module RJGit

  import 'java.io.ByteArrayInputStream'
  import 'java.io.FileInputStream'

  import 'org.eclipse.jgit.lib.Constants'
  import 'org.eclipse.jgit.api.Git'
  import 'org.eclipse.jgit.api.AddCommand'
  import 'org.eclipse.jgit.api.RmCommand'
  import 'org.eclipse.jgit.transport.UsernamePasswordCredentialsProvider'
  import 'org.eclipse.jgit.transport.RefSpec'
  import 'org.eclipse.jgit.diff.RenameDetector'
  import 'org.eclipse.jgit.diff.DiffEntry'
  import 'org.eclipse.jgit.treewalk.filter.PathFilter'
  import 'org.eclipse.jgit.api.TransportConfigCallback'
  import 'org.eclipse.jgit.transport.JschConfigSessionFactory'
  import 'org.eclipse.jgit.transport.SshTransport'
  import 'org.eclipse.jgit.revwalk.FollowFilter'
  import 'org.eclipse.jgit.revwalk.TreeRevFilter'
  
  class PatchApplyException < StandardError; end

  class RubyGit

    attr_accessor :jgit
    attr_accessor :jrepo

    RESET_MODES = ["HARD", "SOFT", "KEEP", "MERGE", "MIXED"]
    SSH_TRANSPORTS = ["ssh"]
    HTTP_TRANSPORTS = ["http", "https"]
    FILE_TRANSPORTS = ["file"]
    VALID_TRANSPORTS = SSH_TRANSPORTS + HTTP_TRANSPORTS + FILE_TRANSPORTS

    RJGit.delegate_to(Git, :@jgit)

    def initialize(repository)
      @jrepo = RJGit.repository_type(repository)
      @jgit = Git.new(@jrepo)
    end

    def logs(refs, options = {})
      logs = []
      refs.each do |ref|
        logs << log(nil, ref, options)
      end
      logs
    end

    def log(path = nil, revstring = Constants::HEAD, options = {})
      ref = jrepo.resolve(revstring)
      return [] unless ref
      jcommits = Array.new

      logs = @jgit.log
      logs.add(ref)

      if path && options[:follow]
        cfg       = Configuration.new(nil)
        cfg.add_setting('renames', true, 'diffs', nil)
        follow    = FollowFilter.create(path, cfg.jconfig.get(org.eclipse.jgit.diff.DiffConfig::KEY))
        logs.set_rev_filter(TreeRevFilter.new(RevWalk.new(jrepo), follow))
      elsif path
        logs.addPath(path)
      end

      logs.setMaxCount(options[:max_count]) if options[:max_count]
      logs.setSkip(options[:skip]) if options[:skip]

      if (options[:since] && options[:until])
        revwalk = RevWalk.new(jrepo)
        since_commit = revwalk.parseCommit(jrepo.resolve(options[:since]))
        until_commit = revwalk.parseCommit(jrepo.resolve(options[:until]))
        logs.addRange(since_commit, until_commit)
      end

      if options[:not]
        revwalk = RevWalk.new(jrepo)
        options[:not].each do |ref|
          logs.not(revwalk.parseCommit(jrepo.resolve(ref)))
        end
      end

      if options[:follow] && options[:list_renames]
        df = DiffFormatter.new(DisabledOutputStream::INSTANCE)
        df.set_repository(jrepo)
        df.set_context(0)
        df.set_path_filter(follow)
        df.set_detect_renames(true)
        prev_commit = nil
        pathname = path
      end
      
      commits = logs.call.map do |jcommit|
        if path && options[:follow] && options[:list_renames]
          entries = df.scan(jcommit, prev_commit).to_a
          pathname = entries.empty? ? pathname : entries.last.get_old_path
          prev_commit = jcommit
          TrackingCommit.new(jrepo, jcommit, pathname)
        else
          Commit.new(jrepo, jcommit)
        end
      end

      commits
    end

    def branch_list
      branch = @jgit.branch_list
      array = Array.new
      branch.call.each do |b|
        array << b.get_name
      end
      array
    end

    def commit(message, options = {})
      commit_cmd = @jgit.commit.set_message(message)
      commit_cmd.set_all(options[:all]) unless options[:all].nil?
      commit_cmd.set_amend(options[:amend]) unless options[:amend].nil?
      commit_cmd.set_author(options[:author].person_ident) unless options[:author].nil?
      commit_cmd.set_committer(options[:committer].person_ident) unless options[:committer].nil?
      commit_cmd.set_insert_change_id(options[:insert_change_id]) unless options[:insert_change_id].nil?
      options[:only_paths].each {|path| commit_cmd.set_only(path)} unless options[:only_paths].nil?
      commit_cmd.set_reflog_comment(options[:reflog_comment]) unless options[:reflog_comment].nil?
      Commit.new(jrepo, commit_cmd.call)
    end

    def clone(remote, local, options = {})
      RubyGit.clone(remote, local, options)
    end

    class RJGitSSHConfigCallback
      include TransportConfigCallback
      def initialize(options = {})
        @sshSessionFactory = Class.new(JschConfigSessionFactory) {
          def initialize(options)
            super()
            @private_key_file = options[:private_key_file]
            @private_key_passphrase = options[:private_key_passphrase]
            @username = options[:username]
            @password = options[:password]
            @known_hosts_file = options[:known_hosts_file]
          end

          def configure(host, session)
            session.setUserName(@username) if @username
            session.setPassword(@password) if @password
          end

          def createDefaultJSch(fs)
            default_j_sch = super(fs)
            if @private_key_file
              default_j_sch.removeAllIdentity()
              if @private_key_passphrase
                default_j_sch.addIdentity(@private_key_file, @private_key_passphrase)
              else
                default_j_sch.addIdentity(@private_key_file)
              end
            end
            if @known_hosts_file
              default_j_sch.setKnownHosts(@known_hosts_file)
            end

            return default_j_sch
          end
        }.new(options)
      end

      def configure(ssh_transport)
        ssh_transport.setSshSessionFactory(@sshSessionFactory)
      end
    end

    def self.set_command_transport(command, remote, options = {})
      uri = nil
      begin
        uri = URI.parse(remote) if remote
      rescue URI::InvalidURIError
      end

      if uri && (VALID_TRANSPORTS.include? uri.scheme)
        transport_protocol = uri.scheme
      end

      if (SSH_TRANSPORTS.include? transport_protocol.to_s) || (options[:transport_protocol] == :ssh) || options[:private_key_file]
        command.set_transport_config_callback(RJGitSSHConfigCallback.new(options))
      elsif (HTTP_TRANSPORTS.include? transport_protocol.to_s) || options[:username]
        command.set_credentials_provider(UsernamePasswordCredentialsProvider.new(options[:username], options[:password]))
      end
    end

    def self.clone(remote, local, options = {})
      clone_command = Git.clone_repository
      clone_command.setURI(remote)
      clone_command.set_directory(java.io.File.new(local))
      clone_command.set_bare(true) if options[:is_bare]
      if options[:branch]
        if options[:branch] == :all
          clone_command.set_clone_all_branches(true)
        else
          clone_command.set_branch(options[:branch])
        end
      end

      set_command_transport(clone_command, remote, options)
      clone_command.call
      Repo.new(local)
    end

    def add(file_pattern)
      @jgit.add.add_filepattern(file_pattern).call
    end

    def remove(file_pattern)
      @jgit.rm.add_filepattern(file_pattern).call
    end

    def merge(commit)
      merge_command = @jgit.merge
      merge_command.include(commit.jcommit)
      result = merge_command.call
      if result.get_merge_status.to_string == 'Conflicting'
        return result.get_conflicts.to_hash.keys
      else
        return result
      end
    end

    def tag(name, message = "", commit_or_revision = nil, actor = nil, force = false)
      tag_command = @jgit.tag
      tag_command.set_name(name)
      tag_command.set_force_update(force)
      tag_command.set_message(message)
      tag_command.set_object_id(RJGit.commit_type(commit_or_revision)) if commit_or_revision
      if actor
        actor = RJGit.actor_type(actor)
        tag_command.set_tagger(actor)
      end
      tag_command.call
    end

    def resolve_tag(tagref)
      begin
        walk = RevWalk.new(@jrepo)
        walk.parse_tag(tagref.get_object_id)
      rescue Java::OrgEclipseJgitErrors::IncorrectObjectTypeException
        nil
      end
    end

    def create_branch(name)
      @jgit.branch_create.setName(name).call
    end

    def delete_branch(name)
      @jgit.branch_delete.set_branch_names(name).call
    end

    def rename_branch(old_name, new_name)
      @jgit.branch_rename.set_old_name(old_name).set_new_name(new_name).call
    end

    def checkout(branch_name = "master", options = {})
      checkout_command = @jgit.checkout.set_name(branch_name)
      # call :setStartPoint directly to avoid ambiguity warning
      if options[:commit].is_a?(org.eclipse.jgit.revwalk.RevCommit)
        checkout_command.java_send :setStartPoint, [org.eclipse.jgit.revwalk.RevCommit], options[:commit]
      else
        checkout_command.java_send :setStartPoint, [java.lang.String], options[:commit]
      end
      options[:paths].each {|path| checkout_command.add_path(path)} if options[:paths]
      checkout_command.set_create_branch(true) if options[:create]
      checkout_command.set_force(true) if options[:force]
      result = {}
      begin
        checkout_command.call
        result[:success] = true
        result[:result] = @jgit.get_repository.get_full_branch
      rescue Java::OrgEclipseJgitApiErrors::CheckoutConflictException => conflict
        result[:success] = false
        result[:result] = conflict.get_conflicting_paths
      end
      result
    end

    def apply(input_stream)
      begin
        apply_result = @jgit.apply.set_patch(input_stream).call
      rescue Java::OrgEclipseJgitApiErrors::PatchApplyException
        raise RJGit::PatchApplyException
      end
      updated_files = apply_result.get_updated_files
      updated_files_parsed = []
      updated_files.each do |file|
        updated_files_parsed << file.get_absolute_path
      end
      updated_files_parsed
    end

    def apply_patch(patch_content)
      input_stream = ByteArrayInputStream.new(patch_content.to_java_bytes)
      apply(input_stream)
    end

    def apply_file(patch_file)
      input_stream = FileInputStream.new(patch_file)
      apply(input_stream)
    end

    def clean(options = {})
      clean_command = @jgit.clean
      clean_command.set_dry_run(true) if options[:dryrun]
      clean_command.set_paths(java.util.Arrays.asList(options[:paths])) if options[:paths]
      clean_command.call
    end

    def reset(ref, mode = "HARD", paths = nil)
      return nil if mode != nil && !RESET_MODES.include?(mode)
      reset_command = @jgit.reset
      if paths then
        paths.each do |path|
          reset_command.addPath(path)
        end
      end
      reset_command.setRef(ref.id)
      reset_command.setMode(org.eclipse.jgit.api.ResetCommand::ResetType.valueOf(mode)) unless mode == nil
      reset_command.call
    end

    def revert(commits)
      revert_command = @jgit.revert
      commits.each do |commit|
        revert_command.include commit.jcommit
      end
      Commit.new(jrepo, revert_command.call)
    end

    def status
      @jgit.status.call
    end

    def push_all(remote, options = {})
      push_command = @jgit.push
      push_command.set_dry_run(true) if options[:dryrun]
      push_command.set_force(true) if options[:force]
      push_command.set_remote(remote)
      push_command.set_push_all
      push_command.set_push_tags

      self.class.set_command_transport(push_command, remote, options)
      push_command.call
    end

    def push(remote = nil, refs = [], options = {})
      push_command = @jgit.push
      push_command.set_dry_run(true) if options[:dryrun]
      push_command.set_force(true) if options[:force]
      push_command.set_remote(remote) if remote
      if(refs.to_a.size > 0)
        refs.map!{|ref| RefSpec.new(ref)}
        push_command.set_ref_specs(refs)
      end
      self.class.set_command_transport(push_command, remote, options)
      push_command.call
    end

    def pull(remote = nil, remote_ref = nil, options = {})
      pull_command = @jgit.pull
      pull_command.set_dry_run(true) if options[:dryrun]
      pull_command.set_rebase(options[:rebase]) if options[:rebase]
      pull_command.set_remote(remote) if remote
      pull_command.set_remote_branch_name(remote_ref) if remote_ref
      self.class.set_command_transport(pull_command, remote, options)
      pull_command.call
    end

    def fetch(remote = nil, options = {})
      fetch_command = @jgit.fetch
      fetch_command.set_dry_run(true) if options[:dryrun]
      fetch_command.set_thin(true) if options[:thin]
      fetch_command.set_check_fetched_objects(true) if options[:check_fetched_objects]
      fetch_command.set_remove_deleted_refs(true) if options[:remove_deleted_refs]
      fetch_command.set_remote(remote) if remote
      fetch_command.set_ref_specs(options[:refspecs]) if options[:refspecs]
      self.class.set_command_transport(fetch_command, remote, options)
      fetch_command.call
    end

  end
end