#!/usr/bin/env bash
# Build (and optionally install) the Pad Android APK for the local emulator.
#
# Usage:
#   ./scripts/build_emu.sh              # build + install to the connected device
#   ./scripts/build_emu.sh --no-install # build only
#
# Output: cmd/pad/pad-emu.apk
#
# Prereqs on this workstation (the script checks each and explains what is
# missing):
#   - JDK 17 (java on PATH)
#   - Go + gogio v0.10.0 (~/go/bin)
#   - Android SDK at ~/android-sdk (platform-tools, build-tools 35.0.0)
#   - debug keystore at ~/.android/debug.keystore
# apktool is not a prerequisite: if it is missing, the script downloads
# v3.0.3 to the stable location ~/android-sdk/tools/apktool.jar.
#
# Why the apktool detour: gogio does not offer a way to add
# MANAGE_EXTERNAL_STORAGE to the manifest, and Android 11+ blocks the app's
# directory listing without it. So we decode the gogio APK, inject the
# permission, rebuild, and re-sign with the debug key.
set -euo pipefail

REPO=$(cd "$(dirname "$0")/.." && pwd)
export ANDROID_HOME=${ANDROID_HOME:-$HOME/android-sdk}
export PATH=$PATH:$ANDROID_HOME/platform-tools:$ANDROID_HOME/build-tools/35.0.0:$HOME/go/bin

INSTALL=1
[ "${1:-}" = "--no-install" ] && INSTALL=0

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

command -v java      >/dev/null 2>&1 || die "java not found (need JDK 17)"
command -v gogio     >/dev/null 2>&1 || die "gogio not found (need v0.10.0 in ~/go/bin)"
command -v apksigner >/dev/null 2>&1 || die "apksigner not found (need $ANDROID_HOME/build-tools/35.0.0)"
command -v adb       >/dev/null 2>&1 || die "adb not found (need $ANDROID_HOME/platform-tools)"
[ -f "$HOME/.android/debug.keystore" ] || die "debug keystore missing: $HOME/.android/debug.keystore"

# apktool: auto-download to a stable location if missing (never /tmp, which
# gets wiped between sessions).
APKTOOL="$ANDROID_HOME/tools/apktool.jar"
if [ ! -f "$APKTOOL" ]; then
	echo "=== apktool missing; downloading v3.0.3 to $APKTOOL ==="
	mkdir -p "$ANDROID_HOME/tools"
	curl -fsSL -o "$APKTOOL" \
		https://github.com/iBotPeaches/Apktool/releases/download/v3.0.3/apktool_3.0.3.jar \
		|| die "apktool download failed"
fi

WORK=$(mktemp -d)
trap 'rm -rf "$WORK"' EXIT

echo "=== gogio (Go -> APK) ==="
# targetSdk 34: targeting 35 makes Android 15 force edge-to-edge. We keep 34
# and instead consume the IME insets ourselves (PadInsetsListener patch below);
# on API 30+ devices setDecorFitsSystemWindows(false) gets us the same
# inset delivery without the blanket edge-to-edge enforcement.
(cd "$REPO/cmd/pad" && gogio -target android -targetsdk 34 -arch amd64 -o "$WORK/pad-raw.apk" .)

echo "=== apktool decode ==="
java -jar "$APKTOOL" d "$WORK/pad-raw.apk" -o "$WORK/decoded" -f >/dev/null

echo "=== inject MANAGE_EXTERNAL_STORAGE ==="
grep -q "MANAGE_EXTERNAL_STORAGE" "$WORK/decoded/AndroidManifest.xml" || \
	sed -i '0,/<application/s#<application#<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>\n  <application#' \
		"$WORK/decoded/AndroidManifest.xml"
grep -q "MANAGE_EXTERNAL_STORAGE" "$WORK/decoded/AndroidManifest.xml" || die "permission injection failed"

# Consume the IME insets in the app. The Gio window contains a SurfaceView
# (GioView), which unconditionally marks the window FORMAT_TRANSLUCENT
# (SurfaceView.requestTransparentRegion -> ViewRootImpl). Translucent windows
# are never resized by the IME, so windowSoftInputMode=adjustResize is dead
# and the keyboard covers the bottom bar. The supported fix: on API 30+ opt
# out of decor auto-fitting (setDecorFitsSystemWindows(false)) and shrink the
# GioView by the IME inset height; the Go side sees the surface resize and
# lays the bottom bar above the keyboard. On API < 30 there are no IME insets
# and the keyboard overlaps (accepted limitation).
echo "=== patch IME insets handling ==="
python3 - "$WORK/decoded" << 'PYEOF'
import sys, pathlib
base = pathlib.Path(sys.argv[1])

# 1. New class: shrinks the GioView by the current IME inset.
listener = '''
.class public Lorg/gioui/PadInsetsListener;
.super Ljava/lang/Object;
.source "PadInsetsListener.java"

# interfaces
.implements Landroid/view/View$OnApplyWindowInsetsListener;


# instance fields
.field private final mView:Landroid/view/View;


# direct methods
.method public constructor <init>(Landroid/view/View;)V
    .locals 0

    invoke-direct {p0}, Ljava/lang/Object;-><init>()V

    iput-object p1, p0, Lorg/gioui/PadInsetsListener;->mView:Landroid/view/View;

    return-void
.end method


# virtual methods
.method public onApplyWindowInsets(Landroid/view/View;Landroid/view/WindowInsets;)Landroid/view/WindowInsets;
    .locals 4

    # int imeBottom = 0;
    const/4 v0, 0x0

    # if (Build.VERSION.SDK_INT >= 30)
    #     imeBottom = insets.getInsets(WindowInsets.Type.ime()).bottom;
    sget v1, Landroid/os/Build$VERSION;->SDK_INT:I

    const/16 v2, 0x1e

    if-lt v1, v2, :cond_pad_noime

    const/16 v1, 0x8

    invoke-virtual {p2, v1}, Landroid/view/WindowInsets;->getInsets(I)Landroid/graphics/Insets;

    move-result-object v1

    iget v0, v1, Landroid/graphics/Insets;->bottom:I

    :cond_pad_noime
    # int h = displayHeight - imeBottom;
    iget-object v1, p0, Lorg/gioui/PadInsetsListener;->mView:Landroid/view/View;

    invoke-virtual {v1}, Landroid/view/View;->getResources()Landroid/content/res/Resources;

    move-result-object v1

    invoke-virtual {v1}, Landroid/content/res/Resources;->getDisplayMetrics()Landroid/util/DisplayMetrics;

    move-result-object v1

    iget v1, v1, Landroid/util/DisplayMetrics;->heightPixels:I

    sub-int v1, v1, v0

    # if (mView.getLayoutParams().height != h) { ... = h; requestLayout(); }
    iget-object v2, p0, Lorg/gioui/PadInsetsListener;->mView:Landroid/view/View;

    invoke-virtual {v2}, Landroid/view/View;->getLayoutParams()Landroid/view/ViewGroup$LayoutParams;

    move-result-object v2

    iget v3, v2, Landroid/view/ViewGroup$LayoutParams;->height:I

    if-eq v3, v1, :cond_pad_done

    iput v1, v2, Landroid/view/ViewGroup$LayoutParams;->height:I

    iget-object v3, p0, Lorg/gioui/PadInsetsListener;->mView:Landroid/view/View;

    invoke-virtual {v3}, Landroid/view/View;->requestLayout()V

    :cond_pad_done
    return-object p2
.end method
'''
(base / "smali" / "org" / "gioui" / "PadInsetsListener.smali").write_text(listener)

# 2. Wire it up in GioActivity.onCreate (and opt out of decor auto-fit).
p = base / "smali" / "org" / "gioui" / "GioActivity.smali"
t = p.read_text()
old = """    invoke-virtual {p1, v0}, Landroid/widget/FrameLayout;->addView(Landroid/view/View;)V

    .line 32"""
new = """    invoke-virtual {p1, v0}, Landroid/widget/FrameLayout;->addView(Landroid/view/View;)V

    # Pad: consume IME insets by shrinking the GioView (API 21+).
    sget v1, Landroid/os/Build$VERSION;->SDK_INT:I

    const/16 v2, 0x15

    if-lt v1, v2, :cond_pad_insets

    new-instance v1, Lorg/gioui/PadInsetsListener;

    invoke-direct {v1, v0}, Lorg/gioui/PadInsetsListener;-><init>(Landroid/view/View;)V

    invoke-virtual {v0, v1}, Landroid/view/View;->setOnApplyWindowInsetsListener(Landroid/view/View$OnApplyWindowInsetsListener;)V

    :cond_pad_insets

    # Pad: API 30+ opt out of decor auto-fit so IME insets are dispatched.
    sget v1, Landroid/os/Build$VERSION;->SDK_INT:I

    const/16 v2, 0x1e

    if-lt v1, v2, :cond_pad_nofit

    invoke-virtual {p0}, Lorg/gioui/GioActivity;->getWindow()Landroid/view/Window;

    move-result-object v1

    const/4 v2, 0x0

    invoke-virtual {v1, v2}, Landroid/view/Window;->setDecorFitsSystemWindows(Z)V

    :cond_pad_nofit

    .line 32"""
if old not in t:
    sys.exit("ERROR: GioActivity addView anchor not found")
t = t.replace(old, new)
old2 = ".method public onCreate(Landroid/os/Bundle;)V\n    .locals 2"
new2 = ".method public onCreate(Landroid/os/Bundle;)V\n    .locals 3"
if old2 not in t:
    sys.exit("ERROR: GioActivity onCreate .locals anchor not found")
t = t.replace(old2, new2)
p.write_text(t)
print("patched: GioActivity IME insets wiring")
PYEOF

echo "=== apktool rebuild ==="
java -jar "$APKTOOL" b "$WORK/decoded" -o "$WORK/pad-unsigned.apk" >/dev/null

echo "=== sign ==="
apksigner sign \
	--ks "$HOME/.android/debug.keystore" --ks-pass pass:android \
	--key-pass pass:android --ks-key-alias androiddebugkey \
	--out "$REPO/cmd/pad/pad-emu.apk" "$WORK/pad-unsigned.apk"

if [ "$INSTALL" = "1" ]; then
	echo "=== install ==="
	adb get-state >/dev/null 2>&1 || die "no adb device (start the emulator or plug in a phone)"
	adb install -r "$REPO/cmd/pad/pad-emu.apk"
fi

echo "=== DONE: $REPO/cmd/pad/pad-emu.apk ==="