lament/src/bin/cli.lua

-- bin/cli.lua - The LAMENT command-line tool
--
--     Copyright (C) 2024-2025  Kıvılcım Defne Öztürk
--
-- 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 3 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 <https://www.gnu.org/licenses/>.

-- TODO: fix this shit

local argparse = require("argparse")
local pretty = require("pl.pretty")
local util = require("./util")

local function print_help()
   print("lament - Alters or reads configuration files based on instructions.")
   print("See lament(8) for more information")
   print("Usage:")
   print("  lament <key> <action> [options]")
   print("  lament --apply [options]")
   print("  lament --recalibrate [options]")
   print("  lament --cross-calibrate [options]")
   print("  lament --help")
   print()
   print("Arguments:")
   print("  <key>                            Key for configuration elements.")
   print("  <action>                         Either get or set, what to do with the key")
   print()
   print("Global Options:")
   print("  --apply, -A                          Forwards apply the changes to the system's configuration")
   print(
      "  --recalibrate, -B                    Backwards apply the changes in configuration to LAMENT's own configuration")
   print(
      "  --cross-calibrate, -C                [VERY EXPERIMENTAL] Perform application or recalibration based on which side is newer")
   print()
   print("Options for lament <key> set:")
   print("  <value>                          Used for most keys. Dictates the value of the key to be set.")
   print("  --clear                          Clear the value of optional keys. Will error if used with compulsory keys.")
   print("  --append, -a <value>             Only used for list keys. Add a value to the end of the list on the key")
   print("                                   <value>: The value to append.")
   print(
      "  --prepend, -p <value>            Only used for list keys. Add a value to the beginning of the list on the key.")
   print("                                   <value>: The value to prepend.")
   print("  --set-index, -s <index> <value>  Only used for list keys. Amend a single index of the keys.")
   print(
      "                                   Cannot be used to amend dictionaries. Dictionaries must be amended with the object path resolution.")
   print(
      "                                   <index>: Must be a positive natural number. The index of the list to amend.")
   print("                                   <value>: The value at the index to amend")
   print("  --nil-index, -n <index>          Only used for list keys. Set the value of <index> to nil.")
   print(
      "                                   This is different from --del-index which deletes the member of the array at the said index.")
   print(
      "  --del-index, -d <index>          Only used for list keys. Delete the index from the sequence. Cannot be used with dictionaries.")
   print("                                   After this operation the length of the value reduces by one.")
   print("                                   <index>: Must be a positive natural number. The index to delete.")
   print()
   print("Options for lament <key> get:")
   print("  --index, --at, -i <index>        Only used for list keys. Get the value on the specified index.")
   print("                                   <index>: Must be a postive natural number. The index to get the value of.")
end


-- local entry point for the script
local parser = argparse() {
   name = "lament",
   description = "Alters or reads configuration files based on instructions",
   epilog = "See lament(8) for more info."
}

local global_flags = parser:mutex(
   parser:flag("-A --apply", "Forwards apply the changes to the system's configuration"),
   parser:flag("-B --recalibrate", "Backwards apply the changes in configuration to LAMENT's own configuration"),
   parser:flag("-C --cross-calibrate",
      "[VERY EXPERIMENTAL] Perform application or recalibration based on which side is newer")
)

-- Positional args - optional here, will check after parsing
parser:argument("key", "Key for configuration elements"):args("?")
parser:argument("action", "Action to perform: get or set"):args("?"):choices({ "get", "set" })

local args, err = parser:parse(arg)
if err then
   io.stderr:write(pretty(err))
   os.exit(1)
end

local global_flag_count = 0
if args.apply then global_flag_count = global_flag_count + 1 end
if args.recalibrate then global_flag_count = global_flag_count + 1 end
if args.cross_calibrate then global_flag_count = global_flag_count + 1 end

local has_key_and_action = args.key ~= nil and args.action ~= nil

-- Enforce exclusivity and presence rules:
if global_flag_count == 1 and not has_key_and_action then
   -- OK, user chose exactly one global flag, no key/action - good
elseif global_flag_count == 0 and has_key_and_action then
   -- OK, user provided key and action without global flags - good
else
   -- Any other combination is invalid
   io.stderr:write(
   "Error: you must specify exactly one of the global flags (-A, -B, or -C) OR both <key> and <action>.\n\r")
   io.stderr:write(parser:get_usage())
   os.exit(1)
end

-- Now handle the logic depending on the input mode:

if global_flag_count == 1 then
   -- handle the global flag mode
   if args.apply then
      print("Forwards application invoked")
   elseif args.recalibrate then
      print("Recalibration invoked.")
   elseif args.cross_calibrate then
      print("Cross calibration invoked.")
   end
elseif has_key_and_action then
   -- handle <key> <action> commands

   print("key:", args.key)
   print("action:", args.action)

   -- verify key syntax
   if not util.verify_key_syntax(args.key) then
      io.stderr:write(string.format("Syntax for key \"%s\" is invalid", args.key))
      os.exit(1)
   end

   if args.action == "set" then
      -- create key setting parser
      local set_parser = argparse("set", "Options for lament <key> set")
      set_parser:argument("value", "Value to set"):args("?")
      set_parser:flag("--clear, -c", "Clear the value for optional keys")
      set_parser:option("-a --append", "Append <value> to the list"):args(1)
      set_parser:option("-p --prepend", "Prepend <value> to the list"):args(1)
      set_parser:option("-s --set-index", "Set a list index to <value>"):args(2)
      set_parser:option("-n --nil-index", "Set a list index to nil"):args(1)
      set_parser:option("-d --del-index", "Delete the list index"):args(1)

      local set_args, err = set_parser:parse(arg, 3)
      if err then
         io.stderr:write("Error parsing set options:", assert(pretty.write(err)))
         os.exit(1)
      end

      print(pretty.write(set_args))
   elseif args.action == "get" then
      local get_parser = argparse("get", "Options for lament <key> get")
      get_parser:option("-i --index --at", "Get the value at the specified index"):args(1)

      local get_args, err = get_parser:parse(arg, 3)
      if err then
         print("Error parsing get options:", err)
         os.exit(1)
      end

      print("Get options:")
      for k, v in pairs(get_args) do
         print(" ", k, v)
      end
   else
      parser:get_usage()
   end
end