-- Author: AylinCE
-- Source: https://forum.cheatengine.org/viewtopic.php?p=5795321#5795321
-- Usage:
--  - Copy this LUA file into CE's autorun folder

-- ============================================================================
-- OpenDialog Preview Pane Controller Module (ByAylinCE)
-- ============================================================================
local DialogPreviewManager = {}

local tempFile = os.getenv("TEMP") .. "\\ce_reg_cmd.txt"

-- Helper function to execute registry commands via cmd silencer
local function execRegCmd(cmdStr)
    local fullCmd = string.format('cmd.exe /c "reg.exe %s > "%s" 2>&1"', cmdStr, tempFile)
    runCommand(fullCmd)
    local f = io.open(tempFile, "r")
    if f then
        f:close()
        os.remove(tempFile)
    end
end

--- Configures the preview pane state for OpenDialog
-- @param state number: 0 = Force Disable Preview Pane, 1 = Force Enable Preview Pane
function DialogPreviewManager.setPreviewState(state)
    local advKey = [[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced]]
    local cidKey = [[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\CIDOpen]]
    local mruKey = [[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32\CIDSizeMRU]]

    if state == 1 then
        -- ENABLE PREVIEW PANE (1):
        -- Set registry flag to 1
        execRegCmd(string.format('add "%s" /v "ShowPreviewPane" /t REG_DWORD /d 1 /f', advKey))

        -- Send Alt+P key combination to toggle preview pane on if cached as hidden
        local t = createTimer(nil, false)
        t.Interval = 50
        local tries = 0
        t.OnTimer = function(sender)
            tries = tries + 1
            local hwnd = findWindow(nil, MainForm.OpenDialog1.Title)
            if hwnd and hwnd ~= 0 then
                executeCodeLocalEx('user32.SetForegroundWindow', hwnd)
                executeCodeLocalEx('user32.keybd_event', 0x12, 0, 0, 0) -- Alt Down
                executeCodeLocalEx('user32.keybd_event', 0x50, 0, 0, 0) -- P Down
                executeCodeLocalEx('user32.keybd_event', 0x50, 0, 2, 0) -- P Up
                executeCodeLocalEx('user32.keybd_event', 0x12, 0, 2, 0) -- Alt Up
                sender.destroy()
                return
            end
            if tries >= 10 then sender.destroy() end
        end
        t.Enabled = true
    else
        -- DISABLE PREVIEW PANE (0):
        -- Clear cache to reset dialog geometry and set registry flag to 0
        execRegCmd(string.format('delete "%s" /f', cidKey))
        execRegCmd(string.format('delete "%s" /f', mruKey))
        execRegCmd(string.format('add "%s" /v "ShowPreviewPane" /t REG_DWORD /d 0 /f', advKey))
    end
end


-- ============================================================================
-- USAGE EXAMPLE
-- ============================================================================

MainForm.OpenDialog1.Title = "Open File"
MainForm.OpenDialog1.Options = '[ofHideReadOnly, ofFileMustExist, ofEnableSizing]'

-- Test 0: Disabled (Close)
-- Test 1: Enabled  (Open)
DialogPreviewManager.setPreviewState(0)
--[[

if MainForm.OpenDialog1.execute() then
    print("Selected File: " .. MainForm.OpenDialog1.FileName)
end
]]--