#!/bin/bash
# fix-lomiri-spinner-install.sh
#
# Fixes Lomiri's 30-40% idle CPU usage when X11/XMir apps (e.g. Firefox) run.
# NO ROOT REQUIRED. Persists across reboots. Only touches files in $HOME.
#
# Usage:
#   ./fix-lomiri-spinner-install.sh              # install and restart lomiri
#   ./fix-lomiri-spinner-install.sh uninstall    # remove fix and restart lomiri
#   ./fix-lomiri-spinner-install.sh status       # check fix state
#
# ─── THE BUG ────────────────────────────────────────────────────────────────
#
# When an X11 app (e.g. Firefox) runs via XMir/Xwayland, Lomiri creates a
# placeholder ApplicationWindow for it. The Xwayland surface arrives under a
# different app identity ("xwayland.qtmir" instead of the real app ID), so
# the placeholder never gets filled with the actual surface. Its splash screen
# spins an ActivityIndicator forever — invisible behind Firefox, but its
# RotationAnimator still drives the entire Qt render loop at 60fps (~33% CPU).
#
# ─── THE FIX ────────────────────────────────────────────────────────────────
#
# We override ActivityIndicatorStyle.qml (the Lomiri theme file that defines
# the spinning animation) to add a 15-second safety timeout. Normal apps
# finish loading in <5 seconds, so the timeout only fires for stuck splash
# screens. After 15 seconds the spinner stops, the animation driver goes idle,
# and Lomiri drops to 0% CPU.
#
# ─── HOW IT WORKS ───────────────────────────────────────────────────────────
#
# Qt's QML engine resolves "import Lomiri.Components 1.3" by searching
# QML2_IMPORT_PATH directories (left to right) for a matching qmldir file.
# We prepend our override directory, so Qt finds OUR qmldir first:
#
#   QML2_IMPORT_PATH=/home/phablet/.local/share/lomiri-qml-fix
#                                         ↓
#   .../lomiri-qml-fix/Lomiri/Components/Themes/Ambiance/qmldir
#      (found first → this module "wins" over the system one)
#
# Our qmldir is a copy of the system's, so it declares the same module
# with the same type mappings. Since qmldir uses RELATIVE paths (e.g.
# "./1.3/ActivityIndicatorStyle.qml"), Qt resolves them relative to OUR
# directory — where we have our patched file. All other files are symlinks
# back to the system originals, so they stay up to date.
#
# ─── DIRECTORY LAYOUT ───────────────────────────────────────────────────────
#
#  ~/.local/share/lomiri-qml-fix/Lomiri/Components/Themes/Ambiance/
#  ├── qmldir                  ← copy of system's (module definition file)
#  ├── artwork/                ← symlink → system's artwork/
#  │   └── spinner@{8,16,32}.png   (DPI variants of the spinner image)
#  ├── 1.2/                    ← symlink → system's 1.2/ (entire directory)
#  └── 1.3/                    ← real directory (NOT a symlink, explained below)
#      ├── ActivityIndicatorStyle.qml  ← OUR PATCHED FILE (the only real file)
#      ├── ButtonStyle.qml     ← symlink → system's 1.3/ButtonStyle.qml
#      ├── SliderStyle.qml     ← symlink → system's 1.3/SliderStyle.qml
#      └── ... (47 more symlinks to system 1.3/ files)
#
# WHY each part is needed:
#
# qmldir (copy, not symlink):
#   Must be a real file in our directory for Qt to "claim" this module.
#   If it were a symlink, Qt would follow it and resolve relative paths
#   against the system directory, defeating the whole override.
#
# artwork/ (symlink to system):
#   ActivityIndicatorStyle.qml loads "Qt.resolvedUrl("../artwork/spinner.png")".
#   The "../" resolves relative to the QML file's location, which is now our
#   1.3/ dir. Without the artwork symlink at our level, the image 404s.
#   Other styles (ButtonStyle, ScrollbarStyle, etc.) also reference ../artwork/.
#
# 1.2/ (symlink to system):
#   The qmldir maps many types (API versions 0.1 through 1.2) to files in
#   the ./1.2/ subdirectory. These are older Lomiri Components API versions
#   that apps compiled against earlier SDKs still use. Without this symlink,
#   any app using "import Lomiri.Components 1.2" would get broken styles
#   (no buttons, no sliders, no text fields, etc.).
#
# 1.3/ (real dir with per-file symlinks):
#   We need to replace ONE file (ActivityIndicatorStyle.qml) while keeping
#   all ~48 other files from the system's 1.3/. We can't symlink the whole
#   directory (that would include the original file), so we create a real
#   directory and symlink each file individually — except our override.
#
# ─── UPDATE ROBUSTNESS ──────────────────────────────────────────────────────
#
# When the system lomiri-ui-toolkit package updates:
#
# ✓ Changes to any 1.2/ file:  Transparent — our 1.2/ is a symlink to system.
# ✓ Changes to any 1.3/ file OTHER than ActivityIndicatorStyle.qml:
#   Transparent — our per-file symlinks point to the system originals.
# ✓ New files added to 1.3/:  Harmless — they won't have symlinks in our dir,
#   but they'll only be missing from our override module, not from the system.
#   This only matters if the qmldir is also updated to reference them.
# ⚠ Changes to 1.3/ActivityIndicatorStyle.qml:  Our override masks the update.
#   This is extremely unlikely (the file hasn't changed in years), and even if
#   it did, our version is a strict superset (only adds a Timer). Use the
#   "status" command to detect this.
# ⚠ Changes to qmldir (new types, new versions like 1.4):  Our copy becomes
#   stale. The "status" command detects this. Re-running install refreshes it.
# ⚠ If a new 1.4/ directory is added:  Needs re-install to create symlinks.
#   The "status" command detects this too.
#
# TL;DR: Run "./fix-lomiri-spinner-install.sh status" after OTA updates. If
# it says "stale", re-run install. In practice updates to this theme are rare.
#
set -euo pipefail

# ─── Configuration ──────────────────────────────────────────────────────────
SYSDIR=/usr/lib/aarch64-linux-gnu/qt5/qml/Lomiri/Components/Themes/Ambiance
FIXBASE="$HOME/.local/share/lomiri-qml-fix"
FIXDIR="$FIXBASE/Lomiri/Components/Themes/Ambiance"
DROPIN_DIR="$HOME/.config/systemd/user/lomiri-full-shell.service.d"
DROPIN_FILE="$DROPIN_DIR/fix-spinner.conf"
HASH_FILE="$FIXBASE/.system-qmldir-sha256"
OVERRIDE_FILE="ActivityIndicatorStyle.qml"
TIMEOUT_SECS=15

# ─── Helpers ────────────────────────────────────────────────────────────────

die() { echo "ERROR: $*" >&2; exit 1; }

# Compute sha256 of a file (portable: works with sha256sum or shasum)
file_hash() {
    sha256sum "$1" 2>/dev/null | cut -d' ' -f1 || shasum -a 256 "$1" | cut -d' ' -f1
}

# ─── Status ─────────────────────────────────────────────────────────────────
status() {
    echo "=== Lomiri spinner fix status ==="
    local issues=0

    # Check override directory
    if [ -d "$FIXDIR/1.3" ] && [ -f "$FIXDIR/1.3/$OVERRIDE_FILE" ]; then
        echo "✓ Override directory exists"
    else
        echo "✗ Override directory missing — fix is NOT installed"
        issues=$((issues + 1))
    fi

    # Check systemd drop-in
    if [ -f "$DROPIN_FILE" ]; then
        echo "✓ Systemd drop-in exists"
    else
        echo "✗ Systemd drop-in missing — fix is NOT installed"
        issues=$((issues + 1))
    fi

    # Check if lomiri actually has the env var
    local lpid
    lpid=$(pgrep -f "lomiri --mode=full-shell" | head -1)
    if [ -n "$lpid" ] && cat /proc/"$lpid"/environ 2>/dev/null | tr '\0' '\n' | grep -q "QML2_IMPORT_PATH=.*lomiri-qml-fix"; then
        echo "✓ Running lomiri has QML2_IMPORT_PATH set"
    elif [ -n "$lpid" ]; then
        echo "⚠ Running lomiri does NOT have QML2_IMPORT_PATH (restart needed?)"
        issues=$((issues + 1))
    else
        echo "- Lomiri not running, can't check env"
    fi

    # Check if system qmldir has changed since install
    if [ -f "$HASH_FILE" ] && [ -f "$SYSDIR/qmldir" ]; then
        local saved_hash current_hash
        saved_hash=$(cat "$HASH_FILE")
        current_hash=$(file_hash "$SYSDIR/qmldir")
        if [ "$saved_hash" = "$current_hash" ]; then
            echo "✓ System qmldir unchanged since install"
        else
            echo "⚠ System qmldir has CHANGED — re-run install to update"
            issues=$((issues + 1))
        fi
    fi

    # Check if system 1.3/ has new files we don't have symlinks for
    if [ -d "$FIXDIR/1.3" ] && [ -d "$SYSDIR/1.3" ]; then
        local missing=0
        for f in "$SYSDIR/1.3/"*; do
            local name
            name=$(basename "$f")
            if [ ! -e "$FIXDIR/1.3/$name" ]; then
                echo "⚠ Missing from override: 1.3/$name (new file in system?)"
                missing=$((missing + 1))
            fi
        done
        if [ "$missing" -eq 0 ]; then
            echo "✓ All system 1.3/ files accounted for"
        fi
        issues=$((issues + missing))
    fi

    echo ""
    if [ "$issues" -eq 0 ]; then
        echo "Status: INSTALLED and UP TO DATE"
    else
        echo "Status: $issues issue(s) found — consider re-running install"
    fi
}

# ─── Uninstall ──────────────────────────────────────────────────────────────
uninstall() {
    echo "=== Uninstalling lomiri spinner fix ==="

    echo "Removing QML override directory..."
    rm -rf "$FIXBASE"

    echo "Removing systemd drop-in..."
    rm -f "$DROPIN_FILE"
    rmdir "$DROPIN_DIR" 2>/dev/null || true

    echo "Reloading systemd..."
    systemctl --user daemon-reload

    echo "Restarting lomiri (screen will flash)..."
    systemctl --user restart lomiri-full-shell.service

    echo ""
    echo "✓ Fix removed. Lomiri is back to stock behavior."
}

# ─── Install ────────────────────────────────────────────────────────────────
install() {
    echo "=== Installing lomiri spinner fix ==="

    # ── Preflight checks ────────────────────────────────────────────────
    [ -d "$SYSDIR/1.3" ] || die "System QML directory not found at $SYSDIR/1.3 — is this Ubuntu Touch with Lomiri Components 1.3?"
    [ -f "$SYSDIR/qmldir" ] || die "System qmldir not found at $SYSDIR/qmldir"
    [ -f "$SYSDIR/1.3/$OVERRIDE_FILE" ] || die "System $OVERRIDE_FILE not found — nothing to override"

    # ── Step 1: Create override directory structure ──────────────────────
    echo ""
    echo "Step 1: Creating QML override directory..."
    echo "  (This shadows the system Ambiance theme module so we can replace one file)"
    rm -rf "$FIXBASE"
    mkdir -p "$FIXDIR/1.3"

    # Copy qmldir — the module definition that tells Qt which QML types exist
    # and where their .qml files are. Must be a real copy (not symlink) so that
    # Qt resolves the relative paths (./1.2/*, ./1.3/*) against OUR directory.
    echo "  Copying qmldir (module definition)..."
    cp "$SYSDIR/qmldir" "$FIXDIR/qmldir"

    # Save a hash so we can detect if the system qmldir changes in an update
    file_hash "$SYSDIR/qmldir" > "$HASH_FILE"

    # Symlink artwork/ — contains spinner@{8,16,32}.png (DPI variants).
    # Our patched QML file loads Qt.resolvedUrl("../artwork/spinner.png"),
    # which resolves relative to 1.3/, so artwork/ must exist at our level.
    echo "  Symlinking artwork/ (spinner images, referenced as ../artwork/ from QML)..."
    ln -s "$SYSDIR/artwork" "$FIXDIR/artwork"

    # Symlink 1.2/ — the qmldir maps ~25 types (API versions 0.1–1.2) to files
    # in ./1.2/. These are older Lomiri Components APIs that existing apps still
    # use. Without this, any app using "import Lomiri.Components 1.2" would get
    # broken styles (no buttons, text fields, sliders, etc.).
    echo "  Symlinking 1.2/ (older API versions — used by existing apps)..."
    ln -s "$SYSDIR/1.2" "$FIXDIR/1.2"

    # Populate 1.3/ with per-file symlinks. We can't symlink the whole 1.3/
    # directory because we need to replace one file inside it. So we create a
    # real directory and symlink each file individually — except our override.
    echo "  Symlinking 1.3/ files (one-by-one, so we can replace $OVERRIDE_FILE)..."
    local count=0
    for f in "$SYSDIR/1.3/"*; do
        local name
        name=$(basename "$f")
        if [ "$name" != "$OVERRIDE_FILE" ]; then
            ln -s "$f" "$FIXDIR/1.3/$name"
            count=$((count + 1))
        fi
    done
    echo "    $count symlinks to system files"

    # ── Step 2: Write the patched ActivityIndicatorStyle.qml ─────────────
    echo ""
    echo "Step 2: Writing patched $OVERRIDE_FILE..."
    echo "  (Adds a ${TIMEOUT_SECS}-second timeout to the infinite RotationAnimator)"
    cat > "$FIXDIR/1.3/$OVERRIDE_FILE" << 'QML'
/*
 * Copyright 2012 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * PATCHED: Added safety timeout to stop the RotationAnimator after 15 seconds.
 * Without this, Lomiri burns 30-40% CPU when an X11/XMir app's splash screen
 * placeholder never gets its surface filled (Xwayland surface matching bug in
 * TopLevelWindowModel::prependSurface). The spinner is invisible behind the
 * real app window but its animator still drives the Qt render loop at 60fps.
 */

import QtQuick 2.4
import Lomiri.Components 1.3

Image {
    id: container

    smooth: true
    visible: styledItem.running && styledItem.visible
    fillMode: Image.PreserveAspectFit
    horizontalAlignment: Image.AlignHCenter
    verticalAlignment: Image.AlignVCenter
    source: visible ? Qt.resolvedUrl("../artwork/spinner.png") : ""
    asynchronous: true

    RotationAnimator on rotation {
        id: rotationAnim
        running: styledItem.running
        from: 0
        to: 360
        loops: Animation.Infinite
        duration: LomiriAnimation.SleepyDuration
    }

    // Safety timeout: stop spinning after 15 seconds.
    // Normal apps finish loading in <5s. This only fires for stuck splash
    // screens (e.g. X11 apps whose Xwayland surface never fills the placeholder).
    Timer {
        interval: 15000
        running: rotationAnim.running
        onTriggered: styledItem.running = false
    }
}
QML
    echo "    1 patched file"

    # ── Step 3: Create systemd user drop-in ──────────────────────────────
    echo ""
    echo "Step 3: Creating systemd user drop-in..."
    echo "  (Sets QML2_IMPORT_PATH so lomiri finds our override before the system's)"
    mkdir -p "$DROPIN_DIR"
    cat > "$DROPIN_FILE" << EOF
# Lomiri spinner fix: prepend our QML override directory so Qt finds our
# patched ActivityIndicatorStyle.qml before the system's.
# See: fix-lomiri-spinner-install.sh
[Service]
Environment=QML2_IMPORT_PATH=$FIXBASE
EOF
    echo "    Written to: $DROPIN_FILE"

    # ── Step 4: Apply ────────────────────────────────────────────────────
    echo ""
    echo "Step 4: Reloading systemd and restarting lomiri..."
    echo "  (Screen will flash briefly as the shell restarts)"
    systemctl --user daemon-reload
    systemctl --user restart lomiri-full-shell.service

    echo ""
    echo "════════════════════════════════════════════════════════════════════"
    echo "  ✓ Fix installed!"
    echo ""
    echo "  • Applies automatically on every boot (no manual steps needed)"
    echo "  • To verify: launch Firefox, wait 30s, check CPU with:"
    echo "      top -p \$(pgrep -f 'lomiri --mode=full-shell' | head -1)"
    echo "      (should be ~0% instead of 30-40%)"
    echo "  • After OTA updates: $0 status"
    echo "  • To remove:         $0 uninstall"
    echo "════════════════════════════════════════════════════════════════════"
}

# ─── Main ───────────────────────────────────────────────────────────────────
case "${1:-install}" in
    install)        install ;;
    uninstall|remove) uninstall ;;
    status|check)   status ;;
    -h|--help|help)
        echo "Usage: $0 [install|uninstall|status]"
        echo ""
        echo "Fixes Lomiri burning 30-40% CPU when X11 apps (Firefox) run via Xwayland."
        echo "Overrides ActivityIndicatorStyle.qml to add a 15s safety timeout to the"
        echo "splash screen spinner. No root required; persists across reboots."
        echo ""
        echo "Commands:"
        echo "  install    Install the fix and restart lomiri (default)"
        echo "  uninstall  Remove the fix and restart lomiri"
        echo "  status     Check if fix is installed and up to date"
        ;;
    *)
        echo "Unknown command: $1" >&2
        echo "Usage: $0 [install|uninstall|status]" >&2
        exit 1
        ;;
esac