---------------------------
-- SmartFS: Smart Formspecs
-- License: CC0 or WTFPL
--    by Rubenwardy
---------------------------

local has_inventory_plus = core.get_modpath("inventory_plus") and true or false
local has_unified_inventory = core.get_modpath("unified_inventory") and true or false

smartfs = {
    _fdef = {},
    _edef = {},
    opened = {},
    inv = {}
}

-- the smartfs() function
function smartfs.__call(_, name)
    return smartfs._fdef[name]
end

-- Register forms and elements
function smartfs.create(name, onload)
    if smartfs._fdef[name] then
        error("SmartFS - (Error) Form " .. name .. " already exists!")
    end
    if smartfs.loaded and not smartfs._loaded_override then
        error("SmartFS - (Error) Forms should be declared while the game loads.")
    end

    smartfs._fdef[name] = {
        _reg = onload,
        name = name,
        show = smartfs._show_
    }

    return smartfs._fdef[name]
end
function smartfs.override_load_checks()
    smartfs._loaded_override = true
end

core.after(0, function()
    smartfs.loaded = true
end)
function smartfs.dynamic(name, player)
    if not smartfs._dynamic_warned then
        smartfs._dynamic_warned = true
        print("SmartFS - (Warning) On the fly forms are being used. May cause bad things to happen")
    end
    local state = smartfs._makeState_({ name = name }, player, nil, false)
    state.show = state._show_
    smartfs.opened[player] = state
    return state
end
function smartfs.element(name, data)
    if smartfs._edef[name] then
        error("SmartFS - (Error) Element type " .. name .. " already exists!")
    end
    smartfs._edef[name] = data
    return smartfs._edef[name]
end

function smartfs.inventory_mod()
    if has_unified_inventory then
        return "unified_inventory"
    elseif has_inventory_plus then
        return "inventory_plus"
    else
        return nil
    end
end

function smartfs.add_to_inventory(form, icon, title)
    if has_unified_inventory then
        unified_inventory.register_button(form.name, {
            type = "image",
            image = icon,
        })
        unified_inventory.register_page(form.name, {
            -- (player, formspec)
            get_formspec = function(player)
                local name = player:get_player_name()
                local opened = smartfs._show_(form, name, nil, true)
                return { formspec = opened:_getFS_(false) }
            end
        })
        return true
    elseif has_inventory_plus then
        core.register_on_joinplayer(function(player)
            inventory_plus.register_button(player, form.name, title)
        end)
        core.register_on_player_receive_fields(function(player, formname, fields)
            if formname == "" and fields[form.name] then
                local name = player:get_player_name()
                local opened = smartfs._show_(form, name, nil, true)
                inventory_plus.set_inventory_formspec(player, opened:_getFS_(true))
            end
        end)
        return true
    else
        return false
    end
end

function smartfs._makeState_(form, player, params, is_inv)
    return {
        _ele = {},
        def = form,
        player = player,
        param = params or {},
        is_inv = is_inv,
        get = function(self,name)
            return self._ele[name]
        end,
        close = function(self)
            self.closed = true
        end,
        size = function(self, w, h)
            self._size = { w = w, h = h }
        end,
        _getFS_ = function(self,size)
            local res = ""
            if self._size and size then
                res = "size[" .. self._size.w .. "," .. self._size.h .. "]"
            end
            for _, val in pairs(self._ele) do
                res = res .. val:build()
            end
            return res
        end,
        _show_ = function(self)
            if self.is_inv then
                if has_unified_inventory then
                    unified_inventory.set_inventory_formspec(
                        core.get_player_by_name(self.player), self.def.name)
                elseif has_inventory_plus then
                    inventory_plus.set_inventory_formspec(
                        core.get_player_by_name(self.player), self:_getFS_(true))
                end
            else
                local res = self:_getFS_(true)
                core.show_formspec(player, form.name, res)
            end
        end,
        load = function(self, file_name)
            local file = io.open(file_name, "r")
            if file then
                local data = core.deserialize(file:read("*all"))
                file:close()
                if type(data) == "table" then
                    if data.size then
                        self._size = data.size
                    end
                    for _, val in pairs(data.ele) do
                        self:element(val.type, val)
                    end
                    return true
                end
            end
            return false
        end,
        save = function(self, file_name)
            local res = { ele = {} }

            if self._size then
                res.size = self._size
            end

            for key, val in pairs(self._ele) do
                res.ele[key] = val.data
            end

            local file = io.open(file_name, "w")
            if file then
                file:write(core.serialize(res))
                file:close()
                return true
            end
            return false
        end,
        setparam = function(self, key, value)
            if not key then return end
            self.param[key] = value
            return true
        end,
        getparam = function(self, key, default)
            if not key then return end
            return self.param[key] or default
        end,
        button = function(self, x, y, w, h, name, text, exitf)
            if exitf == nil then exitf = false end
            return self:element("button", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                value = text,
                closes = exitf
            })
        end,
        label = function(self, x, y, name, text)
            return self:element("label", {
                pos = { x = x, y = y },
                name = name,
                value = text
            })
        end,
        toggle = function(self, x, y, w, h, name, list)
            return self:element("toggle", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                id = 1,
                list = list
            })
        end,
        field = function(self, x, y, w, h, name, label)
            return self:element("field", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                value = "",
                label = label
            })
        end,
        pwdfield = function(self, x, y, w, h, name, label)
            local res = self:element("field", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                value = "",
                label = label
            })
            res:isPassword(true)
            return res
        end,
        textarea = function(self, x, y, w, h, name, label)
            local res = self:element("field", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                value = "",
                label = label
            })
            res:isMultiline(true)
            return res
        end,
        image = function(self, x, y, w, h, name, img)
            return self:element("image", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                value = img
            })
        end,
        checkbox = function(self, x, y, name, label, selected)
            return self:element("checkbox", {
                pos = { x = x, y = y },
                name = name,
                value = selected,
                label = label
            })
        end,
        listbox = function(self, x, y, w, h, name, selected, transparent)
            return self:element("list", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name,
                selected = selected,
                transparent = transparent
            })
        end,
        inventory = function(self, x, y, w, h, name)
            return self:element("inventory", {
                pos = { x = x, y = y },
                size = { w = w, h = h },
                name = name
            })
        end,
        element = function(self, typen, data)
            local type = smartfs._edef[typen]

            if not type then
                error("Element type " .. typen .. " does not exist!")
            end

            if self._ele[data.name] then
                error("Element " .. data.name .. " already exists")
            end
            data.type = typen

            local ele = {
                name = data.name,
                root = self,
                data = data,
                remove = function(self2)
                    self2.root._ele[self2.name] = nil
                end
            }

            for key, val in pairs(type) do
                ele[key] = val
            end

            self._ele[data.name] = ele

            return self._ele[data.name]
        end
    }
end

-- Show a formspec to a user
function smartfs._show_(form, player, params, is_inv)
    local state = smartfs._makeState_(form, player, params, is_inv)
    state.show = state._show_
    if form._reg(state) ~= false then
        if not is_inv then
            smartfs.opened[player] = state
            state:_show_()
        else
            smartfs.inv[player] = state
        end
    end
    return state
end

-- Receive fields from formspec
local function _sfs_recieve_(state, name, fields)
    if fields.quit == "true" then
        if not state.is_inv then
            smartfs.opened[name] = nil
        end
        return true
    end

    for key, val in pairs(fields) do
        if state._ele[key] then
            state._ele[key].data.value = val
        end
    end
    for _, val in pairs(state._ele) do
        if val.submit then
            if val:submit(fields) == true then
                return true
            end
        end
    end
    if state.closed ~= true then
        state:_show_()
    else
        core.show_formspec(name, "",
            "size[5,1]label[0,0;Formspec closing not yet created!]")
        if not state.is_inv then
            smartfs.opened[name] = nil
        end
    end
    return true
end

core.register_on_player_receive_fields(function(player, formname, fields)
    local name = player:get_player_name()
    if smartfs.opened[name] and not smartfs.opened[name].is_inv then
        if smartfs.opened[name].def.name == formname then
            local state = smartfs.opened[name]
            return _sfs_recieve_(state, name, fields)
        else
            smartfs.opened[name] = nil
        end
    elseif smartfs.inv[name] and smartfs.inv[name].is_inv then
        local state = smartfs.inv[name]
        _sfs_recieve_(state, name, fields)
    end
    return false
end)


-----------------------------------------------------------------
-------------------------  ELEMENTS  ----------------------------
-----------------------------------------------------------------

smartfs.element("button", {
    build = function(self)
        local common_prefix = self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," ..self.data.size.h
        local common_sufix = ";" .. self.name
            .. ";" .. self.data.value
            .. "]"
        if self.data.img then
            return "image_button["
                .. common_prefix
                .. ";" .. self.data.img
                .. common_sufix
        else
            if self.data.closes then
                return "button_exit[" .. common_prefix .. common_sufix
            else
                return "button[" .. common_prefix .. common_sufix
            end
        end
    end,
    -- (self, fields, state)
    submit = function(self, fields)
        if fields[self.name] and self._click then
            self:_click(self.root)
        end

        if self.data.closes then
            return true
        end
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    onClick = function(self, func)
        self._click = func
    end,
    click = function(self, func)
        self._click = func
    end,
    setText = function(self, text)
        self.data.value = text
    end,
    getText = function(self)
        return self.data.value
    end,
    setImage = function(self, image)
        self.data.img = image
    end,
    getImage = function(self)
        return self.data.img
    end,
    setClose = function(self, bool)
        self.data.closes = bool
    end
})

smartfs.element("toggle", {
    build = function(self)
        return "button["
            .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," .. self.data.size.h
            .. ";" .. self.name
            .. ";" .. self.data.list[self.data.id]
            .. "]"
    end,
    submit = function(self, fields)
        if fields[self.name] then
            self.data.id = self.data.id + 1
            if self.data.id > #self.data.list then
                self.data.id = 1
            end
            if self._tog then
                self:_tog(self.root)
            end
        end
    end,
    onToggle = function(self, func)
        self._tog = func
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    setId = function(self, id)
        self.data.id = id
    end,
    getId = function(self)
        return self.data.id
    end,
    getText = function(self)
        return self.data.list[self.data.id]
    end
})

smartfs.element("label", {
    build = function(self)
        return "label["
            .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.value
            .. "]"
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setText = function(self, text)
        self.data.value = text
    end,
    getText = function(self)
        return self.data.value
    end
})

smartfs.element("field", {
    build = function(self)
        local common = self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," .. self.data.size.h
            .. ";" .. self.name
            .. ";" .. self.data.label
        if self.data.ml then
            return "textarea["
                .. common
                .. ";" .. self.data.value
                .. "]"
        elseif self.data.pwd then
            return "pwdfield["
                .. common
                .. "]"
        else
            return "field["
                .. common
                .. ";" .. self.data.value
                .. "]"
        end
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    setText = function(self, text)
        self.data.value = text
    end,
    getText = function(self)
        return self.data.value
    end,
    isPassword = function(self, bool)
        self.data.pwd = bool
    end,
    isMultiline = function(self, bool)
        self.data.ml = bool
    end
})

smartfs.element("image", {
    build = function(self)
        return "image["
            .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," .. self.data.size.h
            .. ";" .. self.data.value
            .. "]"
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    setImage = function(self, text)
        self.data.value = text
    end,
    getImage = function(self)
        return self.data.value
    end
})

smartfs.element("checkbox", {
    build = function(self)
        local out = "checkbox["
            .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.name
            .. ";" .. self.data.label
        if self.data.value then
            return out .. ";true]"
        else
            return out .. ";false]"
        end
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    setText = function(self, text)
        self.data.value = text
    end,
    getText = function(self)
        return self.data.value
    end
})

smartfs.element("list", {
    build = function(self)
        if not self.data.items then
            self.data.items = {}
        end
        local listformspec = "textlist["
            .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," .. self.data.size.h
            .. ";" .. self.data.name
            .. ";" .. table.concat(self.data.items, ",")
            .. ";" .. tostring(self.data.selected or "")
            .. ";" .. tostring(self.data.transparent or "false")
            .. "]"

        return listformspec
    end,
    submit = function(self, fields)
        if fields[self.name] then
            local _type = string.sub(fields[self.data.name], 1, 3)
            local index = string.sub(fields[self.data.name], 5)
            if _type == "CHG" and self._click then
                self:_click(self.root, index)
            elseif _type == "DCL" and self._doubleClick then
                self:_doubleClick(self.root, index)
            end
        end
    end,
    onClick = function(self, func)
        self._click = func
    end,
    click = function(self, func)
        self._click = func
    end,
    onDoubleClick = function(self, func)
        self._doubleClick = func
    end,
    doubleclick = function(self, func)
        self._doubleClick = func
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    addItem = function(self, item)
        if not self.data.items then
            self.data.items = {}
        end
        table.insert(self.data.items, item)
    end,
    removeItem = function(self, idx)
        if not self.data.items then
            self.data.items = {}
        end
        table.remove(self.data.items, idx)
    end,
    popItem = function(self)
        if not self.data.items then
            self.data.items = {}
        end
        local item = self.data.items[#self.data.items]
        table.remove(self.data.items)
        return item
    end
})

smartfs.element("inventory", {
    build = function(self)
        return "list["
            .. (self.data.location or "current_player")
            .. ";" .. self.name
            .. ";" .. self.data.pos.x .. "," .. self.data.pos.y
            .. ";" .. self.data.size.w .. "," .. self.data.size.h
            .. ";" .. (self.data.index or "")
            .. "]"
    end,
    setPosition = function(self, x, y)
        self.data.pos = { x = x, y = y }
    end,
    getPosition = function(self)
        return self.data.pos
    end,
    setSize = function(self, w, h)
        self.data.size = { w = w, h = h }
    end,
    getSize = function(self)
        return self.data.size
    end,
    -- available inventory locations
    -- "current_player": Player to whom the menu is shown
    -- "player:<name>": Any player
    -- "nodemeta:<X>,<Y>,<Z>": Any node metadata
    -- "detached:<name>": A detached inventory
    -- "context" does not apply to smartfs, since there is no node-metadata as context available
    setLocation = function(self, location)
        self.data.location = location
    end,
    getLocation = function(self)
        return self.data.location or "current_player"
    end,
    usePosition = function(self, pos)
        self.data.location = string.format("nodemeta:%d,%d,%d", pos.x, pos.y, pos.z)
    end,
    usePlayer = function(self, name)
        self.data.location = "player:" .. name
    end,
    useDetached = function(self, name)
        self.data.location = "detached:" .. name
    end,
    setIndex = function(self, index)
        self.data.index = index
    end,
    getIndex = function(self)
        return self.data.index
    end
})

smartfs.element("code", {
    build = function(self)
        if self._build then
            self:_build()
        end

        return self.data.code
    end,
    submit = function(self, fields)
        if self._sub then
            self:_sub(fields)
        end
    end,
    onSubmit = function(self, func)
        self._sub = func
    end,
    onBuild = function(self, func)
        self._build = func
    end,
    setCode = function(self, code)
        self.data.code = code
    end,
    getCode = function(self)
        return self.data.code
    end
})