local Ansi     = require('opus.ansi')
local Config   = require('opus.config')
local Packages = require('opus.packages')
local UI       = require('opus.ui')
local Util     = require('opus.util')

local colors   = _G.colors
local term     = _G.term

UI:configure('PackageManager', ...)

local config = Config.load('package')

local page = UI.Page {
	grid = UI.ScrollingGrid {
		x = 2, ex = 14, y = 2, ey = -6,
		values = { },
		columns = {
			{ heading = ' Package', key = 'displayName' },
		},
		sortColumn = 'name',
		autospace = true,
		help = 'Space to select, Enter to toggle',
	},
	installSelected = UI.Button {
		x = 2, y = -3,
		text = ' + ',
		event = 'batch_action',
		operation = 'install',
		operationText = 'Install',
		help = 'Install or update selected',
	},
	removeSelected = UI.Button {
		x = 8, y = -3,
		text = ' - ',
		event = 'batch_action',
		operation = 'uninstall',
		operationText = 'Remove',
		help = 'Remove selected',
	},
	updateall = UI.Button {
		ex = -2, y = -3, width = 12,
		text = 'Update All',
		event = 'updateall',
		help = 'Update all installed packages',
	},
	description = UI.TextArea {
		x = 16, y = 3, ey = -5,
		marginRight = 2, marginLeft = 0,
	},
	UI.Checkbox {
		x = 3, y = -5,
		label = 'Compress',
		textColor = 'yellow',
		backgroundColor = 'primary',
		value = config.compression,
		help = 'Compress packages (experimental)',
	},
	action = UI.SlideOut {
		titleBar = UI.TitleBar {
			event = 'hide-action',
		},
		button = UI.Button {
			x = -10, y = 3,
			text = ' Begin ', event = 'begin',
		},
		output = UI.Embedded {
			y = 5, ey = -2, x = 2, ex = -2,
			visible = true,
		},
	},
	statusBar = UI.StatusBar { },
	accelerators = {
		[ 'control-q' ] = 'quit',
	},
}

function page:loadPackages()
	self.grid.values = { }
	self.statusBar:setStatus('Downloading...')
	self:sync()

	for k in pairs(Packages:list()) do
		local manifest = Packages:getManifest(k)
		if not manifest then
			manifest = {
				invalid = true,
				description = 'Unable to download manifest',
				title = '',
			}
		end
		table.insert(self.grid.values, {
			installed = not not Packages:isInstalled(k),
			selected = false,
			name = k,
			displayName = k,
			manifest = manifest,
		})
	end
	self.grid:update()
	self.grid:setIndex(1)
	self.grid:emit({
		type = 'grid_focus_row',
		selected = self.grid:getSelected(),
		element = self.grid,
	})
	self.statusBar:setStatus('Updated packages')
end

function page.grid:getRowTextColor(row, selected)
	if row.selected then
		return colors.cyan
	end
	if row.installed then
		return colors.yellow
	end
	return UI.Grid.getRowTextColor(self, row, selected)
end

function page:getSelectedPackages()
	local selected = { }
	for _, row in pairs(self.grid.values) do
		if row.selected then
			table.insert(selected, row)
		end
	end
	return selected
end

function page:getSelectedCount()
	local count = 0
	for _, row in pairs(self.grid.values) do
		if row.selected then
			count = count + 1
		end
	end
	return count
end

function page:toggleSelection(row)
	row.selected = not row.selected
	row.displayName = row.selected and ('\187 ' .. row.name) or row.name
	self.grid:draw()
	self:updateStatus()
end

function page:clearSelection()
	for _, row in pairs(self.grid.values) do
		row.selected = false
		row.displayName = row.name
	end
	self.grid:draw()
end

function page:updateStatus()
	local count = self:getSelectedCount()
	if count > 0 then
		self.statusBar:setStatus(count .. ' package(s) selected')
	else
		local focused = self.grid:getSelected()
		if focused then
			self.statusBar:setStatus(focused.installed and 'Installed' or '')
		end
	end
end

function page.action:show()
	self.output.win:clear()
	UI.SlideOut.show(self)
end

function page:run(operation, name)
	local oterm = term.redirect(self.action.output.win)
	self.action.output:clear()
	local cmd = string.format('package %s %s', operation, name)
	term.setCursorPos(1, 1)
	term.clear()
	term.setTextColor(colors.yellow)
	print(cmd .. '\n')
	term.setTextColor(colors.white)
	local s, m = Util.run(_ENV, '/sys/apps/package.lua', operation, name)

	if not s and m then
		_G.printError(m)
	end
	term.redirect(oterm)
	self.action.output:draw()
end

function page:updateSelection(selected)
	-- no-op: buttons are always active for batch operations
end

function page:eventHandler(event)
	if event.type == 'focus_change' then
		self.statusBar:setStatus(event.focused.help)

	elseif event.type == 'grid_focus_row' then
		local manifest = event.selected.manifest

		self.description:setValue(string.format('%s%s\n\n%s%s',
			Ansi.yellow, manifest.title,
			Ansi.white, manifest.description))
		self.description:draw()
		self:updateStatus()

	elseif event.type == 'grid_select' then
		-- Space or Enter toggles selection
		local row = self.grid:getSelected()
		if row then
			self:toggleSelection(row)
		end

	elseif event.type == 'checkbox_change' then
		config.compression = not config.compression
		Config.update('package', config)

	elseif event.type == 'updateall' then
		self.operation = 'updateall'
		self.operationTargets = { }
		self.action.button.text = ' Begin '
		self.action.button.event = 'begin'
		self.action.titleBar.title = 'Update All'
		self.action:show()

	elseif event.type == 'batch_action' then
		local targets = self:getSelectedPackages()
		local operation = event.button.operation

		-- fall back to focused row if nothing selected
		if #targets == 0 then
			local focused = self.grid:getSelected()
			if focused then
				targets = { focused }
			end
		end

		if #targets == 0 then return end

		-- for install: update already-installed packages, install new ones
		if operation == 'install' then
			self.operation = 'install'
		else
			-- filter to only installed packages for uninstall
			local installed = { }
			for _, t in ipairs(targets) do
				if t.installed then
					table.insert(installed, t)
				end
			end
			targets = installed
			if #targets == 0 then return end
			self.operation = 'uninstall'
		end

		self.operationTargets = targets
		local title = #targets == 1
			and targets[1].manifest.title
			or (#targets .. ' packages')
		self.action.button.text = ' Begin '
		self.action.button.event = 'begin'
		self.action.titleBar.title = string.format('%s %s',
			operation == 'install' and 'Install/Update' or 'Remove', title)
		self.action:show()

	elseif event.type == 'hide-action' then
		self.action:hide()

	elseif event.type == 'begin' then
		if self.operation == 'updateall' then
			self:run('updateall', '')
		else
			for _, target in ipairs(self.operationTargets) do
				local op = self.operation
				if op == 'install' and target.installed then
					op = 'update'
				end
				self:run(op, target.name)
				target.installed = Packages:isInstalled(target.name)
			end
			self:clearSelection()
			self:updateStatus()
		end

		self.action.button.text = ' Done  '
		self.action.button.event = 'hide-action'
		self.action.button:draw()

	elseif event.type == 'quit' then
		UI:quit()
	end
	UI.Page.eventHandler(self, event)
end

UI:setPage(page)
page.statusBar:setStatus('Downloading...')
page:sync()
Packages:downloadList()
page:loadPackages()
page:sync()

UI:start()