usm/installer/pm_base.sh

#!/bin/bash
# pm_base.sh - Base package manager interface for USM installer
# 
# This file provides the generic interface that dispatches to the
# appropriate package manager implementation.
#
# To add a new package manager:
#   1. Create pm_<name>.sh with:
#      - pm_<name>_detect: Returns 0 if available, 1 otherwise
#      - pm_<name>_get_missing_deps: Prints missing package names
#      - pm_<name>_install_missing_deps: Installs missing packages
#   2. The compiler will automatically pick it up

# Detect the available package manager
# Sets PM_TYPE and returns 0 on success, 1 if no supported PM found
detect_package_manager() {
    # Try each PM implementation
    for pm_impl in "${PM_IMPLEMENTATIONS[@]}"; do
        if "pm_${pm_impl}_detect" 2>/dev/null; then
            PM_TYPE="$pm_impl"
            return 0
        fi
    done
    
    PM_TYPE="unknown"
    return 1
}

# Get missing dependencies using the detected package manager
pm_get_missing_deps() {
    case "$PM_TYPE" in
        apt) pm_apt_get_missing_deps "$@" ;;
        dnf) pm_dnf_get_missing_deps "$@" ;;
        *)
            log_error "No package manager detected"
            echo ""
            ;;
    esac
}

# Install missing dependencies using the detected package manager
pm_install_missing_deps() {
    case "$PM_TYPE" in
        apt) pm_apt_install_missing_deps "$@" ;;
        dnf) pm_dnf_install_missing_deps "$@" ;;
        *)
            log_error "No package manager detected"
            return 1
            ;;
    esac
}

# Count missing dependencies
count_missing_deps() {
    local missing=$(pm_get_missing_deps)
    if [[ -z "$missing" ]]; then
        echo 0
    else
        echo "$missing" | wc -w
    fi
}