#!/bin/sh
# termenv - independent native plugin environment for Terminal
# This is a POSIX sh environment, not a Linux userland.  Packages are
# Terminal-compatible .deb files (scripts or iOS/Darwin arm64 binaries).

ROOT="${TERM_ROOT:-$HOME/Documents/.terminal}"
APPDIR="${APPDIR:-/Applications/Terminal.app}"
PROFILE="$ROOT/etc/profile"
SOURCES="$ROOT/etc/apt/sources.list"

usage() {
    printf '%s\n' "Usage: termenv <command>"
    printf '%s\n' ""
    printf '%s\n' "  init            Create the independent prefix and the local apt repository"
    printf '%s\n' "  status          Show prefix, PATH, apt/dpkg and installed packages"
    printf '%s\n' "  enter           Print the command that activates the environment"
    printf '%s\n' "  run <cmd...>    Run a command inside the environment"
    printf '%s\n' "  on              Add activation to ~/Documents/.profile"
    printf '%s\n' "  off             Remove activation from ~/Documents/.profile"
    printf '%s\n' "  selftest        init + apt update + install the sample \"hello\" package"
    printf '%s\n' "  clean           Remove apt caches and temporary files"
    printf '%s\n' ""
    printf '%s\n' "Environment:"
    printf '%s\n' "  TERM_ROOT=~/Documents/.terminal"
    printf '%s\n' "  PREFIX=$TERM_ROOT"
}
ensure_dirs() {
    mkdir -p "$ROOT/bin" "$ROOT/sbin" "$ROOT/lib" "$ROOT/include" \
             "$ROOT/share/man" "$ROOT/etc/apt" \
             "$ROOT/var/lib/dpkg/info" "$ROOT/var/lib/apt/lists" \
             "$ROOT/var/cache/apt/archives" "$ROOT/var/log" \
             "$ROOT/tmp" "$ROOT/repo/pool" "$ROOT/home"
    [ -f "$ROOT/var/lib/dpkg/status" ] || : > "$ROOT/var/lib/dpkg/status"
}

write_profile() {
    if [ ! -f "$PROFILE" ]; then
        cat > "$PROFILE" <<EOF
# Terminal plugin environment (generated by termenv init)
TERM_ROOT="\$HOME/Documents/.terminal"
export TERM_ROOT
PREFIX="\$TERM_ROOT"
export PREFIX
TERM_PLUGIN_ENV=1
export TERM_PLUGIN_ENV
PATH="\$TERM_ROOT/bin:\$TERM_ROOT/sbin:\$TERM_ROOT/usr/bin:\$PATH"
export PATH
LD_LIBRARY_PATH="\$TERM_ROOT/lib:\$TERM_ROOT/usr/lib:\$LD_LIBRARY_PATH"
export LD_LIBRARY_PATH
CPATH="\$TERM_ROOT/include:\$CPATH"
export CPATH
LIBRARY_PATH="\$TERM_ROOT/lib:\$TERM_ROOT/usr/lib:\$LIBRARY_PATH"
export LIBRARY_PATH
PKG_CONFIG_PATH="\$TERM_ROOT/lib/pkgconfig:\$PKG_CONFIG_PATH"
export PKG_CONFIG_PATH
MANPATH="\$TERM_ROOT/share/man:\$MANPATH"
export MANPATH
EOF
    fi
}

write_sources() {
    LOCAL_LINE="deb [trusted=yes] file://$ROOT/repo ./"
    PROCURUS_LINE="deb [trusted=yes] https://repo.procurs.us/ ./"
    HAVOC_LINE="deb [trusted=yes] https://repo.havoc.app/ ./"
    if [ ! -f "$SOURCES" ]; then
        {
            printf '%s\n' "$LOCAL_LINE"
            printf '%s\n' "$PROCURUS_LINE"
            printf '%s\n' "$HAVOC_LINE"
        } > "$SOURCES"
        return
    fi
    TMP="$ROOT/tmp/sources.$$"
    awk -v desired="$LOCAL_LINE" '
        /^deb .*file:\/\/.*\/\.terminal\/repo/ { print desired; found=1; next }
        { print }
        END { if (!found) print desired }
    ' "$SOURCES" > "$TMP"
    mv "$TMP" "$SOURCES"
    if ! grep -qF "https://repo.procurs.us/" "$SOURCES"; then
        printf '%s\n' "$PROCURUS_LINE" >> "$SOURCES"
    fi
    if ! grep -qF "https://repo.havoc.app/" "$SOURCES"; then
        printf '%s\n' "$HAVOC_LINE" >> "$SOURCES"
    fi
}

make_sample() {
    if grep -q '^Package: hello$' "$ROOT/repo/Packages" 2>/dev/null; then
        return 0
    fi
    SAMPLE="$ROOT/share/termenv/samples/hello"
    mkdir -p "$SAMPLE/bin"
    cat > "$SAMPLE/bin/hello" << 'EOF'
#!/bin/sh
echo "Hello from the Terminal plugin environment."
echo "PREFIX=$PREFIX"
echo "TERM_ROOT=$TERM_ROOT"
if [ -d "$HOME/Documents/_sandbox" ]; then
    echo "Sandbox escape: available (see $HOME/Documents/_sandbox)"
fi
EOF
    chmod +x "$SAMPLE/bin/hello"
    if [ -f "$APPDIR/bin/mkdeb" ]; then
        sh "$APPDIR/bin/mkdeb" hello 1.0.0 "$SAMPLE" iphoneos-arm64
        echo "termenv: mkdeb exit=$?"
    fi
}

do_init() {
    echo "termenv: creating directories..."
    ensure_dirs
    echo "termenv: writing profile/sources..."
    write_profile
    write_sources
    [ -f "$ROOT/repo/Packages" ] || : > "$ROOT/repo/Packages"
    echo "termenv: creating sample package..."
    make_sample
    echo "termenv: sample ready"
    echo "Prefix: $ROOT"
    echo "Profile: $PROFILE"
    echo "Run: source \"$PROFILE\"    (or: termenv on)"
}

do_status() {
    ensure_dirs
    echo "Terminal native plugin environment"
    echo "  prefix:   $ROOT"
    echo "  profile:  $PROFILE"
    echo "  apt:      $APPDIR/bin/apt"
    echo "  dpkg:     $APPDIR/bin/dpkg"
    echo "  sources:  $SOURCES"
    if [ -f "$SOURCES" ]; then
        sed 's/^/            /' "$SOURCES"
    fi
    echo "  packages:"
    if [ -s "$ROOT/var/lib/dpkg/status" ]; then
        awk '/^Package: /{printf "            %s", substr($0,10)} /^Version: /{printf " %s", substr($0,10)} /^Status: /{status=substr($0,9)} /^$/{if(status ~ /installed/) print ""}' "$ROOT/var/lib/dpkg/status"
    else
        echo "            (none)"
    fi
    echo "  sandbox:  $HOME/Documents/_sandbox"
}

do_run() {
    if [ $# -eq 0 ]; then
        echo "usage: termenv run <command...>" >&2
        exit 2
    fi
    if [ -f "$PROFILE" ]; then
        . "$PROFILE"
    fi
    "$@"
}

do_on() {
    do_init
    PROFILE_FILE="$HOME/Documents/.profile"
    MARK_BEGIN="# >>> Terminal plugin environment >>>"
    MARK_END="# <<< Terminal plugin environment <<<"
    if grep -qF "$MARK_BEGIN" "$PROFILE_FILE" 2>/dev/null; then
        echo "Activation already present in $PROFILE_FILE"
        return 0
    fi
    {
        echo "$MARK_BEGIN"
        echo "source \"\$HOME/Documents/.terminal/etc/profile\""
        echo "$MARK_END"
    } >> "$PROFILE_FILE"
    echo "Activation added to $PROFILE_FILE"
}

do_off() {
    PROFILE_FILE="$HOME/Documents/.profile"
    if [ ! -f "$PROFILE_FILE" ]; then
        echo "No $PROFILE_FILE"
        return 0
    fi
    TMP="$ROOT/tmp/profile.$$"
    awk '
        /# >>> Terminal plugin environment >>>/ {skip=1; next}
        /# <<< Terminal plugin environment <<</ {skip=0; next}
        !skip {print}
    ' "$PROFILE_FILE" > "$TMP"
    mv "$TMP" "$PROFILE_FILE"
    echo "Activation removed from $PROFILE_FILE"
}

do_clean() {
    rm -rf "$ROOT/tmp"/*
    rm -f "$ROOT/var/cache/apt/archives/"*.deb
    echo "Cleaned caches"
}

do_selftest() {
    do_init
    . "$PROFILE"
    echo "=== apt update ==="
    APT_SKIP_REMOTE=1 sh "$APPDIR/bin/apt" update
    echo "=== apt install hello ==="
    sh "$APPDIR/bin/apt" install hello
    echo "=== hello ==="
    hello
    echo "=== installed packages ==="
    sh "$APPDIR/bin/apt" list --installed
    echo "=== dpkg -l ==="
    sh "$APPDIR/bin/dpkg" -l
}

case "${1:-}" in
    init) do_init ;;
    status) do_status ;;
    enter) echo "source \"$PROFILE\"" ;;
    run) shift; do_run "$@" ;;
    on) do_on ;;
    off) do_off ;;
    clean) do_clean ;;
    selftest) do_selftest ;;
    ""|-h|--help|help) usage ;;
    *) usage; exit 2 ;;
esac