--:Minify:--
-- supports +i/-i (immutable) stored in the file's cmeta/xattr field
local name = syscall.getTask(syscall.getpid()).name
local cloptions = { R = false, help = false }
local args = {}
local modeStr = nil

for _, v in ipairs({ ... }) do
    if v:sub(1, 2) == "--" then
        local opt = v:sub(3)
        if cloptions[opt] == nil then
            print(name .. ": unrecognized option '" .. v .. "'")
            print("try '" .. name .. " --help' for more information.")
            syscall.exit(1); return
        end
        cloptions[opt] = true
    elseif v:sub(1, 1) == "-" and not v:match("^%-[%+%-]") then
        local isFlag = true
        for i = 2, #v do
            local c = v:sub(i,i)
            if cloptions[c] ~= nil then
                cloptions[c] = true
            else
                isFlag = false; break
            end
        end
        if not isFlag then
            modeStr = v
        end
    elseif v:sub(1,1) == "+" or (v:sub(1,1) == "-" and v:match("^%-[a-zA-Z]")) then
        modeStr = v
    else
        table.insert(args, v)
    end
end

if cloptions.help then
    print("Usage: " .. name .. " [OPTION]... +-= ATTRS FILE...")
    print("Change file attributes on a filesystem.")
    print("")
    print("Attributes:")
    print("  i    immutable: file cannot be modified, renamed, or deleted")
    print("  a    append-only: file can only be appended to")
    print("")
    print("Operators:  +attr  add,  -attr  remove")
    print("Example:  " .. name .. " +i /etc/passwd")
    print("")
    print("Options:")
    print("  -R          operate on files and directories recursively")
    print("  --help      display this help and exit")
    return
end

if not modeStr or #args < 1 then
    print(name .. ": missing operand")
    print("try '" .. name .. " --help' for more information.")
    syscall.exit(1); return
end

local op    = modeStr:sub(1, 1)
local attrs = modeStr:sub(2)

if op ~= "+" and op ~= "-" then
    print(name .. ": invalid operator '" .. op .. "' (use + or -)")
    syscall.exit(1); return
end

local function getXattr(path)
    local stat = pcall(function() return syscall.stat(path) end) and syscall.stat(path)
    if stat then return stat.xattr or "" end
    return ""
end

local IMMUTABLE_TAG  = "|i"
local APPENDONLY_TAG = "|a"

local function attrTag(c)
    if c == "i" then return IMMUTABLE_TAG
    elseif c == "a" then return APPENDONLY_TAG
    else return nil end
end

local function chattrPath(path)
    local stat = syscall.stat(path)
    if not stat then
        print(name .. ": cannot stat '" .. path .. "': No such file or directory")
        return false
    end
    if stat.etype == 0x01 then
        return true
    end

    if not syscall.setxattr then
        print(name .. ": kernel does not expose setxattr syscall; cannot modify attributes")
        syscall.exit(1); return false
    end

    local xattr = stat.xattr or ""

    for i = 1, #attrs do
        local c = attrs:sub(i, i)
        local tag = attrTag(c)
        if not tag then
            print(name .. ": unsupported attribute '" .. c .. "'")
            syscall.exit(1); return false
        end
        local hasTag = xattr:find(tag, 1, true)
        if op == "+" and not hasTag then
            xattr = xattr .. tag
        elseif op == "-" and hasTag then
            xattr = xattr:gsub(tag:gsub("|", "%%|"), "")
        end
    end

    local ok, err = pcall(syscall.setxattr, path, xattr)
    if not ok then
        print(name .. ": cannot set attributes on '" .. path .. "': " .. tostring(err))
        return false
    end
    return true
end

local function chattrRecursive(path)
    if not chattrPath(path) then return end
    if syscall.type(path) == "directory" then
        local ok, list = pcall(syscall.listdir, path)
        if ok then
            for _, entry in ipairs(list) do
                local child = path
                if child:sub(-1) ~= "/" then child = child .. "/" end
                chattrRecursive(child .. entry)
            end
        end
    end
end

local cwd = syscall.getcwd()
local function absPath(p)
    if p:sub(1,1) ~= "/" then p = cwd .. "/" .. p end
    return p
end

if not syscall.setxattr then
    print(name .. ": kernel does not expose setxattr; attributes cannot be persisted")
    print(name .. ": add  sys[\"setxattr\"] = vfs.setxattr  to 10_vfs.kmod to enable this")
    syscall.exit(1); return
end

local exitCode = 0
for i = 1, #args do
    local path = absPath(args[i])
    if not syscall.exists(path) then
        print(name .. ": cannot access '" .. args[i] .. "': No such file or directory")
        exitCode = 1
    elseif cloptions.R then
        chattrRecursive(path)
    else
        if not chattrPath(path) then exitCode = 1 end
    end
end

syscall.exit(exitCode)