--functions

-- DATA
-- vowels
vowel_table = 					{"a","e","i","o","u"}
symbol_vowel = 				{"","","","",""}
symbol_extending_vowel = 		{"","","","",""}
-- consonants
consonant_table = 				{"g","sh","r","ny","ch","n","y","f","t","k","w","l","p","b","d","h","m"}
symbol_consonant = 			{"","","","","","","","","","","","","","","","",""}
symbol_extending_consonant = 	{"","","","","","","","","","","","","","","","",""}
-- composites
composing_consonant_table =		{"g","sh","r","ny","ch","m","y","f","t","k","w","l","p","b","d","h"}
symbol_composite = {
							{"","","","","","","","","","","","","","","",""},
							{"","","","","","","","","","","","","","","",""},
							{"","","","","","","","","","","","","","","",""},
							{"","","","","","","","","","","","","","","",""},
							{"","","","","","","","","","","","","","","",""}
}

-- program start
function mod_convertToHeonian(text)
	local step = true -- this is set to false when a conclusion has been reached
	local transcribed = false
	local transcribed_text = ""
	
	local debug = false
	local autocopy = false
	
	for _, v in pairs(arg) do	
		if v == "-v" or v == "--verbose" then debug = true end
		if v == "-c" or v == "--copy" then autocopy = true end
	end		
	
	-- if its necessary to run the script, then we continue :D
	if step  then
	-- prepare text
		-- 1. add syllable marker at start if it isn't already present.
			if string.sub(text,1,1) ~= "." then text = "." .. text end
		-- 2. turn [x] into [ksh]
			text = string.gsub(text,"x","ksh")
		-- 3. turn [z] into [dsh]
			text = string.gsub(text,"z","d.sh")
		-- 4. turn [j] into [y]
			text = string.gsub(text,"j","y")
	
	-- read input and transcribe	
		-- debug log
		if debug then print("") end
		if debug then print("src: ".. text) end
		if debug then PrintPosition(text) end
				
		-- sort through all the letters
		local i = 1
		while  i <  string.len(text)+1 do
			local pos = i
			-- know current pos, since we will be modifying i but still evaluating from the position
			local char_step = true 
			-- this is false when a conclusion has been reached about what symbol does the next segment correspond to
			local debug_s = ""
			-- debug string
			local new_syllable = false 
			-- this is true when a new syllable begins, and is used to distinguish normal vowels and consonants from trailing ones
			
			if i == 1 then new_syllable = true end
			
			if string.sub(text,i,i) == "\t" 
			or string.sub(text,i,i) == "-" then  -- check if its an unsupported symbol to skip it.
				-- adjust i
				i = i + 1
				pos = i
				char_step = false
			end
			-- init checkup
			if string.sub(text,i,i) == "." 
			or string.sub(text,i,i) == "'"
			or string.sub(text,i,i) == " "
			or string.sub(text,i,i) == "’" then  -- this forces the new syllable, since . is the syllable separator, also skips the symbol and repositions
				if string.sub(text,i,i) == " " then -- spaces are exception
					transcribed_text = transcribed_text .. " "
					new_syllable = true
				end				
				-- debug log
				if debug then print("") end
				if debug then print(" @[".. tostring(i).."]"..debug_s.." new syllable MARKER found") end
				-- start syllable
				new_syllable = true
				debug_s = ""
				-- adjust i
				i = i + 1
				-- debug log
				if debug then print("    >>> adjusting by (1) from [".. pos .. "] to [".. i .. "]" ) end
				-- adjust pos
				pos = i
			end
				
			-- debug log
			if debug then print("") end
			if debug then print(" @[".. tostring(i).."]"..debug_s.." checking string: ".. string.sub(text,i,i)) end -- debug print positional info
			
			-- lets check if it is a composite
			if char_step == true then
				local cons_id = 0
				local length = 0	
				-- check if its valid consonant for a composite
				for _, consonant in pairs(composing_consonant_table) do
					cons_id = cons_id + 1
					-- get consonant length its checking against, so we can properly compare.
					length = string.len(consonant)
					-- debug log 
					--if debug then print("     checking composite consonant: " .. composing_consonant_table[cons_id]) end
					if string.sub(text,i,i+length-1) == consonant then
						-- debug log 
						if debug then print("    (!) valid consonant: " .. composing_consonant_table[cons_id]) end
						-- check if its a valid vowel AFTER the valid consonant, while sorting through all vowels
						local vowel_id = 0
						for _, vowel in pairs(vowel_table) do		
							vowel_id = vowel_id + 1
							--if debug then print("        checking composite: " .. composing_consonant_table[cons_id]..vowel_table[vowel_id]) end
							if string.sub(text,i+length,i+length) == vowel then	
								-- adjust by consonant length + vowel
								i = i + string.len(consonant) + 1 
								-- debug log 
								if debug then print("    (!) valid composite: " .. consonant .. vowel ..", length: "..length+1) end
								if debug then print("    >>> adjusting by ("  .. tostring(length+1) .. ") from [".. pos .. "] to [".. i .. "]" ) end
								-- transcribe; conclude;
								transcribed_text = transcribed_text .. symbol_composite[vowel_id][cons_id]
								char_step = false
								break
							end
						end
						-- no need to check for more consonants if one is valid
						break
					end
				end
				if debug then if char_step ~= false then print("    [!] invalid composite") end end
			end
			
			-- lets check if it is a non composite vowel
			if char_step == true then
				local id = 0
				local length = 0	
				for _, vowel in pairs(vowel_table) do
					id = id+ 1
					-- get vowel length its checking against, so we can properly compare.
					length = string.len(vowel)
					-- debug log 
					--if debug then print("     checking standalone vowel: " .. vowel_table[id]) end
					if string.sub(text,i,i+length-1) == vowel then
						i = i + string.len(vowel) 
						-- debug log 
						if debug then print("    (!) valid vowel: " .. vowel_table[id]) end
						if debug then print("    >>> adjusting by ("  .. tostring(length) .. ") from [".. pos .. "] to [".. i .. "]" ) end
						-- transcribe; conclude;
						local table = nil
						if new_syllable then
							table = symbol_vowel
						else
							table = symbol_extending_vowel
						end
						transcribed_text = transcribed_text .. table[id]
						char_step = false
						break
					end
				end
			end
			
			
			-- lets check if it is a non composite consonant
			if char_step == true then
				local id = 0
				local length = 0	
				for _, consonant in pairs(consonant_table) do
					id = id+ 1
					-- get consonant length its checking against, so we can properly compare.
					length = string.len(consonant)
					-- debug log 
					--if debug then print("     checking standalone consonant: " .. consonant_table[id]) end
					if string.sub(text,i,i+length-1) == consonant then
						i = i + string.len(consonant) 
						-- debug log 
						if debug then print("    (!) valid consonant: " .. consonant_table[id]) end
						if debug then print("    >>> adjusting by ("  .. tostring(length) .. ") from [".. pos .. "] to [".. i .. "]" ) end
						-- transcribe; conclude;
						local table = nil
						if new_syllable then
							table = symbol_consonant
						else
							table = symbol_extending_consonant
						end
						transcribed_text = transcribed_text .. table[id]
						char_step = false
						break
					end
				end
			end
					
			-- if no idea, move on, and just be confused. prints ?
			if char_step == true then
				-- debug log
				if debug then print("    [!] no idea; moving on to next [".. pos + 1 .."]") end
				-- no idea
				transcribed_text = transcribed_text .. string.sub(text,i,i)
				i = i + 1
				-- debug log
				if debug then print("    >>> adjusting by (1) from [".. pos .. "] to [".. i .. "]" ) end
			end
		end
		return transcribed_text 
	end
end