run

-- Run scripts in workspace.
-- 
-- Usage:
--   - **show scripts**: <lua> run
--   - **run a script**: <lua> run <script_name> [<args>]

local cwd = debug.getinfo(1, 'S').source:match('^@?(.*)[/\\]') or '.'
local sep = package.config:sub(1, 1)
local win = sep == "\\"

local function ujoin(...)
    local n = select('#', ...)
    local u = {...}
    for i = 1, n do if not u[i] then
        u[i] = ''
    end end
    return table.concat(u, sep, 1, n)
end

local function list_scripts(dir)
    local scripts = {}
    local command = (win and 'dir /b "%s"' or 'ls "%s"'):format(dir)
    local phandle = io.popen(command, 'r')
    if not phandle then return scripts end
    for name in (phandle:read('*a') or ''):gmatch('[^\r\n]+') do
        if name:match('(.+)%.lua$') then
            table.insert(scripts, name:sub(1, -5))
        end
    end
    phandle:close()
    table.sort(scripts)
    return scripts
end

local function shell_quote(value)
    value = tostring(value)
    if win then return '"' .. value:gsub('"', '""') .. '"' end
    return "'" .. value:gsub("'", "'\\''") .. "'"
end

local function find_lua_command()
    local LUA = os.getenv('LUA')
    if LUA and LUA ~= '' then return LUA end

    -- Lua stores the interpreter and its options at negative arg indexes.
    -- The exact index differs between Lua versions and invocation forms.
    for i = -1, -10, -1 do
        local value = arg[i]
        if type(value) == 'string' then
            local name = value:gsub('^.*[/\\]', ''):lower()
            if name:match('^lua') or name:match('^luajit') then
                return value
            end
        end
    end

    if pcall(require, 'jit') then return 'luajit' end
    local major, minor = (_VERSION or ''):match('Lua%s+(%d+)%.(%d+)')
    if major and minor then return 'lua' .. major .. minor end
    return 'lua'
end

if #arg == 0 then
    local scripts = list_scripts(ujoin(cwd, "scripts"))
    if #scripts == 0 then os.exit(1) end
    local cwd_short = cwd:match((("&([^&]+)$"):gsub("&", sep))) or 'workspace'
    print("Scripts available in "..cwd_short.." via `lua run`:")
    for _, v in ipairs(scripts) do print("-  "..v) end
    os.exit(0)
end

local scriptname = arg[1] or ''
local scriptpath = ujoin(cwd, "scripts", scriptname..".lua")
local scriptFile = io.open(scriptpath, 'r')

if not scriptFile then
    io.write(io.stderr, "lua error Missing script: \""..scriptname.."\"\n")
    io.write(io.stderr, "lua error\n")
    io.write(io.stderr, "lua error To see a list of scripts, run:\n")
    io.write(io.stderr, "lua error   lua run\n")
    os.exit(1)
end
scriptFile:close()

local command = (win and 'call ' or '')
    .. shell_quote(find_lua_command()) .. ' ' .. shell_quote(scriptpath)
for i = 2, #arg do command = command .. ' ' .. shell_quote(arg[i]) end
local a, b, c = os.execute(command)
local code
if type(a) == 'number' then
    code = a
elseif a then
    code = c or 0
else
    code = c or b or 1
end
os.exit(code)