-- Global 'nil' value
NIL = {}

-- Localise for faster access
local pcall			= pcall

local string_len	= string.len
local string_sub	= string.sub
local string_find	= string.find
local string_gsub	= string.gsub

local table_concat	= table.concat
local table_insert	= table.insert
local table_sort	= table.sort


-- Stream interface
local gSet  -- Set grep pattern

local gMsgF -- Print fragment
local gMsgN -- Print newline
local gMsgC -- Set print color

do
	local grep_color   = Color(235, 70, 70)

	-- Grep parameters (static between gBegin/gEnd)
	local grep
	local grep_raw

	local grep_proximity


	-- Current line parameters
	local buffer
	local colors
	local markers

	local baseColor
	local currColor

	local length

	-- History
	local history
	local remain


	-- Actual printing
	local function gCheckMatch( buffer )
		local raw = table_concat(buffer)

		return raw, string_find(raw, grep, 0, grep_raw)
	end

	local function gFlushEx( raw, markers, colors, baseColor )

		-- Print entire buffer
		local len = string_len(raw)

		-- Keep track of the current line properties
		local index  = 1
		local marker = 1

		local currColor = baseColor

		-- Method to print to a preset area
		local function printToIndex( limit, color )
			local mark = markers and markers[marker]

			-- Print all marker areas until we would overshoot
			while mark and mark < limit do

				-- Catch up to the marker
				MsgC(color or currColor, string_sub(raw, index, mark))
				index = mark +1

				-- Set new color
				currColor = colors[marker]

				-- Select next marker
				marker = marker +1
				mark   = markers[marker]

			end

			-- Print the remaining between the last marker and the limit
			MsgC(color or currColor, string_sub(raw, index, limit))
			index = limit +1
		end

		-- Grep!
		local match, last = 1
		local from, to = string_find(raw, grep, 0, grep_raw)

		while from do
			printToIndex(from -1)
			printToIndex(to, grep_color)

			last     = to +1
			from, to = string_find(raw, grep, last, grep_raw)
		end

		printToIndex(len)
		MsgN()
	end


	local function gCommit()
		if grep_proximity then
			-- Check if the line has at least one match
			local raw, match = gCheckMatch(buffer)

			if match then

				-- Divide matches
				if history[grep_proximity] then
					MsgN("...")
				end

				-- Flush history
				if grep_proximity != 0 then
					local len = #history

					for index = len -1, 1, -1 do
						local entry = history[index]
							history[index] = nil

						gFlushEx( entry[1], entry[2], entry[3], entry[4] )
					end

					history[len] = nil
				end

				-- Flush line, allow next X lines to get printed
				gFlushEx( raw, markers, colors, baseColor )
				remain = grep_proximity -1

				history[grep_proximity +1] = nil
			elseif remain > 0 then
				-- Flush immediately
				gFlushEx( raw, markers, colors, baseColor )
				remain = remain -1
			else
				-- Store in history
				table_insert(history, 1, {raw, markers, colors, baseColor})
				history[grep_proximity +1] = nil
			end
		else
			-- Flush anyway
			gFlushEx( table_concat(buffer), markers, colors, baseColor )
		end

		-- Reset state
		length = 0
		buffer = {}

		markers = nil
		colors  = nil

		baseColor = nil
		currColor = nil
	end

	-- State machine
	function gBegin( new, prox )
		grep = isstring(new) and new

		if grep then
			grep_raw       = !pcall(string_find, ' ', grep)
			grep_proximity = isnumber(prox) and prox

			-- Reset everything
			buffer  = {}
			history = {}
		end

		length = 0
		remain = 0

		baseColor = nil
		currColor = nil
	end

	function gFinish()
		if grep_proximity and history and history[1] then
			MsgN("...")
		end

		-- Free memory
		buffer  = nil
		markers = nil
		colors  = nil

		history = nil
	end


	function gMsgC( color )
		if grep then

			-- Try to save some memory by not immediately allocating colors
			if length == 0 then
				baseColor = color
				return
			end

			-- Record color change
			if color != currColor then
				if !markers then
					markers = {}
					colors  = {}
				end

				-- Record color change
				table_insert(markers, length)
				table_insert(colors,  color)
			end
		end

		currColor = color
	end

	function gMsgF( str )
		if grep then

			-- Split multiline fragments to separate ones
			local fragColor = currColor or baseColor

			local last = 1
			local from, to = string_find(str, '\n')

			while from do
				local frag = string_sub(str, last, from -1)
				local len  = from - last

				-- Merge fragment to the line
				length = length + len
				table_insert(buffer, frag)

				-- Print finished line
				gCommit()

				-- Assign base color as previous fragColor
				baseColor = fragColor

				-- Look for more
				last     = to +1
				from, to = string_find(str, '\n', last)
			end

			-- Push last fragment
			local frag = string_sub(str, last)
			local len  = string_len(str) - last +1

			length = length + len
			table_insert(buffer, frag)
		else
			-- Push immediately
			MsgC(currColor or baseColor, str)
		end
	end

	function gMsgN()
		-- Print everything in the buffer
		if grep then
			gCommit()
		else
			MsgN()
		end

		baseColor = nil
		currColor = nil
	end
end


local type_weight = {
	[TYPE_FUNCTION] = 1,
	[TYPE_TABLE]    = 2,
}

local type_colors = {
	[TYPE_BOOL]	    = Color(175, 130, 255),
	[TYPE_NUMBER]	= Color(175, 130, 255),
	[TYPE_STRING]	= Color(230, 220, 115),
	[TYPE_FUNCTION] = Color(100, 220, 240)
}

local color_neutral   = Color(220, 220, 220)
local color_name      = Color(260, 150,  30)

local color_reference = Color(150, 230,  50)
local color_comment   = Color( 30, 210,  30)


local function InternalPrintValue( value )

	-- 'nil' values can also be printed
	if value == NIL then
		gMsgC(color_comment)
		gMsgF("nil")
		return
	end

	local color = type_colors[ TypeID(value) ]

	-- For strings, place quotes
	if isstring(value) then
		if string_len(value) <= 1 then
			value = string.format([['%s']], value)
		else
			value = string.format([["%s"]], value)
		end

		gMsgC(color)
		gMsgF(value)
		return
	end

	-- Workaround for userdata not using MetaName
	if string_sub(tostring(value), 0, 8) == "userdata" then
		local meta = getmetatable(value)

		if meta and meta.MetaName then
			value = string.format("%s: %p", meta.MetaName, value)
		end
	end

	-- General print
	gMsgC(color)
	gMsgF(tostring(value))

	-- For functions append source info
	if isfunction(value) then
		local info = debug.getinfo(value, 'S')
		local aux

		if info.what == 'C' then
			aux = "\t-- [C]: -1"
		else
			if info.linedefined != info.lastlinedefined then
				aux = string.format("\t-- [%s]: %i-%i", info.short_src, info.linedefined, info.lastlinedefined)
			else
				aux = string.format("\t-- [%s]: %i", info.short_src, info.linedefined)
			end
		end

		gMsgC(color_comment)
		gMsgF(aux)
	end
end


-- Associated to object keys
local objID

local function isprimitive( value )
	local id = TypeID(value)

	return id <= TYPE_FUNCTION and id != TYPE_TABLE
end

local function InternalPrintTable( table, path, prefix, names, todo )

	-- Collect keys and some info about them
	local keyList  = {}
	local keyStr   = {}

	local keyCount = 0

	for key, value in pairs( table ) do
		-- Add to key list for later sorting
		table_insert(keyList, key)

		-- Describe key as string
		if isprimitive(key) then
			keyStr[key] = tostring(key)
		else
			-- Lookup already known name
			local name = names[key]

			-- Assign a new unique identifier
			if !name then
				objID = objID +1
				name  = string.format("%s: obj #%i", tostring(key), objID)

				names[key] = name
				todo[key]  = true
			end

			-- Substitute object with name
			keyStr[key] = name
		end

		keyCount = keyCount +1
	end


	-- Exit early for empty tables
	if keyCount == 0 then
		return
	end


	-- Determine max key length
	local keyLen = 4

	for key, str in pairs(keyStr) do
		keyLen = math.max(keyLen, string.len(str))
	end

	-- Sort table keys
	if keyCount > 1 then
		table_sort( keyList, function( A, B )

			-- Sort numbers numerically correct
			if isnumber(A) and isnumber(B) then
				return A < B
			end

			-- Weight types
			local wA = type_weight[ TypeID( table[A] ) ] or 0
			local wB = type_weight[ TypeID( table[B] ) ] or 0

			if wA != wB then
				return wA < wB
			end

			-- Order by string representation
			return keyStr[A] < keyStr[B]

		end )
	end

	-- Determine the next level ident
	local new_prefix = string.format( "%s║%s", prefix, string.rep(' ', keyLen) )

	-- Mark object as done
	todo[table] = nil

	-- Start describing table
	for index, key in ipairs(keyList) do
		local value = table[key]

		-- Assign names to already described keys/values
		local kName = names[key]
		local vName = names[value]

		-- Decide to either fully describe, or print the value
		local describe = !isprimitive(value) and ( !vName or todo[value] )

		-- Ident
		gMsgF(prefix)

		-- Fancy table guides
		local moreLines = (index != keyCount) or describe

		if index == 1 then
			gMsgF(moreLines and '╦ ' or '═ ')
		else
			gMsgF(moreLines and '╠ ' or '╚ ')
		end

		-- Print key
		local sKey = kName or keyStr[key]

		gMsgC(kName and color_reference or color_name)
		gMsgF(sKey)

		-- Describe non primitives
		local describe = istable(value) and ( !names[value] or todo[value] ) and value != NIL

		-- Print key postfix
		local padding = keyLen - string.len(sKey)
		local postfix = string.format(describe and ":%s" or "%s = ", string.rep(' ', padding))

		gMsgC(color_neutral)
		gMsgF(postfix)

		-- Print the value
		if describe then
			gMsgN()

			-- Expand access path
			local new_path = sKey

			if isnumber(key) or kName then
				new_path = string.format("%s[%s]", path or '', key)
			elseif path then
				new_path = string.format("%s.%s", path, new_path)
			end

			-- Name the object to mark it done
			names[value] = names[value] or new_path

			-- Describe
			InternalPrintTable(value, new_path, new_prefix, names, todo)
		else
			-- Print the value (or the reference name)
			if vName and !todo[value] then
				gMsgC(color_reference)
				gMsgF(string.format("ref: %s",vName))
			else
				InternalPrintValue(value)
			end

			gMsgN()
		end
	end

end

function PrintTableGrep( table, grep, proximity )
	local base = {
		[_G]    = "_G",
		[table] = "root"
	}

	gBegin(grep, proximity)
		objID = 0
		InternalPrintTable(table, nil, "", base, {})
	gFinish()
end

function PrintLocals( level )
	local level = level or 2
	local hash  = {}

	for index = 1, 255 do
		local name, value = debug.getlocal(2, index)

		if !name then
			break
		end

		if value == nil then
			value = NIL
		end

		hash[name] = value
	end

	PrintTableGrep( hash )
end