--[[
  [[ User program to compute SHA-256 hashes of files for Halude
  [[ Copyright (C) 2026  tema5002
  [[
  [[ This program is free software; you can redistribute it and/or
  [[ modify it under the terms of the GNU General Public License
  [[ as published by the Free Software Foundation; either version 2
  [[ of the License, or (at your option) any later version.
  [[
  [[ This program is distributed in the hope that it will be useful,
  [[ but WITHOUT ANY WARRANTY; without even the implied warranty of
  [[ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  [[ GNU General Public License for more details.
  [[
  [[ You should have received a copy of the GNU General Public License
  [[ along with this program; If not, see <http://www.gnu.org/licenses/>.
  ]]--

local files = {...}
local sha256 = import("sha256")
local fs = import("filesystem")
if not files or not files[1] then
    shell.run("help sha256sum")
    return
end

for _, file in ipairs(files) do
    if file:sub(1, 1) ~= "/" then
        file = fs.concat(shell.workingDirectory, file)
    end
    if not fs.exists(file) then
        print("\27[91mFile does not exist.")
        goto continue
    end
    local handle = fs.open(file, "r")
    local ctx = sha256.init()
    while true do
        local chunk = handle:read(256)
        if not chunk then break end
        sha256.update(ctx, chunk)
    end
    handle:close()
    local hash_bytes = sha256.final(ctx)
    termlib.write(sha256.to_hex(hash_bytes).."  "..file.."\n")
    ::continue::
end