--[[ Modified from the simple \k replacer script by Niels Martin Hansen Copyright (c) 2005
Modifications written by xess, Copyright (c) 2006
Copyright (c) 2005, Niels Martin Hansen
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:

   * Redistributions of source code must retain the above copyright notice,
     this list of conditions and the following disclaimer.
   * Redistributions in binary form must reproduce the above copyright notice,
     this list of conditions and the following disclaimer in the documentation
     and/or other materials provided with the distribution.
   * Neither the name of the Aegisub Group nor the names of its contributors
     may be used to endorse or promote products derived from this software
     without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 ]]

--[[ 
  Hints: This program uses the same variables you see in the simple \k replacer program, $DUR, $END, etc. However, they are timed per line, not per syllable. This script is useful to insert any kind of text or substation alpha code into the front of each line. Examples are like {\fade} effects which needs to has the times entered manually. This script can help automate that.
]]

include("karaskel.lua")

name = "Inserter"

Description ="Inserts code at beginning of each line."

configuration = {
	[1] = {
    		name="help";
		kind="label";
    		label=[[Variables:
  $START = Start-time of syllable (ms), should be 0
  $END = End-time of syllable (ms)
  $MID = Time midways through the syllable (ms)
  $DUR = Duration of line (ms)  
  Enclose with % to do calculations
    e.g. %$DUR+200%]];
    		hint=""
  	};
  	[2] ={
  		name = "insstr";
  		kind = "text";
  		label = "Code";
  		hint = "This line will be added to the start of every line.";
 		default = ""
	}
}


version, kind =3, 'basic_ass'

function do_line_start(meta, styles, config, line) 
	local text

	line["dur"] = line.duration
	line["start"] = line.start_time
	line["end"] = line.end_time
	line["mid"] = line.duration/2

	text = config.insstr

	-- Function for replacing the variables
	local function var_replacer(varname)
  		varname = string.lower(varname)
		if line[varname] ~= nil then
			return line[varname]
		else
			aegisub.output_debug(string.format("Unknown variable name: %s", varname))
			return "$" .. varname
		end
	end   
	-- Replace the variables in the ktext
	text = string.gsub(text, "$(%a+)", var_replacer)
	
	-- Function for evaluating expressions
	local function expression_evaluator(expression)
		chunk, err = loadstring(string.format("return (%s)", expression))
		if (err) ~= nil then
			aegisub.output_debug(string.format("Error parsing expression:\n%s", expression, err))
			return "%" .. expression .. "%"
		else
			return chunk()
		end
	end
	
	-- Find and evaluate expressions
	text = string.gsub(text, "%%([^%%]*)%%", expression_evaluator)

	return text .. line.text
end

function do_syllable(meta, styles, config, line, syl) 
	return ""
end