require 'sprockets'
require 'tilt'

module JserrorRails
  class JserrorTemplate < Tilt::Template

    def self.default_mime_type
      'application/javascript'
    end

    def prepare
    end

    def evaluate(scope, locals, &block)
      data_copy = data
      scanning_data = data
      functions = []
      capture = true
      while capture
        function = (/(^.*= function.*$)/).match(scanning_data)
        if function
          old_lines = []
          new_code_lines = []

          scanning_data = function.post_match
          method_line = function.captures.first
          
          tabs = method_line.partition(method_line.strip[0]).first
          name = method_line.match(/(.*) = function/).captures.first.strip
          
          arguments = method_line.gsub(tabs, '').gsub(name, '').gsub(/\s*=\s*function\s*\(/, '').gsub(/\)\s*{.*$/, '').strip.split(', ').map {|a| "{#{a}: #{a}}"}

          new_code_lines << method_line
          old_lines << method_line
          
          new_code_lines << "\n#{tabs}\ttry {"

          bracket_count = 1 #start scanning until we find the ending bracket
          scanning_data.each_line do |line|
            line.chars do |char|
              bracket_count += 1 if char == '{'
              bracket_count -= 1 if char == '}'
            end
            new_code_lines << "\t" + line
            old_lines << line
            break if bracket_count <= 0
          end
          
          new_code_lines.pop #pop of the last }; to add catch block before closing bracket in function

          console_line = "javascript_error({name: '#{name.gsub('\'', '"')}',  
                                      error_message: e.message, 
                                      error_name: e.name, 
                                      code_block: '#{old_lines.join('').gsub("\n", '[::n::]').gsub('\'', '')}', 
                                      arguments: [#{arguments.join(', ')}], 
                                      source: $('*').html()
                          });"
          
          new_code_lines << "#{tabs}\t} catch (e) { \n#{tabs}\t\t#{console_line}\n#{tabs}\t}\n"
          new_code_lines << "#{tabs}};\n"
          functions << {:replace => old_lines.join(''), :new => new_code_lines.join('')}
        else
          capture = false
        end
      end
      
      scanning_data = data_copy.clone
      capture = true
      while capture
        function = (/(.*\(.+function\(.*\).*\{.*$)/).match(scanning_data)
        if function
          old_lines = []
          new_code_lines = []

          scanning_data = function.post_match
          method_line = function.captures.first
          
          tabs = method_line.partition(method_line.strip[0]).first
          
          name = method_line
          arguments = (/.*\(.+function\((.*)\).*\{.*$/).match(method_line).captures.first.split(', ').map {|a| "{#{a}: #{a}}"}

          new_code_lines << method_line
          old_lines << method_line
          
          new_code_lines << "\n#{tabs}\ttry {"

          bracket_count = 1 #start scanning until we find the ending bracket
          scanning_data.each_line do |line|
            line.chars do |char|
              bracket_count += 1 if char == '{'
              bracket_count -= 1 if char == '}'
            end
            new_code_lines << "\t" + line
            old_lines << line
            break if bracket_count <= 0
          end
          
          new_code_lines.pop #pop of the last }; to add catch block before closing bracket in function

          console_line = "javascript_error({name: '#{name.gsub('\'', '"')}',  
                                      error_message: e.message, 
                                      error_name: e.name, 
                                      code_block: '#{old_lines.join('').gsub("\n", '[::n::]').gsub('\'', '')}', 
                                      arguments: [#{arguments.join(', ')}], 
                                      source: $('*').html()
                          });"
          
          new_code_lines << "#{tabs}\t} catch (e) { \n#{tabs}\t\t#{console_line}\n#{tabs}\t}\n"
          new_code_lines << "#{tabs}});\n"
          functions << {:replace => old_lines.join(''), :new => new_code_lines.join('')}
        else
          capture = false
        end
      end
      

      functions.each do |s|
        data_copy.gsub!(s[:replace], s[:new])
      end
      
      output = "try {"
      output << data_copy
      output << "} catch (e) { javascript_error({name: 'unfound javascript error', error_message: e.message, error_name: e.name, code_block: '#{scope.logical_path.to_s}', arguments: [], source: $('*').html()}); }"
      output
    end
  end
end