-- Setup process switching
local parentTerm = term.current()
local w,h = parentTerm.getSize()

local tProcesses = {}
local nCurrentProcess = nil
local nRunningProcess = nil
local multishell = {}



function freeSpace (space)
	for i=1,space,1 do
		write(" ")
	end
end

function multishell.printTable (tab,dep,...)
	local filter={...}

	if dep==nil then
	dep=1
	end
	print ("")
	freeSpace(dep-1)
	print ("{")
	for i,v in pairs (tab) do
		local filMatch=false
		for j,w in pairs (filter) do
			if w==i then
				filMatch=true
			end
		end
		if not filMatch then
			freeSpace(dep)
			write (i.."    ")
			if type(v) =="table" then
				dep=dep+1
				multishell.printTable(v,dep,unpack(filter))
				dep=dep-1
			else
				print (v)
			end
			local curX,curY = term.getCursorPos()
			local sizeX,sizeY = term.getSize()
			if curY == sizeY then
				os.pullEvent("key")
			end
		end
	end
	freeSpace(dep-1)
	print ("}")
end

local function selectProcess( n )
    if nCurrentProcess ~= n then
        if nCurrentProcess then
            local tOldProcess = tProcesses[ nCurrentProcess ]
            tOldProcess.window.setVisible( false )
        end
        nCurrentProcess = n
        if nCurrentProcess then
            local tNewProcess = tProcesses[ nCurrentProcess ]
            tNewProcess.window.setVisible( true )
            tNewProcess.bInteracted = true
        end
    end
end

local function setProcessTitle( n, sTitle )
    tProcesses[ n ].sTitle = sTitle
end

function resumeProcess( nProcess, sEvent, ... )
    local tProcess = tProcesses[ nProcess ]
    local sFilter = tProcess.sFilter
    if sFilter == nil or sFilter == sEvent or sEvent == "terminate" then
        local nPreviousProcess = nRunningProcess
        nRunningProcess = nProcess
        term.redirect( tProcess.terminal )
        local ok, result = coroutine.resume( tProcess.co, sEvent, ... )
        tProcess.terminal = term.current()
        if ok then
            tProcess.sFilter = result
        else
            printError( result )
        end
        nRunningProcess = nPreviousProcess
    end
end

function multishell.killProcess (ID)
	if ID~=1 then
		resumeProcess( ID, "terminate")
	end
end
local nLastProcess = 0
local function launchProcess( tProgramEnv, sProgramPath, ... )
    local tProgramArgs = { ... }
	nLastProcess = nLastProcess + 1 
    local nProcess = nLastProcess
    local tProcess = {}
    tProcess.sTitle = fs.getName( sProgramPath )
    tProcess.window = window.create( parentTerm, 1, 1, w, h, false )
    tProcess.co = coroutine.create( function()
		--if nLastProcess~=1 then
	--		parallel.waitForAny( 
	--		function() os.run( tProgramEnv, sProgramPath, unpack( tProgramArgs ) ) end,
	--		function() endProcess(nProcess) end
	--		)
		--else
			os.run( tProgramEnv, sProgramPath, unpack( tProgramArgs ) )
		--end
	    if not tProcess.bInteracted then
            term.setCursorBlink( false )
            print( "Press any key to continue" )
            os.pullEvent( "char" )
        end
		if nCurrentProcess==nProcess then
			selectProcess (1)
		end
    end )
	
    tProcess.sFilter = nil
    tProcess.terminal = tProcess.window
    tProcess.bInteracted = false
    tProcesses[ nProcess ] = tProcess
    resumeProcess( nProcess )
    return nProcess
end

local function cullProcess( nProcess )
	
    local tProcess = tProcesses[ nProcess ]
	--printTable(tProcess)
	--local cor = tProcess.co
	--print (cor)
	--print (coroutine.status(cor))
    if coroutine.status( tProcess.co ) == "dead" then
		multishell.printTable(tProcess,1,"window","terminal")
		if nCurrentProcess~=1 then
			if nCurrentProcess == nProcess then
				selectProcess( 1 )
			end
			if nCurrentProcess~= 1 then
				tProcesses[ nProcess ] = nil
			end
		end
    end
end

local function cullProcesses()
    local culled = false
    for n=multishell.getCount(),1,-1 do
        culled = culled or cullProcess( n )
    end
    return culled
end








function multishell.getFocus()
    return nCurrentProcess
end

function multishell.setFocus( n )
    if n >= 1 and n <= multishell.getCount() then
        selectProcess( n )
        return true
    end
    return false
end

function multishell.getTitle( n )
    if n >= 1 and n <= multishell.getCount() then
        return tProcesses[n].sTitle
    end
    return nil
end

function multishell.setTitle( n, sTitle )
    if n >= 1 and n <= multishell.getCount() then
        setProcessTitle( n, sTitle )
    end
end

function multishell.getCurrent()
    return nRunningProcess
end

function multishell.launch( tProgramEnv, sProgramPath, ... )
    local previousTerm = term.current()
    local nResult = launchProcess( tProgramEnv, sProgramPath, ... )
    term.redirect( previousTerm )
    return nResult
end

function multishell.getCount()
    local count = 0

    for id, proc in pairs(tProcesses) do
        count = count + 1
    end

    return count
end

-- Begin
--parentTerm.clear()
selectProcess( launchProcess( {
    ["shell"] = shell,
    ["multishell"] = multishell,
}, "/rom/programs/shell" ) )

-- Run processes
while multishell.getCount() > 0 do
    -- Get the event
    local tEventData = { os.pullEventRaw() }
    local sEvent = tEventData[1]

    if sEvent == "char" or sEvent == "key" or sEvent == "paste" or sEvent == "terminate" then
        -- Keyboard event
        -- Passthrough to current process
        resumeProcess( nCurrentProcess, unpack( tEventData ) )
        cullProcess( nCurrentProcess )

    elseif sEvent == "mouse_click" or sEvent == "mouse_drag" or sEvent == "mouse_scroll" then
        -- Click event
        local button, x, y = tEventData[2], tEventData[3], tEventData[4]
		-- Passthrough to current process
		resumeProcess( nCurrentProcess, sEvent, button, x, y )
	--	cullProcess( nCurrentProcess )
    elseif sEvent == "process_kill" then
	
		resumeProcess( tEventData[2], unpack( tEventData ) )

    else
        -- Other event
        -- Passthrough to all processes
		print (sEvent)
        local nLimit = multishell.getCount() -- Storing this ensures any new things spawned don't get the event
		for n=2,nLimit do
			resumeProcess( n, unpack( tEventData ) )
		end
	--	cullProcesses() 

    end
end

-- Shutdown
term.redirect( parentTerm )