#!/usr/bin/env bash
# ------------------------------------------------------------------------------
# Copyright (c) 2013-2026 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# Protected by the BSD3 license. Please read bellow for details.
#
# * Redistribution and use in source and binary forms,
# * with or without modification, are permitted provided
# * that the following conditions are met:
# *
# *   Redistributions of source code must retain the above
# *   copyright notice, this list of conditions and the
# *   following disclaimer.
# *
# *   Redistributions in binary form must reproduce the above
# *   copyright notice, this list of conditions and the following
# *   disclaimer in the documentation and/or other materials
# *   provided with the distribution.
# *
# *   Neither the name of the copyright holder nor the names
# *   of any other contributors may be used to endorse or
# *   promote products derived from this software without
# *   specific prior written permission.
# *
# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# * OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Detect the active package manager of the current distribution.
# Detection is based on /etc/os-release (ID / ID_LIKE), then falls back to
# checking available binaries in a fixed priority order.
# Echoes one of: apt dnf yum zypper pacman apk portage xbps nix
# Returns 1 if no known package manager could be identified.
_get_pkgmgr()
{
    local distro_id="" distro_like=""
    if [[ -r /etc/os-release ]]; then
        # shellcheck disable=SC1091 
        distro_id=$( . /etc/os-release 2>/dev/null; printf '%s' "${ID:-}" )
        # shellcheck disable=SC1091
        distro_like=$( . /etc/os-release 2>/dev/null; printf '%s' "${ID_LIKE:-}" )
    fi

    # Map distro IDs/families to a package manager.
    # ID_LIKE is space-separated and may list multiple families.
    local id
    for id in $distro_id $distro_like; do
        case "${id,,}" in
            debian|ubuntu|linuxmint|raspbian|pop|kali|elementary|zorin|neon|parrot)
                echo "apt"; return 0 ;;
            fedora)
                echo "dnf"; return 0 ;;
            rhel|centos|rocky|almalinux|ol|scientific|amzn)
                command -v dnf >/dev/null 2>&1 && { echo "dnf"; return 0; }
                echo "yum"; return 0 ;;
            opensuse*|sles|sled)
                echo "zypper"; return 0 ;;
            arch|manjaro|endeavouros|garuda|artix|cachyos)
                echo "pacman"; return 0 ;;
            alpine)
                echo "apk"; return 0 ;;
            gentoo)
                echo "portage"; return 0 ;;
            void)
                echo "xbps"; return 0 ;;
            nixos)
                echo "nix"; return 0 ;;
        esac
    done

    # Fallback: check for binaries in priority order.
    local bin
    for bin in apt-get dnf yum zypper pacman apk emerge xbps-install nix-env; do
        command -v "$bin" >/dev/null 2>&1 && {
            case "$bin" in
                apt-get)      echo "apt"     ;;
                emerge)       echo "portage" ;;
                xbps-install) echo "xbps"    ;;
                nix-env)      echo "nix"     ;;
                *)            echo "$bin"    ;;
            esac
            return 0
        }
    done

    return 1
}
export -f _get_pkgmgr
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Look for a package within installed one
# Usage: pkgs <string>
pkgs()
{
    local ignore_case=${PKGS_DEFAULT_IGNORE_CASE:-0}

    local PARSED
    PARSED=$(getopt -o hi --long help,ignore-case -n 'pkgs' -- "$@")
    # shellcheck disable=SC2181 # getopt return code is checked immediately after
    if [[ $? -ne 0 ]]; then
        disp E "Invalid options, use \"pkgs --help\" to display usage."
        return 1
    fi
    eval set -- "$PARSED"

    while true; do
        case "$1" in
            -h|--help)
                printf "pkgs: Look for an installed package by its name.\n\n"
                printf "Usage: pkgs [options] <string>\n\n"
                printf "Options:\n"
                printf "\t-h, --help\tDisplay this help screen\n"
                printf "\t-i, --ignore-case\tIgnore case distinctions\n"
                return 0
                ;;
            -i|--ignore-case)
                ignore_case=1
                shift
                ;;
            --)
                shift
                break
                ;;
            *)
                disp E "Invalid option: $1"
                return 1
                ;;
        esac
    done

    local pkg="$1"
    [[ -z "$pkg" ]] && {
        disp E "Please specify a package name, without space, eventually partial."
        return 1
    }

    # Build grep command
    local grep_opt=""
    (( ignore_case )) && grep_opt="-i"

    local pkgmgr
    pkgmgr=$(_get_pkgmgr) || {
        disp E "No usable package manager could be detected on this system."
        return 2
    }

    local -a list_cmd
    case "$pkgmgr" in
        apt) list_cmd=(dpkg-query -l) ;;
        dnf|yum|zypper) list_cmd=(rpm -qa) ;;
        pacman) list_cmd=(pacman -Q) ;;
        apk) list_cmd=(apk list --installed) ;;
        portage) list_cmd=(qlist -I) ;;
        xbps) list_cmd=(xbps-query -l) ;;
        nix) list_cmd=(nix-env -q) ;;
        *)
            disp E "Package manager '$pkgmgr' is not supported by pkgs."
            return 2
            ;;
    esac

    "${list_cmd[@]}" | grep ${grep_opt:+"$grep_opt"} "$pkg"
}
export -f pkgs
# ------------------------------------------------------------------------------


load_conf "packages"

# EOF