#!/bin/bash
# mkit - simple install helper
# See LICENSE file for copyright and license details.

init_core() {
    #
    # Load core modules (or die)
    #
    #shellcheck disable=SC1090
    . "$MKIT_DIR/include/mkit.sh" \
     && . "$MKIT_DIR/include/vars.sh" \
     && return 0
    echo "failed to load core; check if MKIT_DIR is set properly: $MKIT_DIR" >&2
    exit 9
}

#
# Path to MKit dir (where 'include' is)
#
MKIT_DIR=${MKIT_DIR:-$(dirname "$0")}

init_core

declare -A MKIT_INIT_LICENSES
MKIT_INIT_LICENSES[GPLv1]="http://www.gnu.org/licenses/old-licenses/gpl-1.0.md"
MKIT_INIT_LICENSES[GPLv2]="http://www.gnu.org/licenses/old-licenses/gpl-2.0.md"
MKIT_INIT_LICENSES[GPLv3]="http://www.gnu.org/licenses/gpl-3.0.md"
MKIT_INIT_LICENSES[LGPLv2]="http://www.gnu.org/licenses/old-licenses/lgpl-2.1.md"
MKIT_INIT_LICENSES[LGPLv3]="http://www.gnu.org/licenses/lgpl-3.0.md"
MKIT_INIT_LICENSES[AGPLv3]="http://www.gnu.org/licenses/agpl-3.0.md"
MKIT_INIT_LICENSES[FDLv1.3]="http://www.gnu.org/licenses/fdl-1.3.md"
MKIT_INIT_LICENSES[FDLv1.2]="http://www.gnu.org/licenses/old-licenses/fdl-1.2.md"
MKIT_INIT_LICENSES[FDLv1.1]="http://www.gnu.org/licenses/old-licenses/fdl-1.1.md"


deploy() {
    local file=$1       # which known file?
    local any_name=${NiceName:-$PackageName}
    mkdir -p "$(dirname "$file")"
    case $file in

        Makefile)
            echo -n "# $any_name"
            test -n "$Tagline" && echo -n " - $Tagline"
            echo
            echo '# See LICENSE.md file for copyright and license details.'
            echo ''
            echo 'MKIT_DIR=utils/mkit'
            #shellcheck disable=SC2016
            echo 'include $(MKIT_DIR)/mkit.mk'
            ;;

        README.md)
            echo "$any_name"
            tr -c '=\n' '=' <<<"$any_name"
            echo ''
            echo ''
            if test -n "$Tagline"; then
                echo "$Tagline"
            else
                echo "(Nothing to say about this project.)"
            fi
            ;;

        mkit.ini)
            echo "[project]"
            echo "    version     = 0.0.0"
            test -n "$Codename"     && echo "    codename    = $Codename"
            test -n "$NiceName"     && echo "    name        = $NiceName"
            test -n "$Tagline"      && echo "    tagline     = $Tagline"
            test -n "$PackageName"  && echo "    pkgname     = $PackageName"
            test -n "$Maintainer"   && echo "    maintainer  = $Maintainer"
            test -n "$VcsBrowser"   && echo "    vcs_browser = $VcsBrowser"
            test -n "$RelSrc"       && echo "    relsrc      = $RelSrc"
            test -n "$RelDst"       && echo "    reldst      = $RelDst"
            echo ""
            echo "[dist]"
            echo "    tarball = LICENSE.md"
            $MkMakefile && echo "    tarball = Makefile"
            $MkReadme   && echo "    tarball = README.md"
            echo "    tarball = mkit.ini"
            $MkPackaging && echo "    tarball = packaging"
            echo "    tarball = src"
            echo "    tarball = tests"
            echo "    tarball = utils"
            $MkPackaging && echo "    rpmstuff = packaging/template.spec"
            $MkPackaging && echo "    debstuff = packaging/debian"
            echo ""
            echo "[ENV]"
            echo "    PREFIX = /usr/local"
            echo ""
            echo "[roots]"
            echo "    bin     = [ENV:PREFIX]/bin"
            echo "    doc     = [ENV:PREFIX]/share/doc/$PackageName"
            echo ""
            echo "[tokens]"
            echo "    __BIN_DIR__ = [roots:bin]"
            echo ""
            echo "[modes]"
            echo "    bin     = 755"
            echo "    doc     = 644"
            echo ""
            echo "[files]"
            echo "    bin      = src/$PackageName"
            $MkLicense && echo "    doc      = LICENSE.md"
            $MkReadme  && echo "    doc      = README.md"
            echo ""
            echo "#mkit version=$MKIT_VERSION"
            ;;

        packaging/template.spec)
            echo 'Name:		__MKIT_PROJ_PKGNAME__'
            echo 'Version:	__MKIT_PROJ_VERSION__'
            echo 'Release:	1%{?dist}'
            echo 'Summary:	__MKIT_PROJ_NAME__ - __MKIT_PROJ_TAGLINE__'
            echo ''
            $MkLicense && echo "License:	$License"
            echo 'Source0:	%{name}-%{version}.tar.gz'
            echo ''
            echo 'BuildArch:	noarch'
            echo 'BuildRequires:	coreutils git'
            echo 'Requires:	MKIT_NEWSTUB_REQUIRES'
            echo ''
            echo '%description'
            echo 'MKIT_NEWSTUB_DESCRIPTION'
            echo ''
            echo '%prep'
            echo '%setup -q'
            echo ''
            echo '%build'
            echo 'make %{?_smp_mflags}'
            echo ''
            echo '%install'
            echo '%make_install'
            echo ''
            echo '%files'
            echo 'MKIT_NEWSTUB_FILELIST'
            echo ''
            echo '%changelog'
            echo ''
            echo '# specfile built with MKit __MKIT_SELF_VERSION__'
            ;;

        packaging/debian/copyright)
            echo ""
            ;;

        packaging/debian/control)
            echo 'Source: __MKIT_PROJ_PKGNAME__'
            echo 'Maintainer: __MKIT_PROJ_MAINTAINER__'
            test -n "$VcsBrowser" && echo 'Vcs-Browser: __MKIT_PROJ_VCS_BROWSER__'
            echo 'Section: misc'
            echo 'Priority: extra'
            echo 'Standards-Version: 3.9.2'
            echo 'Build-Depends: debhelper (>= 9)'
            echo ''
            echo 'Package: __MKIT_PROJ_PKGNAME__'
            echo 'Architecture: all'
            echo 'Depends: MKIT_NEWSTUB_REQUIRES'
            echo 'Description: __MKIT_PROJ_NAME__ - __MKIT_PROJ_TAGLINE__'
            echo ' MKIT_NEWSTUB_DESCRIPTION'
            echo ''
            echo '# control file built with MKit __MKIT_SELF_VERSION__'
            ;;

        packaging/debian/changelog)
            echo '__MKIT_PROJ_PKGNAME__ (__MKIT_PROJ_VERSION__-1) UNRELEASED; urgency=medium'
            echo ''
            echo '  * Initial release. (Closes: #XXXXXX)'
            echo ''
            echo " -- __MKIT_PROJ_MAINTAINER__  $(date -R)"
            ;;

        packaging/debian/compat)
            echo 9
            ;;

        packaging/debian/rules)
            echo '#!/usr/bin/make -f'
            echo ''
            echo '%:'
            echo ''
            echo '	dh $@'
            echo ''
            echo 'override_dh_auto_install:'
            echo ''
            echo '	make install DESTDIR=debian/tmp'
            echo ''
            echo 'override_dh_usrlocal:'
            echo ''
            echo '	@true'
            ;;

        packaging/debian/source/format)
            echo '3.0 (quilt)'
            ;;

        packaging/debian/*.install)
            echo MKIT_NEWSTUB_FILELIST
            ;;

        src/*.skel)
            echo 'echo "my version is: __MKIT_PROJ_VERSION__"'
            echo 'echo "And that'"'"'s all, folks!"'
            ;;

        LICENSE.md)
            local url   # license URL
            url="${MKIT_INIT_LICENSES[$License]}"
            curl -sf "$url" \
             || die "failed to download license: $url"
            ;;

        .mkit/autoclean)
            ;;

        MKIT_NEWSTUB_README.md)
            echo "FINISHING MKIT CONFIGURATION"
            echo "============================"
            echo ""
            echo "Congratulations, your new project has been configured!"
            echo ""
            echo "However, the *newstub* script is not able to figure out"
            echo "everything, so few things still need to be done manually."
            echo "This document will guide you throught the rest of the"
            echo "process."

            echo ""
            echo ""
            echo "Structure"
            echo "---------"
            echo ""
            echo "First, let's go through the directory structure:"
            echo ""
            echo " *  *src* directory - here is your main place to store"
            echo "    source files.  This includes also documents like user"
            echo "    manuals---IOW, anything intended to end up on user's"
            echo "    machine should be uder 'src'."
            echo ""
            echo "    Note that during build time, files named ending with"
            echo "    '.skel' are subject to token expansion, see mkit.ini"
            echo "    section below for details."
            echo ""
            echo " *  *notes* directory - here you shall store notes"
            echo "    intended for people contributing to your project,"
            echo "    for instance, guidelines, coding style documents,"
            echo "    TODOs, ideas, plans..."
            echo ""
            echo " *  *utils* directory - here you shall store utilities"
            echo "    and scripts that will help you with project maintenance,"
            echo "    and that, unlike software like compilers or versioning"
            echo "    systems, can (and should) be embedded inside the"
            echo "    repository."
            echo ""
            echo "    MKit itself is one nice example. :)"

            if $MkPackaging; then
            echo ""
            echo " *  *packaging* directory contains templates that enable"
            echo "    MKit create raw stuffs used to create DEB or RPM"
            echo "    packages.  Similar to '.skel' files in 'src', all files"
            echo "    here are automatically considered for token expansion,"
            echo "    no matter how they are named (see mkit.ini section"
            echo "    below)."
            echo ""
            echo "    NOTE: these templates, as well as any packages created by"
            echo "    them are intended only for experimental, private use and"
            echo "    testing."
            echo ""
            echo "    Should you have ambition to create 'real' packages for"
            echo "    OS distribution such as Debian or Fedora (what a great"
            echo "    idea!), be prepared that you will need to follow their"
            echo "    guidelines.  This will most probably mean huge changes"
            echo "    to these packages or even changes to your workflow."

            echo ""
            echo ""
            echo "Placeholders"
            echo "------------"
            echo ""
            echo "At places where *newstub* script did not have way to get all"
            echo "information automatically, it has inserted placeholders."
            echo "You will need to go through all of these placeholders and"
            echo "replace them with proper data."
            echo ""
            echo "Please follow instructions:"
            echo ""
            echo " 1. Look for placeholders starting with \`MKIT_NEWSTUB_\`"
            echo "    prefix by calling this command:"
            echo ""
            echo "        grep -lw MKIT_NEWSTUB_ -r"
            echo ""
            echo " 2. Go through each file and locate the placeholder.  (You"
            echo "    will also see placeholders like \`__MKIT_*__\`, you can"
            echo "    ignore those."
            echo ""
            echo " 3. Replace placeholder with appropriate information:"
            echo ""
            echo "     *  \`MKIT_NEWSTUB_REQUIRES\` - Requirements of your"
            echo "        project."
            echo ""
            echo "     *  \`MKIT_NEWSTUB_DESCRIPTION\` - Description of your"
            echo "        project (few sentences to paragraphs)."
            echo ""
            echo "     *  \`MKIT_NEWSTUB_FILELIST\` - List of full paths to"
            echo "        your files after installation."
            echo ""
            echo "    Refer to these documents for further details:"
            echo ""
            echo "        http://rpm-guide.readthedocs.io/"
            echo "        https://www.debian.org/doc/manuals/maint-guide/"
            fi

            echo ""
            echo ""
            echo "mkit.ini"
            echo "--------"
            echo ""
            echo "Most sections still need to be reviewed. In order to do"
            echo "that, you will need to understand how MKit works:"
            echo ""
            echo " 1. First, you need to define *roles* your files will play"
            echo "    when they are installed on user's file systems.  These"
            echo "    roles then imply where and how the files should be"
            echo "    deployed."
            echo ""
            echo "    Typical example of a role is e.g. 'bin' for commands"
            echo "    (normally under '/usr/bin' or '/usr/local/bin'), 'doc'"
            echo "    for documents or 'lib' for libraries."

            echo ""
            echo " 2. Next, in \`[roots]\` section, you have to set target"
            echo "    root directory for each role.  However, in order to"
            echo "    enable people to implement local conventions, it is"
            echo "    considered a good manner to also respect PREFIX"
            echo "    environment variable.  For this reason, most paths"
            echo "    need to start with \`[ENV:PREFIX]\`."
            echo ""

            echo " 3. \`[files]\` section is where you assign actual files"
            echo "    from your repository to their final paths.  The format"
            echo "    is \`ROLE = REPOPATH [RENAMED]\`, where ROLE is file's"
            echo "    role, REPOPATH is relative path to the file."
            echo ""
            echo "    Final path is then composed by taking path assigned to"
            echo "    ROLE and appending file's name.  However, if you need"
            echo "    the deployed file to have different name than in the"
            echo "    codebase, you can specify the other name as RENAMED."
            echo ""
            echo "    Note that you don't need to address every single file"
            echo "    individually, if in your repo you have a directory with"
            echo "    100 files of the same role, you can add just path to the"
            echo "    directory itself."

            echo ""
            echo " 4. If some roles require special permissions on your files,"
            echo "    \`[modes]\` section is your friend.  Permissions here"
            echo "    should be in UNIX octal format."

            echo ""
            echo " 5. Next, \`[tokens]\` section allows you to define own"
            echo "    placeholders that will be replaced when your scripts are"
            echo "    built.  Each file in 'src' directory that is named with"
            echo "    '.skel' suffix, and each file from 'packaging' directory"
            echo "    (no matter its name), can contain one or more of tokens"
            echo "    defined here, plus range of tokens automatically defined"
            echo "    by MKit.  During build, these tokens are replaced with"
            echo "    their actual values."

            echo ""
            echo " 6. Less interesting, but important section is \`[dist]\`,"
            echo "    which lists files in your codebase that will be added"
            echo "    to distribution tarball (part of \"stuffs\" mentioned"
            echo "    above).  Listing directory here will include all its"
            echo "    contents, and normally it's OK to be very inclusive, so"
            echo "    most of the time this section should be OK."

            echo ""
            echo " 7. Even less interesting is section \`[ENV]\`.  It is"
            echo "    special in that it provides *default* value for an"
            echo "    environment variable.  You almost never need to touch"
            echo "    this."
            echo ""

            echo " 8. Finally, the most interesting section!  \`[project]\`,"
            echo "    provides most general information for your project such"
            echo "    as name and version."
            echo ""
            echo "    Note that the \`version\` key is another \"special"
            echo "    snowflake\" -- it is now set to 0.0.0, and you **should"
            echo "    not need** to change  it manually.  When you feel you"
            echo "    a are ready to release next version of your evolving"
            echo "    project, simply call \`make vbump\` and MKit will take"
            echo "    care of everything!"

            if $MkMakefile; then
            echo ""
            echo ""
            echo "Makefile"
            echo "--------"
            echo ""
            echo "*newstub* script also created a Makefile for you, but all"
            echo "it really does is include MKit's own mkit.mk, which in turn"
            echo "only maps \`make\` targets to actual mkit script calls."
            echo "Unless your project already uses GNU Make, you should not"
            echo "need to change this file."
            fi

            if $MkReadme; then
            echo ""
            echo ""
            echo "README.md"
            echo "---------"
            echo ""
            echo "Each serious project needs a serious README.  Which is why"
            echo "*newstub* has created a 'stub' of one for you."
            fi

            echo ""
            echo ""
            echo "The final touch"
            echo "---------------"
            echo ""
            echo "Once you have reviewed everything, just delete this file!"
            ;;

    esac >"$file"
}

known_licenses() {
    local key
    local first=true
    for key in "${!MKIT_INIT_LICENSES[@]}"; do
        $first && echo "$key"  && continue
        echo ", $key"
    done
}

usage() {
    {
        echo "Usage:"
        echo "   newstub [options] NAME"
        echo "   newstub -L"
        echo ""
        echo "Options:"
        echo ""
        echo "    -c CODENAME   your project codename"
        echo "    -t TAGLINE    your project tagline"
        echo "    -b RELSRC     pre-release branch"
        echo "    -B RELDST     post-release branch"
        echo "    -n NICENAME   your project's 'nice' name"
        echo "    -l LICENSE    your options's license (see -L)"
        echo "    -m MAINT      project maintainer's name and e-mail"
        echo "    -v URL        URL to public code browser"
        echo "    -a            enable autoclean ('make clean' after"
        echo "                  each 'make install')"
        echo "    -g            make git commits before and adter"
        echo "                  (implies -y)"
        echo "    -y            don't ask, just do it"
        echo "    -R            skip creating README.md"
        echo "    -M            skip creating Makefile"
        echo "    -P            skip creating packaging templates"
        echo "    -L            list know licenses and exit"
        echo ""
        echo "NAME should be packaging-friendly name, ie. consist"
        echo "only of small letters, numbers, underscore and dash."
        echo "For your 'real' name, use NICENAME, which can be any"
        echo "string."
    } >&2
    exit 2
}

confirm() {
    local response      # user's response to our warning
    $Force && return 0
    {
        echo "Warning: This operation can be destructive for your"
        echo "current codebase.  At least following files will be"
        echo "created or overwritten:"
        echo ""
        $MkPackaging    && echo " *  'packaging' directory (pass -P to avoid)"
        $MkMakefile     && echo " *  'Makefile' (pass -M to avoid)"
        $MkReadme       && echo " *  'README.md' (pass -R to avoid)"
        $MkLicense      && echo " *  'LICENSE.md' (omit -l to avoid)"
        echo " *  'mkit.ini'"
        echo ""
        read -p "Type 'yes' to proceed: " -r response
    } >&2
    test "$response" == "yes" && return 0
    warn "Aborting."
    return 1
}

mkcommit_backup() {
    git ls-files --others \
      | grep -qv -e '^utils/mkit$' -e '^utils/mkit/' \
     || { warn "nothing to back up"; return 0; }
    git add .                           || return
    git rm -r --cached utils/mkit       || return
    git commit -m "WIP [mkit/newstub] backup"   || return
}

mkcommit_mkit_code() {
    git ls-files --others \
      | grep -q -e '^utils/mkit$' -e '^utils/mkit/' \
     || return 0
    git add utils/mkit                                         || return
    git commit -m "WIP [mkit/newstub] Add MKit version v$MKIT_VERSION" || return
}

mkcommit_mkit_conf() {
    git add .                                                  || return
    git commit -m "WIP [mkit/newstub] Add MKit configuration stub" || return
}

deploy_packaging() {
    rm -rf packaging
    deploy packaging/template.spec
    deploy packaging/debian/copyright
    deploy packaging/debian/control
    deploy packaging/debian/changelog
    deploy packaging/debian/compat
    deploy packaging/debian/rules
    deploy packaging/debian/source/format
    deploy packaging/debian/"$PackageName".install
    deploy packaging/template.spec
}

main() {
    local NiceName          # human-readable project name
    local PackageName       # machine-safe project (package) name
    local RelSrc            # pre-release branch
    local RelDst            # post-release branch
    local Codename          # release codename
    local Tagline           # project tagline
    local Maintainer        # project maintainer (Name + e-mail)
    local VcsBrowser        # VCS browser (eg. GitHub URL)
    local AutoClean=false   # touch .mkit/autoclean?
    local MkCommits=false   # create pre/post git commits?
    local Force=false       # go without asking?
    local MkReadme=true     # create README.md?
    local MkMakefile=true   # create Makefile?
    local MkPackaging=true  # create packaging templates?
    local MkLicense=false   # create LICENSE.md file
    while true; do case $1 in
        -n) NiceName=$2;        shift 2 || usage ;;
        -b) RelSrc=$2;          shift 2 || usage ;;
        -B) RelDst=$2;          shift 2 || usage ;;
        -c) Codename=$2;        shift 2 || usage ;;
        -t) Tagline=$2;         shift 2 || usage ;;
        -l) License=$2;         shift 2 || usage ;;
        -m) Maintainer=$2;      shift 2 || usage ;;
        -v) VcsBrowser=$2;      shift 2 || usage ;;
        -M) MkMakefile=false;   shift ;;
        -R) MkReadme=false;     shift ;;
        -a) AutoClean=true;     shift ;;
        -y) Force=true;         shift ;;
        -g) MkCommits=true;     shift ;;
        -P) MkPackaging=false;  shift ;;
        -L) known_licenses | tr , '\n'; exit 0 ;;
        -*) usage ;;
        *)  break ;;
    esac done
    PackageName="$1"
    test -n "$PackageName" || usage
    if test -n "$License"; then
        known_licenses | grep -qxF "$License" \
         || die "unknown license (use -L to get list): $License"
        MkLicense=true
    fi
    if $MkCommits; then
        mkcommit_backup || die "failed creating backup commit"
        Force=true
    fi
    confirm            || return 1
    deploy mkit.ini
    deploy src/"$PackageName".skel
    $MkMakefile     && deploy Makefile
    $MkReadme       && deploy README.md
    $MkLicense      && deploy LICENSE.md
    $AutoClean      && deploy .mkit/autoclean
    $MkPackaging    && deploy_packaging
    if $MkCommits; then
        mkcommit_mkit_code || die "failed creating post-commit"
        mkcommit_mkit_conf || die "failed creating post-commit"
    fi
    deploy MKIT_NEWSTUB_README.md
    warn "Configuration stub built, follow instructions in"
    warn "MKIT_NEWSTUB_README.md to finish configuration."
    return 0
}

main "$@"