update

-- Viewer installer/updater
-- Connects to GitHub to retrieve the latest version available

-- Clear log files
if fs.exists("/logs/viewerUpdater.log") then
    fs.delete ("/logs/viewerUpdater.log")
end

--Check filesystem dependencies
if not fs.exists("/logs") then
    fs.makeDir("/logs")
end
if not fs.exists("/temp") then
    fs.makeDir("/temp")
end

-- Debug tool
local function logfile(input)
    local file = fs.open("/logs/viewerUpdater.log", "a")
    file.write(input.."\n")
    file.close()
end

-- Installer code
local files = {
    "main",
    "gui",
    "update",
    "settings",
    "alias",
    }

local args = {...}
logfile("Updater started, checking for updates for "..#files.." files")
if not http then
    logfile("HTTP API not enabled! Please enable the HTTP API in the ComputerCraft config file, or ask your server administrator to do so.")
    print("HTTP API not enabled! Please enable the HTTP API in\nthe ComputerCraft config file, or ask your server/nadministrator to do so.")
    return
else
    logfile("Checking for settings.")
    if not fs.exists("settings") then
        logfile("Settings not found!")
        local file = fs.open("settings", "w")
        local site = http.get("https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/settings")
        local content = site.readAll()
        if not content then
            logfile("No response from GitHub. Please check the ComputerCraft config and ensure that the GitHub url has been whitelisted.")
            return
        else
            file.write(content)
            file.close()
            logfile("Settings retrieved from GitHub successfully")
        end
    end
    logfile("Loading settings into API")
    os.loadAPI("settings")
    if args[1] == nil then
        for i,filename in pairs(files) do
            sleep(0)
            if filename == "settings" then
                -- Load current settings, download update, then try to merge them somehow
            end
            logfile("Checking for updates for '"..filename.."':")
            local site = http.get("https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/"..filename)
            local content = site.readAll()
            if not content then 
                logfile("    No response from GitHub. Please check the ComputerCraft config and ensure that the GitHub url has been whitelisted.")
                print("No response from GitHub. Please check the\nComputerCraft config and ensure that the GitHub url\nhas been whitelisted.")
                return
            else
                logfile("    Retrieved file from https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/"..filename)
                local tempFile = fs.open("/temp/new_settings", "w")
                local tempSite = http.get("https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/settings").readAll()
                tempFile.write(tempSite)
                tempFile.close()
                os.loadAPI("/temp/new_settings")
                print("Current version for '"..filename.."': "..settings[filename].version.."\n    Updated version: "..new_settings[filename].version)
                if not fs.exists(filename) then
                    logfile("    No file found for '"..filename.."'!\n    Downloading file now...")
                    local file = fs.open(filename, "w")
                    file.write(content)
                    file.close()
                    logfile("    Downloaded!")
                elseif new_settings[filename].version > settings[filename].version then
                    logfile("    Newer version found for '"..filename.."'.\n        Current version: "..settings[filename].version.."\n        New version: "..new_settings[filename].version)
                    local file = fs.open(filename, "w")
                    file.write(content)
                    file.close()
                    print("    Updated!")
                    logfile("    Updated!")
                else
                    print("    Skipping...")
                    logfile("    No new version found for '"..filename.."', skipping.")
                end
            end
        end
    elseif args[1] == "--force" or args[1] == "-f" then
        logfile("Forcing update of all files")
        for i, filename in pairs(files) do
            local site = http.get("https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/"..filename)
            local content = site.readAll()
            if not content then 
                logfile("    No response from GitHub. Please check the ComputerCraft config and ensure that the GitHub url has been whitelisted.")
                print("No response from GitHub. Please check the\nComputerCraft config and ensure that the GitHub url\nhas been whitelisted.")
                return
            else
                logfile("    Retrieved file from https://raw.githubusercontent.com/thatcraniumguy/Viewer/master/"..filename)
                local file = fs.open(filename, "w")
                file.write(content)
                file.close()
                logfile("    Downloaded!")
            end
        end
    end
end
logfile("Updater completed checking for updates")