--   This file is part of Reno desktop.
--
--  Reno desktop is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
--
--  Reno desktop is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License along with Reno desktop. If not, see <https://www.gnu.org/licenses/>.
-- Asynchronous XDG data aggregator (library)
local menu_utils = require("menubar.utils")
local awful = require("awful")
local gears = require("gears")
local json = require("dkjson")
local lib = {}

function lib.init_xdg_struct()
    -- Global xdg data struct
    local xdg = {
        directory_integrity = {},
        directory_listings = {},
        apps = {},
        categories = {
            Other = {
                icon = "applications-other",
                apps = {}
            },
            Wine = {
                icon = "wine",
                apps = {}
            }
        }
    }
    return xdg
end

function lib.load_xdg_cache()
    -- Load cached applications
    local cache_file = io.open(gears.filesystem.get_xdg_cache_home()..".reno_xdg_cache.json","r")
    local cache
    if cache_file then
        cache = json.decode(cache_file:read("*a"))
        cache_file:close()
    end
    return cache
end

function lib.add_categories(xdg, categories)
    -- Add missing category entries as defined by awesome
    for _,v in pairs(categories) do
        xdg.categories[v.app_type] = {
            name = v.name,
            icon = v.icon_name,
            apps = {}
        }
    end
end

function lib.async_process_dirs(xdg, dirs, cache, on_dir_done)
    -- Asynchronous scanning process
    for _,v in pairs(dirs) do
        xdg.directory_listings[v] = {}
        awful.spawn.with_line_callback("find "..tostring(v).." -maxdepth 1 -name *.desktop",{
            stdout = function(line)
                -- Assume the cache is valid for a listed file
                if cache and cache.directory_listings[v][line] then
                    xdg.directory_listings[v][line] = true
                    xdg.apps[line] = cache.apps[line]
                    xdg.categories[cache.apps[line].category].apps[line] = cache.apps[line]
                    return
                end
                local data = menu_utils.parse_desktop_file(line)
                if data.NoDisplay then
                    return
                end
                local appdata = {
                    name = data.Name,
                    category = "Other",
                    exec = data.Exec,
                    icon = (data.Icon and menu_utils.lookup_icon(data.Icon)),
                    description = data.Comment
                }
                -- Match first available cateogry for sorting
                for _,vv in pairs(data.Categories or {"Other"}) do
                    if xdg.categories[vv] then
                        appdata.category = vv
                        break
                    end
                    -- Oh how do I love those Wine applications and their categories
                    if vv:match("^Wine") then
                        appdata.category = "Wine"
                        break
                    end
                end
                -- Open terminal apps in the terminal (duh)
                if data.Terminal then
                    appdata.exec = global.terminal.." -e "..appdata.exec
                end
                -- Just for you, Wine - special case because you're being a shit
                if (appdata.exec and appdata.exec:find("%W?wine ")) then
                    appdata.category = "Wine"
                end
                xdg.apps[line] = appdata
                xdg.categories[appdata.category].apps[line] = appdata
                -- Add the file to the listing of cached ones
                xdg.directory_listings[v][line] = true
            end,
            output_done = function(...) on_dir_done(v,...) end
        })
    end
end

function lib.generate_meta_patch(xdg)
    local patch = {apps = {}}
    for k,v in pairs(xdg.apps) do
        patch.apps[k] = {}
        for kk,vv in pairs(v) do
            patch.apps[k][kk] = vv
        end
        patch.apps[k].name = nil
        patch.apps[k].category = nil
        patch.apps[k].exec = nil
        patch.apps[k].icon = nil
        patch.apps[k].description = nil
    end
    return patch
end

function lib.apply_meta_patch(xdg,patch)
    for k,v in pairs(patch.apps) do
        if xdg.apps[k] then
            for kk,vv in pairs(v) do
                xdg.apps[k][kk] = vv
            end
        end
    end
end

return lib