#!/usr/bin/env bash
# -*-coding:utf-8 -*-
# -------------------------------------------------------------------------
# Path          - /home/repo/.local/bin/lmgr
# GitHub        - https://github.com/The-Repo-Club/
# Author        - The-Repo-Club [wayne6324@gmail.com]
# Start On      - Sun 23 January 2022, 11:51:17 am (GMT)
# Modified On   - Sun 06 February 2022, 11:53:51 am (GMT) 
# -------------------------------------------------------------------------
Version=2022.02.06
# -------------------------------------------------------------------------

set -e

usage() {
    echo " License manager v$Version"
    echo ' manage, switch and template licenses'
    echo ''
    echo " $(basename "$0") <flag | @license>"
    echo ''
    echo '  -help --help     -h                     show usage'
    echo '  -list-licenses   -l                     list awailable licenses'
    echo '  -current-license -c                     show current active project license'
    echo '  -pick-license    -p                     pick a license in a FZF menu'
    echo '  -preview-license -P @license_name       preview a license template'
    echo '  -remove-license  -r                     remove all licenses from the current project'
    echo "  -search-license  -s '<query | patten>'  search for license"
}

error() {
    if ! [ "$2" -eq "$2" ] 2>/dev/null; then
        echo 'error(): argument 2 was expected to be an intager.'
        exit 3
    fi

    echo " * ERROR: $1" 1>&2
    exit "$2"
}

warn() {
    echo " * WARNING: $1" 1>&2
}

list_licenses() {
    if ! [ -d "${HOME}"/.config/licenses ]; then
        warn "${HOME}/.config/licenses does not exist. Creating it."
        mkdir -p "${HOME}"/.config/licenses
    fi

    find -L "${HOME}"/.config/licenses -maxdepth 1 -type f -printf " * @%f\n"
}

make_new_config() {
    mkdir -p "${HOME}"/.config

    {
        echo '#!/usr/bin/env sh'
        echo "export AUTHOR_FULL_NAME='$(git config user.name || echo "${USER}")'"
        echo "export AUTHOR_EMAIL='$(git config user.email || echo "${USER}@gmail.com")'"
    } >"${HOME}"/.config/license.conf
}

show_license() {
    l_name='LICENSE'
    if [ -f UNLICENSE ]; then
        l_name='UNLICENSE'
    fi

    if [ -f "$l_name" ]; then
        head -n1 "$l_name" | sed 's/^\s*//; s/\s*$//'
    else
        echo 'Strong copyright (no license)'
    fi
}

get_license() {
    if ! [ -f "${HOME}"/.config/licenses/"$1" ]; then
        echo " * No licence by the name of $1" 1>&2
        list_licenses
        echo ' * Use of of the above'

        exit 5
    elif [ -f ./LICENSE ] || [ -f ./UNLICENSE ]; then
        echo " * Found license: $(show_license)"

        printf '   Switch licenses? [y/n] '
        read -r yn

        if ! [ "$yn" = "y" ]; then
            exit
        fi
    fi

    l_name='LICENSE'
    if [ "$(head -n1 "${HOME}"/.config/licenses/"$1")" = 'UNLICENSE' ]; then
        l_name='UNLICENSE'
    fi

    cp -fiL "${HOME}"/.config/licenses/"$1" "$l_name"

    sed -i "$l_name" \
        -e "s/{{PROJECT_NAME}}/$(basename "$PWD")/g" \
        -e "s/{{CURRENT_YEAR}}/$(date '+%Y')/g" \
        -e "s/{{AUTHOR_NAME}}/${AUTHOR_FULL_NAME}/g" \
        -e "s/{{AUTHOR_EMAIL}}/$AUTHOR_EMAIL/g"

    echo " * Current license now is set to $(show_license)"
}

license_picker() {
    license="$(list_licenses | awk '{ print $2 }' | sed 's/^@//' | FZF_DEFAULT_OPTS='' fzf --layout=reverse --height=20 --no-mouse -i --preview "cat ${HOME}/.config/licenses/{}" || echo '')"

    if ! [ "$license" ]; then
        license_picker
    fi

    get_license "$license"
}

search_license() {
    for lic in $(list_licenses | awk '{ print $2 }' | sed 's/^@//'); do
        if echo "$lic $(head -n5 "${HOME}"/.config/licenses/"$lic")" | grep -iq "$1"; then
            echo " * @$lic"
        fi
    done
}

remove_license() {
    rm -f UNLICENSE LICENSE 2>/dev/null || true
    echo " * Current license now is set to $(show_license)"
}

main() {
    if [ -f "${HOME}/.config/license.conf" ]; then
        # shellcheck disable=1091
        . "${HOME}/.config/license.conf"
    else
        warn 'No configuration file found. Creating it.'
        make_new_config
        exit 4
    fi

    if [ ! "$1" ]; then
        usage
        exit 1
    fi

    case "$1" in
    -help | --help | -h) usage ;;
    -list-licenses | -l) list_licenses ;;
    -current-license | -c) echo " * $(show_license)" ;;
    -pick-license | -p) license_picker ;;
    -preview-license | -P) less -NrIMJ --use-color --incsearch --line-num-width=2 "${HOME}"/.config/licenses/"$(echo "$2" | sed 's/^@//')" 2>/dev/null || echo "* License $2 not found" ;;
    -remove-license | -r) remove_license ;;
    -search-license | -s) search_license "$2" ;;

    @*) get_license "$(echo "$1" | sed 's/^@//')" ;;
    *) error "Flag $1 is not known." 2 ;;
    esac
}

main "$@"