local MODULE = {}
MODULE.Order = 0

local resourceExtensions = include("downloader/resources.lua")

local shouldScan = CreateConVar("downloader_legacy_scan_danger", 0, FCVAR_ARCHIVE,
    "Should scan for legacy addons (DANGER!!!)")
local shouldDumpLegacyCache = CreateConVar("downloader_dump_legacy_cache", 0, FCVAR_ARCHIVE,
    "Should dump the next Legacy Addon resources scan into a txt file")

local function DumpLegacyCache(legacyFilesPerAddon)
    local cacheFile = "uwd/dump_legacy_cache.txt"
    local cache = "if SERVER then\n"

    for addonName, files in SortedPairs(legacyFilesPerAddon) do
        cache = cache .. "    -- " .. addonName .. "\n"
        for _, legacyFile in SortedPairs(files) do
            cache = cache .. "    resource.AddSingleFile(\"" .. legacyFile .. "\")\n"
        end
    end

    cache = cache .. "end\n"

    shouldDumpLegacyCache:SetBool(false)

    file.Write(cacheFile, cache)

    print("[DOWNLOADER] LEGACY ADDON RESOURCES DUMPED INTO '" .. cacheFile .. "'")
end

local function AddFiles(originPath, currentPath, legacyFiles)
    local files, dirs = file.Find(originPath .. currentPath .. "*", "MOD")

    if files then
        for _, subFile in ipairs(files) do
            local ext = string.GetExtensionFromFilename(subFile)
            if resourceExtensions[ext] then
                table.insert(legacyFiles, currentPath .. subFile)
            end
        end
    end

    if dirs then
        for _, subDir in ipairs(dirs) do
            AddFiles(originPath, currentPath .. subDir .. "/", legacyFiles)
        end
    end
end

local function ScanAddons(context)
    local _, folders = file.Find("addons/*", "MOD")
    local currentMap = game.GetMap()
    local legacyFilesPerAddon = {}

    print("[DOWNLOADER] SCANNING " .. #folders .. " LEGACY ADDONS TO ADD RESOURCES...")

    for _, folder in ipairs(folders or {}) do
        legacyFilesPerAddon[folder] = {}

        AddFiles("addons/" .. folder .. "/", "", legacyFilesPerAddon[folder])

        local mapFiles = file.Find("addons/" .. folder .. "/maps/*.bsp", "MOD") or {}
        for _, mapFile in ipairs(mapFiles) do
            if string.StripExtension(mapFile) == currentMap then
                table.insert(legacyFilesPerAddon[folder], "maps/" .. mapFile)
            end
        end
    end

    local isFastDL = GetConVar("sv_downloadurl"):GetString() ~= ""
    local isServerDL = not isFastDL
    local downloadSize = 0
    local fileQuantity = 0

    local netMaxFileSize = GetConVar("net_maxfilesize"):GetInt()

    for addonName, legacyFiles in pairs(legacyFilesPerAddon) do
        print(string.format("[DOWNLOADER] [+] LEGACY %4d FILES ADDED FOR %s", #legacyFiles, addonName))

        for _, legacyFile in ipairs(legacyFiles) do
            resource.AddSingleFile(legacyFile)

            local extension = isFastDL and file.Exists(legacyFile .. ".bz2", "GAME") and ".bz2" or ""
            local fileSize = math.Round(file.Size(legacyFile .. extension, "GAME") / 1000000, 2)
            if isServerDL and fileSize > netMaxFileSize then
                ErrorNoHalt(string.format(
                    "[DOWNLOADER] [WARNING] LEGACY FILE '%s' IS TOO BIG (%d MB)!! CURRENT LIMIT IS %d MB. EXECUTE 'net_maxfilesize' COMMAND TO INCREASE THE SIZE UP TO 64 MB!\n",
                    legacyFile, fileSize, netMaxFileSize))
            end

            downloadSize = downloadSize + fileSize
            fileQuantity = fileQuantity + 1
        end
    end

    print(string.format("[DOWNLOADER] FINISHED TO ADD LEGACY ADDONS: %d MB OF %d FILES SELECTED", downloadSize,
        fileQuantity))

    if isFastDL then
        print("[DOWNLOADER] USING FASTDL. DOWNLOAD TIME CHANGES ACCORDING TO INTERNET SPEED")
    else
        -- Note: ServerDL speed is limited to 30KBps, but commonly reaches 20KBps or less, so I'm using 25KBps to approximate time
        local time = downloadSize * 1000 / 25 / 60
        print(string.format("[DOWNLOADER] USING SERVERDL. APPROXIMATE FULL DOWNLOAD TIME: %.2f MINUTES", time))
    end

    if isServerDL and not GetConVar("sv_allowdownload"):GetBool() then
        ErrorNoHalt("[DOWNLOADER] WARNING! YOU ARE TRYING TO USE SERVERDL WITH 'sv_allowdownload' SET TO 0!\n")
    end

    if fileQuantity > 8192 then
        ErrorNoHalt("[DOWNLOADER] WARNING! YOU ARE TRYING TO DOWNLOAD MORE THAN 8192 FILES WITH SERVERDL!\n")
    end

    if context then
        context.legacyAddons = table.Count(legacyFilesPerAddon)
        context.legacyDownloadSize = downloadSize
    end

    if shouldDumpLegacyCache:GetBool() then
        DumpLegacyCache(legacyFilesPerAddon)
    end
end

function MODULE:Run(context)
    context.legacyScan = shouldScan:GetBool()
    if context.legacyScan then
        ScanAddons(context)
    end
end

cvars.AddChangeCallback("downloader_legacy_scan_danger", function(convar_name, value_old, value_new)
    if value_new == "1" then
        ScanAddons()
    end
end, "downloader_legacy_scan_danger")

return MODULE