#--
# rbmh/context.rb : rbmhshow 0.4.2
#
# Copyright (C) 2004--2005  Merlin Hughes  <ruby AT merlin DOT org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#++
# RBMH context

require 'rmail/parser'
require 'rbmh/handler'
require 'rbmh/rmail'
require 'rbmh/pager'
require 'rbmh/prompter'
require 'rbmh/shower'
require 'rbmh/suffixes'

class MyStreamHandler < RMail::Parser::Handler
  def initialize(prefix, context)
    super()
    @prefix = prefix
    @context = context
  end

  attr_reader :prefix

  def preprocess_part
    @parts.last.context = @context
    @parts.last.parent = @parts[@parts.length - 2] if @parts.length > 1
# for headers during parse...
#   if count == 1
#     emit_headers(part)
#   end
  end

  def body_begin
    preprocess_part
# streaming toc
#   puts RBMH::ANSI.color("white") + section + RBMH::ANSI.color("bold") + name + RBMH::ANSI.uncolor + " (" + type + ")"
    super
  end

  def multipart_body_begin
    preprocess_part
# streaming toc
#   puts RBMH::ANSI.color("white") + section + RBMH::ANSI.uncolor + type
    if @parts.last.header.content_type == "multipart/signed"
      @parts.last.raw = RBMH::Parser::capture_raw
    end
    super
  end
end # class MyStreamHandler

# TODO: make parse a method of @parser

module RBMH
  class Exception < Exception
  end # class Exception

  class Context
    def initialize
      @profile = RBMH::Profile.new(self)
      @pager = RBMH::Pager.new(self)
      @prompter = RBMH::Prompter.new(self)
      @suffixes = RBMH::MimeSuffixes.new(self)
      @shower = RBMH::Shower.new(self)
      @handlers = RBMH::Handlers.new(self)
      @folder = @message = @range_str = @range = @range_index = nil
      @color_name = RBMH::ANSI.color(*(@profile['rbmh-color-name'] or '').split(' '))
      @color_error = RBMH::ANSI.color(*(@profile['rbmh-color-error'] or '').split(' '))
      @uncolor = RBMH::ANSI.uncolor
      @no_scissors = false # awful hack to suppress leading scissors
    end

    attr_reader :profile, :pager, :prompter, :suffixes, :handlers, :shower
    attr_reader :folder, :message, :range_str
    attr_accessor :no_scissors

    # sets $FOLDER and $MESSAGE; updates cur, folder, unseen; parses msg
    def cur()
      ENV['FOLDER'] = @folder
      ENV['MESSAGE'] = @message
      filename = profile.mhpath(@folder, @message)
      raise RBMH::Exception, "message #{@message} does not exist in folder #{@folder}" unless FileTest.file?(filename)
      # TODO: Don't redisplay for same message
      puts "(Message #{@color_name}#{@folder}:#{@message}#{@uncolor})"
      STDOUT.flush ; STDERR.flush
      fork { # mark message as seen and set current in child process
        system "mark #{@message} +#{@folder} -sequence #{profile.unseen_sequence} -delete </dev/null >/dev/null 2>&1" if profile.unseen_sequence
        exec "folder #{@message} +#{@folder} -nocreate -fast </dev/null >/dev/null 2>&1"
      }
      parse(filename)
    end

    def show(what)
      if @message.nil? || what !~ /^(first|prev|cur|next|last)$/
        # TODO: show unseen:first shows range unseen with index -> first
        folder = nil
        messages = ''
        what.split.each { |str|
          if str =~ FolderRE
            raise RBMH::Exception, "multiple folders in #{what}" if folder
            folder = $1
          else
            messages << (messages.empty? ? '' : ' ') << str
          end
        }
        folder = `folder -fast </dev/null 2>/dev/null`.chomp if folder.nil?
        messages = 'cur' if messages.empty?
        range = `pick #{messages} +#{folder} </dev/null 2>/dev/null`.split
        # TODO: utility fn that captures `` stderr so I can raise it s/pick: //
        raise RBMH::Exception, "pick #{messages} failed" if $?.exitstatus != 0
        @folder = folder
        @message = range[0]
        if messages =~ SingleMessageRE
          @range = @range_index = @range_str = nil
        else
          @range = range; @range_index = 0; @range_str = messages
        end
      elsif @range.nil?
        # hack to reset cur so next/prev will work; will fail after rmm
        # but is only needed if another session changes cur so okay..
        # race condition but wtf..
        system "folder #{@message} +#{@folder} -nocreate -fast </dev/null >/dev/null 2>&1" if @message && @folder
        message = `pick #{what} </dev/null 2>/dev/null`.chomp
        raise RBMH::Exception, "no #{what}" if $?.exitstatus != 0
        @message = message
      else
        delta = (what =~ /^(next|first)$/) ? 1 : (what == 'cur') ? 0 : -1
        index = (what == 'first') ? -1 : (what == 'last') ? @range.length : @range_index
        loop do
          index = index + delta
          # if you reach the end of unseen, merge in any new ones.
          if (what == 'next') && (index >= @range.length) && profile.unseen_sequence && profile.unseen_sequence[@range_str] # TODO: match on word boundaries..
            # backtrack to after previous extant message
            while (index > 0) && !FileTest.file?(profile.mhpath(@folder, @range[index - 1]))
              index = index - 1
            end
            # merge in new unread messages; ignore errors (if no unseen)
            messages = `pick #{@range_str} +#{@folder} </dev/null 2>/dev/null`.split
            @range[index .. -1] = messages
            # nmh message sequences are always sorted
            @range.sort!.uniq!
            # will mess up if new unseen are added early, but wtf
          end
          indices = 0 ... @range.length
          break if indices.include?(index) && FileTest.file?(profile.mhpath(@folder, @range[index]))
          raise RBMH::Exception, "no #{what} in sequence" if !indices.include?(index) || (delta == 0)
        end
        @range_index = index
        @message = @range[index]
      end
    end

    def parse(source, prefix = "", mime = false)
      handler = MyStreamHandler.new(prefix, self)
      if source.is_a?(String)
        raise RBMH::Exception, "not a file - #{source}" unless FileTest.file?(source)
        raise RBMH::Exception, "not readable - #{source}" unless FileTest.readable?(source)
        File.open(source) { |file|
          parser = RMail::StreamParser.new(file, handler)
          mime ? parser.parse_mime : parser.parse
        }
        handler.message.path = source
      else
        parser = RMail::StreamParser.new(source, handler)
        mime ? parser.parse_mime : parser.parse
      end
      handler.message
    end

    def error(str, delay = 0.3)
      puts "#{@color_error}rbmhshow:#{@uncolor} #{str}"
      sleep(delay) if delay > 0
    end

    FolderRE = /^\+(.+)$/ # should be alpha(alnum*)
    SingleMessageRE = /^(\d+|cur|(\S+:)?(first|last|next|prev))$/ # 1 | cur | unseen:first
  end # class Context
end # module RBMH