local S = classroom.S
local FS = classroom.FS
local infos = {
	{
		title = S"Shout?",
		type = "priv",
		privs = { shout = true },
	},
	{
		title = S"Fly?",
		type = "priv",
		privs = { fly = true },
	},
	{
		title = S"Fast?",
		type = "priv",
		privs = { fast = true },
	},
}

local function get_group(context)
	if context and context.groupname then
		return classroom.get_group_students(context.groupname)
	else
		return classroom.get_students()
	end
end

sfinv.register_page("classroom:edu", {
	title = S"Classroom",
	check_perm = function(self, player)
		return minetest.check_player_privs(player:get_player_name(), { teacher = true })
	end,
	is_in_nav = function(self, player, context)
		return self:check_perm(player)
	end,
	get = function(self, player, context)
		if not self:check_perm(player) then
			return "label[0,0;" .. FS"Access denied" .. "]"
		end

		local fs = {
			"tablecolumns[color;text"
		}

		context.select_toggle = context.select_toggle or "all"

		for i, col in pairs(infos) do
			fs[#fs + 1] = ";color;text,align=center"
			if i == 1 then
				fs[#fs + 1] = ",padding=2"
			end
		end

		fs[#fs + 1] = "]"
		do
			fs[#fs + 1] = "tabheader[0.3,1.1;group;"
			fs[#fs + 1] = FS"All"
			local selected_group_idx = 1
			local i = 2
			for name, group in pairs(classroom.get_all_groups()) do
				fs[#fs + 1] = ","
				fs[#fs + 1] = minetest.formspec_escape(name)
				if context.groupname and name == context.groupname then
					selected_group_idx = i
				end
				i = i + 1
			end
			fs[#fs + 1] = ";"
			fs[#fs + 1] = tostring(selected_group_idx)
			fs[#fs + 1] = "]"
		end
		fs[#fs + 1] = "table[0,0.8;5,8;students;,Name"
		for _, col in pairs(infos) do
			fs[#fs + 1] = ",," .. col.title
		end

		local students = get_group(context)
		local selection_id = ""
		context.students = table.copy(students)
		for i, student in pairs(students) do
			fs[#fs + 1] = ",,"
			fs[#fs + 1] = minetest.formspec_escape(student)

			if student == context.selected_student then
				selection_id = tostring(i + 1)
			end

			for _, col in pairs(infos) do
				local color, value
				if col.type == "priv" then
					local has_priv = minetest.check_player_privs(student, col.privs)
					color = has_priv and "green" or "red"
					value = has_priv and FS"Yes" or FS"No"
				end

				fs[#fs + 1] = ","
				fs[#fs + 1] = color
				fs[#fs + 1] = ","
				fs[#fs + 1] = minetest.formspec_escape(value)
			end
		end

		fs[#fs + 1] = ";"
		fs[#fs + 1] = selection_id
		fs[#fs + 1] = "]"

		fs[#fs + 1] = "button[5.25,-0.2;1.4,1;new_group;"
		fs[#fs + 1] = FS"New Group"
		fs[#fs + 1] = "]"
		if context.groupname then
			fs[#fs + 1] = "button[6.65,-0.2;1.4,1;edit_group;"
			fs[#fs + 1] = FS"Edit Group"
			fs[#fs + 1] = "]"
		else
			fs[#fs + 1] = "box[6.65,-0.1;1.2,0.7;#222]"
			fs[#fs + 1] = "label[6.8,0.05;"
			fs[#fs + 1] = FS"Edit Group"
			fs[#fs + 1] = "]"
			fs[#fs + 1] = "tooltip[6.65,-0.2;1.4,1;"
			fs[#fs + 1] = FS"Please select a group first"
			fs[#fs + 1] = "]"
		end

		fs[#fs + 1] = "container[5.25,1.1]"
		fs[#fs + 1] = "box[-0.25,-0.3;3.1,1.15;#666]"
		fs[#fs + 1] = "label[0,-0.3;"
		fs[#fs + 1] = FS"Run actions on:"
		fs[#fs + 1] = "]"
		if context.select_toggle == "all" then
			fs[#fs + 1] = "box[0,0.1;0.8,0.7;#53ac56]"
			fs[#fs + 1] = "label[0.3,0.25;"
			fs[#fs + 1] = FS"All"
			fs[#fs + 1] = "]"
		else
			fs[#fs + 1] = "button[0,0;1,1;select_all;"
			fs[#fs + 1] = FS"All"
			fs[#fs + 1] = "]"
		end
		if not context.groupname then
			fs[#fs + 1] = "box[0.9,0.1;0.8,0.7;#333]"
			fs[#fs + 1] = "label[1.05,0.25;"
			fs[#fs + 1] = FS"Group"
			fs[#fs + 1] = "]"
			fs[#fs + 1] = "tooltip[0.9,0;1,1;"
			fs[#fs + 1] = FS"Please select a group first"
			fs[#fs + 1] = "]"
		elseif context.select_toggle == "group" then
			fs[#fs + 1] = "box[0.9,0.1;0.8,0.7;#53ac56]"
			fs[#fs + 1] = "label[1.05,0.25;"
			fs[#fs + 1] = FS"Group"
			fs[#fs + 1] = "]"
		else
			fs[#fs + 1] = "button[0.9,0;1,1;select_group;"
			fs[#fs + 1] = FS"Group"
			fs[#fs + 1] = "]"
		end
		if not context.selected_student then
			fs[#fs + 1] = "box[1.8,0.1;0.8,0.7;#333]"
			fs[#fs + 1] = "label[1.85,0.25;"
			fs[#fs + 1] = FS"Selected"
			fs[#fs + 1] = "]"
			fs[#fs + 1] = "tooltip[1.8,0;1,1;"
			fs[#fs + 1] = FS"Please select a student first"
			fs[#fs + 1] = "]"
		elseif context.select_toggle == "selected" then
			fs[#fs + 1] = "box[1.8,0.1;0.8,0.7;#53ac56]"
			fs[#fs + 1] = "label[1.85,0.25;"
			fs[#fs + 1] = FS"Selected"
			fs[#fs + 1] = "]"
		else
			fs[#fs + 1] = "button[1.8,0;1,1;select_selected;"
			fs[#fs + 1] = FS"Selected"
			fs[#fs + 1] = "]"
		end

		fs[#fs + 1] = "label[0,0.9;"
		fs[#fs + 1] = FS"Actions:"
		fs[#fs + 1] = "]"

		local x = 0
		local y = 1.2
		for _, action in pairs(classroom.get_actions()) do
			fs[#fs + 1] = "button["
			fs[#fs + 1] = tostring(x)
			fs[#fs + 1] = ","
			fs[#fs + 1] = tostring(y)
			fs[#fs + 1] = ";1,1;action_"
			fs[#fs + 1] = action.name
			fs[#fs + 1] = ";"
			fs[#fs + 1] = minetest.formspec_escape(action.title)
			fs[#fs + 1] = "]"

			fs[#fs + 1] = "tooltip[action_"
			fs[#fs + 1] = action.name
			fs[#fs + 1] = ";"
			fs[#fs + 1] = minetest.formspec_escape(action.description)
			fs[#fs + 1] = "]"

			if x < 1.5 then
				x = x + 0.9
			else
				x = 0
				y = y + 0.8
			end
		end

		y = y + 0.25

		if context.selected_student then
			fs[#fs + 1] = "container[0,"
			fs[#fs + 1] = tostring(y)
			fs[#fs + 1] = "]"

			fs[#fs + 1] = "label[0,-0.1;"
			fs[#fs + 1] = FS("Selected user: @1", context.selected_student)
			fs[#fs + 1] = "]"
			fs[#fs + 1] = "button[0,0.3;1.5,1;teleport;"
			fs[#fs + 1] = FS"Teleport to"
			fs[#fs + 1] = "]"

			fs[#fs + 1] = "container_end[]"
		end

		fs[#fs + 1] = "container_end[]"

		return sfinv.make_formspec(player, context, table.concat(fs, ""), false)
	end,
	on_player_receive_fields = function(self, player, context, fields)
		if not self:check_perm(player) then
			sfinv.set_page(player, sfinv.get_homepage_name(player))
			return true
		end

		if fields.students then
			local evt = minetest.explode_table_event(fields.students)
			local i = (evt.row or 0) - 1
			if evt.type == "CHG" and i >= 1  and i <= #context.students then
				context.selected_student = context.students[i]
				sfinv.set_player_inventory_formspec(player)
				return true
			end
		end

		if fields.group then
			if fields.group == "1" then
				context.groupname = nil
			else
				local i = 2
				for name, _ in pairs(classroom.get_all_groups()) do
					if i == tonumber(fields.group) then
						context.groupname = name
						break
					end
					i = i + 1
				end
			end
			sfinv.set_player_inventory_formspec(player)
			return true
		end

		if fields.select_all then
			context.select_toggle = "all"
			sfinv.set_player_inventory_formspec(player)
			return true
		elseif fields.select_group then
			context.select_toggle = "group"
			sfinv.set_player_inventory_formspec(player)
			return true
		elseif fields.select_selected then
			context.select_toggle = "selected"
			sfinv.set_player_inventory_formspec(player)
			return true
		end

		if fields.teleport and context.selected_student then
			local student = minetest.get_player_by_name(context.selected_student)
			if student then
				player:set_pos(student:get_pos())
				return true
			else
				context.selected_student = nil
				sfinv.set_player_inventory_formspec(player)
				return true
			end
		end

		if fields.new_group then
			classroom.show_new_group(player)
			return true
		end

		if fields.edit_group and context.groupname then
			classroom.show_edit_group(player, context.groupname)
			return true
		end

		for _, action in pairs(classroom.get_actions()) do
			if fields["action_" .. action.name] then
				local selector
				if context.select_toggle == "all" then
					selector = "*"
				elseif context.select_toggle == "group" then
					selector = "group:" .. context.groupname
				elseif context.select_toggle == "selected" then
					selector = "user:" .. context.selected_student
				else
					error("Unknown selector")
				end

				classroom.run_action(action.name, player, selector)
				sfinv.set_player_inventory_formspec(player)
				return true
			end
		end
	end,
})

local function on_grant_revoke(grantee, granter, priv)
    if priv ~= "teacher" then
        return
    end

    local player = minetest.get_player_by_name(grantee)
    if not player then
        return
    end

	minetest.after(0, function()
		sfinv.set_player_inventory_formspec(player)
	end)
end

minetest.register_on_priv_grant(on_grant_revoke)
minetest.register_on_priv_revoke(on_grant_revoke)


function classroom.show_new_group(player)
	if not minetest.check_player_privs(player:get_player_name(), { teacher = true }) then
		return
	end

	minetest.show_formspec(player:get_player_name(), "classroom:new_group", table.concat({
		"size[5,1.8]",
		"field[0.2,0.4;5,1;name;", FS"Name", ";]",
		"button[1.5,1;2,1;create;", FS"Create", "]",
	}, ""))
end


minetest.register_on_player_receive_fields(function(player, formname, fields)
	if formname ~= "classroom:new_group" or
			not minetest.check_player_privs(player:get_player_name(), { teacher = true }) or
			not fields.create then
		return false
	end

	local group = classroom.create_group(fields.name)
	if group then
		sfinv.set_player_inventory_formspec(player)
		classroom.show_edit_group(player, group.name)
	else
		classroom.show_new_group(player, fields.name)
	end
end)

local _contexts = {}

function classroom.show_edit_group(player, groupname)
	local name = player:get_player_name()
	if not minetest.check_player_privs(name, { teacher = true }) then
		return
	end

	local context = _contexts[name] or {}
	_contexts[name] = context

	context.groupname = groupname or context.groupname
	context.index_l = context.index_l or 1
	context.index_r = context.index_r or 1

	local fs = {
		"size[5.55,6]",
		"label[0,-0.1;", FS"Other students", "]",
		"label[3.3,-0.1;",
		FS("Students in group @1", context.groupname),
		"]",
		"button[2.25,0.5;1,1;go_right;", minetest.formspec_escape(">"), "]",
		"button[2.25,1.5;1,1;go_left;", minetest.formspec_escape("<"), "]",
	}

	local members = classroom.get_group_students(groupname)
	if #members > 0 then
		if context.index_r > #members then
			context.index_r = #members
		end
		fs[#fs + 1] = "textlist[3.25,0.5;2,5.5;right;"
		for i, member in pairs(members) do
			if i > 1 then
				fs[#fs + 1] = ","
			end
			fs[#fs + 1] = minetest.formspec_escape(member)
		end

		fs[#fs + 1] = ";"
		fs[#fs + 1] = tostring(context.index_r)
		fs[#fs + 1] = "]"
	else
		fs[#fs + 1] = "label[3.5,0.7;"
		fs[#fs + 1] = FS("No students")
		fs[#fs + 1] = "]"
	end

	local not_members = classroom.get_students_except(members)
	if #not_members > 0 then
		if context.index_l > #not_members then
			context.index_l = #members
		end

		fs[#fs + 1] = "textlist[0,0.5;2,5.5;left;"

		for i, member in pairs(not_members) do
			if i > 1 then
				fs[#fs + 1] = ","
			end
			fs[#fs + 1] = minetest.formspec_escape(member)
		end

		fs[#fs + 1] = ";"
		fs[#fs + 1] = tostring(context.index_l)
		fs[#fs + 1] = "]"
	else
		fs[#fs + 1] = "label[0.4,0.7;"
		fs[#fs + 1] = FS("No students")
		fs[#fs + 1] = "]"
	end

	minetest.show_formspec(player:get_player_name(), "classroom:edit_group", table.concat(fs, ""))
end

minetest.register_on_player_receive_fields(function(player, formname, fields)
	if formname ~= "classroom:edit_group" or
			not minetest.check_player_privs(player:get_player_name(), { teacher = true }) then
		return false
	end

	local context = _contexts[player:get_player_name()]
	if not context or not context.groupname then
		return false
	end

	if fields.left then
		local evt = minetest.explode_textlist_event(fields.left)
		if evt.type == "CHG" then
			context.index_l = evt.index
			return true
		end
	end

	if fields.right then
		local evt = minetest.explode_textlist_event(fields.right)
		if evt.type == "CHG" then
			context.index_r = evt.index
			return true
		end
	end

	if fields.quit then
		_contexts[player:get_player_name()] = nil
	end

	if fields.go_right and context.index_l then
		local students = classroom.get_group_students(context.groupname)
		local not_members = classroom.get_students_except(students)
		local student = not_members[context.index_l]
		if student then
			classroom.add_student_to_group(context.groupname, student)
			classroom.show_edit_group(player, context.groupname)
			sfinv.set_player_inventory_formspec(player)
			return true
		end
	end

	if fields.go_left and context.index_r then
		local students = classroom.get_group_students(context.groupname)
		local student = students[context.index_r]
		if student then
			classroom.remove_student_from_group(context.groupname, student)
			classroom.show_edit_group(player, context.groupname)
			sfinv.set_player_inventory_formspec(player)
			return true
		end
	end
end)

minetest.register_on_leaveplayer(function(player)
	_contexts[player:get_player_name()] = nil
end)