-- @description  Script that provides incremental saving capability. Every time the script is called, the project will be saved with a new (unused) file name that counts up. E.g. my_project_0001.ocs, my_project_0002.ocs, etc.
-- @author       me :)
-- @shortcut     alt + s
-- @version      0.1


local function showError(text)
    octane.gui.showDialog{
        type  = octane.gui.dialogType.BUTTON_DIALOG,
        title = "Error",
        text  = text }
end


-- currently we don't support incremental saving for packages
if octane.project.loadedFromPackage() then
    showError("Incremental saving for packages is currently not supported.")
    return
end

-- get current project file name
local projectPath = octane.project.getCurrentProject()

-- if we don't have a file name yet, the project hasn't been saved yet:
if not projectPath or (projectPath == "") then
    -- let user choose a file name for the project
    local newPath = octane.gui.showDialog{
        type            = octane.gui.dialogType.FILE_DIALOG,
        browseDirectory = false,
        path            = octane.project.getPreferences():getAttribute(octane.A_LAST_PROJECT_DIRECTORY),
        save            = true,
        title           = "Please specify the project file name",
        wildcards       = "*.ocs" }
    projectPath = newPath.result
    -- if no path is returned, the user cancelled the dialog -> stop script
    if projectPath == "" then return end
end

-- split path into directory, file name without exension
local projectDir = octane.file.getParentDirectory(projectPath)
local projectFile = octane.file.getFileNameWithoutExtension(projectPath)

-- if the directory of the file path doesn't exist, create it
if not octane.file.isDirectory(projectDir) then
    if not octane.file.createDirectory(projectDir) then
        showError(string.format("Can't save project, because directory '%s' could not be created."))
        return
    end
end

-- if the file name doesn't end with a number, append "_0001"
if not projectFile:find("%d+$") then
    projectFile = projectFile .. "_0001"
end

-- loop until we find an unused file name
while true do

    -- if we found an unused file name, save the project and return
    projectPath = octane.file.join(projectDir, projectFile .. ".ocs")
    if not octane.file.exists(projectPath) then
        if not octane.project.saveAs(projectPath) then
            showError(string.format("Found unused file name '%s', but can't save project into it."))
        end
        return
    end
    
    -- ok increment the number in the file name and then try again.
    local ix = projectFile:len()
    while true do
        -- if the current character index is 0, the file name consists only of digits and we have
        -- the maximum possible number. add a "1" in front of it and break.
        if ix < 1 then
            projectFile = "1" .. projectFile
            break
        end
        -- get digit at character position ix
        local digit = tonumber(projectFile:sub(ix, ix))
        -- if digit is not a digit, insert a "1" and break
        if not digit then
            projectFile = projectFile:sub(1, ix) .. "1" .. projectFile:sub(ix + 1)
            break
        end
        -- increment the digit and if it's still less than 10, just replace the old digit with the
        -- incremented one
        digit = digit + 1
        if digit < 10 then
            projectFile = projectFile:sub(1, ix-1) .. tostring(digit) .. projectFile:sub(ix + 1)
            break
        -- if we have an overflow, replace the old digit with "0" and continue with next left digit
        else
            projectFile = projectFile:sub(1, ix-1) .. "0" .. projectFile:sub(ix + 1)
        end
        ix = ix - 1
    end
end