#!/usr/bin/env bash
# ============================================================
# Messages Mod+ Standalone Script
# Fix RCS on rooted Android devices by reinstalling
# Google Messages as a user-space app
#
# Run from a computer with ADB connected to a rooted device
# ============================================================

set -euo pipefail

# ---- USER CONFIGURABLE VARIABLES ----
# Set these manually, or leave empty for auto-detection
MSG_PKG=""          # e.g. "com.google.android.apps.messaging"
BACKUP_DIR=""       # e.g. "./messages_backup"
# ---- END USER CONFIG ----

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
BOLD='\033[1m'
NC='\033[0m'

log()  { echo -e "${BLUE}[*]${NC} $1"; }
ok()   { echo -e "${GREEN}[+]${NC} $1"; }
warn() { echo -e "${YELLOW}[!]${NC} $1"; }
err()  { echo -e "${RED}[-]${NC} $1"; }
hdr()  { echo -e "\n${BOLD}${CYAN}=== $1 ===${NC}\n"; }

su_cmd() {
    adb shell su -c "$1" 2>&1
}

check_adb() {
    if ! command -v adb &>/dev/null; then
        err "ADB not found in PATH"
        exit 1
    fi

    local devices
    devices=$(adb devices | grep -w "device" | grep -v "List")
    if [ -z "$devices" ]; then
        err "No ADB device connected"
        exit 1
    fi

    local serial
    serial=$(echo "$devices" | head -1 | awk '{print $1}')
    ok "Device connected: ${serial}"
}

check_root() {
    local whoami
    whoami=$(su_cmd 'id -u' | tr -d '[:space:]')
    if [ "$whoami" != "0" ]; then
        err "Root shell not available (su failed)"
        err "Make sure KernelSU, Magisk, or another root solution is active"
        exit 1
    fi
    ok "Root shell verified"
}

auto_detect() {
    log "Auto-detecting Google Messages package..."

    # Try the standard package name
    local found
    found=$(adb shell pm list packages 2>/dev/null | grep "com.google.android.apps.messaging" || true)

    if [ -n "$found" ]; then
        MSG_PKG="com.google.android.apps.messaging"
        ok "Found: ${MSG_PKG}"
    else
        # Broader search
        warn "Standard package not found, searching..."
        found=$(adb shell pm list packages 2>/dev/null | grep -i "messaging\|messages" || true)
        if [ -n "$found" ]; then
            echo ""
            echo "Found messaging packages:"
            echo "$found" | sed 's/package:/  /' | nl
            echo ""
            read -rp "Enter the number of the correct package (or type it manually): " choice
            if [[ "$choice" =~ ^[0-9]+$ ]]; then
                MSG_PKG=$(echo "$found" | sed 's/package://' | sed -n "${choice}p" | tr -d '[:space:]')
            else
                MSG_PKG="$choice"
            fi
        else
            err "No messaging packages found on device"
            exit 1
        fi
    fi

    BACKUP_DIR="${BACKUP_DIR:-./messages_backup_$(date +%Y%m%d)}"
}

manual_config() {
    echo ""
    read -rp "Enter Messages package name [com.google.android.apps.messaging]: " input_pkg
    MSG_PKG="${input_pkg:-com.google.android.apps.messaging}"

    read -rp "Enter local backup directory [./messages_backup]: " input_dir
    BACKUP_DIR="${input_dir:-./messages_backup}"

    # Verify package exists
    if ! adb shell pm list packages | grep -q "$MSG_PKG"; then
        err "Package '${MSG_PKG}' not found on device"
        exit 1
    fi
    ok "Package verified: ${MSG_PKG}"
}

backup_databases() {
    hdr "Backing Up Databases"
    mkdir -p "${BACKUP_DIR}/databases"

    # SMS/MMS
    local sms_db="/data/data/com.android.providers.telephony/databases/mmssms.db"
    log "Backing up SMS/MMS database..."
    adb shell su -c "cat '${sms_db}'" > "${BACKUP_DIR}/databases/mmssms.db" 2>/dev/null && \
        ok "SMS/MMS: $(du -h "${BACKUP_DIR}/databases/mmssms.db" | cut -f1)" || \
        warn "SMS/MMS database not found or empty"

    # RCS / Bugle
    local rcs_db="/data/data/${MSG_PKG}/databases/bugle_db"
    log "Backing up RCS database..."
    adb shell su -c "cat '${rcs_db}'" > "${BACKUP_DIR}/databases/bugle_db.db" 2>/dev/null && \
        ok "RCS: $(du -h "${BACKUP_DIR}/databases/bugle_db.db" | cut -f1)" || \
        warn "RCS database not found or empty"

    # Remove zero-byte files from failed backups
    find "${BACKUP_DIR}/databases" -size 0 -delete 2>/dev/null || true
}

pull_apks() {
    hdr "Pulling APK Splits"
    mkdir -p "${BACKUP_DIR}/apks"

    local apk_paths
    apk_paths=$(adb shell su -c "pm path '${MSG_PKG}'" | sed 's/package://' | tr -d '\r')

    if [ -z "$apk_paths" ]; then
        err "Could not find APK paths for ${MSG_PKG}"
        exit 1
    fi

    local count=0
    while IFS= read -r apk_path; do
        apk_path=$(echo "$apk_path" | tr -d '[:space:]')
        [ -z "$apk_path" ] && continue
        local apk_name
        apk_name=$(basename "$apk_path")
        log "Pulling ${apk_name}..."
        adb shell su -c "cat '${apk_path}'" > "${BACKUP_DIR}/apks/${apk_name}"
        local size
        size=$(du -h "${BACKUP_DIR}/apks/${apk_name}" | cut -f1)
        ok "  ${apk_name} (${size})"
        count=$((count + 1))
    done <<< "$apk_paths"

    ok "Pulled ${count} APK split(s)"
}

disable_system() {
    hdr "Disabling System Messages"
    log "Disabling ${MSG_PKG}..."
    local result
    result=$(adb shell su -c "pm disable-user --user 0 '${MSG_PKG}'" 2>&1)
    echo "  ${result}"

    if echo "$result" | grep -q "disabled"; then
        ok "System app disabled"
    else
        warn "Disable command returned unexpected output"
    fi
}

reinstall_userspace() {
    hdr "Reinstalling as User-Space App"

    local apk_files
    apk_files=$(ls -1 "${BACKUP_DIR}/apks/"*.apk 2>/dev/null)
    local apk_count
    apk_count=$(echo "$apk_files" | wc -l)

    if [ -z "$apk_files" ] || [ "$apk_count" -eq 0 ]; then
        err "No APK files found in ${BACKUP_DIR}/apks/"
        exit 1
    fi

    log "Installing ${apk_count} APK split(s)..."
    local install_args=""
    while IFS= read -r apk; do
        install_args="${install_args} ${apk}"
    done <<< "$apk_files"

    local result
    if [ "$apk_count" -gt 1 ]; then
        result=$(adb install-multiple $install_args 2>&1)
    else
        result=$(adb install $install_args 2>&1)
    fi

    echo "  ${result}"

    if echo "$result" | grep -qi "success"; then
        ok "Installation successful"
    else
        err "Installation failed"
        warn "Attempting to re-enable system app..."
        adb shell pm enable "$MSG_PKG" 2>/dev/null
        exit 1
    fi
}

reenable_package() {
    hdr "Re-enabling Package"
    local result
    result=$(adb shell pm enable "$MSG_PKG" 2>&1)
    echo "  ${result}"
    ok "Package enabled"
}

verify() {
    hdr "Verification"
    local flags
    flags=$(adb shell su -c "dumpsys package '${MSG_PKG}'" | grep "pkgFlags" | head -1)

    if echo "$flags" | grep -q "UPDATED_SYSTEM_APP"; then
        ok "Messages is running as UPDATED_SYSTEM_APP (user-space)"
        echo ""
        echo -e "${GREEN}${BOLD}  Messages Mod+ applied successfully!${NC}"
        echo ""
        echo "  Next steps on your device:"
        echo "    1. Open Google Messages"
        echo "    2. Set as default SMS app if prompted"
        echo "    3. Grant permissions"
        echo "    4. RCS should provision normally"
        echo ""
    else
        warn "Package flags: ${flags}"
        warn "State may not be as expected - verify on device"
    fi
}

revert_to_stock() {
    hdr "Reverting to Stock"
    log "Removing user-space updates..."
    adb shell pm uninstall-updates "$MSG_PKG" 2>&1 || true
    adb shell pm enable "$MSG_PKG" 2>/dev/null

    local flags
    flags=$(adb shell su -c "dumpsys package '${MSG_PKG}'" | grep "pkgFlags" | head -1)
    if echo "$flags" | grep -q "UPDATED_SYSTEM_APP"; then
        warn "Revert may not have completed fully"
    else
        ok "Messages reverted to stock system app"
    fi
}

show_menu() {
    echo ""
    echo -e "${BOLD}${CYAN}Messages Mod+${NC}"
    echo -e "Fix RCS on rooted Android devices"
    echo ""
    echo "  1) Apply mod (full process)"
    echo "  2) Backup databases only"
    echo "  3) Revert to stock"
    echo "  4) Check status"
    echo "  5) Exit"
    echo ""
    read -rp "Select option [1-5]: " choice
    echo ""
    return "$choice"
}

show_status() {
    hdr "Current Status"
    local flags
    flags=$(adb shell su -c "dumpsys package '${MSG_PKG}'" 2>/dev/null | grep "pkgFlags" | head -1 || echo "not found")
    local code_path
    code_path=$(adb shell su -c "dumpsys package '${MSG_PKG}'" 2>/dev/null | grep "codePath=" | head -1 | sed 's/.*codePath=//' || echo "unknown")
    local enabled
    enabled=$(adb shell pm list packages -e 2>/dev/null | grep -q "$MSG_PKG" && echo "Yes" || echo "No")

    echo "  Package:  ${MSG_PKG}"
    echo "  Path:     ${code_path}"
    echo "  Enabled:  ${enabled}"
    echo "  Flags:    ${flags}"

    if echo "$flags" | grep -q "UPDATED_SYSTEM_APP"; then
        ok "State: MODDED (user-space)"
    elif echo "$flags" | grep -q "SYSTEM"; then
        warn "State: SYSTEM (stock)"
    else
        log "State: Unknown"
    fi
}

# ============================================================
# Main
# ============================================================

echo ""
echo -e "${BOLD}${CYAN}╔══════════════════════════════════╗${NC}"
echo -e "${BOLD}${CYAN}║       Messages Mod+ v1.0.0       ║${NC}"
echo -e "${BOLD}${CYAN}║   Fix RCS on Rooted Devices      ║${NC}"
echo -e "${BOLD}${CYAN}╚══════════════════════════════════╝${NC}"
echo ""

# Preflight
check_adb
check_root

# Detection mode
echo ""
echo "Configuration mode:"
echo "  1) Auto-detect (recommended)"
echo "  2) Manual"
echo ""
read -rp "Select [1/2]: " mode

case "$mode" in
    2) manual_config ;;
    *) auto_detect ;;
esac

BACKUP_DIR="${BACKUP_DIR:-./messages_backup_$(date +%Y%m%d)}"
mkdir -p "$BACKUP_DIR"
log "Backup directory: ${BACKUP_DIR}"

# Main menu loop
while true; do
    show_menu
    opt=$?

    case "$opt" in
        1)
            backup_databases
            pull_apks
            disable_system
            reinstall_userspace
            reenable_package
            verify
            ;;
        2)
            backup_databases
            ;;
        3)
            revert_to_stock
            ;;
        4)
            show_status
            ;;
        5)
            echo "Bye!"
            exit 0
            ;;
        *)
            warn "Invalid option"
            ;;
    esac
done