#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

#==========================
# graph.rb
#==========================
#
# Image utility functions to inspect text font metrics
#
# This file is part of RSyntaxTree, which is a ruby port of Andre Eisenbach's
# excellent program phpSyntaxTree.
#
# Copyright (c) 2007-2018 Yoichiro Hasebe <yohasebe@gmail.com>
# Copyright (c) 2003-2004 Andre Eisenbach <andre@ironcreek.net>

require 'rmagick'
include Magick

class Graph

  def initialize(e_list, metrics, symmetrize, color, leafstyle, multibyte, font, font_size)

    # Set class-specific parameters beforehand in subclass

    # Store parameters
    @e_list     = e_list
    @m          = metrics
    @multibyte  = multibyte
    @leafstyle  = leafstyle
    @symmetrize = symmetrize

    # Calculate image dimensions
    @e_height = font_size + @m[:e_padd] * 2
    h         = @e_list.get_level_height
    w         = calc_level_width(0)
    @width    = w + @m[:b_side] * 2
    @height   = h * @e_height + (h-1) * (@m[:v_space] + font_size) + @m[:b_topbot] * 2

    # Initialize the image and colors
    @col_bg   = "none"
    @col_fg   = "black"
    @col_line = "black"

    if color
      @col_node  = "blue"
      @col_leaf  = "green"
      @col_trace = "red"
    else
      @col_node  = "black"
      @col_leaf  = "black"
      @col_trace = "black"
    end
    
    @main_height = img_get_txt_height("l", font, font_size)
    @sub_size = (font_size * SUBSCRIPT_CONST)
    @sub_space_width = img_get_txt_width("l", font, @sub_size)
  end

  def img_get_txt_metrics(text, font, font_size, multiline)

    background = Image.new(500, 250)

    gc = Draw.new
    gc.annotate(background, 0, 0, 0, 0, text) do |gc|
      gc.font = font
      gc.pointsize = font_size
      gc.gravity = CenterGravity
      gc.stroke = 'none'
    end

    if multiline
      metrics = gc.get_multiline_type_metrics(background, text)
    else
      metrics = gc.get_type_metrics(background, text)
    end

    return metrics
  end

  # Calculate the width of the element. If the element is
  # a node, the calculation will be performed recursively
  # for all child elements.
  def calc_element_width(e)
    w = 0

    children = @e_list.get_children(e.id)

    if(children.length == 0)
      w = img_get_txt_width(e.content, @font, @font_size) + @font_size
    else
      children.each do |child|
        child_e = @e_list.get_id(child)
        w += calc_element_width(child_e)
      end

      tw = img_get_txt_width(e.content, @font, @font_size) + @font_size
      if(tw > w)
        fix_child_size(e.id, w, tw)
        w = tw
      end
    end

    @e_list.set_element_width(e.id, w)
    return w
  end

  # Calculate the width of all elements in a certain level
  def calc_level_width(level)
    w = 0
    e = @e_list.get_first
    while e
      if(e.level == level)
        w += calc_element_width(e)
      end
        e = @e_list.get_next
    end
    return w
  end

  def calc_children_width(id)
    left = 0
    right = 0
    c_list = @e_list.get_children(id)
    return nil if c_list.empty?

    c_list.each do |c|
      left =  c.indent if indent == 0 or left > c.indent
    end
    c_list.each do |c|
      right = c.indent + e.width if c.indent + c.width > right
    end
    return [left, right]
  end

  def get_children_indent(id)
    calc_children_width(id)[0]
  end

  def get_children_width(id)
    calc_children_width(id)[1] - get_children_indent(id)
  end

  # Parse the elements in the list top to bottom and
  #   draw the elements into the image.
  #   As we it iterate through the levels, the element
  #   indentation is calculated.
  def parse_list

    # Calc element list recursively....
    e_arr = @e_list.get_elements

    h = @e_list.get_level_height
    h.times do |i|
      x = 0
      e_arr.each do |j|

        if (j.level == i)
          cw = @e_list.get_element_width(j.id)
          parent_indent = @e_list.get_indent(j.parent)
          if (x <  parent_indent)
            x = parent_indent
          end
          @e_list.set_indent(j.id, x)

          if !@symmetrize
            draw_element(x, i, cw, j.content, j.type)
            if(j.parent != 0 )
              words = j.content.split(" ")
              unless @leafstyle == "nothing" && ETYPE_LEAF == j.type
                if (@leafstyle == "triangle" && ETYPE_LEAF == j.type && x == parent_indent && words.length > 0)
                  txt_width = img_get_txt_width(j.content, @font, @font_size)
                  triangle_to_parent(x, i, cw, txt_width, @symmetrize)
                elsif (@leafstyle == "auto" && ETYPE_LEAF == j.type && x == parent_indent)
                   if words.length > 1 || j.triangle
                     txt_width = img_get_txt_width(j.content, @font, @font_size)
                     triangle_to_parent(x, i, cw, txt_width, @symmetrize)
                   else
                     line_to_parent(x, i, cw, @e_list.get_indent(j.parent), @e_list.get_element_width(j.parent))
                   end
                else
                  line_to_parent(x, i, cw, @e_list.get_indent(j.parent), @e_list.get_element_width(j.parent))
                end
              end
            end
          end

          x += cw
        end
      end
    end
    return true if !@symmetrize
    h.times do |i|
      curlevel = h - i - 1
      indent = 0
      e_arr.each_with_index do |j, idx|
        if (j.level == curlevel)
          # Draw a line to the parent element
          children = @e_list.get_children(j.id)

          tw = img_get_txt_width(j.content, @font, @font_size)
          if children.length > 1
            left, right = -1, -1
            children.each do |child|          
              k = @e_list.get_id(child)
              kw = img_get_txt_width(k.content, @font, @font_size)              
              left = k.indent + kw / 2 if k.indent + kw / 2 < left or left == -1
              right = k.indent + kw / 2 if k.indent + kw / 2 > right
            end
            draw_element(left, curlevel, right - left, j.content, j.type)
            @e_list.set_indent(j.id, left + (right - left) / 2 -  tw / 2)

            children.each do |child|
              k = @e_list.get_id(child)
              words = k.content.split(" ")
              dw = img_get_txt_width(k.content, @font, @font_size)
              unless @leafstyle == "nothing" && ETYPE_LEAF == k.type
                if (@leafstyle == "triangle" && ETYPE_LEAF == k.type && k.indent == j.indent && words.length > 0)
                  txt_width = img_get_txt_width(k.content, @font, @font_size)
                  triangle_to_parent(k.indent, curlevel + 1, dw, txt_width)
                elsif (@leafstyle == "auto" && ETYPE_LEAF == k.type && k.indent == j.indent)
                  if words.length > 1 || k.triangle
                    txt_width = img_get_txt_width(k.content, @font, @font_size)
                    triangle_to_parent(k.indent, curlevel + 1, dw, txt_width)
                  else
                    line_to_parent(k.indent, curlevel + 1, dw, j.indent, tw)
                  end
                else
                  line_to_parent(k.indent, curlevel + 1, dw, j.indent, tw)
                end
              end
            end

          else
            unless children.empty?
              k = @e_list.get_id(children[0])
              kw = img_get_txt_width(k.content, @font, @font_size)              
              left = k.indent
              right = k.indent + kw
              draw_element(left, curlevel, right - left, j.content, j.type)
              @e_list.set_indent(j.id, left + (right - left) / 2 -  tw / 2)
            else
             parent = @e_list.get_id(j.parent)
             pw = img_get_txt_width(parent.content, @font, @font_size)
             pleft = parent.indent
             pright = pleft + pw
             left = j.indent
             right = left + tw
             if pw > tw
               left = pleft
               right = pright
             end
             draw_element(left, curlevel, right - left, j.content, j.type) 
             @e_list.set_indent(j.id, left + (right - left) / 2 -  tw / 2)             
            end

            unless children.empty?
              k = @e_list.get_id(children[0])
              words = k.content.split(" ")
              dw = img_get_txt_width(k.content, @font, @font_size)
              unless @leafstyle == "nothing" && ETYPE_LEAF == k.type
                if (@leafstyle == "triangle" && ETYPE_LEAF == k.type && words.length > 0)
                  txt_width = img_get_txt_width(k.content, @font, @font_size)
                  triangle_to_parent(k.indent, curlevel + 1, dw, txt_width)
                elsif (@leafstyle == "auto" && ETYPE_LEAF == k.type)
                  if words.length > 1 || k.triangle
                    txt_width = img_get_txt_width(k.content, @font, @font_size)
                    triangle_to_parent(k.indent, curlevel + 1, dw, txt_width)
                  else
                    line_to_parent(k.indent, curlevel + 1, dw, j.indent, tw)
                  end
                else
                  line_to_parent(k.indent, curlevel + 1, dw, j.indent, tw)
                end
              end
            end
          end
        end
      end
    end
  end

  # Calculate top position from row (level)
  def row2px(row)
   @m[:b_topbot] + @e_height * row + (@m[:v_space] + @font_size) * row
  end

  def get_txt_only(text)
    text = text.strip
    if /\A([\+\-\=\*]+).+/ =~ text
      prefix = $1
      prefix_l = Regexp.escape(prefix)
      prefix_r = Regexp.escape(prefix.reverse)
      if /\A#{prefix_l}(.+)#{prefix_r}\z/ =~ text
        return $1
      end
    end
    return text
  end

  def img_get_txt_height(text, font, font_size, multiline = false)
    metrics = img_get_txt_metrics(text, font, font_size, multiline)
    y = metrics.height
    return y
  end
end