midcraft-commander

-----------------------------------------------------------------------------
-- Midcraft Commander
-- Author: MewK
-- Version: 0.1.2
--
-- This program is released under the MIT License (MIT).
-----------------------------------------------------------------------------

local args = { ... }
if # args == 1 and (args[1] == '-h' or args[1] == '?') then
	print('Midcraft Commander 0.1.2')
	print('')
	print('Keys:')
	print('  Ctrl  Activates the menu') 
	print('  Tab   Activates the integrated shell')
	print('')
	print('Menu:')
	print('  Run   Run with parameters command') 
	print('  Ed    Edit command')
	print('  Cp    Copy command') 
	print('  Ct    Cut command')
	print('  Pst   Paste command') 
	print('  Dl    Delete command') 
	print('  Rn    Rename Command') 
	print('  NwFl  New File command') 
	print('  NwDr  New directory command') 
	print('  Qt    Exit command')
	return
end

local running = true

local w, h = term.getSize() -- int
local hw = math.floor(w / 2)

local views = {}
views[1] = { x = 1, y = 2, width = hw - 1, height = h - 3, active = true, scrollOffset = 0, selectionIndex = 1, currentDirectory = '', entryList = {} }
views[2] = { x = hw + 2, y = 2, width = hw - 1, height = h - 3, active = false, scrollOffset = 0, selectionIndex = 1, currentDirectory = '', entryList = {} }
local _activeView = 1;
local function activeView() return views[_activeView] end

local menuActive = false
local menuItems = { 'Run', 'Ed', 'Cp', 'Ct', 'Pst', 'Dl', 'Rn', 'NwFl', 'NwDr', 'Qt' }
local menuItemSelection = 1

local commandHistory = {}
local copyIndex = 0
local cutIndex = 0
local copyCache = nil
local cutCache = nil

-- GUI

local function trimString(text, width)
	if width > 6 and string.len(text) > 0 and string.len(text) > width then
		text = string.sub(text, 0, width - 3)..'...'
	end
	return text
end

local function drawEntries(view)
	local drawIndex = 0
	local startIndex = view.scrollOffset + 1
	local endIndex = view.scrollOffset + view.height
	if endIndex > # view.entryList then
		endIndex = # view.entryList
	end
	
	for index = startIndex, endIndex do
		local entry = view.entryList[index]
		local _entry = trimString(entry, view.width - 5)
		
		-- Selection indicator
		if view.active and view.selectionIndex == index then
			_entry = '» '.._entry
		else
			_entry = '  '.._entry
		end
		
		-- Copy indicator
		
		if copyCache ~= nil and copyIndex == index then
			local copyName = fs.getName(copyCache)
			if fs.isDir(copyCache) then 
				copyName = '/'..copyName 
			end
			if copyName == entry then
				_entry = _entry..' +'
			end
			
		-- Cut indicator
		
		elseif cutIndex == index and cutCache ~= nil then
			local cutName = fs.getName(cutCache)
			if fs.isDir(cutCache) then 
				cutName = '/'..cutName 
			end
			if cutName == entry then
				_entry = _entry..' -'
			end
		end
		
		term.setCursorPos(view.x, view.y + drawIndex)
		term.write(_entry)
		
		drawIndex = drawIndex + 1
	end
end

local function drawLineH(x, y, length)
    term.setCursorPos(x, y)
	for i = 1, length do
		term.write('-')
	end
end

local function drawLabeledLineH(x, y, length, text)
	text = trimString(text, length - 5)
	drawLineH(x, y, length)
    term.setCursorPos(x + 1, y)
	term.write(' '..text..' ')
end

local function drawLineV(x, y, length)
	for i = 0, length - 1 do
		term.setCursorPos(x, y + i)
		if i == 0 or i == length - 1 then
			term.write('+')
		else
			term.write('|')
		end
	end
end

local function redraw()
	term.clear()

	-- Draw frame
    drawLabeledLineH(1, 1, hw, views[1].currentDirectory)
	drawLabeledLineH(hw + 2, 1, hw, views[2].currentDirectory)
	
	drawLineH(1, h - 1, w)
	drawLineV(hw + 1, 1, h - 1)
	drawLineV(hw, 1, h - 1)
	
	-- Draw dir lists
	for index, view in ipairs(views) do
		drawEntries(view)
	end
	
	-- Draw scroll indicators
	-- Left top
	if views[1].scrollOffset > 0 then
		term.setCursorPos(hw, 2)
		term.write('#')
	end
	-- Left bottom
	if # views[1].entryList - views[1].scrollOffset > views[1].height then
		term.setCursorPos(hw, h - 2)
		term.write('#')
	end
	-- Right top
	if views[2].scrollOffset > 0 then
		term.setCursorPos(hw + 1, 2)
		term.write('#')
	end
	-- Right bottom
	if # views[2].entryList - views[2].scrollOffset > views[2].height then
		term.setCursorPos(hw + 1, h - 2)
		term.write('#')
	end
	
	-- Draw menu
	term.setCursorPos(3, h)
	term.clearLine()
	for index, item in ipairs(menuItems) do
		if index == menuItemSelection and menuActive then
			term.write('['..item..']')
		else
			term.write(' '..item..' ')
		end
	end
end

-- I/O

local function readUserLine(prefix, commandHistory)
	term.setCursorPos(1, h)
	term.clearLine()
	term.write(prefix)

	local line = read(nil, commandHistory)
	return line
end

local function moveEntry(source, destination, copyMode, forceOverwrite)
	-- Input validation
	if not source or not destination or not fs.exists(source) then
		return 0
	end

	-- File equals
	if source == destination then
		return -1
	end

	-- File exists		
	if fs.exists(destination) then
		local overwrite
		
		if forceOverwrite then
			overwrite = 'y'
		else
			overwrite = readUserLine('File exists. Overwrite? (y/n): ', nil)
		end
			
		if overwrite == 'y' then
			fs.delete(destination)
			if copyMode then
				fs.copy(source, destination)
			else
				fs.move(source, destination)
			end
			return 2
		else
			return -2
		end
	else
		if copyMode then
			fs.copy(source, destination)
		else
			fs.move(source, destination)
		end
		return 1
	end
end

local function readDirectory(path)
	-- Sort into dirs/files
	local files = {}
	local dirs = {}

	if path ~= '/' then
		table.insert(dirs, '/..')
	end
	
	for index, entry in pairs(fs.list(path)) do
		local sPath = fs.combine(path, entry)
		if fs.isDir(sPath) then
			table.insert(dirs, '/'..entry)
		else
			table.insert(files, entry)
		end
	end
				
	table.sort(dirs)
	table.sort(files)
	
	for index, file in ipairs(files) do
		table.insert(dirs, file)
	end
	
	return dirs
end

-- Other

local function refreshViews()
	for n, view in ipairs(views) do
		view.entryList = readDirectory(view.currentDirectory)
	end
	redraw()
end

local function clearCache() 
	copyCache = nil
	cutCache = nil
	copyIndex = 0
	cutIndex = 0
end

-- Execution

local function runProgram(path, ...)
	term.clear()
	term.setCursorPos(1, 1)
	shell.run(path, ...)
	
	-- Wait for user action if text is on screen
	local cx,cy = term.getCursorPos()
	if cx ~= 1 or cy ~= 1 then
		local text = '< Press any key to continue >'
		term.setCursorPos(hw - math.floor(string.len(text) / 2), h)
		term.clearLine()
		term.write(text)
		
		repeat
			local event, param = os.pullEvent()
		until event == 'key'
	end
	
	redraw()
end

local function runCommand(command)
	local words = {}
	for match in string.gmatch(command, "[^ \t]+") do
		table.insert(words, match)
	end

	if words[1] then
		runProgram(words[1], unpack(words, 2))
		refreshViews()
	end
end

local function executeEntry(path)
	if fs.exists(path) then
		if fs.isDir(path) then
			return readDirectory(path)
		else
			runProgram(path)
			refreshViews()
		end
	end
	return nil
end

-- Menu

local menuFunctions = {
	-- Run with parameters command
	['Run'] = function(path)
		local parameter = readUserLine('Parameters: ', nil)
		runCommand(path..' '..parameter)
		redraw()
	end,
	
	-- Edit command
	['Ed'] = function(path)
		if not fs.isDir(path) then
			runProgram('edit', path)
		end
	end,
	
	-- Copy command
	['Cp'] = function(path)
		clearCache()
		copyCache = path
		copyIndex = activeView().selectionIndex
		redraw()
	end,
	
	-- Cut command
	['Ct'] = function(path)
		clearCache()
		cutCache = path
		cutIndex = activeView().selectionIndex
		redraw()
	end,
	
	-- Paste command
	['Pst'] = function(path)
		if copyCache ~= nil or cutCache ~= nil then
			local code
			
			-- Copy
			if copyCache ~= nil	then	
				code = moveEntry(copyCache, fs.combine(activeView().currentDirectory, fs.getName(copyCache)), true, false)
			
			-- Move
			else
				code = moveEntry(cutCache, fs.combine(activeView().currentDirectory, fs.getName(cutCache)), false, false)
			end
			
			-- Overwrite canceled
			if code == -2 then
				redraw()
				
			-- Source equals destination or invalid parameter
			elseif code == -1 or code == 0 then
				clearCache()
				redraw()
				
			-- Attempt successful
			elseif code == 1 or code == 2 then
				clearCache()
				refreshViews()
			end
		end
	end,
	
	-- Delete command
	['Dl'] = function(path)
		path = shell.resolve(path)
		fs.delete(path)
		activeView().selectionIndex = activeView().selectionIndex - 1
		if (activeView().selectionIndex < 1) then
			activeView().selectionIndex = 1
		end
		refreshViews()
	end,
	
	-- New File command
	['Rn'] = function(path)
		local name = readUserLine('New Name: ', nil)
		if name ~= '' then
			moveEntry(path, fs.combine(activeView().currentDirectory, name), false, true)
			refreshViews()
		end
	end,
	
	-- New File command
	['NwFl'] = function(path)
		local name = readUserLine('Name: ', nil)
		if name ~= '' then
			path = shell.resolve('/'..fs.combine(activeView().currentDirectory, name))
			local file = io.open(path, 'w')
			file:write(' ') -- edit can't handle empty files
			file:close()
			refreshViews()
		else
			redraw()
		end
	end,
	
	-- New directory command
	['NwDr'] = function(path)
		local name = readUserLine('Name: ', nil)
		if name ~= '' then
			path = shell.resolve('/'..fs.combine(activeView().currentDirectory, name))
			fs.makeDir(path)
			refreshViews()
		else
			redraw()
		end
	end,
	
	-- Exit command
	['Qt'] = function(path)
		running = false
	end
}

local function callMenuItem(name, path)
	local menuFunction = menuFunctions[menuItems[name]]
	if menuFunction then
		menuFunction(path)
	end

	menuActive = false
	redraw()
end

-- Body

for n, view in ipairs(views) do
	view.currentDirectory = '/'..shell.dir();
	view.entryList = readDirectory(view.currentDirectory);
end

redraw()

while running do
  local event, param = os.pullEvent()
  if event == 'key' then
	-- Up
    if param == 200 then
		-- Move entry selection
		if not menuActive then
			if activeView().selectionIndex > 1 then
				activeView().selectionIndex = activeView().selectionIndex - 1
				if activeView().selectionIndex <= activeView().scrollOffset then
					activeView().scrollOffset = activeView().scrollOffset - activeView().height
				end
				redraw()
			end
		end
	
	-- Down
	elseif param == 208 then
		-- Move entry selection
		if not menuActive then
			if activeView().selectionIndex < # activeView().entryList then
				activeView().selectionIndex = activeView().selectionIndex + 1
				if activeView().selectionIndex > activeView().height + activeView().scrollOffset then
					activeView().scrollOffset = activeView().scrollOffset + activeView().height
				end
				redraw()
			end
		end

	-- Left
	elseif param == 203 then
		-- Change active side
		if not menuActive then
			if _activeView == 2 then
				activeView().active = false
				_activeView = 1
				activeView().active = true
				redraw()
			end
			
		-- Move menu selection
		else
			menuItemSelection = menuItemSelection - 1
			if menuItemSelection < 1 then
				menuItemSelection = # menuItems
			end
			redraw()
		end
	
	-- Right
	elseif param == 205 then
		-- Change active side
		if not menuActive then
			if _activeView == 1 then
				activeView().active = false
				_activeView = 2
				activeView().active = true
				redraw()
			end
			
		-- Move menu selection
		else
			menuItemSelection = menuItemSelection + 1
		  	if menuItemSelection > # menuItems then
				menuItemSelection = 1
		  	end
		  	redraw()
		end
	
	-- Enter
	elseif param == 28 then
		local targetPath = '/'..fs.combine(activeView().currentDirectory, activeView().entryList[activeView().selectionIndex])
		-- Run
		if not menuActive then
			local newEntryList = executeEntry(targetPath)
			if newEntryList ~= nil then
				activeView().currentDirectory = targetPath
				activeView().selectionIndex = 1
				activeView().entryList = newEntryList
				redraw()
			end
			
		-- Menu selection
		else
			callMenuItem(menuItemSelection, targetPath)
		end
	
	-- Ctrl (menu toggle)
	elseif param == 29 then
		menuActive = not menuActive
		if menuActive then
			menuItemSelection = 1
		end
		redraw()
	
	-- Tab (command line toggle)
	elseif param == 15 then
		local command
		repeat
			command = readUserLine(shell.dir()..'> ', commandHistory)
			if command ~= '' then
				if command ~= commandHistory[# commandHistory] then
					table.insert(commandHistory, command)
				end
				runCommand(command)
			end
		until command == ''
		
		redraw()
	end
  end
end

term.clear()
term.setCursorPos(1, 1)