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

# CATEGORY
#   01-file-and-directory
#
# SYNOPSIS
#   du [--disk|--dir|--dua] [args...]
#
# DESCRIPTION
#   Smart disk-usage dispatcher. Without flags, routes to the most appropriate
#   tool by context; explicit flags force one. Falls back to system du when the
#   preferred tool is not installed.
#
# ARGUMENTS
#   --disk   Force duf  (disk-level free/used overview)
#   --dir    Force dust (per-directory tree breakdown)
#   --dua    Force dua  (fast interactive space analyzer)
#   args...  Files/directories or flags forwarded to the selected tool
#
# EXAMPLE
#   du ~/Downloads
#   du --disk
function du --description 'Execute du'
    # Opinionated guard (C1): fall back to bare command du when disabled.
    if not __fish_config_op_enabled __fish_config_op_aliases
        command du $argv
        return $status
    end

    set cmd ""
    set args

    # Parse override flags and gather remaining args
    for arg in $argv
        switch $arg
            case --disk
                set cmd duf
            case --dir
                set cmd dust
            case --dua
                set cmd dua
            case '*'
                set args $args $arg
        end
    end

    # Autodetect if no override flag given
    if test -z "$cmd"
        if count $args
            set first_arg $args[1]
            if test -d "$first_arg" -o -f "$first_arg"
                set cmd dust
            else
                set cmd duf
            end
        else
            set cmd duf
        end
    end

    # Tool execution with graceful fallback
    switch $cmd
        case duf
            if type -q duf
                duf $args
            else
                echo "(duf not found — falling back to du)"
                command du -sh $args
            end
        case dust
            if type -q dust
                dust $args
            else
                echo "(dust not found — falling back to du)"
                command du -sh $args
            end
        case dua
            if type -q dua
                dua $args
            else
                echo "(dua not found — falling back to du)"
                command du -sh $args
            end
        case '*'
            # This shouldn't happen, but just in case
            command du -sh $args
    end
end