << line if line.present? and line !~ /^\s*#/
    end
    list_registry_rules do |rules|
      rules[:ADD].each do |item|
        next if !list.include?(item)
      end
      rules[:REM].each do |item|
        next if list.include?(item)
      end
      return true
    end
    return false
  end

  def json_registry_rules(&block)
    return @json_registry_rules unless @json_registry_rules.nil? or block
    rules = {ADD: {}, REM: {}, OPT: {}}
    File.open(registry_filepath).each_line do |line|
      rule_changes = MultiJson.load(line.split(':', 2)[1], symbolize_keys: true)
      update_json_registry_rules(:ADD, rule_changes[:ADD], rules, '.') if rule_changes[:ADD]
      update_json_registry_rules(:REM, rule_changes[:REM], rules, '.') if rule_changes[:REM]
      update_json_registry_rules(:OPT, rule_changes[:OPT], rules, '.') if rule_changes[:OPT]
      block.call(rules) if block
    end
    @json_registry_rules = rules
  end

  def update_json_registry_rules(type, rule_changes, rules, key_path)
    rule_changes.each do |rule_key, rule_value|
      next update_json_registry_rules(type, rule_value, rules, "#{key_path}.#{rule_key}") if rule_value.is_a?(Hash)
      if type == :ADD
        json_rule(rules, :ADD, key_path, true)[rule_key] = rule_value
        (rule = json_rule rules, :REM, key_path) && rule.delete(rule_key)
        (rule = json_rule rules, :OPT, key_path) && rule.delete(rule_key)
      elsif type == :REM
        (rule = json_rule rules, :ADD, key_path) && rule.delete(rule_key)
        json_rule(rules, :REM, key_path, true)[rule_key] = rule_value
        (rule = json_rule rules, :OPT, key_path) && rule.delete(rule_key)
      elsif type == :OPT
        (rule = json_rule rules, :ADD, key_path) && rule.delete(rule_key)
        (rule = json_rule rules, :REM, key_path) && rule.delete(rule_key)
        json_rule(rules, :OPT, key_path, true)[rule_key] = rule_value
      end
    end
  end

  def json_rule(rules, type, key_path, create_hash_if_nil=false)
    rule = rules[type]
    key_path.gsub(/\.\./, '.').split('.').each do |key|
      next if key.blank?
      rule[key.to_sym] ||= {} if create_hash_if_nil
      rule = rule[key.to_sym]
    end
    rule
  end

  def json_matches_latest_registry?(json)
    hash = MultiJson.load(json, symbolize_keys: true)
    subtract_hash_from_hash!(json_registry_rules[:OPT], hash)
    return false if !hash_keys_match_hash_keys(json_registry_rules[:ADD], hash)
    return false if hash_keys_overlap_hash_keys(json_registry_rules[:REM], hash)
    return true
  end

  def json_exists_in_registry?(json)
    original_hash = MultiJson.load(json, symbolize_keys: true)
    json_registry_rules do |rules|
      hash = original_hash.clone
      subtract_hash_from_hash!(rules[:OPT], hash)
      next if !hash_keys_match_hash_keys(rules[:ADD], hash)
      next if hash_keys_overlap_hash_keys(rules[:REM], hash)
      return true
    end
    return false
  end

  def subtract_hash_from_hash!(hash_to_subtract, hash_to_retain)
    hash_to_subtract.each do |k,v|
      next subtract_hash_from_hash!(v, hash_to_retain[k]) if v.is_a?(Hash) and hash_to_retain[k].is_a?(Hash)
      hash_to_retain.delete(k) if hash_to_retain.is_a?(Hash)
    end
  end

  def hash_keys_match_hash_keys(hash1, hash2)
    hash1.each do |k,v|
      return false if !hash_keys_match_hash_keys(v, hash2[k]) if v.is_a?(Hash) and hash2[k].is_a?(Hash)
      return false if v.is_a?(Hash) and !hash2[k].is_a?(Hash)
      return false if !hash2.has_key?(k)
    end
    return true
  end

  def hash_keys_overlap_hash_keys(hash1, hash2)
    hash1.each do |k,v|
      return true if hash_keys_overlap_hash_keys(v, hash2[k]) if v.is_a?(Hash) and hash2[k].is_a?(Hash)
      return true if hash2.has_key?(k)
    end
    return false
  end

  def current_digest
    return @current_digest unless @current_digest.nil?
    if [:image,:file,:partial].include?(scaffold_type)
      @current_digest = Digest::SHA1.file(filepath).hexdigest.strip
    else
      raise "There is no digest scaffold type: #{scaffold_type}"
    end
  end

  def scaffold_digest
    return @scaffold_digest unless @scaffold_digest.nil?
    if [:image,:file].include?(scaffold_type)
      @scaffold_digest = Digest::SHA1.file(scaffold_filepath).hexdigest.strip
    elsif [:partial].include?(scaffold_type)
      @scaffold_digest = Digest::SHA1.hexdigest(extract_partial(File.open(scaffold_filepath).read, scaffold_filepath)).strip
    elsif [:items].include?(scaffold_type)
      @scaffold_digest = Digest::SHA1.hexdigest(extract_items_from_scaffold).strip
    else
      raise "There is no digest scaffold type: #{scaffold_type}"
    end
  end

  def updated_digest
    return @updated_digest unless @updated_digest.nil?
    @updated_digest = Digest::SHA1.hexdigest(updated_content).strip
  end

  def app_factory_line_for_gemfile
    line = "gem 'fanforce-app-factory'"
    return line if !config[:app_factory_gem].is_a?(Hash)

    line += ", '#{config[:app_factory_gem][:version]}'" if config[:app_factory_gem][:version].present?
    line += ", :path => '#{config[:app_factory_gem][:path]}'" if config[:app_factory_gem][:path].present?
    line += ", :git => '#{config[:app_factory_gem][:git]}'" if config[:app_factory_gem][:git].present?
    line
  end

  ######################################################################################################################

  def extract_partial(content, filepath)
    raise if scaffold_type != :partial
    partial = ''
    found_end = false
    content.lines.each do |line|
      break found_end = true if is_line_ending_partial?(line)
      partial += line
    end
    raise "END PARTIAL could not be found for #{extract_relativepath(filepath)}" if !found_end
    return partial
  end

  def extract_post_partial(content, filepath)
    raise if scaffold_type != :partial
    post_partial = ''
    found_end = false
    content.lines.each do |line|
      found_end ||= is_line_ending_partial?(line) || next
      post_partial += line
    end
    error "END PARTIAL could not be found for #{extract_relativepath(filepath)}" if !found_end
    return post_partial
  end

  def is_line_ending_partial?(line)
    return true if extension_type == :haml and line =~ /^\s*-#\s*END PARTIAL/
    return true if [:css,:scss,:js].include?(extension_type) and line =~ /^\s*\/\/\s*END PARTIAL/
    return true if [:gemfile,:rb,:gitignore,:ru,:rakefile,:coffee,:txt].include?(extension_type) and line =~ /^\s*#\s*END PARTIAL/
  end

  def updated_content
    if is_missing? or [:file,:image].include?(scaffold_type)
      File.open(scaffold_filepath).read
    elsif [:partial].include?(scaffold_type)
      scaffold_partial = extract_partial(File.open(scaffold_filepath).read, scaffold_filepath)
      current_post_partial = extract_post_partial(File.open(filepath).read, filepath)
      cleanse_content(scaffold_partial + current_post_partial)
    elsif [:items].include?(scaffold_type)
      content = ''
      items_to_add = list_registry_rules[:ADD].clone
      items_to_rem = list_registry_rules[:REM].clone
      File.open(filepath).read.lines do |line|
        item = line.strip
        content += line if !items_to_rem.include?(item)
        items_to_add.delete(item)
      end
      content += "\n" if content !~ /\n$/
      items_to_add.each do |item|
        content += "#{item}\n"
      end
      cleanse_content(content)
    elsif [:json].include?(scaffold_type)
      hash = MultiJson.load(File.open(filepath).read, symbolize_keys: true)
      json_registry_rules[:ADD].each {|k,v| hash[k] = v if !hash.has_key?(k) }
      json_registry_rules[:REM].each {|k,v| hash.delete(k) }
      cleanse_content(hash)
    end
  end

  ######################################################################################################################

  def cleanse_content(contents)
    if scaffold_filepath =~ /\/config\.json$/
      cleanup_config_json(contents)
    elsif scaffold_filepath =~ /\/Gemfile$/
      cleanup_gemfile(contents)
    else
      contents
    end
  end

  def cleanup_config_json(contents)
    hash = contents.is_a?(Hash) ? contents : MultiJson.load(contents, symbolize_keys: true)
    hash[:_id] ||= app._id
    hash[:name] ||= app._id.titleize
    hash[:description] ||= 'This is where you put a short app description.'
    hash[:fanforce_version_dependency] = config[:fanforce_version_dependency]
    hash[:created_with_app_factory_version] = Fanforce::AppFactory::VERSION
    cleaned = JSON.pretty_generate(hash)
    return cleaned
  end

  def cleanup_gemfile(contents)
    contents.gsub('gem FANFORCE-APP-FACTORY', app_factory_line_for_gemfile)
  end

  ######################################################################################################################

  def filepath
    @filepath || (raise 'app is not set' if !app)
  end

  def relativepath
    @relativepath || (raise 'app is not set' if !app)
  end

  def extract_relativepath(filepath)
    filepath.gsub("#{Fanforce::CLI::DIR}/", '')
  end

end