#!/bin/bash

. "$MKIT_DIR/include/ini.sh" || die "cannot import ini.sh"


build() {
    #
    # Add meat to all skeletons
    #
    local srcpath
    find src -type f -name '*.skel' \
     | while read srcpath;
       do
           build1 "$srcpath"
       done
}

build1() {
    #
    # Process one skeleton
    #
    local srcpath="$1"
    local dstpath="$2"
    local ftype="$3"
    test -n "$dstpath"  || dstpath=${srcpath%.skel}
    test -n "$ftype"    || ftype=$(guess_ftype "$dstpath")
    debug_var srcpath dstpath ftype
    <"$srcpath" build1_ftype "$ftype" >"$dstpath"
    mkdir -p "$MKIT_LOCAL"
    echo "$dstpath" >> "$MKIT_LOCAL/built.lst"
}

guess_ftype() {
    #
    # Guess file type from destination path $1
    #
    local dstpath="$1"
    case $dstpath in
        *.md) echo markdown    ;;
        *)    echo MKIT_COMMON ;;
    esac
}

build1_ftype() {
    #
    # Build a file of type $1
    #
    local ftype="$1"
    case $ftype in
        MKIT_COMMON)    expand_variables "vars" ;;
        markdown)       expand_includes | expand_variables "vars" ;;
        rpmstuff)       expand_variables "vars" "rpmstuff:vars" ;;
        *)              die "unknown file type: $ftype" ;;
    esac
}

build_manpages() {
    local manfile mdfile
    if command -v ronn >/dev/null;
    then
        ini lskeys "files:man" \
          | while read manfile;
            do
                mdfile="$manfile.md"
                ronn -r "$mdfile"
                mkdir -p "$MKIT_LOCAL"
                echo "$manfile" >> "$MKIT_LOCAL/built.lst"
            done
    else
        echo "ronn is not installed"
        return 1
    fi
}

clean() {
    #
    # Clean up tree after building
    #
    test -f "$MKIT_LOCAL/built.lst" && {
        <"$MKIT_LOCAL/built.lst" grep -v -e '\.\.' -e ^/ \
          | xargs -r rm -rf
        rm -f "$MKIT_LOCAL/built.lst"
        rmdir --ignore-fail-on-non-empty "$MKIT_LOCAL"
    }
    true
}

dist() {
    #
    # Create distributable tarball
    #
    #FIXME: lacking Makefile skills, we do this step twice fot
    #       rpmstuff, hence -f hack for gzip
    #
    local version=$(get_version)
    local dirname=$MKIT_PROJ_PKGNAME-$version
    mkdir -p "$dirname"
    ini values "lists:dist" | xargs -I DIST_ITEM cp -R DIST_ITEM "$dirname"
    update_version "$version" "$dirname/mkit.ini"
    tar -cf "$dirname.tar" "$dirname"
    gzip -f "$dirname.tar"      # see above FIXME
    mkdir -p "$MKIT_LOCAL"
    echo "$dirname.tar.gz" >> "$MKIT_LOCAL/built.lst"
    rm -rf "$dirname"
}

debstuff() {
    #
    # Build Debian stuff (eamed tarball, debian dir)
    #
    local version="$(get_version)"

    # tarball - we should already have by means of 'dist'
    #
    mv "${MKIT_PROJ_PKGNAME}-$version.tar.gz" \
       "${MKIT_PROJ_PKGNAME}_$version.orig.tar.gz" \
     || die "could not rename tarball"
    echo "${MKIT_PROJ_PKGNAME}_$version.orig.tar.gz" >> "$MKIT_LOCAL/built.lst"

    # read content of each mandatory file from debian_skel
    #
    local debian_skel=$(ini 1value debstuff:debian_skel)
    test -n "$debian_skel" || die "debstuff:debian_skel not specified"
    test -d "$debian_skel" || die "debian directory template found: $debian_skel"
    mkdir -p debian/source
    local dfsrc dftgt
    find "$debian_skel" -type f \
      | while read dfsrc;
        do
            dftgt="debian/${dfsrc#$debian_skel}"
            mkdir -p "$(dirname "$dftgt")"
            build1 "$dfsrc" "$dftgt"
        done
    echo debian >> "$MKIT_LOCAL/built.lst"
}

rpmstuff() {
    #
    # Build specfile
    #
    local specname="$MKIT_PROJ_PKGNAME.spec"
    local specsrc="$(ini 1value "rpmstuff:spec_skel")"
    test -n "$specsrc" || die "rpmstuff:spec_skel not specified"
    test -f "$specsrc" || die "specfile template not found: $specsrc"
    build1 "$specsrc" "$specname"
}

expand_includes() {
    #
    # Expand include directives
    #
    # Expand e.g. `<!-- include4: foo.sh -->` to include code of foo.sh
    #
    perl -we '
        use strict;
        my $text;
        while (<>) {
            chomp;
            if (m/<!-- include4: (\S+) -->/) {
                open my $fh, $1 or warn "cannot find: $1";
                my $text = do { local($/); <$fh> };
                close $fh;
                $text =~ s/^(.)/    $1/gm;
                chomp $text;
                print "$text\n";
            } else {
                print "$_\n";
            }
        }
    '
}

expand_variables() {
    #
    # Expand variables from sections $@
    #
    local script=$(mktemp --tmpdir mkit-tmp.XXXXXXXXXX)
    local section varname varvalue
    {
        for section in "$@";
        do
            debug_var section
            ini lskeys "$section" \
              | while read varname;
                do
                    varvalue="$(ini 1value "$section:$varname" | sed -e 's/\$/\\$/' )"
                    echo "s|$varname|$varvalue|;"
                    debug_var varname varvalue
                done
        done
        echo "s|__MKIT_PROJ_CODENAME__|$(ini 1value project:codename)|;"
        echo "s|__MKIT_PROJ_PKGNAME__|$(ini 1value project:pkgname)|;"
        echo "s|__MKIT_PROJ_TAGLINE__|$(ini 1value project:tagline)|;"
        echo "s|__MKIT_PROJ_VERSION__|$(get_version)|;"
        echo "s|__MKIT_SELF_VERSION__|$MKIT_VERSION|;"
    } >> "$script"
    perl -wp "$script" || die "expand_variables failed"
    rm "$script"
}

get_version() {
    #
    # Build semver version string with build metadata
    #
    # Build version string from available info using following
    # logic:
    #
    #  1. use project.version (from mkit.ini)
    #  2. if we are in git, override the version with last tag
    #  3. if set, add project:prerl (from mkit.ini) as pre-release ID
    #     (afer dash)
    #  4. if we are at a later commit than the last tag, add branch
    #     name and commit sha1 to build metadata (after plus sign)
    #  5. if the tree is "dirty", i.e. has uncommited changes,
    #     add "dirty" to build metadata
    #
    # The version is compatible with SemVer 2.0.0.
    #
    # Examples:
    #
    #     myprog v1.0.7                         # all clear
    #     myprog v1.0.7-alpha                   # mkit.ini: project:prerl="alpha"
    #     myprog v1.0.7-alpha+g1aef811.master   # ^^ + some commits after
    #     myprog v1.0.7-alpha+gf14fc4f.api2     # ^^ + on a feature branch
    #     myprog v1.0.7-alpha+gf14fc4f.api2.dirty  # ^^ + tree edited
    #     myprog v1.0.7-alpha+dirty             # tag OK but tree edited
    #     myprog v1.0.7+dirty                   # ^^ but no pre-release id
    #
    # Note that versions with "dirty" should be perceived as kind of
    # dangerous outside developer's own machine.  Versions with sha1 are
    # safer but must not be released.
    #
    # I have considered decorating the git commit refs to make them
    # sort of sortable (e.g. "r1.g1aef811"), but on second thought,
    # I don't think it's good idea to give *any* semantics to meta-data
    # at all.  First, there is no rule that r1<r2<r3; a commit can be
    # removing what other just added and one change can be split to
    # multiple commits.  Also, the whole thing breaks anyway once you
    # rebase your branch (no, it's not a sin).  The sole purpose of
    # meta-data is to *identify* the code, and provide safe path back
    # to tree; commit refs are already perfect for that.
    #
    # FIXME:  Using project:prerl for release IDs may not be compatible with
    #         release strategy implemented in release.sh
    #
    local version=$(ini 1value project:version)
    local prerl=$(ini 1value project:prerl)
    grep ":" <<<"$prerl" && warn "colon in project:prerl may corrupt version data: $prerl"
    if git rev-parse HEAD >&/dev/null;
    then    # we are in git repo... so we can get smart
        local latest_tag=$(
            git log --format="%D" \
              | sed 's/,/\n/g' \
              | sed 's/^[[:blank:]]*//; ' \
              | grep -E '^tag: v[[:digit:]]+\.' \
              | cut -d' ' -f2 \
              | head -1
        )
        if ! git describe --tags --exact-match HEAD >&/dev/null;
        then    # we are at a later commit than the last tag
            local sha=g$(git log -1 --pretty=format:%h HEAD)
            local curbranch=$(git rev-parse --abbrev-ref HEAD)
            local commit="$curbranch.$sha"
        fi
        if test "$(git diff --shortstat 2>/dev/null)" != "";
        then    # the tree is "dirty", i.e. has been edited
            local dirty=dirty
        fi
        test -n "$latest_tag" && version=${latest_tag:1}
        local suffix=""
        case "$commit:$dirty" in
            :)       suffix=""                ;;
            :dirty)  suffix="+$dirty"         ;;
            *:)      suffix="+$commit"        ;;
            *:dirty) suffix="+$commit.$dirty" ;;
        esac
        test -b "$prerl" && suffix="-$prerl$suffix"
        version="$version$suffix"
    fi
    echo "$version"
}