#! /usr/bin/env sh

# defaults
CD_DEFAULT_DNS="\
9.9.9.9 \
"
CD_DEFAULT_REPO_ALMA="https://repo.almalinux.org/almalinux"
CD_DEFAULT_REPO_DEBIAN="https://deb.debian.org/debian"

CD_PYTHON_MODULES="\
cd \
rwx \
"

# main
cd_main () {
    cd_set_environment_variables
    cd_set_dns_resolving
    cd_set_packages_repositories
    cd_set_packages_configuration
    cd_set_https_verification_off
    cd_update_packages_catalog
    cd_install_packages_tools
    cd_install_ca_certificates
    cd_write_ca_certificates
    cd_update_ca_certificates
    cd_set_https_verification_on
    cd_update_packages_catalog
    cd_upgrade_packages
    cd_install_git
    cd_install_python
    cd_clean_packages_cache
    cd_install_python_modules ${CD_PYTHON_MODULES}
    cd_execute_python_module ${CD_PYTHON_MODULES}
}

# steps

cd_set_environment_variables () {
    cd_step "Set environment variables"
    #
    [ "${CD_CA_1}" ] && CD_CA=true
    #
    case "$(cd_grep_os ID)" in
        "almalinux")
            CD_OS_ID="${CD_OS_ALMA}"
            CD_OS_VERSION="$(cd_grep_os VERSION_ID)"
        ;;
        "debian")
            CD_OS_ID="${CD_OS_DEBIAN}"
            CD_OS_VERSION="$(cd_grep_os VERSION_CODENAME)"
        ;;
    esac
    #
    CD_CA_PACKAGE="ca-certificates"
    CD_DNS_FILE="/etc/resolv.conf"
    CD_GIT_PACKAGE="git"
    #
    case "${CD_OS_ID}" in
        "${CD_OS_ALMA}")
            CD_OS_REPO="${CD_DEFAULT_REPO_ALMA}"
            [ "${CD_REPO_ALMA}" ] && CD_OS_REPO="${CD_REPO_ALMA}"
            case "${CD_OS_VERSION}" in
                "8."*|"9."*) cd_nop ;;
                *) cd_error_os "CD_OS_VERSION" ;;
            esac
            CD_CA_ROOT="/etc/pki/ca-trust/source/anchors"
            CD_CMD_CA="update-ca-trust"
            CD_CMD_CLEAN="dnf clean all"
            CD_CMD_INSTALL="dnf install --assumeyes"
            CD_CMD_UPDATE="dnf makecache"
            CD_CMD_UPGRADE="dnf upgrade --assumeyes"
            CD_PKG_PKG=""
            CD_PM_CONF_PATH="/etc/dnf/dnf.conf"
            CD_PM_CONF_TEXT="\
[main]
best=True
clean_requirements_on_remove=True
gpgcheck=1
installonly_limit=3
skip_if_unavailable=False
"
            CD_PM_HTTPS_PATH="/etc/dnf/dnf.conf.d/https.conf"
            CD_PM_HTTPS_TEXT="sslverify=False"
            CD_PYTHON_COMMAND="python3.11"
            CD_PYTHON_PACKAGE="python3.11"
            CD_PYTHON_PACKAGES="/usr/lib64/python3.11/site-packages"
        ;;
        "${CD_OS_DEBIAN}")
            export DEBIAN_FRONTEND="noninteractive"
            #
            CD_OS_REPO="${CD_DEFAULT_REPO_DEBIAN}"
            [ "${CD_REPO_DEBIAN}" ] && CD_OS_REPO="${CD_REPO_DEBIAN}"
            case "${CD_OS_VERSION}" in
                "bookworm"|"bullseye") cd_nop ;;
                *) cd_error_os "CD_OS_VERSION" ;;
            esac
            CD_CA_ROOT="/usr/local/share/ca-certificates"
            CD_CMD_CA="update-ca-certificates"
            CD_CMD_CLEAN="apt-get clean"
            CD_CMD_INSTALL="apt-get install --assume-yes"
            CD_CMD_UPDATE="apt-get update"
            CD_CMD_UPGRADE="apt-get upgrade --assume-yes"
            CD_PKG_PKG="apt-utils"
            CD_PM_CONF_PATH="/etc/apt/apt.conf.d/apt.conf"
            CD_PM_CONF_TEXT="\
Acquire::Check-Valid-Until True;
APT::Get::Show-Versions True;
APT::Install-Recommends False;
APT::Install-Suggests False;
Dir::Etc::SourceParts \"\";
"
            CD_PM_HTTPS_PATH="/etc/apt/apt.conf.d/https"
            CD_PM_HTTPS_TEXT="Acquire::https::Verify-Peer False;"
            CD_PYTHON_COMMAND="python3"
            CD_PYTHON_PACKAGE="python3"
            CD_PYTHON_PACKAGES="/usr/lib/python3/dist-packages"
        ;;
        *) cd_error_os "CD_OS_ID" ;;
    esac
    # continuous integration platform
    if [ "${GITHUB_ACTIONS}" ] ; then
        # forgejo / gitea / github
        CD_SERVER_URL="${GITHUB_SERVER_URL}"
        CD_PROJECTS_GROUP="$(dirname "${GITHUB_REPOSITORY}")"
        CD_PROJECT_NAME="$(basename "${GITHUB_REPOSITORY}")"
        CD_PROJECT_BRANCH="${GITHUB_REF_NAME}"
    elif [ "${GITLAB_CI}" ] ; then
        # gitlab
        CD_SERVER_URL="${CI_SERVER_URL}"
        CD_PROJECTS_GROUP="$(dirname "${CI_PROJECT_PATH}")"
        CD_PROJECT_NAME="$(basename "${CI_PROJECT_PATH}")"
        CD_PROJECT_BRANCH="${CI_COMMIT_BRANCH}"
    else
        # unsupported
        cd_error_ci "ø"
    fi
    #
    [ "${CD_SERVER_URL}" ] || cd_error_ci "CD_SERVER_URL"
    [ "${CD_PROJECTS_GROUP}" ] || cd_error_ci "CD_PROJECTS_GROUP"
    [ "${CD_PROJECT_NAME}" ] || cd_error_ci "CD_PROJECT_NAME"
    [ "${CD_PROJECT_BRANCH}" ] || cd_error_ci "CD_PROJECT_BRANCH"
    #
    CD_PROJECTS_URL="${CD_SERVER_URL}/${CD_PROJECTS_GROUP}"
    CD_PROJECT_URL="${CD_PROJECTS_URL}/${CD_PROJECT_NAME}"
    #
    cd_echo "CD_CA"
    cd_split
    cd_echo "CD_OS_ID" "CD_OS_VERSION"
    cd_split
    cd_echo "CD_DNS_FILE"
    cd_split
    cd_echo "CD_PYTHON_PACKAGE" "CD_PYTHON_PACKAGES" "CD_CA_ROOT"
    cd_split
    cd_echo "CD_SERVER_URL" \
        "CD_PROJECTS_GROUP" "CD_PROJECT_NAME" "CD_PROJECT_BRANCH"
    cd_split
    cd_echo "CD_PROJECTS_URL" "CD_PROJECT_URL"
}

cd_set_dns_resolving () {
local server
local servers
local text=""
    cd_step "Set DNS resolving"
    [ "${CD_DNS}" ] && servers="${CD_DNS}" || servers="${CD_DEFAULT_DNS}"
    for server in ${servers} ; do
        text="${text}nameserver ${server}
"
    done
    cd_write "${CD_DNS_FILE}" "${text}"
}

cd_set_packages_repositories () {
local expression
local file
    cd_step "Set packages repositories"
    case "${CD_OS_ID}" in
        "${CD_OS_ALMA}")
            file="/etc/yum.repos.d/almalinux.repo"
            cd_sed "${file}" \
            "|^mirrorlist|# mirrorlist|" \
            "|${CD_DEFAULT_REPO_ALMA}|${CD_OS_REPO}|" \
            "|^# baseurl|baseurl|"
            cd_cat "${file}"
        ;;
        "${CD_OS_DEBIAN}")
            cd_write "/etc/apt/sources.list" "\
deb ${CD_OS_REPO} ${CD_OS_VERSION} main
deb ${CD_OS_REPO} ${CD_OS_VERSION}-backports main
deb ${CD_OS_REPO} ${CD_OS_VERSION}-updates main
deb ${CD_OS_REPO}-security ${CD_OS_VERSION}-security main
"
        ;;
    esac
}

# agnostic steps

cd_set_packages_configuration () {
    cd_step "Set packages configuration"
    cd_write "${CD_PM_CONF_PATH}" "${CD_PM_CONF_TEXT}"
}

cd_set_https_verification_off () {
    if [ "${CD_CA}" -o "${CD_OS_ID}" = "${CD_OS_DEBIAN}" ] ; then
        cd_step "Set HTTPS verification off"
        cd_mkdir "$(dirname "${CD_PM_HTTPS_PATH}")"
        cd_write "${CD_PM_HTTPS_PATH}" "${CD_PM_HTTPS_TEXT}"
    fi
}

cd_update_packages_catalog () {
    cd_step "Update packages catalog"
    ${CD_CMD_UPDATE} || exit
}

cd_install_packages_tools () {
    cd_step "Install packages tools"
    cd_install_package "${CD_PKG_PKG}"
}

cd_install_ca_certificates () {
    cd_step "Install CA"
    cd_install_package "${CD_CA_PACKAGE}"
}

cd_write_ca_certificates () {
local index
local text
    cd_step "Write CA certificates"
    cd_mkdir "${CD_CA_ROOT}"
    index=1
    eval "text=\"\${CD_CA_${index}}\""
    while [ "${text}" ] ; do
        cd_write "${CD_CA_ROOT}/${index}.crt" "${text}"
        index=$((index+1))
        eval "text=\"\${CD_CA_${index}}\""
    done
}

cd_update_ca_certificates () {
    cd_step "Update CA certificates"
    ${CD_CMD_CA} || exit
}

cd_set_https_verification_on () {
    if [ "${CD_CA}" -o "${CD_OS_ID}" = "${CD_OS_DEBIAN}" ] ; then
        cd_step "Set HTTPS verification on"
        cd_rm "${CD_PM_HTTPS_PATH}"
    fi
}

cd_upgrade_packages () {
    cd_step "Upgrade packages"
    ${CD_CMD_UPGRADE} || exit
}

cd_install_git () {
    cd_step "Install Git"
    cd_install_package "${CD_GIT_PACKAGE}"
}

cd_install_python () {
    cd_step "Install Python"
    cd_install_package "${CD_PYTHON_PACKAGE}"
    cd_split
    cd_ln_python "${CD_PYTHON_COMMAND}"
}

cd_clean_packages_cache () {
    cd_step "Clean packages cache"
    ${CD_CMD_CLEAN} || exit
}

cd_install_python_modules () {
local path
local repository
local root
local url
    cd_step "Install Python modules"
    root="$(mktemp --directory)" || exit
    echo "${root}"
    for repository in "${@}" ; do
        cd_split
        url="${CD_PROJECTS_URL}/${repository}"
        echo -n "\
${url}
↓
"
        git clone \
        "${url}" "${root}/${repository}" \
        || exit
        path="${root}/${repository}/${repository}"
        echo -n "\
${path}
↓
${CD_PYTHON_PACKAGES}
"
        cp --recursive \
        "${path}" "${CD_PYTHON_PACKAGES}" \
        || exit
    done
    cd_split
    cd_rm "${root}"
}

cd_execute_python_module () {
local self
    cd_step "Execute Python module"
    self="$(realpath "${0}")"
    echo -n "\
${self}
↓
${1}
"
    "${CD_PYTHON_COMMAND}" -m "${1}" "${CD_STEP}" "${self}"
}

# functions

cd_cat () {
    if [ -f "${1}" ] ; then
        echo "╭╴$(realpath "${1}")"
        cat "${1}" || exit
    fi
}

cd_echo () {
local name
    if [ "${1}" ] ; then
        for name in "${@}" ; do
            eval "echo ${name}=\${${name}}"
        done
    fi
}

cd_error_ci () {
    echo "× CI: ${1}"
    exit ${CD_ERROR_CI}
}

cd_error_os () {
local variable="${1}"
    echo -n "× OS: "
    cd_echo "${variable}"
    exit ${CD_ERROR_OS}
}

cd_grep_os () {
local variable="${1}"
    if [ "${variable}" ] ; then
        grep "^${variable}=" "/etc/os-release" \
        | sed "s|^${variable}=||" \
        | sed "s|^\"\(.*\)\"$|\1|"
    fi
}

cd_install_package () {
    if [ "${1}" ] ; then
        ${CD_CMD_INSTALL} "${1}" || exit
    fi
}

cd_ln_python () {
    if [ "${1}" ] ; then
        echo "python3 → ${1}"
        ln --force --symbolic "${1}" "/usr/bin/python3" || exit
    fi
}

cd_mkdir () {
    if [ "${1}" ] ; then
        echo "→ ${1}"
        mkdir --parents "${1}" || exit
    fi
}

cd_nop () { true ; }

cd_rm () {
    if [ -e "${1}" ] ; then
        echo "← $(realpath "${1}")"
        rm --recursive "${1}" || exit
    fi
}

cd_sed () {
local expression
local file
    if [ -f "${1}" ] ; then
        file="${1}"
        shift
        for expression in "${@}" ; do
            sed --in-place "s${expression}g" "${file}" || exit
        done
    fi
}

cd_split () {
    echo -n "\
╶─╌╌┄┄┈┈
"
}

cd_step () {
    if [ "${1}" ] ; then
        CD_STEP=$((CD_STEP+1))
        echo -n "\
╭─╌╌┄┄┈┈
│ ${CD_STEP} ${1}
╰─╌╌┄┄┈┈
"
    fi
}

cd_write () {
local file="${1}"
local text="${2}"
    if [ "${file}" ] ; then
        echo -n "${text}" > "${file}" || exit
        cd_cat "${file}"
    fi
}

# constants

CD_ERROR_CI=2
CD_ERROR_OS=1

CD_OS_ALMA="alma"
CD_OS_DEBIAN="debian"

# run
cd_main