common.lua

local _, table_clear = pcall(require, 'table.clear')
local format = string.format

local common = {}

local ripairsIterator = function(t, i)
	if i == 1 then
		return nil
	end
	i = i - 1
	return i, t[i]
end

function common.noop() end
function common.pass(...) return ... end

common.empty = setmetatable({}, {
	__metatable = false,
	__newindex = function() end
})

function common.isEmpty(t)
	return nil == next(t)
end

function common.array(...)
	local arr = {}
	local length = 0
	for v in ... do
		length = length + 1
		arr[length] = v
	end
	return arr
end

function common.array2(...)
	local arr = {}
	local length = 0
	for v1, v2 in ... do
		length = length + 1
		arr[length] = {v1, v2}
	end
	return arr
end

function common.get(t, ...)
	for i = 1, select('#', ...) do
		if type(t) ~= 'table' then
			return nil
		end
		t = t[select(i, ...)]
	end
	return t
end

function common.set(t, ...)
	local argLen = select('#', ...)
	assert(argLen > 0)
	if argLen == 1 then
		return (...)
	end
	for i = 1, argLen - 2 do
		local key = select(i, ...)
		if t[key] == nil then
			t[key] = {}
		end
		t = t[key]
		assert(type(t) ~= 'string', 'tried to index a string, but it\'s not allowed')
	end
	t[select(argLen - 1, ...)] = select(argLen, ...)
	return t
end

function common.delete(t, ...)
	local argLen = select('#', ...)
	assert(argLen > 0)
	if argLen == 1 then
		local key = ...
		t[key] = nil
		if common.isEmpty(t) then
			return nil
		end
		return t
	end
	local path = {
		t
	}
	for i = 1, argLen - 1 do
		local key = select(i, ...)
		t = t[key]
		if type(t) ~= 'table' then
			return path[1]
		end
		path[i + 1] = t
	end
	for i = argLen, 1, -1 do
		local key = select(i, ...)
		t = path[i]
		t[key] = nil
		if not common.isEmpty(t) then
			return path[1]
		end
	end
	return nil
end

common.clear = table_clear or function(t)
	for k in pairs(t) do
		rawset(t, k, nil)
	end
	return t
end

common.pack = table.pack or function(...)
	return {
		n = select('#', ...),
		...
	}
end

function common.packCaptures(start, stop, ...)
	return start, stop, common.pack(...)
end

common.unpack = table.unpack or unpack

function common.toPacked(t, len)
	t.n = len or #t
	return t
end

function common.toUnpacked(t)
	t.n = nil
	return t
end

function common.sub(t, i, j)
	local tlen = #t
	j = j or -1
	if j < 0 then j = j + tlen + 1 end
	if i < 0 then i = i + tlen + 1 end
	if i < 1 then i = 1 end
	if j > tlen then j = tlen end
	
	local newT = {}
	for k = i, j do
		newT[k - i + 1] = t[k]
	end
	return newT
end

function common.ripairs(t)
	return ripairsIterator, t, #t + 1
end

function common.keys(t)
	local keys = {}
	for k in pairs(t) do
		table.insert(keys, k)
	end
	return keys
end

function common.values(t)
	local values = {}
	for _, v in pairs(t) do
		table.insert(values, v)
	end
	return values
end

function common.singleToMulti(func)
	return function(...)
		local count = select('#', ...)
		local values = {}
		for i = 1, count do
			values[i] = func((select(i, ...)))
		end
		return common.unpack(values, 1, count)
	end
end

local qmap = {
	[7]  = 'a',
	[8]  = 'b',
	[9]  = 't',
	[11] = 'v',
	[12] = 'f',
	[13] = 'r',
}
local function quote(value)
	local str = format('%q', value)
	str = str:gsub('(\\+)([\n%d]+)', function(bslash, match)
		if #bslash % 2 == 1 then
			if string.byte(match) == 10 then
				return bslash .. 'n' .. match:sub(2)
			end
			local num = tonumber(match:sub(1, 3))
			if num then
				local map = qmap[num]
				if map then
					return bslash .. map .. match:sub(4)
				end
			end
		end
	end)
	return str
end

common.quote = common.singleToMulti(quote)

local indentString = '    '
local function indentation(indent)
	return indentString:rep(indent)
end

local function pretty(value, indent, refmap)
	indent = indent or 0
	local vtype = type(value)
	if vtype == 'string' then
		return quote(value)
	elseif vtype == 'number' or vtype == 'boolean' then
		return tostring(value)
	end
	
	refmap = refmap or {}
	
	if vtype == 'table' and not refmap[value] then
		if common.isEmpty(value) then
			return '{}'
		end
		
		refmap[value] = true
		
		local sequential = {}
		local maxI = -1
		local count = 0
		local isArray = true
		for k in pairs(value) do
			if type(k) == 'number' and k >= 1 and k % 1 == 0 then
				table.insert(sequential, k)
				maxI = math.max(maxI, k)
			else
				isArray = false
			end
			count = count + 1
		end
		
		if isArray and count == maxI then
			do
				indent = indent + 1
				local str = {'{\n'}
				for _, v in ipairs(value) do
					table.insert(str, format('%s%s,\n', indentation(indent), pretty(v, indent, refmap)))
				end
				indent = indent - 1
				table.insert(str, indentation(indent))
				table.insert(str, '}')
				
				local final = table.concat(str)
				local indentCharCount = ((indent + 1) * #indentString * count)
				if #final - indentCharCount > 40 then -- If it's too short we just wanna do 1 line
					return final
				end
			end
			
			local str = {}
			for _, v in ipairs(value) do
				table.insert(str, pretty(v, indent, refmap))
			end
			return format('{ %s }', table.concat(str, ', '))
		end
		
		indent = indent + 1
		
		local str = {'{\n'}
		for k, v in pairs(value) do
			if type(k) == 'string' then
				if not k:match('^[%a_][%w_]*$') then
					k = format('[%q]', k)
				end
			else
				k = format('[%s]', pretty(k, 0, refmap))
			end
			table.insert(str, format('%s%s = %s,\n', indentation(indent), k, pretty(v, indent, refmap)))
		end
		indent = indent - 1
		
		table.insert(str, indentation(indent))
		table.insert(str, '}')
		
		return table.concat(str)
	end
	
	return format('<%s>', value)
end

common.pretty = common.singleToMulti(pretty)

function common.fpprint(file, ...)
	local values = {}
	local vlen = select('#', ...)
	for i = 1, vlen do
		values[i] = pretty((select(i, ...)))
	end
	file:write(table.concat(values, ', ', 1, vlen), '\n')
end

function common.pprint(...)
	common.fpprint(io.stdout, ...)
end

function common.epprint(...)
	common.fpprint(io.stderr, ...)
end

local function readStream(stream, bytes)
	if bytes == nil then bytes = -1 end
	
	local result, err
	if bytes < 0 then
		if bytes == -1 then
			result, err = stream:read '*a'
		else
			local size = stream:seek 'end'
			stream:seek 'set'
			result, err = stream:read(size + bytes + 1)
		end
	else
		result, err = stream:read(bytes)
	end
	
	if not result then
		stream:close()
		return nil, err or 'could not read from stream'
	end
	
	local status
	status, err = stream:close()
	if not status then
		return nil, err
	end
	
	return result
end

local function writeStream(stream, data)
	local status, err = stream:write(data)
	if not status then
		stream:close()
		return false, err or 'could not write to stream'
	end
	
	status, err = stream:close()
	if not status then
		return false, err
	end
	
	return true
end

function common.readFile(path, bytes)
	local stream, err = io.open(path, 'rb')
	if not stream then
		return nil, err
	end
	return readStream(stream, bytes)
end

local function writeFile(path, data, mode)
	local stream, err = io.open(path, mode)
	if not stream then
		return false, err
	end
	return writeStream(stream, data)
end

function common.writeFile(path, data)
	return writeFile(path, data, 'wb')
end

function common.appendFile(path, data)
	return writeFile(path, data, 'ab')
end

function common.fileLines(path)
	local stream, err = io.open(path, 'r')
	if not stream then
		return nil, err
	end
	
	-- FIXME: technically this does not explicitly close the stream. It still gets closed when garbage collected
	-- If we provide our own iterator we can close it, though it still wouldn't be closed on loop break
	return stream:lines()
end

if jit then
	common.isWindows = jit.os == 'Windows'
else
	common.isWindows = os.getenv('OS') == 'Windows_NT'
end

if common.isWindows then
	local escapes = {
		[ '\0'] = '\\0',
		['\10'] = '\\n',
		['\13'] = '\\r',
		[  '%'] = '"%"',
	}
	function common.formCommand(program, ...)
		assert(program)
		local args = common.pack(program:gsub('/', '\\'), ...)
		for i = 1, args.n do
			if not args[i]:match('^[%w_%-/\\:%?]+$') then
				local val = args[i]:gsub('[%z\10\13%%]', function(char)
					return escapes[char]
				end)
				args[i] = string.format('"%s"', val:gsub('(\\*)(")', function(bslash, dquote)
					return bslash:rep(2) .. '\\' .. dquote
				end))
			end
		end
		return string.format('"%s"', table.concat(args, ' ', 1, args.n))
	end
else
	local escapes = {
		['\0'] = '\\0',
	}
	function common.formCommand(program, ...)
		assert(program)
		local args = common.pack(program, ...)
		for i = 1, args.n do
			if not args[i]:match('^[%w_-/]+$') then
				local val = args[i]:gsub('[%z\10\13]', function(char)
					return escapes[char]
				end)
				args[i] = string.format("'%s'", val:gsub("'", "'\\''"))
			end
		end
		return table.concat(args, ' ', 1, args.n)
	end
end

function common.execute(program, ...)
	return os.execute(common.formCommand(program, ...))
end

function common.readProcess(program, ...)
	local line = common.formCommand(program, ...)
	local mode = common.isWindows and 'rb' or 'r'
	local stream, err = io.popen(line, mode)
	if not stream then
		return nil, err
	end
	return readStream(stream)
end

function common.writeProcess(data, program, ...)
	local line = common.formCommand(program, ...)
	local mode = common.isWindows and 'wb' or 'w'
	local stream, err = io.popen(line, mode)
	if not stream then
		return false, err
	end
	return writeStream(stream, data)
end

function common.processLines(program, ...)
	local line = common.formCommand(program, ...)
	local stream, err = io.popen(line, 'r')
	if not stream then
		return nil, err
	end
	
	-- FIXME: technically this does not explicitly close the stream. It still gets closed when garbage collected
	-- If we provide our own iterator we can close it, though it still wouldn't be closed on loop break
	return stream:lines()
end

function common.readCommand(command)
	local mode = common.isWindows and 'rb' or 'r'
	local stream, err = io.popen(command, mode)
	if not stream then
		return nil, err
	end
	return readStream(stream)
end

function common.writeCommand(data, command)
	local mode = common.isWindows and 'wb' or 'w'
	local stream, err = io.popen(command, mode)
	if not stream then
		return false, err
	end
	return writeStream(stream, data)
end

function common.commandLines(command)
	local stream, err = io.popen(command, 'r')
	if not stream then
		return nil, err
	end
	
	-- FIXME: technically this does not explicitly close the stream. It still gets closed when garbage collected
	-- If we provide our own iterator we can close it, though it still wouldn't be closed on loop break
	return stream:lines()
end

function common.equalAny(value, ...)
	local count = select('#', ...)
	if count == 0 then return true end
	for i = 1, count do
		if value == select(i, ...) then
			return true
		end
	end
	return false
end

function common.equalOne(value, ...)
	local count = select('#', ...)
	for i = 1, count do
		if value == select(i, ...) then
			return true
		end
	end
	return false
end

function common.equalAll(value, ...)
	local count = select('#', ...)
	for i = 1, count do
		if value ~= select(i, ...) then
			return false
		end
	end
	return true
end

return common