# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later

# SYNOPSIS
#   _replace_command_token
#
# DESCRIPTION
#   Removes the first command token from the commandline buffer and
#   positions the cursor for immediate replacement. If the command starts
#   with sudo, preserves sudo and removes the token after it instead. If
#   the commandline is empty, first recalls the most recent history entry
#   (like pressing Up) before doing the token replacement on it.
#   Intended to be bound to a key in key_bindings.fish.
#
# EXAMPLE
#   bind \cx _replace_command_token
function _replace_command_token --description 'Remove first command token (or first after sudo) and place cursor for replacement'
    set -l cmd (commandline)

    # Empty prompt: recall the last history entry first, same as it would
    # behave if that command were already on the commandline.
    if string match -rq '^\s*$' -- "$cmd"
        set cmd (history --max 1)
    end

    # 1. Logic for commands starting with sudo
    if string match -rq '^sudo\s+' -- "$cmd"
        # regex explanation: 
        # ^sudo\s+  -> Matches 'sudo' and the following whitespace
        # \S+       -> Matches the actual command (e.g., 'rm')
        # \s*       -> Consumes the space after the command so it's not captured
        # (.*)      -> Captures everything else (the arguments) into $1
        set -l rest (string replace -r '^sudo\s+\S+\s*(.*)' 'sudo  $1' -- "$cmd")
        commandline -- "$rest"

        # Place cursor between the two spaces after sudo
        # 'sudo ' is 5 characters (indices 0-4), so index 5 is the sweet spot
        commandline -C 5

        # 2. Logic for standard commands (no sudo)
    else
        # regex explanation:
        # ^\S+      -> Matches the first word/command
        # \s*       -> Consumes the trailing space
        # (.*)      -> Captures the rest of the line into $1
        set -l rest (string replace -r '^\S+\s*(.*)' ' $1' -- "$cmd")
        commandline -- "$rest"

        # Place cursor at index 0 to immediately start typing the replacement
        commandline -C 0
    end
end