#!/usr/bin/env lua

--

-- publictext

-- ucspi-tcp text://protocol server

--

local assert = assert

local io = require( 'io' )

local ipairs = ipairs

local os = require( 'os' )

local pcall = pcall

local table = require( 'table' )

local tonumber = tonumber

local tostring = tostring

_ENV = nil

local EOL = '\r\n'

local SP = ' '

local _request = nil

local function REQUEST( aRequest )

_request = aRequest or _request or io.stdin:read() or os.exit( false )

return _request

end

local function LOG( aStatus, aSize )

local aBuffer = {}

aBuffer[ #aBuffer + 1 ] = os.getenv( 'TCPREMOTEHOST' ) or os.getenv( 'TCPREMOTEIP' ) or '-' -- remotehost

aBuffer[ #aBuffer + 1 ] = os.getenv( 'TCPREMOTEINFO' ) or '-' -- rfc931

aBuffer[ #aBuffer + 1 ] = '-' -- authuser

aBuffer[ #aBuffer + 1 ] = ( '[%s]' ):format( os.date( '!%Y-%m-%dT%TZ' ) ) -- [date]

aBuffer[ #aBuffer + 1 ] = ( '%q' ):format( REQUEST() or '' ) -- "request"

aBuffer[ #aBuffer + 1 ] = tostring( aStatus or '-' ) -- status

aBuffer[ #aBuffer + 1 ] = tostring( aSize or '0' ) -- bytes

io.stderr:write( table.concat( aBuffer, ' ' ), '\n' )

end

local function STATUS( aStatus, aDescription )

local aStatus = assert( tonumber( aStatus ) )

assert( aDescription )

assert( 0 ~= aDescription:len() )

assert( 1024 >= aDescription:len() )

assert( not aDescription:find( '%c' ) )

io.stdout:write( aStatus, SP, aDescription, EOL )

io.stdout:flush()

end

local function CHUNK( aFile )

return function() return aFile:read( 4096 ) end

end

local function OK( aFile, aType, aSize )

STATUS( 20, assert( aType ) )

LOG( 20, assert( aSize ) )

for aChunk in CHUNK( assert( aFile ) ) do

io.stdout:write( aChunk )

io.stdout:flush()

end

aFile:close()

os.exit( true )

end

local function REDIRECT( aLocation )

STATUS( 30, aLocation )

LOG( 30 )

os.exit( true )

end

local function NOK()

STATUS( 40, 'NOK' )

LOG( 40 )

os.exit( false )

end

local function LINK( aFile, aType )

if aType ~= '.lnk' then return end

local aLocation = assert( aFile:read():match( '^(%C+)' ) )

assert( aFile:close() )

REDIRECT( aLocation )

end

local function QUOTE( anArgument )

return ( "'%s'" ):format( assert( anArgument ):gsub( "'", "'\\''" ) )

end

local function TYPE( aFileName )

local aCommand = ( 'file --brief --mime-type --mime-encoding %s 2>/dev/null' ):format( assert( QUOTE( aFileName ) ) )

local aHandle = assert( io.popen( aCommand, 'r' ) )

local aType = assert( aHandle:read() )

assert( aHandle:close() )

return aType

end

local function FILE( aName, anExtension )

local someTypes = { '.lnk', '' }

for _, aType in ipairs( someTypes ) do

local aFileName = ( '%s.%s%s' ):format( aName, anExtension, aType )

local aFile = io.open( aFileName, 'rb' )

if aFile then

local aSize = assert( aFile:seek( 'end' ) )

assert( aFile:seek( 'set' ) )

LINK( aFile, aType )

return aFile, TYPE( aFileName ), aSize

end

end

end

local function HANDLE()

local aRequest = REQUEST()

assert( aRequest )

aRequest = assert( REQUEST( aRequest:match( '^(%C+)' ) ) )

assert( 0 ~= aRequest:len() )

assert( 1024 >= aRequest:len() )

assert( not aRequest:find( '%s' ) )

assert( aRequest == aRequest:lower() )

assert( 'text://' == aRequest:sub( 1, 7 ) )

local aName, anExtension = aRequest:match( '/([%w-]+)%.(%w+)$' )

if '/' == aRequest:sub( -1, -1 ) then aName = 'index' anExtension = 'txt' end

if not aName then REDIRECT( ( '%s/' ):format( aRequest ) ) end

assert( aName )

assert( 0 ~= aName:len() )

assert( 128 >= aName:len() )

assert( anExtension )

assert( 0 ~= anExtension:len() )

assert( 3 >= anExtension:len() )

local aFile, aType, aSize = FILE( aName, anExtension )

OK( aFile, aType, aSize )

end

if not pcall( HANDLE ) then NOK() end