#!/usr/bin/ruby

require 'yaml'
require 'time'
require 'singleton'

class Filter
  include Singleton
  @config = {}
  @cleanup = []

  attr_accessor :config, :cleanup
  
  def initialize
    @config = {}
    @cleanup = []
  end

  def cleanup
    @cleanup.each do |f| 
      if File.exists? f; File.unlink(f); end
    end
  end

  def recalc_pixels
    if @config['print']
      if @config['width_inches'] && @config['width_inches'] != 0
        @config['width'] = @config['width_inches'].to_i * @config['dpi'].to_i
      end
      if @config['height_inches'] && @config['height_inches'] != 0
        @config['height'] = @config['height_inches'].to_i * @config['dpi'].to_i
      end  
    end
  end

  #
  # Set the config
  #
  def config=(c)
    @config = c
    
    recalc_pixels
  end

  #
  # Build a temporary PNG from an SVG file
  #
  def inkscape(input, target)
    params = []

    width = @config['width']
    height = @config['height']
    inkscape_target = target
    
    if @config['rotate']
      case @config['rotate']
        when 90, -90
          t = width; width = height; height = t
          inkscape_target = target + "-pre.png"
      end
    end

    if width; params << "-w #{width} "; end
    if height; params << "-h #{height} "; end

    system("inkscape -e \"#{inkscape_target}\" -y 1.0 #{params.join(" ")} \"#{input}\"")    
    
    if @config['rotate']
      command = [
        "\"#{inkscape_target}\"",
        "-rotate #{@config['rotate']}",
        "\"#{target}\""
      ]
      
      convert(command)
      File.unlink(inkscape_target)
    end
  end

  def convert(command, verbose = false)
    system("convert " + (verbose ? "-verbose " : "" ) + [ command ].flatten.join(" "))
  end

  #
  # Get the dimensions of a file
  #
  def get_dimensions(input)
    dimensions = nil
    IO.popen("identify -format '%w,%h' \"#{input}\"") do |fh|
      dimensions = fh.readlines.first.split(",").collect { |d| d.to_i }
    end
    dimensions
  end
end

class InputFilter < Filter
  OutputFilename = "tmp.png"
end

class OutputFilter < Filter
  #
  # get the output filename for this filter
  #
  def filename(info)
    target = @config['target']
    info.each { |k,v| target = target.gsub("{#{k}}", v.to_s) }    
    target
  end  

  #
  # get the output targets for this filter
  #
  def targets(info); filename(info); end
end

module PrintHandling
  #
  # calculate the page size in PPI
  #
  def calculate_page_size
    if @config['dpi']
      if @config['page_size']
        case @config['page_size'].downcase
          when "letter", "letter_portrait"
            page_width = 8.5; page_height = 11
          when "letter_landscape"
            page_width = 11; page_height = 8.5
          when "half_letter_landscape"
            page_width = 5.5; page_height = 8.5
        end
      else
        page_width = @config['page_width_inches']
        page_height = @config['page_height_inches']
      end
      
      page_width  *= @config['dpi']
      page_height *= @config['dpi']
    else
      page_width = @config['page_width']
      page_height = @config['page_height']
    end

    [ page_width, page_height ]
  end

  #
  # align the provided image on a white page
  #
  def build_for_print(input, output, side = "none")
    page_width, page_height = calculate_page_size
    command = [
      "-density #{config['dpi']}",
      "-size #{page_width.to_i}x#{page_height.to_i}",
      "xc:white"
    ]
    
    case side
      when "none"
        command << "-gravity Center"
      when "left"
        command << "-gravity East"
      when "right"
        command << "-gravity West"
    end

    command << "-draw 'image Over 0,0 0,0 \"#{input}\"'"
    command << "\"#{output}\""
    
    convert(command)
  end
end

class SVGToTempBitmap < InputFilter
  include PrintHandling
  
  #
  # select which build method to use based on the number of provided images.
  #
  def build(input)
    (input.instance_of? Array) ? multiple(input) : single(input)
  end
  
  #
  # process a single input file, possibly splitting it into two output files if it's a spread
  #
  def single(input)
    filename = Dir.pwd + '/' + OutputFilename
    inkscape(input, filename)
    @cleanup << filename

    if @config['spread']
      width, height = get_dimensions(filename)
      targets = []
      
      [ [ "left", 0 ], [ "right", width / 2 ] ].each do |side, offset|
        target = filename + "-#{side}.png"
        command = [
          "\"#{filename}\"",
          "-gravity Northwest",
          "-crop #{width/2}x#{height}+#{offset}+0",
          "+repage",
          "\"#{target}\""
        ]
        
        convert(command)
        
        targets << target
        @cleanup << target
      end
      
      return targets
    end
    
    return filename
  end

  #
  # combine multiple input files onto a single page-sized canvas.
  # images are added left-to-right and top-to-bottom starting from the top-left of the page.
  # leave a grid square blank by passing the filename "/blank".
  #
  def multiple(files)
    if @config['spread']; raise "Spreads and grids combined do not make sense"; end
    
    width, height = @config['grid'].split("x").collect { |f| f.to_f }
    joined_files = []
    
    page_width, page_height = calculate_page_size
    
    grid_width = page_width / width
    grid_height = page_height / height
    
    0.upto(files.length - 1) do |i|
      x = i % width
      y = (i / width).floor
      
      if files[i].split('/').last != "blank"
        tmp_svg_output = OutputFilename + "-#{i}.png"
        inkscape(Dir.pwd + '/' + files[i], tmp_svg_output)
        
        joined_files << [ tmp_svg_output, x, y ]
        @cleanup << tmp_svg_output
      end
    end

    command = [
      "-size #{page_width}x#{page_height}",
      "xc:white"
    ]
    
    joined_files.each do |file, x, y|
      image_width, image_height = get_dimensions(file)
      
      x_offset = (grid_width - image_width) / 2
      y_offset = (grid_height - image_height) / 2
      
      command << "-draw 'image Over #{x * grid_width + x_offset},#{y * grid_height + y_offset} 0,0 \"#{file}\"'"
    end
    
    command << OutputFilename
    
    convert(command)
    
    @cleanup << OutputFilename
    OutputFilename
  end
end

#
# Process an input file for the Web
#
class TempBitmapToWeb < OutputFilter
  def build(input, output)
    quality = @config['quality'] ? @config['quality'] : 80
    convert("\"#{input}\" -quality #{quality} \"#{output}\"")
  end
  
  def filename(info)
    if !@config['start_date']; raise "Must define a start date!"; end
    if !@config['period']; raise "Must define a period!"; end
  
    index = info['index'].to_i
    if index == 0 && @config['announce_date']
      comic_date = @config['announce_date']
    else
      day_of_week = 0
      weeks_from_start = 0

      case @config['period']
        when "daily"
          day_of_week = index % 5
          weeks_from_start = (index / 5).floor
        when "weekly"
          weeks_from_start = index
      end
      
      if @config['delay_at_index'] && @config['delay_length_weeks']
        if index >= @config['delay_at_index']
          weeks_from_start += @config['delay_length_weeks']
        end
      end

      comic_date = Time.parse(@config['start_date']) + ((((day_of_week + weeks_from_start * 7) * 24) + 6) * 60 * 60)
    end
    
    info['date'] = comic_date.strftime("%Y-%m-%d")
    super(info)
  end
end

#
# Code to help with pagination
#
module Pagination
  def paginate(files)
    if !files.instance_of? Array; raise "File list must be an array"; end
    if files.length == 0; raise "File list cannot be empty"; end
    if (files.length % 4) != 0; raise "File list must be divisible by 4"; end

    number_of_sheet_faces = (files.length / 4) * 2

    sheet_faces = []

    is_right = 1
    is_descending = 1
    sheet_face_index = 0

    files.each do |file|
      if !sheet_faces[sheet_face_index]; sheet_faces[sheet_face_index] = []; end

      sheet_faces[sheet_face_index][is_right] = file
      is_right = 1 - is_right
      
      sheet_face_index += is_descending
      
      if sheet_face_index == number_of_sheet_faces
        sheet_face_index -= 1
        is_descending = -1
      end
    end

    tmp_pdf_files = []
    0.upto(sheet_faces.length - 1) do |i|
      f = @config['target'] + "-#{i}.pdf"
      process_pagination(f, i, sheet_faces.length, *sheet_faces[i])
      tmp_pdf_files << f
    end
    
    system("pdfjoin #{tmp_pdf_files.collect { |f| "\"#{f}\"" }.join(" ")} --outfile \"#{@config['target']}\"")
  end
end

#
# Convert a bitmap to a single page print for proofing
#
class TempBitmapToPrint < OutputFilter
  include PrintHandling
  def build(input, output)
    build_for_print(input, "tmp2.pbm")

    system("sam2p -c:lzw -m:dpi:#{(72.0 * (72.0 / @config['dpi'].to_f))} tmp2.pbm PDF:\"#{output}\"");
    system("rm tmp2.pbm")  
  end
end

#
# Convert bitmap files to a paginated print-ready file
#
class TempBitmapToPaginatedPrint < OutputFilter
  include PrintHandling, Pagination
  def build(input, output, side = "none")
    build_for_print(input, output, side)
  end

  def targets(info)
    (@config['spread'] == true) ? [ filename(info) + "-left.png", "tmp-right.png" ] : filename(info)
  end

  def process_pagination(output, face, total_faces, left, right)
    page_width, page_height = calculate_page_size
    
    commands = [
        "-size #{page_width * 2}x#{page_height}",
        "xc:white",
        "-gravity Northwest"
    ]
    
    left_creep = 0
    right_creep = 0
    if @config['page_thickness']
      max_creep = (total_faces / 2)

      left_creep = ((max_creep - (face - max_creep).abs) * @config['page_thickness'].to_f * @config['dpi'].to_i).floor
      right_creep = ((max_creep - (total_faces - face - max_creep).abs) * @config['page_thickness'].to_f  * @config['dpi'].to_i).floor
    end
    
    if left
      commands << "-draw 'image Over -#{left_creep.to_i},0 0,0 \"#{left}\"'"
    end
    if right
      commands << "-draw 'image Over #{(page_width + right_creep).to_i},0 0,0 \"#{right}\"'"
    end
    commands << "-channel RGB -depth 8 tmp2.png"

    convert(commands)
    system("sam2p -c:lzw -m:dpi:#{(72.0 * (72.0 / @config['dpi'].to_f))} tmp2.png PDF:\"#{output}\"");
    system("rm tmp2.png")
  end
end

any_rebuilt = false
any_rsync = false

if !ARGV[0]
  puts "Usage: #{File.basename(__FILE__)} <path to YAML file>"
  exit 0
end

config = YAML::load(File.open(ARGV[0], "r"))
global = config['Global']

if !global['path']; exit 1; end

page_index_format = global['page_index_format'] ? global['page_index_format'] : "%0#{Math.log10(Dir[global['path']].length).ceil}d"

page_index = 1
fileinfo_by_file = {}

if global['pages']
  re = nil

  files = global['pages'].collect do |f|
    result = nil
    case f.class.to_s
      when 'String'
        result = global['path'] + f
        if f == "blank"
          fileinfo_by_file[result] = { 'file' => f }
        end
      when 'Hash'
        if f['file']
          case f['file'].class.to_s
            when 'String'
              result = global['path'] + f['file']
              fileinfo_by_file[result] = f
            when 'Array'
              result = f['file'].collect { |sub_f| global['path'] + sub_f }
              fileinfo_by_file[result.join(",")] = f
          end
        else
          result = f
        end
    end
    result
  end
else
  re = Regexp.new(global['match'])
  
  files = Dir[global['path']].sort.collect do |filename|
    if matches = re.match(filename)
      filename
    end
  end
end

paginated_source_files = {}
rsync_files_by_target = {}

files.each do |filename|
  ok = true; matches = nil; fileinfo = {}

  if filename.instance_of? Hash
    if filename['blank']
      ok = false
      config.each do |type, info|
        if info['is_paginated']
          if !paginated_source_files[type]; paginated_source_files[type] = []; end
          paginated_source_files[type] << nil
        end
      end
      page_index += 1
    else
      fileinfo = filename
      filename = fileinfo['file']
    end
  else
    if re; ok = matches = re.match(filename); end
  end

  if ok
    filename_display = (filename.instance_of? Array) ? filename.join(", ") : filename
    
    puts "Examining #{filename_display}..."
    
    filename_parts = {
      'page_index' => sprintf(page_index_format, page_index)
    }
    
    if matches
      all, index, title = matches.to_a  
    else
      index = page_index - 1
      title = ""
    end
    
    if global['title']; title = global['title'].gsub("{index}", index).gsub("{title}", title); end
    filename_parts['index'] = index
    filename_parts['title'] = title

    config.each do |type, info|
      if type != "Global"
        input = nil; output = nil

        fileinfo_key = (filename.instance_of? Array) ? filename.join(",") : filename
  
        file_fileinfo = (fileinfo_by_file[fileinfo_key]) ? fileinfo_by_file[fileinfo_key] : {}

        extension = File.extname((filename.instance_of? Array) ? filename[0] : filename).downcase

        case extension
          when ".svg"
            case File.extname(config[type]['target']).downcase
              when ".jpg", ".jpeg", ".png", ".gif"
                input = SVGToTempBitmap
                output = TempBitmapToWeb
              when ".pdf"
                input = SVGToTempBitmap
                output = (info['is_paginated']) ? TempBitmapToPaginatedPrint : TempBitmapToPrint
            end
        end

        if !input;  raise "No input handler for #{extension} defined"; end
        if !output; raise "No output handler for #{File.extname(config[type]['target']).downcase} defined"; end

        input_obj = input.instance
        input_obj.config = info.dup.merge(fileinfo).merge(file_fileinfo)
        
        output_obj = output.instance
        output_obj.config = info.dup.merge(fileinfo).merge(file_fileinfo)

        if info['is_paginated']
          output_obj.config['target'] += "-{page_index}.png"
        end

        targets = output_obj.targets(filename_parts)
        
        rebuild = false
        
        [ targets ].flatten.each do |t|
          if !File.exists?(t)
            rebuild = true
          else
            [ filename ].flatten.each do |f|
              if File.mtime(f) > File.mtime(t)
                rebuild = true
              end          
            end
          end
        end            
        
        if rebuild
          any_rebuilt = true

          puts "Rebuilding #{filename_display} (#{type})..."

          tmp_files = input_obj.build(filename)

          output_files = []
          case tmp_files.class.to_s
            when "String"
              output_obj.build(tmp_files, targets)
              output_files << targets
            when "Array"
              [0,1].each do |i|
                output_obj.build(tmp_files[i], targets[i], (i == 0) ? "left" : "right")
                output_files << targets[i]
              end
          end

          input_obj.cleanup
        end
        if info['is_paginated']
          if !paginated_source_files[type]; paginated_source_files[type] = []; end
          paginated_source_files[type] << targets
        end
        if info['rsync']
          if !rsync_files_by_target[info['rsync']]; rsync_files_by_target[info['rsync']] = []; end
          rsync_files_by_target[info['rsync']] << targets        
        end
      end
    end
    
    page_index += 1
  end
end

config.each do |type, info|
  if info['is_paginated']
    output = TempBitmapToPaginatedPrint
    
    output_obj = output.instance
    output_obj.config = info.dup
    
    output_obj.paginate(paginated_source_files[type].flatten)
  end
  
  if info['rsync']
    system("echo '#{rsync_files_by_target[info['rsync']].join("\n")}' | rsync -vru --files-from=- . #{info['rsync']}")
  end
end

if global['use_git']
  system("git add .")
  system("git commit -a")
end