---
--- Runs a real-time thread to change the map for the "ArtTest" context.
---
--- This function is likely used for debugging or testing purposes, to quickly
--- switch between different map configurations in the "ArtTest" context.
---
function bat() -- debug function
    CreateRealTimeThread(ChangeMap, "ArtTest")
end

---
--- Gets the lowercase version of the project name.
---
--- @return string The lowercase project name.
---
local project_name = string.lower(const.ProjectName)

---
--- Defines paths to various asset directories and files used in the ArtTest context.
---
--- @class path
--- @field assets table A table containing paths to asset directories.
--- @field assets.root string The root directory for assets.
--- @field assets.entities string The directory for entity assets.
--- @field assets.art_producer_lua string The path to the CurrentArtProducer.lua file.
--- @field assets.exporter string The directory for the HGExporter.
--- @field assets.entity_producers_lua string The path to the EntityProducers.lua file.
--- @field max table A table containing paths to 3DS Max related files and directories.
--- @field max.root string The root directory for 3DS Max scripts.
--- @field max.startup string The path to the HGExporterUtility startup script.
--- @field max.exporter string The directory for the HGExporter scripts.
--- @field max.exporter_startup string The path to the HGExporterUtility startup script in the exporter directory.
--- @field max.art_producer_ms string The path to the CurrentArtProducer.ms file in the exporter directory.
--- @field max.grannyexp_ini string The path to the grannyexp.ini file in the exporter directory.
---
local path = {}
path.assets = {}
path.assets.root = GetExecDirectory() .. "Assets/"
path.assets.entities = path.assets.root .. "Bin/Common/Entities/"
path.assets.art_producer_lua = path.assets.root .. "CurrentArtProducer.lua"
path.assets.exporter = path.assets.root .. "HGExporter/"
path.assets.entity_producers_lua = path.assets.root .. "Spec/EntityProducers.lua"
path.max = {}
path.max.root = "AppData/../../Local/Autodesk/3dsmax/2019 - 64bit/ENU/scripts/"
path.max.startup = path.max.root .. "startup/HGExporterUtility_" .. project_name .. ".ms"
path.max.exporter = path.max.root .. "HGExporter_" .. project_name .. "/"
path.max.exporter_startup = path.max.exporter .. "Startup/HGExporterUtility.ms"
path.max.art_producer_ms = path.max.exporter .. "CurrentArtProducer.ms"
path.max.grannyexp_ini = path.max.exporter .. "grannyexp.ini"

local atprint = CreatePrint({
	"ArtPreview",
	format = "printf",
})

ArtTest = { }

---
--- Opens a dialog to allow the user to choose a new art producer, then sets the new producer and updates the corresponding Lua and Max Script files.
---
--- @function ArtTest.OpenChangeProducerDialog
function ArtTest.OpenChangeProducerDialog()
    local producers = table.icopy(ArtSpecConfig.EntityProducers)
    table.insert(producers, 1, "Any")
    local new_producer = WaitListChoice(terminal.desktop, producers, "Choose art producer:", 1)
    ArtTest.SetProducer(new_producer or "Any")
    CreateRealTimeThread(ChangeMap, "ArtTest")
end

---
--- Sets the new art producer and updates the corresponding Lua and Max Script files.
---
--- @param new_producer string The new art producer to set.
---
function ArtTest.SetProducer(new_producer)
    if not new_producer then
        return
    end

    atprint("Setting new art producer %s", new_producer)

    -- set producer
    rawset(_G, "g_ArtTestProducer", new_producer)

    AsyncCreatePath(path.assets.root)

    -- write to Lua file for the game
    local lua_content = string.format("return \"%s\"", new_producer)
    AsyncStringToFile(path.assets.art_producer_lua, lua_content)

    -- write to Max Script file for the exporter
    local ms_content = string.format("global g_ArtTestProducer = \"%s\"", new_producer)
    AsyncStringToFile(path.max.art_producer_ms, ms_content)

    local os_path_assets = ConvertToOSPath(path.assets.root)
    if string.ends_with(os_path_assets, "\\") then
        os_path_assets = string.sub(os_path_assets, 1, #os_path_assets - 1)
    end

    ArtTest.InstallMaxExporter()
end

---
--- Sets the new art producer and updates the corresponding Autodesk 3DS Max exporter configuration.
---
--- This function is responsible for configuring the Autodesk 3DS Max exporter by updating the `grannyexp.ini` file with the correct assets path. It first checks if the game is run with the `-globalappdirs` command line parameter, which is required for the exporter to function properly. If the parameter is not present, it prints a warning message and returns.
---
--- The function then retrieves the OS-specific path for the assets root directory and checks if it ends with a backslash. If so, it removes the trailing backslash.
---
--- Next, the function checks if the `grannyexp.ini` file exists. If it does, it reads the file and updates the `assetsPath` setting with the correct assets path. If the file does not exist, it creates a new `grannyexp.ini` file with the assets path.
---
--- @param new_producer string The new art producer to set.
---
function ArtTest.SetProducer_3DSMax(new_producer)
    if not new_producer then
        return
    end

    local globalappdirs = string.match(GetAppCmdLine() or "", "-globalappdirs")
    if not globalappdirs then
        atprint(
            "Please run the game with the -globalappdirs command line parameter to install/update the Autodesk 3DS Max exporter")
        return
    end

    local os_path_assets = ConvertToOSPath(path.assets.root)
    if string.ends_with(os_path_assets, "\\") then
        os_path_assets = string.sub(os_path_assets, 1, #os_path_assets - 1)
    end

    if io.exists(path.max.grannyexp_ini) then -- TODO proper ini handling
        local err, ini = AsyncFileToString(path.max.grannyexp_ini)
        local first, last = string.find(ini, "assetsPath=.*\n")
        if first and last and first <= last then
            ini = string.format("%sassetsPath=%s%s", string.sub(ini, 1, first), os_path_assets,
                string.sub(ini, last - 1))
        else
            ini = string.format("%s\n[Directories]\nassetsPath=%s", ini, os_path_assets)
        end
    else
        local ini = string.format("[Directories]\nassetsPath=%s", os_path_assets)
        AsyncStringToFile(path.max.grannyexp_ini, ini)
    end
end

---
--- Installs the Autodesk 3DS Max exporter by creating the necessary folder structure and copying the exporter files.
---
--- This function first checks if the game is run with the `-globalappdirs` command line parameter, which is required for the exporter to function properly. If the parameter is not present, it prints a warning message and returns.
---
--- The function then creates the folder structure where the exported entities will be stored, including the `Bin/`, `Bin/Common/`, and other subfolders.
---
--- Next, the function copies the exporter folder structure from the `path.assets.exporter` directory to the `path.max.exporter` directory. It skips any folders or files that contain `.svn`.
---
--- Finally, the function copies the exporter startup file from `path.max.exporter_startup` to `path.max.startup`, and calls `ArtTest.SetProducer_3DSMax()` with the current art producer.
---
--- @return nil
function ArtTest.InstallMaxExporter()
    local globalappdirs = string.match(GetAppCmdLine() or "", "-globalappdirs")
    if not globalappdirs then
        atprint(
            "Please run the game with the -globalappdirs command line parameter to install/update the Autodesk 3DS Max exporter")
        return
    end

    -- crate assets folder structure (where entities will be exported)
    local structure = {"Bin/", "Bin/Common/", "Bin/Common/Animations", "Bin/Common/Entities", "Bin/Common/Mapping",
        "Bin/Common/Materials", "Bin/Common/Meshes", "Bin/Common/TexturesMeta", "Bin/win32/", "Bin/win32/Textures",
        "Bin/win32/Fallbacks", "Bin/win32/Fallbacks/Textures"}
    for i, subpath in ipairs(structure) do
        local full_path = path.assets.root .. subpath
        local os_path = ConvertToOSPath(full_path)
        local err = AsyncCreatePath(os_path)
        if err then
            atprint("Failed creating exporter target folder structure - %s", err)
            return
        end
    end

    -- copy exporter folder structure
    local err, folders = AsyncListFiles(path.assets.exporter, "*", "recursive,relative,folders")
    if err then
        atprint("Failed listing Autodesk 3DS Max exporter folder structure - %s", err)
        return err
    end

    local os_path = ConvertToOSPath(path.max.exporter)
    local err = AsyncCreatePath(os_path)
    if err then
        atprint("Failed copying Autodesk 3DS Max exporter folder structure - %s", err)
        return err
    end

    for _, folder in ipairs(folders) do
        if not string.find(folder, ".svn") then
            local os_path = ConvertToOSPath(path.max.exporter .. folder)
            local err = AsyncCreatePath(os_path)
            if err then
                atprint("Failed copying Autodesk 3DS Max exporter folder structure - %s", err)
                return err
            end
        end
    end

    -- copy exporter files
    local err, files = AsyncListFiles(path.assets.exporter, "*", "recursive,relative")
    if err then
        atprint("Failed listing Autodesk 3DS Max exporter files - %s", err)
        return err
    end

    for _, file in ipairs(files) do
        if not string.find(file, ".svn") then
            local os_dest_path = ConvertToOSPath(path.max.exporter .. file)
            local err = AsyncCopyFile(path.assets.exporter .. file, os_dest_path, "raw")
            if err then
                atprint("Failed copying Autodesk 3DS Max exporter files - %s", err)
                return err
            end
        end
    end

    -- copy exporter startup file
    local err = AsyncCopyFile(path.max.exporter_startup, path.max.startup)
    if err then
        atprint("Failed copying Autodesk 3DS Max exporter startup file - %s", err)
        return err
    end

    ArtTest.SetProducer_3DSMax(rawget(_G, "g_ArtTestProducer"))

    atprint("Installed Autodesk 3DS Max exporter. Restart Autodesk 3DS Max.")
end
---
--- Starts the art preview mode.
---
--- This function is responsible for initializing the art preview mode. It performs the following steps:
--- 1. Checks if an art producer script exists and loads it.
--- 2. If no art producer is found, it opens a dialog to allow the user to select an art producer.
--- 3. Sets the selected art producer.
--- 4. Loads external entities.
--- 5. Sets up the map for the art preview.
---
--- @function ArtTest.Start
--- @return nil

function ArtTest.Start()
    atprint("Starting art preview mode")

    if io.exists(path.assets.art_producer_lua) then
        local producer = dofile(path.assets.art_producer_lua)
        if type(producer) == "string" then
            rawset(_G, "g_ArtTestProducer", producer)
        end
    end

    local art_producer = rawget(_G, "g_ArtTestProducer")
    local no_art_producer = (art_producer == nil)
    if no_art_producer then
        ArtTest.OpenChangeProducerDialog()
        return
    else
        -- updates all files
        ArtTest.SetProducer(art_producer)
        atprint("Selected art producer %s", art_producer)
    end

    ArtTest.LoadExternalEntities()
    ArtTest.SetUpMap()
end

local mounted
---
--- Loads all external entities required for the art preview mode.
---
--- This function is responsible for loading all the necessary entities, meshes, animations, materials, and textures for the art preview mode. It performs the following steps:
--- 1. Mounts the required folders to make the assets accessible.
--- 2. Enumerates all the entity files in the `path.assets.entities` directory.
--- 3. Loads each entity file using `DelayedLoadEntity`.
--- 4. Opens a loading screen and forces a reload of the bin assets and DLC assets.
--- 5. Waits for the bin assets to finish loading and then closes the loading screen.
--- 6. Waits for any delayed entity loads to complete.
--- 7. Reloads the Lua script.
---
--- @function ArtTest.LoadExternalEntities
--- @return nil
function ArtTest.LoadExternalEntities()
    if not mounted then
        mounted = true

        MountFolder(path.assets.root .. "Bin/Common/Entities/Meshes/", path.assets.root .. "Bin/Common/Meshes/")
        MountFolder(path.assets.root .. "Bin/Common/Entities/Animations/", path.assets.root .. "Bin/Common/Animations/")
        MountFolder(path.assets.root .. "Bin/Common/Entities/Materials/", path.assets.root .. "Bin/Common/Materials/")
        MountFolder(path.assets.root .. "Bin/Common/Entities/Mapping/", path.assets.root .. "Bin/Common/Mapping/")
        MountFolder(path.assets.root .. "Bin/Common/Entities/Textures/", path.assets.root .. "Bin/win32/Textures/")
        atprint("Mounted all entity folders")
    end

    local err, all_entities = AsyncListFiles(path.assets.entities, "*.ent")
    if err then
        atprint("Failed to enumerate entities - %s", err)
        return
    end
    if not all_entities or #all_entities == 0 then
        atprint("No entities to load")
        return
    end

    for i, ent_file in ipairs(all_entities) do
        DelayedLoadEntity(false, false, ent_file)
    end
    atprint("Will load %d entities", #all_entities)

    LoadingScreenOpen("idArtTestLoadEntities", "ArtTestLoadEntities")
    local old_render_mode = GetRenderMode()
    WaitRenderMode("ui")
    ForceReloadBinAssets()
    DlcReloadAssets(DlcDefinitions)
    -- actually reload the assets
    LoadBinAssets(CurrentMapFolder)
    -- wait & unmount
    WaitNextFrame(2)
    while AreBinAssetsLoading() do
        Sleep(1)
    end
    WaitRenderMode(old_render_mode)
    LoadingScreenClose("idArtTestLoadEntities", "ArtTestLoadEntities")
    WaitDelayedLoadEntities()
    -- ReloadClassEntities()
    ReloadLua()
    atprint("Reloaded all entities")
end

--- Sets up the map for the ArtTest module.
---
--- This function performs the following tasks:
--- - Activates the cameraMax camera
--- - Prints a message to the console indicating the camera has been set up
--- - Calls the ArtTest.PlacePreviewObjects() function to place preview objects on the map
--- - If any preview objects were placed, it moves the camera to view the first preview object
function ArtTest.SetUpMap()
    cameraMax.Activate(1)
    atprint("Camera set up")

    local preview_objs = ArtTest.PlacePreviewObjects()

    if preview_objs and next(preview_objs) then
        ViewPos(preview_objs[1]:GetVisualPos())
        atprint("Showing first preview object")
    end
end

--- Returns a list of object classes to preview in the ArtTest module.
---
--- The list of object classes is determined by the current producer set in the
--- `g_ArtTestProducer` global variable. If `g_ArtTestProducer` is set to "Any",
--- then all object classes that have an entry in the `entity_producers_lua` file
--- will be included in the list.
---
--- @return table A list of object class names to preview.
function ArtTest.GetObjectClassesToPreview()
    local current_producer = rawget(_G, "g_ArtTestProducer") or "Any"
    local result = {}

    if io.exists(path.assets.entity_producers_lua) then
        local entity_producers = dofile(path.assets.entity_producers_lua)
        for entity_id, produced_by in pairs(entity_producers) do
            if (current_producer == "Any" or produced_by == current_producer) and g_Classes[entity_id] then
                table.insert(result, entity_id)
            end
        end
    end

    return result
end

local spacing = 10 * guim
--- Places preview objects on the map for the ArtTest module.
---
--- This function places preview objects on the map for each object class that is
--- eligible to be previewed in the ArtTest module. The list of eligible object
--- classes is determined by the current producer set in the `g_ArtTestProducer`
--- global variable.
---
--- For each eligible object class, the function places one preview object for
--- each valid state of the object. The preview objects are placed in a grid
--- pattern, with a spacing of `spacing` units between each object.
---
--- The function returns a list of all the preview objects that were placed.
---
--- @param classes (optional) A list of object class names to preview. If not
---                provided, the function will use the list returned by
---                `ArtTest.GetObjectClassesToPreview()`.
--- @return table A list of preview objects that were placed.
function ArtTest.PlacePreviewObjects(classes)
    local current_producer = rawget(_G, "g_ArtTestProducer") or "Any"

    local y = 0
    local result = {}

    local classes = classes or ArtTest.GetObjectClassesToPreview()
    if not classes or #classes == 0 then
        atprint("No preview objects to place")
        return
    end

    for i, classname in ipairs(classes) do
        local class = g_Classes[classname]
        local entity = class:GetEntity()
        local entity_bbox = GetEntityBBox(entity)
        local _, radius = entity_bbox:GetBSphere()

        local x = 0
        local half_spacing = radius + spacing

        for i, state in pairs(EnumValidStates(entity)) do
            x, y = x + half_spacing, y + half_spacing
            local pos = point(x, y)
            local preview_pos = point(x, y, terrain.GetHeight(x, y))
            x, y = x + half_spacing, y + half_spacing

            local preview_obj = PlaceObject(classname)
            preview_obj:SetPos(preview_pos)
            preview_obj:SetState(state)
            table.insert(result, preview_obj)

            local text_obj = PlaceObject("Text")
            text_obj:SetDepthTest(false)
            text_obj:SetText(entity .. "\n" .. GetStateName(state))
            text_obj:SetPos(pos + point(radius, radius))
        end
    end

    atprint("Placed %d preview objects", #result)
    return result
end

----

function OnMsg.ChangeMapDone()
	if CurrentMap == "ArtTest" then
		CreateRealTimeThread(ArtTest.Start)
	end
end

if FirstLoad and config.ArtTest then
	CreateRealTimeThread(ChangeMap, "ArtTest")
end