path.lua

Path = Path or {}

function Path.ExtractFileName(path)
    path = path:gsub("\\", "/")
    local lastChar = path:sub(-1)
    if lastChar == "/" then
        path = path:sub(1, -2)
    end
    local pos
    local b, init, n = 1, 0, 0
    repeat
        pos, init, n = b, init + 1, n + 1
        b, init = path:find("/", init, true)
    until not b
    if n == 1 then
        return path
    else
        return path:sub(pos + 1)
    end
end

function Path.ExtractDir(path)
    path = path:gsub("\\", "/")
    local lastChar = path:sub(-1)
    if lastChar == "/" then
        path = path:sub(1, -2)
    end
    local pos
    local b, init, n = 1, 0, 0
    repeat
        pos, init, n = b, init + 1, n + 1
        b, init = path:find("/", init, true)
    until not b
    if n == 1 then
        return path
    else
        return path:sub(1, pos)
    end
end

function Path.GetParentDir(dir)
    dir = dir:gsub("\\", "/")
    local lastChar = dir:sub(-1)
    if lastChar == "/" then
        dir = dir:sub(1, -2)
    end
    local pos
    local b, init, n = 1, 0, 0
    repeat
        pos, init, n = b, init + 1, n + 1
        b, init = dir:find("/", init, true)
    until not b
    if n == 1 then
        return ''
    else
        return dir:sub(1, pos)
    end
end

local function _Join(dir, path)
    dir = dir:gsub("\\", "/")
    path = path:gsub("\\", "/")

    local lastCharDir = dir:sub(-1)
    local firstCharPath = path:sub(1, 1)

    -- No slashes
    if lastCharDir ~= "/" and firstCharPath ~= "/" then
        return dir .. "/" .. path
    -- Two slashes
    elseif lastCharDir == "/" and firstCharPath == "/" then
        return dir .. "/" .. path:sub(2)
    -- One Slash
    else
        return dir .. path
    end
end

function Path.Join(dir, ...)
    local fullPath = dir
    for _, path in pairs({...}) do
        fullPath = _Join(fullPath, path)
    end
    return fullPath
end

function Path.GetExt(path)
    -- Find the last dot in the path
    local index = string.find(path, ".[^.]*$")
    if index then
        return path:sub(index)
    end
end

function Path.DirList(...)
    local uniqueFiles = {}
    for _, file in ipairs(VFS.DirList(...)) do
        file, _ = file:gsub("\\", "/")
        uniqueFiles[file] = true
    end
    local files = {}
    for file, _ in pairs(uniqueFiles) do
        table.insert(files, file)
    end
    return files
end

function Path.SubDirs(...)
    local uniqueDirs = {}
    for _, dir in ipairs(VFS.SubDirs(...)) do
        dir, _ = dir:gsub("\\", "/")
        uniqueDirs[dir] = true
    end
    local dirs = {}
    for dir, _ in pairs(uniqueDirs) do
        table.insert(dirs, dir)
    end
    return dirs
end

function Path.Walk(path, f, opts)
    opts = opts or {}
    local WalkFiles = function()
        for _, file in ipairs(Path.DirList(path, "*", opts.mode)) do
            f(file)
        end
    end
    local WalkDirs = function()
        for _, dir in ipairs(Path.SubDirs(path, "*", opts.mode)) do
            Path.Walk(dir, f, opts)
            if opts.apply_folders then
                f(dir)
            end
        end
    end
    if opts.dirs_first then
        WalkDirs()
        WalkFiles()
    else
        WalkFiles()
        WalkDirs()
    end
end

-- Tests
local lu = luaunit
if not lu then
    return
end

-- luacheck: ignore
function testExtractFileName()
    lu.assertEquals(Path.ExtractFileName("abc.txt"), "abc.txt")
    lu.assertEquals(Path.ExtractFileName("xyz/abc.txt"), "abc.txt")
    lu.assertEquals(Path.ExtractFileName("xyz\\abc.txt"), "abc.txt")
    lu.assertEquals(Path.ExtractFileName("xyz/efg/abc.txt"), "abc.txt")
    lu.assertEquals(Path.ExtractFileName("xyz/efg\\abc.txt"), "abc.txt")
end

function testExtractDir()
    -- lu.assertEquals(Path.ExtractDir("xyz/abc.txt"), "xyz")
    -- lu.assertEquals(Path.ExtractDir("xyz"), "xyz")
    -- lu.assertEquals(Path.ExtractDir("xyz/"), "xyz")
    -- lu.assertEquals(Path.ExtractDir("xyz\\"), "xyz")
    -- lu.assertEquals(Path.ExtractDir("xyz\\abc.txt"), "xyz")
end

function testJoin()
    lu.assertEquals(Path.Join("folder", "file"), "folder/file")
    lu.assertEquals(Path.Join("folder/", "file"), "folder/file")
end

if lu then
    lu.LuaUnit.run()
end