local S = minetest.get_translator "advtrains_doc_integration"
local D = advtrains_doc_integration.describe
local H = advtrains_doc_integration.hypertext
local utils = advtrains_doc_integration.utils
local fsescape = minetest.formspec_escape

local function S2(a, b)
	return S(a, S(b))
end

local function addlist(lst, tbl, title, fallback1, fallback2, mapf)
	if not tbl then
		if fallback2 then
			table.insert(lst, fallback2)
		elseif fallback2 == false and fallback1 then
			table.insert(lst, fallback1)
		end
	elseif next(tbl) ~= nil then
		table.insert(lst, title)
		for k, v in pairs(tbl) do
			if mapf then
				k = mapf(k, v)
			end
			table.insert(lst, H.listitem(k, true))
		end
	elseif fallback1 then
		table.insert(lst, fallback1)
	end
end

local function list_itemstring(x)
	local item = ItemStack(x)
	if item:is_empty() then
		return S("Emptyness")
	end
	return string.format("%s: %d", item:get_short_description(), item:get_count())
end

local function blankline(st)
	return table.insert(st, "")
end

local wlivprev = {}

local function get_livery_preview_selection(pname, itemname)
	return (wlivprev[pname] or {})[itemname] or 0
end

local function get_livery_preview(itemname, id)
	local tx = (advtrains_doc_integration.prototypes[itemname] or {}).livery_textures
	return tx[id] or tx[0]
end

local function render_livery_textures(pname, itemname)
	local str = table.concat(utils.map(get_livery_preview(itemname, get_livery_preview_selection(pname, itemname)), fsescape), ",")
	return str
end

local function set_livery_preview_selection(pname, itemname, id)
	local t = wlivprev[pname]
	if not t then
		t = {}
		wlivprev[pname] = t
	end
	t[itemname] = id
end

local function doc_render_wagon_information(prototype, pname)
	local desctext = {}
	if prototype._doc_wagon_longdesc then
		table.insert(desctext, tostring(prototype._doc_wagon_longdesc))
		blankline(desctext)
	end
	table.insert(desctext, H.header(S("Basic Information")))
	table.insert(desctext, S("Itemstring: @1", H.mono(prototype.name)))
	addlist(desctext, prototype.drops, S("Drops:"), S("Drops nothing"), false, function(_, v) return list_itemstring(v) end)
	addlist(desctext, prototype.drives_on, S("Drives on:"), nil, nil, H.mono)
	addlist(desctext, prototype.coupler_types_front, S("Compatible front couplers:"), S2("Front coupler: @1", "Absent"), S2("Front coupler: @1", "Universal"), utils.get_coupler_name)
	addlist(desctext, prototype.coupler_types_back, S("Compatible rear couplers:"), S2("Rear coupler: @1", "Absent"), S2("Rear coupler: @1", "Universal"), utils.get_couple_name)
	table.insert(desctext, S("Wagon span: @1", prototype.wagon_span and D.length(2*prototype.wagon_span) or S("Undefined")))
	table.insert(desctext, S("Maximum speed: @1", prototype.max_speed and D.speed(prototype.max_speed) or S("Undefined")))
	table.insert(desctext, S2("Motive power: @1", prototype.is_locomotive and "Present" or "Absent"))
	table.insert(desctext, S("Horn sound: @1", H.describe_sound("playhorn", prototype.horn_sound)))
	if prototype.doors.open.sound or prototype.doors.close.sound then
		table.insert(desctext, S("Door sound: @1 (when opening), @2 (when closing)",
			H.describe_sound("playdooropen", prototype.doors.open.sound),
			H.describe_sound("playdoorclose", prototype.doors.close.sound)))
	else
		table.insert(desctext, S2("Door sound: @1", "Undefined"))
	end

	blankline(desctext)
	table.insert(desctext, H.header(S("Wagon Capacity")))
	table.insert(desctext, S("Passenger seats: @1", prototype.max_passengers))
	table.insert(desctext, S("Driver seats: @1", prototype.max_drivers))
	if prototype.has_inventory then
		addlist(desctext, prototype.inventory_list_sizes, S("Cargo inventory size:"), S2("Cargo inventory: @1", "Present"), false, function(k, v)
			return string.format("%s: %d", H.mono(k), v)
		end)
	else
		table.insert(desctext, S2("Cargo inventory: @1", "Absent"))
	end
	if techage and prototype.techage_liquid_capacity then
		table.insert(desctext, S("Liquid Capacity (Techage): @1", string.format("%d", prototype.techage_liquid_capacity)))
	end

	blankline(desctext)
	table.insert(desctext, H.header(S("Wagon Appearance")))
	table.insert(desctext, S("Mesh: @1", prototype.mesh and H.mono(prototype.mesh) or "None"))
	addlist(desctext, prototype.textures, S("Textures:"), S("No textures"), false, function(_, v) return H.mono(v) end)

	local livsel = get_livery_preview_selection(pname, prototype.name)
	local livrst = (livsel ~= 0 and not prototype.dlxtrains_livery) and " " .. H.action("preview_0", S("[Reset Preview]")) or ""
	local livids = 0
	local function livprev(desc)
		livids = livids+1
		local label = H.plain(desc)
		if livids == livsel then
			label = H.bold(desc)
		end
		return H.action(string.format("preview_%d", livids), label, true)
	end

	local dlxlivdef = prototype.dlxtrains_livery
	table.insert(desctext, S2("DlxTrains livery system: @1", dlxlivdef and "Supported" or "Unsupported"))
	if dlxlivdef then
		livids = -1
		table.insert(desctext, "Livery presets:")
		for k = 0, dlxlivdef.count-1 do
			table.insert(desctext, H.listitem(string.format("%s (%s, %s)", H.mono(dlxlivdef[k].code), livprev(S("default")), livprev(S("weathered"))), true))
		end
	end

	local bikeliv = S("Unsupported")
	local bikelivdesc = nil
	if prototype.set_livery then
		if prototype.livery_definition then
			bikeliv = S("Supported by the multi_component_liveries mod")
			bikelivdesc = {}
			addlist(bikelivdesc, prototype.livery_definition.components, S("Livery components:"), nil, nil, function(_, v) return H.plain(v.description) end)
			addlist(bikelivdesc, prototype.livery_definition.presets, S("Livery presets:") .. livrst, nil, nil, function(_, v) return livprev(v.description) end)
			bikelivdesc = table.concat(bikelivdesc, "\n")
		else
			bikeliv = S("Supported")
		end
	end
	table.insert(desctext, S("Livery system with bike painter: @1", bikeliv))
	table.insert(desctext, bikelivdesc)

	local atlivdef = prototype.advtrains_livery_tools
	table.insert(desctext, S2("Advtrains livery tools (Marnack): @1", atlivdef and "Supported" or "Unsupported"))
	if atlivdef then
		addlist(desctext, atlivdef.template_names, S("Livery templates:"), nil, nil, function(_, v) return H.plain(v) end)
		addlist(desctext, atlivdef.livery_names, S("Livery presets:") .. livrst, nil, nil, function(_, v) return livprev(v) end)
	end

	blankline(desctext)
	table.insert(desctext, H.header(S("Implementation Details")))
	local attachment_offset_support = S("Unsupported")
	if advtrains_attachment_offset_patch then
		local t = advtrains_attachment_offset_patch
		if prototype.get_on == t.get_on_override and prototype.get_off == t.get_off_override then
			attachment_offset_support = S("Supported")
		end
	end

	table.insert(desctext, S("Proper player attachment positioning: @1", attachment_offset_support))
	for k, v in pairs {
		custom_on_activate = "Custom instantiation callback",
		custom_on_step = "Custom step function",
		custom_on_velocity_change = "Custom velocity change callback",
	} do
		table.insert(desctext, S2(v .. ": @1", prototype[k] and "Defined" or "Undefined"))
	end

	local x0, y0 = doc.FORMSPEC.ENTRY_START_X+0.25, doc.FORMSPEC.ENTRY_START_Y
	local x1, y1 = doc.FORMSPEC.ENTRY_END_X+0.75, doc.FORMSPEC.ENTRY_END_Y+0.625
	local width, height = x1-x0, y1-y0
	local mside = height/2

	local mesh = fsescape(prototype.mesh or "")
	local textures = render_livery_textures(pname, prototype.name)
	local fstext = {
		string.format("hypertext[%f,%f;%f,%f;entry_body;%s]", x0, y0, width-mside, height+0.875, fsescape(table.concat(desctext, "\n"))),
		string.format("item_image[%f,%f;%f,%f;%s]", x1-mside, y0+0.0625, mside, mside, fsescape(prototype.name)),
		string.format("model[%f,%f;%f,%f;%s;%s;%s;%f,%f]",
			x1-mside, y1-mside, mside, mside, "wagon_model", mesh, textures, -30, 135),
	}
	return table.concat(fstext, "\n")
end

if doc then
	advtrains_doc_integration.register_on_prototype_loaded(function(itemname, prototype)
		minetest.override_item(itemname, {_doc_items_create_entry = false})
		doc.add_entry("advtrains_wagons", itemname, {
			name = ItemStack(itemname):get_short_description(),
			data = prototype,
		})
		if doc.sub.identifier then
			doc.sub.identifier.register_object(itemname, "advtrains_wagons", itemname)
		end
	end)

	if doc.sub.items then
		local register_factoid = doc.sub.items.register_factoid
		local function ndef_field_factoid(cat, ftype, f, ...)
			local ftp = type(f)
			if ftp == "string" then
				local desc = f
				f = function(x)
					if x ~= nil then
						return desc
					end
				end
			end
			local keys = {...}
			local idx = function(t)
				for _, k in ipairs(keys) do
					if type(t) ~= "table" then
						return nil
					end
					t = t[k]
				end
				return t
			end
			local function fgen(_, def)
				return f(idx(def)) or ""
			end
			return register_factoid(cat, ftype, fgen)
		end
		local function group_factoid(cat, gr, f)
			local function func(x)
				return f(x or 0)
			end
			return ndef_field_factoid(cat, "groups", func, "groups", gr)
		end
		for cat, cinfo in pairs{
			nodes = {
				not_blocking_trains = S("This block does not block trains."),
				save_in_at_nodedb = S("This block is saved in the Advtrains node database."),
			},
		} do
			for group, ginfo in pairs(cinfo) do
				local tp = type(ginfo)
				if tp == "string" then
					group_factoid(cat, group, function(x)
						if x > 0 then
							return ginfo
						end
					end)
				elseif tp == "function" then
					group_factoid(cat, group, ginfo)
				end
			end
		end
		for fname, t in pairs {
			advtrains = {
				on_train_enter = S("This track reacts to passing trains."),
				on_train_approach = S("This track reacts to approaching trains."),
			},
			luaautomation = {
				fire_event = S("This block handles LuaATC events."),
			},
		} do
			for subfname, val in pairs(t) do
				local function f(x)
					if x ~= nil then
						return val
					end
				end
				ndef_field_factoid("nodes", "groups", f, fname, subfname)
			end
		end
		register_factoid("nodes", "groups", function(_, ndef)
			if ndef.advtrains then
				local atdef = ndef.advtrains
				if atdef.set_aspect then
					return S("This is a signal with a variable aspect.")
				elseif atdef.get_aspect then
					return S("This is a signal with a static aspect.")
				end
			end
			if ndef.at_conns then
				return S("This track has the following conns table by default: @1", D.conns(ndef.at_conns) or "?")
			end
			return ""
		end)
	end

	doc.add_category("advtrains_wagons", {
		name = S("Wagons"),
		build_formspec = doc_render_wagon_information,
	})
end

minetest.register_on_player_receive_fields(function(player, formname, fields)
	if formname ~= "doc:entry" then
		return
	end
	local pname = player:get_player_name()
	local cat, ent = doc.get_selection(pname)
	if cat ~= "advtrains_wagons" or ent == nil then
		return
	end
	local act = fields.entry_body
	local prototype = advtrains_doc_integration.prototypes[ent]
	local sounds = {
		["action:playhorn"] = prototype.horn_sound,
		["action:playdooropen"] = prototype.doors.open.sound,
		["action:playdoorclose"] = prototype.doors.close.sound,
	}
	if not act then
		return
	elseif sounds[act] then
		minetest.sound_play(sounds[act], {to_player = pname}, true)
	else
		local txid = string.match(act, [[^action:preview_(%d+)$]])
		txid = tonumber(txid)
		if txid then
			set_livery_preview_selection(pname, ent, txid)
			doc.show_entry(pname, cat, ent)
		end
	end
end)