#!/bin/bash

# Check if a user exists on the system
#
# usage: ynh_system_user_exists --username=username
# | arg: --username=    - the username to check
# | ret: 0 if the user exists, 1 otherwise.
ynh_system_user_exists() {
    # ============ Argument parsing =============
    local -A args_array=([u]=username=)
    local username
    ynh_handle_getopts_args "$@"
    # ===========================================

    getent passwd "$username" &>/dev/null
}

# Check if a group exists on the system
#
# usage: ynh_system_group_exists --group=group
# | arg: --group=   - the group to check
# | ret: 0 if the group exists, 1 otherwise.
ynh_system_group_exists() {
    # ============ Argument parsing =============
    local -A args_array=([g]=group=)
    local group
    ynh_handle_getopts_args "$@"
    # ===========================================

    getent group "$group" &>/dev/null
}

# Create a system user
#
# usage: ynh_system_user_create --username=user_name [--home_dir=home_dir] [--use_shell] [--groups="group1 group2"]
# | arg: --username=    - Name of the system user that will be create
# | arg: --home_dir=    - Path of the home dir for the user. Usually the final path of the app. If this argument is omitted, the user will be created without home
# | arg: --use_shell    - Create a user using the default login shell if present. If this argument is omitted, the user will be created with /usr/sbin/nologin shell
# | arg: --groups       - Add the user to system groups. Typically meant to add the user to the ssh.app / sftp.app group (e.g. for borgserver, my_webapp)
#
# Create a nextcloud user with no home directory and /usr/sbin/nologin login shell (hence no login capability) :
# ```
# ynh_system_user_create --username=nextcloud
# ```
# Create a discourse user using /var/www/discourse as home directory and the default login shell :
# ```
# ynh_system_user_create --username=discourse --home_dir=/var/www/discourse --use_shell
# ```
ynh_system_user_create() {
    # ============ Argument parsing =============
    local -A args_array=([u]=username= [h]=home_dir= [s]=use_shell [g]=groups=)
    local username
    local home_dir
    local use_shell
    local groups
    ynh_handle_getopts_args "$@"
    use_shell="${use_shell:-0}"
    home_dir="${home_dir:-}"
    groups="${groups:-}"
    # ===========================================

    if ! ynh_system_user_exists --username="$username"; then # Check if the user exists on the system
        # If the user doesn't exist
        if [ -n "$home_dir" ]; then # If a home dir is mentioned
            local user_home_dir="--home-dir $home_dir"
        else
            local user_home_dir="--no-create-home"
        fi
        if [ $use_shell -eq 1 ]; then # If we want a shell for the user
            local shell=""            # Use default shell
        else
            local shell="--shell /usr/sbin/nologin"
        fi
        useradd $user_home_dir --system --user-group $username $shell || ynh_die "Unable to create $username system account"
    fi

    local group
    for group in $groups; do
        usermod -a -G "$group" "$username"
    done
}

# Delete a system user
#
# usage: ynh_system_user_delete --username=user_name
# | arg: --username=    - Name of the system user that will be create
ynh_system_user_delete() {
    # ============ Argument parsing =============
    local -A args_array=([u]=username=)
    local username
    ynh_handle_getopts_args "$@"
    # ===========================================

    # Check if the user exists on the system
    if ynh_system_user_exists --username="$username"; then
        deluser $username
    else
        ynh_print_warn "The user $username was not found"
    fi

    # Check if the group exists on the system
    if ynh_system_group_exists --group="$username"; then
        delgroup $username
    fi
}