#!/bin/sh

# Copyright (c) 2018-2019 TildeLinux Maintainers
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# Email: tildelinux@tildeverse.org

is_substring() {
    case $2 in
    *$1*)
        return 0
        ;;
    *)
        return 1
        ;;
    esac
}

configure_directories() {
    server_name="$1"
    local_dir=""
    remote_dir=""

    printf "What would you like to call the local directory? (~/Remote/...)?\\n"
    read -r answer
    local_dir="${HOME}/Remote/${answer}"
    mkdir -p "$local_dir"
    printf "Created directory %s.\\n" "$local_dir"
    printf "What directory on \"%s\" would you like to link it to? (absolute path)\\n" "$server_name"
    read -r answer
    remote_dir="$answer"
    printf "Linking directory %s to %s on \"%s\".\\n" "$local_dir" "$remote_dir" "$server_name"
    sshfs "${server_name}:${remote_dir}" "$local_dir"
    printf "Done, enjoy!\\n"
}

attempt_login() {
    server_name="$1"
    ssh_temp_config="$2"
    ssh_config="$3"

    printf "Attempting to log in with configuration for \"%s\".\\n" "$server_name"
    if ssh -qF "$ssh_temp_config" "$server_name" exit ; then
        printf "Login successful! Writing ssh config...\\n"
        cp "$ssh_temp_config" "$ssh_config"
        printf "Would you like to configure sshfs for this server? (y/n)\\n"
        read -r answer
        case "$answer" in
        "y")
            configure_directories "$server_name"
            ;;
        "n")
            printf "All right, you're all done!\\n"
            printf "Exiting...\\n"
            ;;
        "*")
            printf "\"%s\" was not recognized as an answer, please enter 'y' or 'n'\\n" "$answer"
        esac
    else
        printf "Login failed, what would you like to do?\\n"
        printf "    1) Try logging in again.\\n"
        printf "    2) Re-configure my credentials.\\n"
        read -r answer
        case "$answer" in
        "1")
            attempt_login "$server_name" "$ssh_temp_config" "$ssh_config"
            ;;
        "2")
            setup_keys "$server_address"
            ;;
        esac
    fi
}

setup_keys() {
    server_address="$1"
    server_name="$2"
    login=""
    key_path=""
    ssh_dir=""
    key_type=""

    printf "Configuring \"%s\" as \"%s\".\\n" "$server_address" "$server_name"
    printf "What is your login name for this server?\\n"
    read -r login
    printf "Where is the private key you use for this account? (absolute path)\\n"
    read -r key_path
    if test -r "$key_path" ; then
        printf "File found, configuring ssh...\\n"
        ssh_dir="${HOME}/.ssh"
        ssh_host_dir="${HOME}/.ssh/${server_name}"
        key_type=$(head -n 1 "$key_path" \
                    | cut -f 2 -d ' ' \
                    | tr '[:upper:]' '[:lower:]')
        test -d "$ssh_dir" || mkdir -p "$ssh_dir"
        test -d "$ssh_host_dir" || mkdir -p "$ssh_host_dir"
        printf "Key appears to be of type \"%s\".\\n" "$key_type"
        printf "Generating public key...\\n"
        ssh-keygen -y -f "$key_path" > "${ssh_host_dir}/id_${key_type}.pub"
        printf "Copying private key...\\n"
        cp "$key_path" "${ssh_host_dir}/id_${key_type}"
        printf "Saving configuration...\\n"
        test -e "${ssh_dir}/config" || touch "${ssh_dir}/config"

        cp "${ssh_dir}/config" "${ssh_dir}/config.tmp"
        {
            printf "Host %s\\n" "$server_name"
            printf "    HostName %s\\n" "$server_address"
            printf "    port 22\\n"
            printf "    User %s\\n" "$login"
            printf "    IdentityFile %s/id_%s\\n" "$ssh_host_dir" "$key_type"
        } >> "${ssh_dir}/config.tmp"
        printf "Right now your configuration looks like this:\\n"
        cat "${ssh_dir}/config.tmp"

        attempt_login "$server_name" "${ssh_dir}/config.tmp" "${ssh_dir}/config"
    else
        printf "%s could not be read.\\n" "$key_path"
        printf "Either it doesn't exist, or you dont have the correct permissions, please try again.\\n"
        setup_keys "$server_address" "$server_name"
    fi
}

pick_account() {
    answers="1 2 3 4"
    answer=""
    printf "What account would you like to configure?\\n"
    printf "    1) tilde.town\\n"
    printf "    2) tilde.team\\n"
    printf "    3) yourtilde.com\\n"
    printf "    4) cosmic.voyage\\n"
    printf "    5) tilde.institute\\n"
    read -r answer

    if is_substring "$answer" "$answers"
    then
        case "$answer" in
        "1")
            setup_keys "tilde.town" "town"
            ;;
        "2")
            setup_keys "tilde.team" "team"
            ;;
        "3")
            setup_keys "yourtilde.com" "your"
            ;;
        "4")
            setup_keys "cosmic.voyage" "cosmic"
            ;;
        "5")
            setup_keys "tilde.institute" "institute"
            ;;
        esac
    else
        printf "\"%s\" is not a valid option.\\n" "$answer"
        pick_account
    fi
}

pick_account