#!/usr/bin/env bash
# SPDX-License-Identifier: LicenseRef-Proprietary
set -euo pipefail

version='0.1.0-preview.20261027.7'
base="https://muzz.in/gravitas/downloads/$version"
selection=desktop
action=install
appearance=yes
duo_top_head=

die() { printf 'Gravitas: %s\n' "$*" >&2; exit 1; }
usage() {
    cat <<'HELP'
Gravitas development preview — Ubuntu 24.04 and 26.04, Intel/AMD 64-bit

  bash install.sh                  Install desktop, all 14 apps, login and boot themes
  bash install.sh --desktop-only   Keep your current login manager and boot theme
  bash install.sh --duo-top-head 0 Enable Duo boot with a calibrated top-panel index (0 or 1)
  bash install.sh --app command    Install only Command (Wayland terminal)
  bash install.sh --app reap       Install only Reap (task manager)
  bash install.sh --app type       Install only Type (text and Markdown editor)
  bash install.sh --app capture    Install only Capture (screen recorder)
  bash install.sh --app drill      Install only Drill (file browser)
  bash install.sh --app image      Install only Image (image viewer and editor)
  bash install.sh --app documents  Install only Documents (PDF reader)
  bash install.sh --app calculator Install only Calculator (scientific calculator)
  bash install.sh --app clocks     Install only Clocks (clocks and timers)
  bash install.sh --app listen     Install only Listen (music player)
  bash install.sh --app video      Install only Video (local video player)
  bash install.sh --app storage    Install only Storage (disk usage)
  bash install.sh --app backups    Install only Backups (local snapshots and restore)
  bash install.sh --app software   Install only Software (PackageKit browser)
  bash install.sh --check          Check compatibility without making changes
  bash install.sh --uninstall      Remove the Gravitas desktop packages
  bash install.sh --app command --uninstall

The full install selects the Gravitas SDDM login screen and Plymouth/GRUB boot
themes for the next reboot. It saves your previous settings for removal.
Ubuntu remains installed and available in the login-screen session menu.
Installation never switches sessions or restarts the display manager.
Re-run the latest installer to update. Removal preserves your personal settings
and leaves Ubuntu dependencies and separately installed Gravitas apps installed.
Remove each app with --app NAME --uninstall. Standalone apps use your Wayland
session; the Gravitas compositor is not required.
The small shared theme package is included with every standalone app.
Duo is off by default. It requires exactly two displays and explicit calibration;
indices are not connector names and can change between boots or driver updates.
Disable it later with: sudo gravitas-appearance duo --disable
HELP
}

while (($#)); do
    case "$1" in
        --app)
            (($# >= 2)) || die '--app needs an app name'
            case "$2" in
                command|reap|type|capture|drill|image|documents|calculator|clocks|listen|video|storage|backups|software) ;;
                *) die "Unknown app: $2. Use --help to list available apps." ;;
            esac
            selection=$2
            shift 2 ;;
        --duo-top-head)
            (($# >= 2)) || die '--duo-top-head needs a calibrated index (0 or 1)'
            [[ $2 == 0 || $2 == 1 ]] || die '--duo-top-head must be 0 or 1'
            duo_top_head=$2
            shift 2 ;;
        --check) action=check; shift ;;
        --desktop-only) appearance=no; shift ;;
        --uninstall) action=uninstall; shift ;;
        -h|--help) usage; exit 0 ;;
        *) die "Unknown option: $1 (use --help)" ;;
    esac
done

if [[ -n $duo_top_head && ($selection != desktop || $appearance != yes || $action == uninstall) ]]; then
    die '--duo-top-head requires a full desktop install with boot themes.'
fi

[[ -r /etc/os-release ]] || die 'Cannot identify this operating system.'
# shellcheck disable=SC1091
source /etc/os-release
[[ ${ID:-} == ubuntu && (${VERSION_ID:-} == 24.04 || ${VERSION_ID:-} == 26.04) ]] || die 'This preview supports Ubuntu 24.04 and 26.04 only.'
[[ $(dpkg --print-architecture) == amd64 && $(uname -m) == x86_64 ]] || die 'This preview needs an Intel/AMD 64-bit (amd64) system.'
command -v apt-get >/dev/null || die 'apt-get is required.'
if [[ $selection == desktop && $action != uninstall ]]; then
    [[ -e /etc/X11/default-display-manager ]] || die 'Install an Ubuntu desktop and display manager first, or use --app command.'
    if [[ $appearance == yes ]]; then
        if [[ ! -f /boot/grub/grub.cfg ]] || ! compgen -G '/boot/initrd.img-*' >/dev/null; then
            die 'Boot themes require GRUB and an existing initramfs. Use --desktop-only to keep your boot/login setup.'
        fi
    fi
fi
if [[ $action == check ]]; then
    printf 'Compatible: Ubuntu %s amd64, %s preview %s. No changes made.\n' "$VERSION_ID" "$selection" "$version"
    exit 0
fi

as_root() {
    if ((EUID == 0)); then "$@"; else sudo -- "$@"; fi
}
if ((EUID != 0)); then command -v sudo >/dev/null || die 'sudo is required; alternatively run the downloaded script as root.'; fi

if [[ $action == uninstall ]]; then
    if [[ $selection != desktop ]]; then
        # apt would otherwise remove the desktop too, since it depends on these apps.
        if dpkg-query -W -f='${Status}' gravitas-desktop 2>/dev/null | grep -qx 'install ok installed'; then
            die "The Gravitas desktop requires this app. Run --uninstall first to remove the desktop, then --app $selection --uninstall."
        fi
        candidates=("gravitas-$selection")
    else
        if command -v gravitas-appearance >/dev/null; then as_root gravitas-appearance restore; fi
        candidates=(gravitas-desktop gravitas-wallpapers gravitas-xwayland gravitas-appearance-qt5 gravitas-appearance-qt6)
    fi
    installed=()
    for package in "${candidates[@]}"; do
        if dpkg-query -W -f='${Status}' "$package" 2>/dev/null | grep -qx 'install ok installed'; then
            installed+=("$package")
        fi
    done
    if ((${#installed[@]})); then as_root apt-get remove -y "${installed[@]}"; fi
    printf 'Removed. Your settings and Ubuntu desktop were preserved.\n'
    exit 0
fi

if [[ $selection != desktop ]] && dpkg-query -W -f='${Status}' gravitas-desktop 2>/dev/null | grep -qx 'install ok installed'; then
    desktop_version=$(dpkg-query -W -f='${Version}' gravitas-desktop)
    [[ $desktop_version == "$version" ]] || die 'Update the full Gravitas desktop together before updating an individual app: run this installer without --app (or with --desktop-only).'
fi

printf 'Installing Gravitas %s preview %s. apt will request administrator permission.\n' "$selection" "$version"
if ! command -v curl >/dev/null || [[ ! -s /etc/ssl/certs/ca-certificates.crt ]]; then
    as_root apt-get update
    as_root apt-get install -y --no-install-recommends curl ca-certificates
fi

umask 077
download_dir=$(mktemp -d /tmp/gravitas-install.XXXXXXXX)
trap 'rm -rf -- "$download_dir"' EXIT
packages=()
download() {
    local name=$1 expected=$2 architecture=${3:-amd64} file
    file="$download_dir/${name}_${version}_${architecture}.deb"
    curl --fail --show-error --silent --location --proto '=https' --proto-redir '=https' \
        --connect-timeout 20 --max-time 600 --retry 2 "$base/${name}_${version}_${architecture}.deb" -o "$file"
    printf '%s  %s\n' "$expected" "$file" | sha256sum --check --status || die "Checksum mismatch for $name; no Gravitas packages were installed."
    packages+=("$file")
}
download gravitas-themes '8a32564acf1ced5a0c9cee2fcb80a3c80ffb5a3756e4cbe5fc7add9a13869b4e' all
if [[ $selection == command || $selection == desktop ]]; then
    download gravitas-command '0d6dceeb5331c9013c13e14ead6b9b346a5970e6e0aa5cd2394efd8aad6098b5'
fi
if [[ $selection == reap || $selection == desktop ]]; then
    download gravitas-reap 'b5768c133bb2ae4858431cee75fc058b75ef903d254563b6757dcc59a9e5bd0e'
fi
if [[ $selection == type || $selection == desktop ]]; then
    download gravitas-type '04758c0d96d54cfd24268649b8f575e18e5931efd770a9c72bd3d18dfdf9ee3e'
fi
if [[ $selection == capture || $selection == desktop ]]; then
    download gravitas-capture '1c4a537db2b0732e611ff3724cd1349e34d807a0c6d72536fd30d0de70466c4b'
fi
if [[ $selection == drill || $selection == desktop ]]; then
    download gravitas-drill '220a741c3b7d4ee15b3751e5dc406b0663149a080ff53a86dcaf6e7358b9375a'
fi
if [[ $selection == image || $selection == desktop ]]; then
    download gravitas-image '905a9b5ddb7f1c26d2ac6f816bb102b26e4b81d55fd1b7d3eb90fccd67d3785b'
fi
if [[ $selection == documents || $selection == desktop ]]; then
    download gravitas-documents '3ed01b7cb65c684b6b0f09ba1bed5e52e8ba940d58d366ed3eb93e95ac3dbd01'
fi
if [[ $selection == calculator || $selection == desktop ]]; then
    download gravitas-calculator 'c6f0af4595ce11e9025e75a5641a0d8cc59064b990e4955ba479e6597e7f9d86'
fi
if [[ $selection == clocks || $selection == desktop ]]; then
    download gravitas-clocks 'e3f72d914f06464c14270583cdde2a17e4d512f377bd3395c197befa353c1a78'
fi
if [[ $selection == listen || $selection == desktop ]]; then
    download gravitas-listen '8e26383ee7d867fc31eb915ec21b2db870d79a93157ecbbf780c8033057e4ee1'
fi
if [[ $selection == video || $selection == desktop ]]; then
    download gravitas-video '25e7dc29325dbc00062ac00515b720836a60112095b7120bd7b0accab43d648f'
fi
if [[ $selection == storage || $selection == desktop ]]; then
    download gravitas-storage '941f1dae17ae3a020c17b86dc01c55e7472285e14aa1b0bff4ed7103412478c0'
fi
if [[ $selection == backups || $selection == desktop ]]; then
    download gravitas-backups '688d9ce93ca2e7abc75db8a6a83604b728104ac56deb4dac4f7283453072307c'
fi
if [[ $selection == software || $selection == desktop ]]; then
    download gravitas-software '3c7ae135daee1207d78f025c0cfc8e33f1f9fbc92824be022a5d74441a2e904d'
fi
if [[ $selection == desktop ]]; then
    download gravitas-wallpapers '37b79ebd743e762965add26dc22343033cff4d4beeaca924d04292faad9cfad2' all
    download gravitas-xwayland '6e92cc2b9fe70515be51c95b8fdcd721b8846f79ad89b4d1012794161a9e98ed'
    download gravitas-desktop '9a18c4ed58ae7c714d914ff12f37898a0580ddb2086d31ec4d0f06c244956f70'
    if [[ $appearance == yes ]]; then
        if [[ $VERSION_ID == 24.04 ]]; then
            download gravitas-appearance-qt5 '0291ab9f9869270ad7350eff1b98918fca8d07b924d9a90b70d32a074108ce63'
        else
            download gravitas-appearance-qt6 '3aaa922575ebeb45ab8c739b2660250ba69322c0041b91ee98ae1ca71f2b6db4'
        fi
        curl --fail --show-error --silent --location --proto '=https' --proto-redir '=https' \
            --connect-timeout 20 --max-time 600 --retry 2 "$base/system-appearance.py" -o "$download_dir/system-appearance.py"
        printf '%s  %s\n' 'd9f941ae1a80b1be4f98f18ad0747940a23765bd6282fdacf0670899f4ee1612' "$download_dir/system-appearance.py" | sha256sum --check --status || die 'Checksum mismatch for the appearance helper; no Gravitas packages were installed.'
    fi
fi

# All payloads must verify before apt is allowed to install any of them.
as_root apt-get update
if [[ $selection == desktop && $appearance == yes ]]; then
    if ! command -v python3 >/dev/null; then as_root env DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends python3; fi
    as_root python3 "$download_dir/system-appearance.py" prepare
fi
apt_options=(--no-install-recommends)
if [[ $selection != desktop ]]; then apt_options+=(--no-remove); fi
if ! as_root env DEBIAN_FRONTEND=noninteractive apt-get install -y "${apt_options[@]}" "${packages[@]}"; then
    if [[ $selection == desktop && $appearance == yes ]]; then as_root python3 "$download_dir/system-appearance.py" restore; fi
    die 'Package installation failed. Resolve the apt error above before retrying.'
fi
if [[ $selection == desktop ]]; then
    if [[ $appearance == yes ]]; then
        as_root gravitas-appearance apply
        if [[ -n $duo_top_head ]]; then as_root gravitas-appearance duo --top-head "$duo_top_head"; fi
        printf 'Save your work and reboot to use the new login and boot themes.\n'
    fi
    cat <<'DONE'
Gravitas is installed. Save your work, log out, and select Gravitas at the login
screen. Super opens apps; Super+Enter opens Command; Super+L locks;
Super+Shift+E logs out. Your previous desktop remains in the login menu.
DONE
elif [[ $selection == command ]]; then
    printf 'Command is installed. Open Command from your app menu in a Wayland session, or run litty.\n'
elif [[ $selection == reap ]]; then
    printf 'Reap is installed. Open Reap from your app menu in a Wayland session, or run gravitas-reap.\n'
elif [[ $selection == capture ]]; then
    printf 'Capture is installed. Open Capture from your app menu, or run gravitas-capture.\n'
else
    printf '%s is installed. Open it from your app menu in a Wayland session, or run gravitas-%s.\n' "${selection^}" "$selection"
fi