#!/bin/bash
hash -r

function spm_abspath() {
    local filename="${1}"
    local start="$(dirname ${filename})"

    pushd "${start}" &>/dev/null
        end="$(pwd)"
    popd &>/dev/null

    if [[ -f ${filename} ]]; then
        end="${end}/$(basename ${filename})"
    fi

    echo "${end}"
}

SPM_ORIGIN=$(dirname $(spm_abspath $0))
TMPDIR=${TMPDIR:-/tmp}
OLD_PATH="${PATH}"

default_script=build.sh
build_order=${SPM_ORIGIN}/include/build.order

build_scripts=$(cat ${build_order})

# TODO: Make this part of MKTC
SPM_PROG_RELOC=reloc
SPM_RELOC_COUNT=0
SPM_PREFIX_BIN=.SPM_PREFIX_BIN
SPM_PREFIX_TEXT=.SPM_PREFIX_TEXT
SPM_DEPENDS=.SPM_DEPENDS
SPM_VERBOSE=0

export prefix_placeholder=_0123456789_0123456789_0123456789_0123456789_0123456789_0123456789_0123456789_
export prefix="/${prefix_placeholder}"
export maxjobs=4
export pkgdir=${SPM_ORIGIN}/pkgs
mkdir -p ${pkgdir}
source ${SPM_ORIGIN}/include/9999-template.sh



function spm_rpath_nearest() {
    local cwd="$(pwd)"
    local start=$(dirname $(spm_abspath ${1}))
    local result=
    local lib_forced=0
    local install_root="${destdir}/${prefix_placeholder}"

    # Determine if package produced its own "lib" directory. If not, generate a symlink
    # pointing back to the build's runtime environment, or create a placeholder.
    if [[ ! -d ${install_root}/lib ]] && [[ ! -L ${install_root}/lib ]]; then
        pushd "${install_root}" &>/dev/null
            if [[ -d ${build_runtime}/lib ]]; then
                ln -sf "${build_runtime}"/lib
            else
                mkdir -p "${install_root}"/lib
            fi

        popd &>/dev/null
        lib_forced=1
    fi

    # Jump to location of file
    cd "$(dirname ${start})"

    # Scan upward until we find a "lib" directory with shared libraries
    # OR when:
    # - Top of filesystem is reached (pretty much total failure [missing local dep])
    # - Top of active environment is reached (post installation)
    # - Top of default installation prefix is reached (during packaging)
    while [[ $(pwd) != / ]]
    do
        result+="../"
        echo "spm_rpath_nearest(): @ $(pwd)" >&2
        if [[ -d $(pwd)/lib/ ]]; then

            echo "spm_rpath_nearest(): found lib directory" >&2
            # There are edge cases when the lib directory one level above an executable
            # doesn't contain any shared libraries (i.e. binutils)
            if (( ! $(find $(pwd)/lib/ -type f \
                \( -name "*.so" -o -name "*.dylib" -o -name "*.a" \) \
                2>/dev/null | wc -l) )); then
                cd ..
                echo "spm_rpath_nearest(): lib directory was not useful" >&2
                continue
            fi
            result+="lib"
            echo "spm_rpath_nearest(): lib directory was useful" >&2
            break
        fi
        cd ..
    done

    # If we created a symlink to the runtime environment, remove it
    if (( $lib_forced > 0)); then
        rm -f "${install_root}/lib"
        lib_forced=0
    fi

    # Sanitize: removing double-slashes (if any)
    result=${result/\/\//\/}

    # Return to where we were instantiated
    cd "${cwd}"

    echo "${result}"
}

function spm_gen_package_rpath() {
    local rpath_orig
    local rpath_new

    # Assimilate all file paths that contain an RPATH
    for path in $(find . -type f -not -name '.SPM_*')
    do
        readelf -d "${path}" 2>/dev/null | grep 'R.\?.\?PATH' &>/dev/null
        if (( $? )); then
            continue
        fi
        rpath_orig="$(readelf -d "${path}" | grep 'R.\?.\?PATH' | awk -F'[][]' '{ print $2 }')"
        rpath_new='$ORIGIN/'"$(spm_rpath_nearest ${path})"
        if [[ ${rpath_origin} == ${rpath_new} ]]; then
            continue
        fi
        echo "${path}: ${rpath_orig} -> ${rpath_new}"
        patchelf --set-rpath "${rpath_new}" "${path}"
    done
}

function spm_gen_package_prefixes() {
    echo "Generating build prefix manifest"
    # Create record files
    >${SPM_PREFIX_BIN}
    >${SPM_PREFIX_TEXT}

    # Assimilate file path for anything containing our prefix
    local count_text=0
    local count_bin=0
    local count_total=0
    local prefixes=(
        ${prefix}
        ${build_runtime}
        ${build_root}
        ${destdir}
    )

    for pkg_prefix in "${prefixes[@]}"; do
        for path in $(find . -type f -not -name ".SPM_*"); do
            # Check for prefix
            grep -l "${pkg_prefix}" "${path}" &>/dev/null

            # Prefix present? (0: yes, 1: no)
            if (( $? )); then
                continue
            fi

            # Get file type
            local mimetype="$(file -i ${path} | awk -F': ' '{ print $2 }')"
            local outfile

            # Record prefix data
            if [[ ${mimetype} = *text/* ]]; then
                outfile=${SPM_PREFIX_TEXT}
                (( count_text++ ))
            else
                outfile=${SPM_PREFIX_BIN}
                (( count_bin++ ))
            fi

            echo "#${pkg_prefix}" >> "${outfile}"
            echo "${path}" >> "${outfile}"

        done
    done

    count_total=$(( count_text + count_bin ))
    if (( ${count_total} )); then
        echo "Text: ${count_text}"
        echo "Binary: ${count_bin}"
        echo "Total: ${count_total}"
    else
        echo "No prefixes detected"
    fi
}


function spm_gen_package_depends() {
    echo "Generating dependency manifest"
    local outfile="${SPM_DEPENDS}"
    >${outfile}

    for dep in "${depends[@]}"; do
        echo "${dep}" >> "${outfile}"
    done
}


_spm_install_depends=()
_spm_install_seen=()
function spm_install() {
    local pkg="$(pkg_match $1)"
    if [[ ! -f ${pkg} ]]; then
        echo "Package not found: ${pkg}" >&2
        exit 1
    fi

    local destroot="$2"
    if [[ -z ${destroot} ]]; then
        echo "destination root undefined" >&2
        exit 1
    elif [[ ! -d ${destroot} ]]; then
        mkdir -p "${destroot}"
    fi

    # extract package into temp directory
    local pkgtmp=$(mktemp -d ${TMPDIR}/spm.XXXX)
    pushd "${pkgtmp}" &>/dev/null
        echo "Unpacking: ${pkg}"
        tar xf "${pkg}"

        local prefix_base

        # relocate binaries
        if [[ -f ${SPM_PREFIX_BIN} ]]; then
            while read path; do
                if [[ -z $path ]]; then
                    continue
                elif [[ $path =~ ^#.* ]]; then
                    prefix_base="${path#\#}"
                    continue
                fi

                if [[ ! -f $path ]]; then
                    echo "WARNING: ${path} does not exist!" >&2
                    continue
                fi

                if [[ $path =~ .pyc$ ]]; then
                    continue
                fi

                if (( $SPM_VERBOSE )); then
                    echo "Relocating binary paths: ${path}"
                fi
                ${SPM_PROG_RELOC} "${prefix_base}" "${destroot}" "${path}" "${path}" >/dev/null
            done < "${SPM_PREFIX_BIN}"
            rm -f ${SPM_PREFIX_BIN}
        fi
        prefix_base=""

        # relocate text
        if [[ -f ${SPM_PREFIX_TEXT} ]]; then
            while read path; do
                if [[ -z $path ]]; then
                    continue
                elif [[ $path =~ ^# ]]; then
                    prefix_base="${path#\#}"
                    continue
                fi

                if [[ ! -f $path ]]; then
                    echo "WARNING: ${path} does not exist!" >&2
                    continue
                fi

                if [[ $path =~ .pyc$ ]]; then
                    continue
                fi

                if (( $SPM_VERBOSE )); then
                    echo "Relocating text paths: ${path}"
                fi
                sed -i -e "s|${prefix_base}|${destroot}|g" "${path}"
            done < "${SPM_PREFIX_TEXT}"
            rm -f ${SPM_PREFIX_TEXT}
        fi

        # service package dependencies
        if [[ -f ${SPM_DEPENDS} ]]; then
            if [[ -z ${_spm_install_depends} ]]; then
                _spm_install_depends=($(cat ${SPM_DEPENDS}))
            else
                _spm_install_depends+=($(cat ${SPM_DEPENDS}))
            fi

            for dep in "${_spm_install_depends[@]}"; do
                # Track dependencies we have already processed to avoid infinite recursion
                if [[ ${_spm_install_seen[@]} =~ $dep ]]; then
                    # Pop dependency and do nothing
                    _spm_install_depends=("${_spm_install_depends[@]:1}")
                    continue
                fi

                # Pop dependency and process it
                _spm_install_depends=("${_spm_install_depends[@]:1}")

                # Stop processing when the array is totally empty
                if (( ${#_spm_install_depends[@]} < 0 )); then
                    _spm_install_depends=()
                    #_spm_install_seen=()
                    break
                fi

                _spm_install_seen+=("${dep}")
                spm_install "${dep}" "${destroot}"
            done

            #FIXME
            #local prev
            #for rec in "${_spm_install_depends[@]}"; do prev="$rec $prev"; done
            #_spm_install_depends=($x)

            #for dep in "${_spm_install_depends[@]}"; do
            #    spm_install "${dep}" "${destroot}"
            #done
            rm -f "${SPM_DEPENDS}"
        fi

        # install package
        echo "Installing: ${pkg}"
        rsync -a ./ "${destroot}"

    popd &>/dev/null
    if [[ -d $pkgtmp ]]; then
        rm -rf "${pkgtmp}"
    fi
}


function builder() {
    for build_script in ${build_scripts}; do
        if [[ ${build_script} =~ ^#.* ]]; then
            continue
        fi
        if [[ ! -f ${build_script} ]]; then
            build_script=$(spm_abspath ${build_script}/build.sh)
            build_script_root=$(dirname ${build_script})
        else
            build_script_root=$(spm_abspath ${build_script})
        fi

        local output_dir="${SPM_ORIGIN}/output/$(basename ${build_script_root})"
        export build_sources="${SPM_ORIGIN}/sources/$(basename ${build_script_root})"
        export build_root="${output_dir}/buildroot"
        export build_runtime="${output_dir}/runtime"
        export destdir="${output_dir}/root"

        export CC=gcc
        export CXX=g++
        export LD_LIBRARY_PATH="${build_runtime}/lib"
        export CFLAGS="-I${build_runtime}/include"
        export CPPFLAGS="${CFLAGS}"
        export LDFLAGS="-L${build_runtime}/lib -Wl,-rpath="'\$$ORIGIN'"/../lib"

        echo "Building: ${build_script}"

        if [[ ! -f ${build_script} ]]; then
            echo "${build_script} does not exist, check ${build_order}" >&2
            exit 1
        fi

        if [[ ! -d ${build_sources} ]]; then
            mkdir -p ${build_sources}
        fi

        if [[ -d ${build_root} ]]; then
            rm -rf ${build_root}
        fi
        mkdir -p ${build_root}

        if [[ -d ${build_runtime} ]]; then
            rm -rf ${build_runtime}
        fi
        mkdir -p ${build_runtime}

        if [[ -d ${destdir} ]]; then
            rm -rf ${destdir}
        fi
        mkdir -p ${destdir}

        export PATH="${build_runtime}/bin:${build_runtime}/sbin:$OLD_PATH"
        export PKG_CONFIG_PATH="${build_runtime}/lib/pkgconfig"

        pushd ${build_root} &>/dev/null
            # Assimilate build script's contents
            source ${build_script}

            if [[ -f ${pkgdir}/${name}-${version}-${revision}.tar.gz ]]; then
                echo "Skipping: Package exists"
                popd &>/dev/null
                continue
            fi

            # Download source files
            for url in "${sources[@]}"; do
                archive_path="${build_sources}/$(basename $url)"
                if [[ -f ${archive_path} ]]; then
                    echo "Cached source: ${archive_path}"
                    continue
                fi
                echo "Downloading source: ${url}"
                curl -L "$url" > "${archive_path}"
            done

            # Copy source files to build root
            for archive in "${build_sources}"/*; do
                echo "Copying source to build root: ${archive}"
                cp -a "${archive}" "${build_root}"
            done

            # Make base package implicit
            if [[ -z $disable_base ]]; then
                base_package=$(pkg_match "base")
                if [[ -n ${base_package} ]]; then
                    # pkg_match returns a path, so just use "base" instead if its there
                    base_package="base"
                    build_depends+=(${base_package})
                    depends+=(${base_package})
                fi
            fi

            # Install build dependencies
            for dep in "${build_depends[@]}"; do
                echo "Build depends on: ${dep}"
                pkg=$(pkg_match "${dep}")
                if [[ -z ${pkg} ]]; then
                    echo "Package not found" >&2
                    exit 1
                fi
                spm_install "${pkg}" "${build_runtime}"
            done

            # Install package dependencies
            for dep in "${depends[@]}"; do
                echo "Depends on: ${dep}"
                pkg=$(pkg_match "${dep}")
                if [[ -z ${pkg} ]]; then
                    echo "Package not found" >&2
                    exit 1
                fi
                spm_install "${pkg}" "${build_runtime}"
            done

            # Rehash the runtime environment
            hash -r

            # No failures allowed in predefined build stages
            set -e
            prepare
            build
            package
            set +e

            # Post-process the installation root (i.e. make install DESTDIR=${destdir})
            if [[ -d ${destdir} ]]; then
                pushd ${destdir} &>/dev/null
                    if [[ -d ${destdir}/${prefix} ]]; then
                        pushd ${destdir}/${prefix} &>/dev/null
                    fi
                    spm_gen_package_rpath
                    spm_gen_package_prefixes
                    spm_gen_package_depends

                    pkg="${pkgdir}/${name}-${version}-${revision}.tar.gz"
                    echo "Creating package: ${pkg}"
                    pwd
                    ls -la
                    tar cfz "${pkg}" .SPM_* .

                    if [[ -d ${destdir}/${prefix} ]]; then
                        popd &>/dev/null
                    fi
                popd &>/dev/null
            fi
        popd &>/dev/null
    done
}

function pkg_match() {
    if [[ -z $1 ]]; then
        echo "pkg_match: missing argument, package" >&2
        exit 1
    fi
    match=$(find "${pkgdir}" -type f -regex ".*${1}\-?[0-9]+?.*" 2>/dev/null | sort | head -n 1)
    echo "${match}"
}

function installer() {
    local root=""
    local packages=()

    while [[ $# != 0 ]]; do
        case "$1" in
            --verbose|-v)
                SPM_VERBOSE=1
                ;;
            --root|-r)
                root="$2"
                shift
                ;;
            -*|--*)
                echo "installer: unknown argument: $1" >&2
                exit 1
                ;;
            *)
                # "Most-likely" match the requested package by name
                p=$(basename $(pkg_match "${1}"))
                packages+=("$p")
                ;;
        esac
        shift
    done

    if [[ -z $root ]]; then
        echo "missing required argument: --root {destination}" >&2
        exit 1
    fi

    export PATH="${root}/bin:${PATH}"
    for pkg in "${packages[@]}"; do
        spm_install "${pkg}" "${root}"
    done
}

function usage() {
echo "Usage: $0 [build|install] {package}

Options:
    --help    (-h)      this message
    --verbose (-v)      increase verbosity

Commands:
    build               build a package
    install             install a package

Positional arguments:
    package             package to interact with

"
}


if [[ $# < 2 ]]; then
    usage
    exit 1
fi

fn=
args=
while [[ $# != 0 ]]; do
    case "$1" in
        --verbose|-v)
            SPM_VERBOSE=1
            ;;
        --help|-h)
            usage
            exit 0
            ;;
        build)
            fn=builder
            if [[ $2 != "all" ]]; then
                build_scripts="$2"
                if [[ $build_scripts =~ .*/build.sh ]]; then
                    build_scripts=$(dirname ${build_scripts})
                fi
            fi
            shift 2
            break
            ;;

        install)
            fn=installer
            shift
            args=("$@")
            break
            ;;

        *)
            echo "unknown argument: $1"
            exit 1
            ;;
    esac
    shift
done

$fn "${args[@]}"