#!/bin/sh -e

# Copyright (c) 2025 Alexander Hill

# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.

# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

#############
# Changelog #
#############

# November 22, 2025 (1.2.0)
# + Added support for the CCACHE environment variable [ahill]
# + Added TT_ARCH [ahill]
# + Added TT_AUTOCONF_COMMON for easy autoconf integration [ahill]
# + Added TT_CMAKE_COMMON for easy CMake integration [ahill]
# + Added TT_MICROARCH for micro-optimization support [ahill]
# * Changed the build path to use TT_MICROARCH instead of TT_TARGET [ahill]
# * Fixed "missing package" error when passing absolute paths to the install
#   subcommand [ahill]
# * Prevented xz from deleting package files [ahill]
# + Started printing the version number in the build logs [ahill]

# November 15, 2025 (1.1.0)
# + Added the ability to incorporate patches into the build [ahill]
# + Added TT_CONFDIR [ahill]
# * Replaced curl with wget to rely purely on Busybox [ahill]

# November 13, 2025 (1.0.2)
# + Added the target triple to the package path [ahill]
# * Prevented fetch from re-downloading packages given a valid hash [ahill]
# * Renamed all TREETAP_* variables to TT_* [ahill]

# November 11, 2025 (1.0.1)
# - Removed bashisms to become POSIX compliant [ahill]

# November 9, 2025 (1.0.0)
# * Initial release [ahill]

########################
# .spec File Reference #
########################

# For everyone trying to build .spec files (including myself), this is the list
# of useful variables to take advantage of. ~ahill

# Specification Functions:
#   build   - Builds the package
#   clean   - Cleans $TT_BUILDDIR for the next build
#   package - Installs the package contents to $TT_INSTALLDIR

# Specification Variables:
#   SRC_FILENAME - The name of the tarball to extract (optional)
#   SRC_HASH     - The hash of the tarball for verification purposes (required)
#   SRC_NAME     - The name of the package being built (required)
#   SRC_PATCHES  - A list of SHA256 hashes followed by their filenames to be
#                  copied to the build directory (optional)
#   SRC_URL      - The URL of the tarball to be downloaded (required)
#   SRC_VERSION  - The version of the package being built (required)

# Treetap Variables:
#   TT_ARCH            - The architecture portion of TT_TARGET
#                        [scope: source]
#   TT_AUTOCONF_COMMON - The default autoconf arguments based on the environment
#                        [scope: source]
#   TT_BINDIR          - The desired path for binaries
#                        [scope: source] [default: /bin]
#   TT_BUILD           - The target triple of the build system
#                        [scope: source]
#   TT_BUILDDIR        - The path to the build directory
#                        [scope: source]
#   TT_CMAKE_COMMON    - The default CMake arguments based on the environment
#                        [scope: source]
#   TT_CONFDIR         - The desired path for configuration files
#                        [scope: source] [default: /etc]
#   TT_DIR             - The path to the treetap directory
#                        [scope: global]
#   TT_INCLUDEDIR      - The desired path for header files
#                        [scope: source] [default: /usr/include]
#   TT_INSTALLDIR      - The path to the install directory
#                        [scope: source]
#   TT_LIBDIR          - The desired path for libraries
#                        [scope: source] [default: /lib]
#   TT_MICROARCH       - The microarchitecture to optimize for
#                        [scope: source]
#   TT_PKGDIR          - The path to the package directory
#                        [scope: global]
#   TT_PREFIX          - The desired prefix for the package
#                        [scope: source] [default: /]
#   TT_PROCS           - The number of processors on the build system
#                        [scope: source]
#   TT_SYSROOT         - The sysroot of the target system
#                        [scope: global]
#   TT_TARGET          - The target triple of the target system
#                        [scope: source]
#   TT_VERSION         - The version of treetap being used
#                        [scope: global]

####################
# Global Variables #
####################

[ -z "$TT_DIR" ] && TT_DIR="$(pwd)/.treetap"
[ -z "$TT_PKGDIR" ] && TT_PKGDIR="$TT_DIR/packages"
[ -z "$TT_SYSROOT" ] && TT_SYSROOT=/
TT_VERSION="1.2.0"

#####################
# Utility Functions #
#####################

# Displays the usage information for treetap
help_message() {
    echo "treetap $TT_VERSION"
    echo
    echo "Package Commands:"
    echo "    $0 install <package> [sysroot]"
    echo "    $0 uninstall <package> [sysroot]"
    echo
    echo "Source Commands:"
    echo "    $0 build <spec>"
    echo "    $0 clean <spec>"
    echo "    $0 fetch <spec>"
    echo "    $0 package <spec>"
    echo "    $0 purge <spec>"
    exit 1
}

# Confirms that the given strings are valid package and sysroot paths
package_check() {
    [ -z "$1" ] && (echo "package_check: Missing package file"; exit 1)
    [ -z "$2" ] && (echo "package_check: Missing sysroot"; exit 1)
    [ ! -f "$1" ] && (echo "package_check: Package file \"$1\" not found"; exit 1)
    [ ! -d "$2" ] && (echo "package_check: Sysroot \"$2\" not found"; exit 1)
    case "$1" in
    "/"*) PKG_FULLPATH=$1 ;;
    *) PKG_FULLPATH=$(pwd)/$1 ;;
    esac
    true
}

# Reads the source specification and ensures it includes the required data
source_spec() {
    # Sanity Check
    [ -z "$1" ] && (echo "source_spec: Missing specification file"; exit 1)
    [ ! -f "$1" ] && (echo "source_spec: Specification file \"$1\" not found"; exit 1)

    # Zhu Li, do the thing!
    . $1

    # Required Fields
    [ -z "$SRC_HASH" ] && (echo "source_spec: SRC_HASH is required but not defined"; exit 1)
    [ -z "$SRC_NAME" ] && (echo "source_spec: SRC_NAME is required but not defined"; exit 1)
    [ -z "$SRC_URL" ] && (echo "source_spec: SRC_URL is required but not defined"; exit 1)
    [ -z "$SRC_VERSION" ] && (echo "source_spec: SRC_VERSION is required but not defined"; exit 1)

    # Optional Fields
    [ -z "$SRC_FILENAME" ] && SRC_FILENAME=$(basename $SRC_URL)

    # Environmental Variables
    [ -z "$TT_BINDIR" ] && TT_BINDIR=/bin
    TT_BUILD=$(clang -dumpmachine)
    [ -z "$TT_TARGET" ] && TT_TARGET=$TT_BUILD
    [ -z "$TT_CONFDIR" ] && TT_CONFDIR=/etc
    [ -z "$TT_INCLUDEDIR" ] && TT_INCLUDEDIR=/usr/include
    [ -z "$TT_LIBDIR" ] && TT_LIBDIR=/lib
    [ -z "$TT_PREFIX" ] && TT_PREFIX=/
    [ -z "$TT_PROCS" ] && TT_PROCS=$(nproc)

    # Attempt to guess TT_MICROARCH if it isn't defined
    TT_ARCH=$(echo $TT_TARGET | cut -d"-" -f1)
    if [ -z "$TT_MICROARCH" ]; then
        case "$TT_ARCH" in
        "x86_64") TT_MICROARCH="skylake";;
        *)
            echo "TT_MICROARCH not defined for $TT_ARCH"
            exit 1
            ;;
        esac
    fi

    # Apply TT_MICROARCH to CFLAGS/CXXFLAGS
    CFLAGS="-march=$TT_MICROARCH $CFLAGS"
    CXXFLAGS="-march=$TT_MICROARCH $CXXFLAGS"

    # Last, but certainly not least, let's define where we want the build to
    # occur and where to put the artifacts. ~ahill
    TT_BUILDDIR="$TT_DIR/sources/$SRC_NAME/$SRC_VERSION/$TT_MICROARCH"\
    TT_INSTALLDIR="$TT_BUILDDIR/install"

    # Create convenience variables
    TT_AUTOCONF_COMMON=$(echo "--bindir=$TT_BINDIR \
        --build=$TT_BUILD \
        --datarootdir=/usr/share \
        --host=$TT_TARGET \
        --includedir=$TT_INCLUDEDIR \
        --libdir=$TT_LIBDIR \
        --libexecdir=$TT_LIBDIR \
        --localstatedir=/var \
        --prefix=$TT_PREFIX \
        --runstatedir=/run \
        --sbindir=$TT_BINDIR \
        --sysconfdir=$TT_CONFDIR \
        --target=$TT_TARGET \
        --with-sysroot=$TT_SYSROOT" | xargs)

    TT_CMAKE_COMMON=$(echo "-DCMAKE_ASM_COMPILER_TARGET=$TT_TARGET \
        -DCMAKE_C_COMPILER_TARGET=$TT_TARGET \
        -DCMAKE_CXX_COMPILER_TARGET=$TT_TARGET \
        -DCMAKE_BUILD_TYPE=Release \
        -DCMAKE_INSTALL_PREFIX=$TT_INSTALLDIR" | xargs)

    # NOTE: CMake doesn't like having a space in CC and CXX, so we manually
    #       define a few things if CCACHE is set. ~ahill
    if [ ! -z "$CCACHE" ]; then
        TT_CMAKE_COMMON=$(echo "$TT_CMAKE_COMMON \
            -DCMAKE_C_COMPILER=$(echo $CC | cut -d" " -f2) \
            -DCMAKE_C_COMPILER_LAUNCHER=$CCACHE \
            -DCMAKE_CXX_COMPILER=$(echo $CXX | cut -d" " -f2)
            -DCMAKE_CXX_COMPILER_LAUNCHER=$CCACHE" | xargs)
    fi

    true
}

###############
# Subcommands #
###############

# Installs a package to the sysroot
package_install() {
    [ ! -z "$2" ] && TT_SYSROOT=$2
    package_check $1 $TT_SYSROOT
    echo "Installing $(basename $1)"
    PUSHD=$(pwd)
    cd $TT_SYSROOT
    xz -cdk $PKG_FULLPATH | cpio -idmu --quiet
    cd $PUSHD
    exit 0
}

# Uninstalls a package from the sysroot
package_uninstall() {
    [ ! -z "$2" ] && TT_SYSROOT=$2
    package_check $1 $TT_SYSROOT
    echo "Uninstalling $(basename $1)"
    PUSHD=$(pwd)
    cd $TT_SYSROOT
    xz -cdk $PKG_FULLPATH | cpio -it --quiet | tail -n +2 | sort -r | while read path; do
        if [ -d $path ]; then
            rmdir --ignore-fail-on-non-empty $path
        else
            rm -f $path
        fi
    done
    cd $PUSHD
    exit 0
}

# Builds the source from the previously fetched tarball
source_build() {
    source_spec $1
    mkdir -p $TT_BUILDDIR
    if [ ! -z "$SRC_PATCHES" ]; then
        echo "Validating patches for $SRC_NAME $SRC_VERSION"
        cd $(dirname $1)
        echo $SRC_PATCHES | sha256sum -c - > /dev/null
        # Is this even the right way to check a return value? ~ahill
        if [ ! "$?" = "0" ]; then
            echo "Failed to validate patches for $SRC_NAME $SRC_VERSION for $TT_MICROARCH ($TT_TARGET)"
            exit 1
        fi
        echo $SRC_PATCHES | while read line; do
            cp $(echo $line | cut -d" " -f2) $TT_BUILDDIR/
        done
    fi
    echo "Building $SRC_NAME $SRC_VERSION for $TT_MICROARCH"
    PUSHD=$(pwd)
    cd $TT_BUILDDIR
    # Please don't use this in your build script. This is meant for
    # troubleshooting purposes. ~ahill
    TT_BUILD_LOG=build-$(date +%Y%m%d%H%M%S).log
    echo "Build started with treetap $TT_VERSION at $(date)" > $TT_BUILD_LOG
    build >> $TT_BUILD_LOG 2>&1
    echo "Build finished at $(date)" >> $TT_BUILD_LOG
    cd $PUSHD
    exit 0
}

# Cleans the source from the previous build
source_clean() {
    source_spec $1
    mkdir -p $TT_BUILDDIR
    PUSHD=$(pwd)
    cd $TT_BUILDDIR
    echo "Cleaning $SRC_NAME $SRC_VERSION"
    clean
    rm -rf $TT_INSTALLDIR
    cd $PUSHD
    exit 0
}

# Fetches and verifies the integrity of the source tarball
source_fetch() {
    source_spec $1
    mkdir -p $TT_BUILDDIR
    PUSHD=$(pwd)
    cd $TT_BUILDDIR/..
    if [ -f $SRC_FILENAME ]; then
        if (echo "$SRC_HASH  $SRC_FILENAME" | sha256sum -c - > /dev/null); then
            echo "Skipping $SRC_FILENAME"
            exit 0
        else
            rm -f $SRC_FILENAME
        fi
    fi
    echo "Fetching $SRC_FILENAME"
    wget -O $SRC_FILENAME $SRC_URL
    echo "Verifying $SRC_FILENAME"
    echo "$SRC_HASH  $SRC_FILENAME" | sha256sum -c - > /dev/null
    cd $PUSHD
    exit 0
}

# Packages the built artifacts for distribution
source_package() {
    source_spec $1
    mkdir -p $TT_BUILDDIR
    mkdir -p $TT_INSTALLDIR
    mkdir -p $TT_PKGDIR/$TT_MICROARCH
    PUSHD=$(pwd)
    cd $TT_BUILDDIR
    echo "Archiving $SRC_NAME $SRC_VERSION for $TT_MICROARCH"
    package > package-$(date +%Y%m%d%H%M%S).log
    cd $TT_INSTALLDIR
    find | cpio -o --quiet | xz -cz > "$TT_PKGDIR/$TT_MICROARCH/$SRC_NAME-$SRC_VERSION-$TT_MICROARCH.cpio.xz"
    rm -rf $TT_INSTALLDIR
    cd $PUSHD
    exit 0
}

# Purges the entire build directory for a source
source_purge() {
    source_spec $1
    rm -rf $TT_BUILDDIR
    exit 0
}

###############
# Entry Point #
###############

case "$1" in
"build") source_build $2 ;;
"clean") source_clean $2 ;;
"fetch") source_fetch $2 ;;
"install") package_install $2 $3 ;;
"package") source_package $2 ;;
"purge") source_purge $2 ;;
"uninstall") package_uninstall $2 $3 ;;
*) help_message ;;
esac