#!/bin/bash

error() {
    echo "$@" >&2
    exit 1
}

usage() {
    echo -e "Usage: $(basename "$0") <unsigned apk file>" >&2
    echo -e "\t\t[-e|--extract path]" >&2
    echo -e "\t\t[-p|--package-id packageID]" >&2
    echo -e "\t\t[-g|--google-services path]" >&2
    echo -e "\t\t[-d|--display-name displayName]" >&2
    echo -e "\t\toutputApk" >&2
    echo "Usage: $(basename "$0") -h|--help" >&2
    echo "Options:" >&2
    echo -e "\t-e, --extract path\t\t\t(Optional) Path to extract the unsigned APK file. By default the path of the unsigned APK is used." >&2
    echo "" >&2
    echo -e "\t-p, --package-id packageID\t\t(Optional) Specify the unique Android application ID." >&2
    echo "" >&2
    echo -e "\t-g, --google-services path\t\t(Optional) Path to the google-services.json file." >&2
    echo -e "\t\t\t\t\t\t\tWill setup the Firebase to receive Push Notifications." >&2
    echo -e "\t\t\t\t\t\t\tWarning: will apply only if packageID is set." >&2
    echo "" >&2
    echo -e "\t-d, --display-name displayName\t\t(Optional) Specify new application display name. By default \"Mattermost\" is used." >&2
    echo "" >&2
    echo -e "\t-h, --help\t\t\t\tDisplay help message." >&2
    exit 2
}

if [ $# -lt 3 ]; then
    usage
fi

if ! command -v apktool &> /dev/null; then
    echo ""
    echo "Apktool not available."
    echo "See installation instructions at https://ibotpeaches.github.io/Apktool/install/"
    echo ""
    exit 1
fi

if ! command -v xmlstarlet &> /dev/null; then
    echo ""
    echo "XMLStarlet not available."
    echo "See installation instructions at https://xmlstar.sourceforge.net/doc/UG/xmlstarlet-ug.html"
    echo ""
    exit 1
fi

if ! command -v jq &> /dev/null; then
    echo ""
    echo "jq not available."
    echo "More info at https://stedolan.github.io/jq/"
    echo ""
    exit 1
fi

ANDROID="${ANDROID_HOME:-$ANDROID_SDK_ROOT}"

if [ -z $ANDROID ]; then
    echo ""
    echo "\$ANDROID_HOME or \$ANDROID_SDK_ROOT environment variable not set."
    echo "More info at https://developer.android.com/studio/command-line/variables#android_sdk_root"
    echo ""
    exit 1
fi

if [ ! -f ~/.gradle/gradle.properties ]; then
    echo ""
    echo "gradle.properties file not found."
    echo "More info at https://mattermost.dev/contribute/mobile/build-your-own/android/#gradle"
    echo ""
    exit 1
else
    source ~/.gradle/gradle.properties
fi

if [ -z $MATTERMOST_RELEASE_STORE_FILE ] || [ -z $MATTERMOST_RELEASE_KEY_ALIAS  ] || [ -z $MATTERMOST_RELEASE_PASSWORD ]; then
    echo ""
    echo "\$MATTERMOST_RELEASE_STORE_FILE, \$MATTERMOST_RELEASE_KEY_ALIAS or \$MATTERMOST_RELEASE_PASSWORD not defined."
    echo "More info at https://mattermost.dev/contribute/mobile/build-your-own/android/#gradle"
    echo ""
    exit 1
fi

APK_FILE_PATH=$1
GOOGLE_SERVICES_PATH=
APK_FILE=$(basename "${APK_FILE_PATH}")
PATH_NAME=`echo "$APK_FILE" | cut -d'.' -f1`
EXTRACT_PATH=`echo $(dirname "${APK_FILE_PATH}")/$PATH_NAME`
STRINGS_VALUES_PATH="$EXTRACT_PATH/res/values/strings.xml"
OUTPUT=`echo $(dirname "${APK_FILE_PATH}")`
PACKAGE_ID=""
APP_NAME=""

shift 1
# Parse args
while [ "$1" != "" ]; do
    case $1 in
    -e | --extract-path )
        shift
        EXTRACT_PATH="$1"
    ;;
    -g | --google-services )
        shift
        GOOGLE_SERVICES_PATH="$1"
    ;;
    -d | --display-name )
        shift
        APP_NAME="$1"
    ;;
    -p | --package-id )
        shift
        PACKAGE_ID="$1"
    ;;
    -h | --help )
        usage
    ;;
    * )
        [[ -n "$NEW_FILE" ]] && error "Multiple output file names specified!"
        [[ -z "$NEW_FILE" ]] && NEW_FILE="$1"
        ;;
    esac
    shift
done

# Check output file name
if [ -z "$NEW_FILE" ]; then
    error "Output file name required"
fi

echo "Extracting APK"
apktool d $APK_FILE_PATH -o $EXTRACT_PATH


if [ "$APP_NAME" != "" ]; then
    echo "Renaming Application"
    xmlstarlet ed -L -u "/resources/string[@name='app_name']" -v "$APP_NAME" "$STRINGS_VALUES_PATH"
fi

if [ "$PACKAGE_ID" != "" ]; then
    echo "Replacing package ID"
    IFS='.' read -r -a DIRS <<< "$PACKAGE_ID"
    PACKAGE_DIR=$( IFS=$'/'; echo "${DIRS[*]}" )
    mkdir -p "$EXTRACT_PATH/smali_classes2/$PACKAGE_DIR"
    SRC="$EXTRACT_PATH/smali_classes2/com/mattermost/rnbeta/*.*"
    DEST="$EXTRACT_PATH/smali_classes2/$PACKAGE_DIR"
    find "$EXTRACT_PATH/smali_classes2/com/mattermost" -type f -exec sed -i '' -e "s~Lcom/mattermost/rnbeta~L$PACKAGE_DIR~g" {} \;
    sed -i '' -e "s/com.mattermost.rnbeta/$PACKAGE_ID/g" "$EXTRACT_PATH/AndroidManifest.xml"
    mv $SRC $DEST

    if [ "$GOOGLE_SERVICES_PATH" != "" ]; then
        echo "Replacing Google Services values"
        GOOGLE_SERVICES=$(jq . "$GOOGLE_SERVICES_PATH")
        PROJECT_NUMBER=$(echo "$GOOGLE_SERVICES" | jq -r .project_info.project_number)
        FIREBASE_URL=$(echo "$GOOGLE_SERVICES" | jq -r .project_info.firebase_url)
        FIREBASE_STORAGE_BUCKET=$(echo "$GOOGLE_SERVICES" | jq -r .project_info.storage_bucket)
        FIREBASE_CLIENT=$(echo "$GOOGLE_SERVICES" | jq ".client[] | select(. | .client_info.android_client_info.package_name == \"$PACKAGE_ID\")")
        FIREBASE_API_KEY=$(echo "$FIREBASE_CLIENT" | jq -r .api_key[].current_key)
        FIREBASE_SDK_APP_ID=$(echo "$FIREBASE_CLIENT" | jq -r .client_info.mobilesdk_app_id)

        xmlstarlet ed -L -u "/resources/string[@name='firebase_database_url']" -v "$FIREBASE_URL" "$STRINGS_VALUES_PATH"
        xmlstarlet ed -L -u "/resources/string[@name='gcm_defaultSenderId']" -v "$PROJECT_NUMBER" "$STRINGS_VALUES_PATH"
        xmlstarlet ed -L -u "/resources/string[@name='google_api_key']" -v "$FIREBASE_API_KEY" "$STRINGS_VALUES_PATH"
        xmlstarlet ed -L -u "/resources/string[@name='google_app_id']" -v "$FIREBASE_SDK_APP_ID" "$STRINGS_VALUES_PATH"
        xmlstarlet ed -L -u "/resources/string[@name='google_crash_reporting_api_key']" -v "$FIREBASE_API_KEY" "$STRINGS_VALUES_PATH"
        xmlstarlet ed -L -u "/resources/string[@name='google_storage_bucket']" -v "$FIREBASE_STORAGE_BUCKET" "$STRINGS_VALUES_PATH"
    fi
fi

echo "Re-Packaging APK"
APP_NAME="${APP_NAME:-Mattermost}"
REPACK_APK="$OUTPUT/$APP_NAME-repack.apk"
apktool b "$EXTRACT_PATH" -o "$REPACK_APK"

if [ "$MATTERMOST_RELEASE_STORE_FILE" != "" ] && [ "$MATTERMOST_RELEASE_KEY_ALIAS" != ""  ] && [ "$MATTERMOST_RELEASE_PASSWORD" != "" ]; then
    echo "Signing APK"
    ALIGNED_APK="$OUTPUT/$APP_NAME-aligned.apk"
    SIGNED_APK="$OUTPUT/$NEW_FILE.apk"
    ZIPALIGN=$(find "$ANDROID" -name zipalign)
    APKSIGNER=$(find "$ANDROID" -name apksigner)
    $ZIPALIGN -v -p 4 "$REPACK_APK" "$ALIGNED_APK"
    $APKSIGNER sign --ks "$MATTERMOST_RELEASE_STORE_FILE" --ks-key-alias "$MATTERMOST_RELEASE_KEY_ALIAS" --ks-pass "pass:$MATTERMOST_RELEASE_PASSWORD" --out "$SIGNED_APK" "$ALIGNED_APK"
    rm "$ALIGNED_APK"
    rm "$REPACK_APK"
fi

rm -rf $EXTRACT_PATH