#!/usr/bin/env bash

set -euo pipefail

readonly repoName="stormux"
readonly repoKeyUrl="https://packages.stormux.org/stormux_repo.pub"
readonly repoKeyId="52ADA49000F1FF0456F8AEEFB4CDE1CD56EF8E82"
readonly pacmanConf="${STORMUX_PACMAN_CONF:-/etc/pacman.conf}"
readonly osRelease="${STORMUX_OS_RELEASE:-/etc/os-release}"
readonly effectiveUid="${STORMUX_TEST_EUID:-${EUID}}"

keyFile=""

cleanup() {
    if [[ -n "$keyFile" && -f "$keyFile" ]]; then
        rm -f "$keyFile"
    fi
}

die() {
    printf 'Error: %s\n' "$1" >&2
    exit 1
}

require_root() {
    [[ "$effectiveUid" == "0" ]] || die "This script must be run as root."
}

require_command() {
    local commandName="$1"

    command -v "$commandName" >/dev/null 2>&1 || die "Required command not found: ${commandName}"
}

is_arch_based_system() {
    local osId=""
    local osIdLike=""

    [[ -f "$osRelease" ]] || return 1

    while IFS='=' read -r keyName keyValue; do
        keyValue="${keyValue%\"}"
        keyValue="${keyValue#\"}"

        case "$keyName" in
            ID)
                osId="$keyValue"
                ;;
            ID_LIKE)
                osIdLike="$keyValue"
                ;;
        esac
    done < "$osRelease"

    [[ "$osId" == "arch" || "$osId" == "archarm" || " ${osIdLike} " == *" arch "* ]]
}

check_prerequisites() {
    require_root
    require_command curl
    require_command pacman
    require_command pacman-key

    is_arch_based_system || die "This script supports Arch-based pacman systems only."
    [[ -f "$pacmanConf" ]] || die "pacman.conf not found: ${pacmanConf}"
}

download_and_trust_key() {
    keyFile="$(mktemp)"
    trap cleanup EXIT

    printf 'Downloading Stormux repository key...\n'
    curl -fsSL "$repoKeyUrl" > "$keyFile"

    printf 'Adding Stormux repository key to pacman keyring...\n'
    pacman-key --add "$keyFile"

    printf 'Locally signing Stormux repository key...\n'
    pacman-key --lsign-key "$repoKeyId"
}

update_pacman_conf() {
    local tempConf

    tempConf="$(mktemp)"
    awk -v repoName="$repoName" '
        function print_repo_block() {
            print "[" repoName "]"
            print "SigLevel = Required DatabaseOptional"
            print "Server = https://packages.stormux.org/$arch"
        }

        /^\[stormux\][[:space:]]*$/ {
            inStormux = 1
            next
        }

        inStormux && /^\[[^]]+\][[:space:]]*$/ {
            inStormux = 0
        }

        inStormux {
            next
        }

        !inserted && /^\[core\][[:space:]]*$/ {
            print_repo_block()
            print ""
            inserted = 1
        }

        {
            print
        }

        END {
            if (!inserted) {
                print ""
                print_repo_block()
            }
        }
    ' "$pacmanConf" > "$tempConf"

    cat "$tempConf" > "$pacmanConf"
    rm -f "$tempConf"
}

refresh_databases() {
    printf 'Refreshing package databases...\n'
    pacman -Sy
}

main() {
    check_prerequisites
    download_and_trust_key
    update_pacman_conf
    refresh_databases
    printf 'Stormux repository is configured.\n'
}

main "$@"