require 'archive/zip'
require 'front_matter_parser'
require 'jekyll'
require 'json'
require 'octopress-hooks'
require 'open-uri'
require 'rake'

require_relative 'util.rb'

module Jekyll
  class FetchRemote < Octopress::Hooks::Site
    priority :highest

    def self.download(url, dest)
      uri = URI.parse(url)
      result = File.join(dest, File.basename(uri.path))
      puts "    Downloading #{url}"
      IO.copy_stream(URI.open(url), result)
      return result
    end

    def self.copy(src, dest)
      if (tmp = Array.try_convert(src))
        tmp.each do |s|
          s = File.path(s)
          yield s, File.join(dest, File.basename(s))
        end
      else
        src = File.path(src)
        if File.directory?(dest)
          yield src, File.join(dest, File.basename(src))
        else
          yield src, File.path(dest)
        end
      end
    end

    def self.resolve_line_numbers(first, last)
      if first.nil? && last.nil?
        first = 0
        last  = -1
      elsif last.nil?
        last = first
      end
      [first.to_i, last.to_i]
    end

    def pre_read(site)
      beginning_time = Time.now
      puts "Starting plugin fetch_remote.rb..."
      site.config['fetch-remote'].each do |entry|
        puts "  Repo #{entry['repo']} (#{entry['ref']})"
        Dir.mktmpdir do |tmpdir|
          tmpfile = FetchRemote.download("#{entry['repo']}/archive/#{entry['ref']}.zip", tmpdir)
          Dir.mktmpdir do |ztmpdir|
            puts "    Extracting #{tmpfile}"
            Archive::Zip.extract(
              tmpfile,
              ztmpdir,
              :create => true
            )
            entry['paths'].each do |path|
              if File.extname(path['dest']) != ""
                if path['src'].size > 1
                  raise "Cannot use file destination #{path['dest']} with multiple sources"
                end
                FileUtils.mkdir_p File.dirname(path['dest'])
              else
                FileUtils.mkdir_p path['dest']
              end

              puts "    Copying files"

              # prepare file list to be copied
              files = FileList[]
              path['src'].each do |src|
                if "#{src}".start_with?("!")
                  files.exclude(File.join(ztmpdir, "*/"+"#{src}".delete_prefix("!")))
                else
                  files.include(File.join(ztmpdir, "*/#{src}"))
                end
              end

              files.each do |file|
                FetchRemote.copy(file, path['dest']) do |s, d|
                  s = File.realpath(s)
                  # traverse source directory
                  FileUtils::Entry_.new(s, nil, false).wrap_traverse(proc do |ent|
                    file_clean = ent.path.delete_prefix(ztmpdir).split("/").drop(2).join("/")
                    destent = FileUtils::Entry_.new(d, ent.rel, false)
                    puts "      #{file_clean} => #{destent.path}"

                    if File.file?(destent.path)
                      fmp = FrontMatterParser::Parser.parse_file(destent.path)
                      if fmp['fetch_remote'].nil?
                        raise "Local file #{destent.path} already exists"
                      end
                      line_start, line_end = FetchRemote.resolve_line_numbers(fmp['fetch_remote'].kind_of?(Hash) ? fmp['fetch_remote']['line_start'] : nil, fmp['fetch_remote'].kind_of?(Hash) ? fmp['fetch_remote']['line_end'] : nil)
                      lines = File.readlines(ent.path)[line_start..line_end]
                      File.open(destent.path, "a") { |fow| fow.puts lines.join }
                    else
                      ent.copy destent.path
                    end

                    next unless File.file?(ent.path) && File.extname(ent.path) == ".md"
                    # set edit and issue url and remote info for markdown files in site config defaults
                    edit_url = "#{entry['repo']}/edit/#{entry['default_branch']}/#{file_clean}"
                    issue_url = "#{entry['repo']}/issues/new?body=File: [#{file_clean}](#{get_docs_url}/#{destent.path.sub(/#{File.extname(destent.path)}$/, '')}/)"
                    puts "        edit_url:  #{edit_url}"
                    puts "        issue_url: #{issue_url}"
                    site.config['defaults'] << {
                      "scope" => { "path" => destent.path },
                      "values" => {
                        "edit_url" => edit_url,
                        "issue_url" => issue_url
                      },
                    }
                  end, proc do |_| end)
                end
              end
            end
          end
        end
      end

      end_time = Time.now
      puts "done in #{(end_time - beginning_time)} seconds"
    end
  end
end