#!/bin/bash

set -euo pipefail

URL_BASE="https://download.red-gate.com/installers/RedgateMonitorLinuxX64"
S3_BUCKET="https://redgate-download.s3.eu-west-1.amazonaws.com"
S3_PREFIX="installers/RedgateMonitorLinuxX64"
STATE_FILE="/var/local/redgate_last_date.txt"
LOG_FILE="/var/log/redgate_update_check.log"
FILENAME="RedgateMonitorLinuxX64.zip"
DOWNLOAD_BASE="/home/redgate/update"
LOCK_FILE="/var/lock/redgate_update.lock"

BASE_MONITOR_SERVICE="redgatemonitor-base"
WEBSITE_SERVICE="redgatemonitor-web"

log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $*" | tee -a "$LOG_FILE"
}

is_installed() {
    local service="$1"
    systemctl cat "${service}.service" &>/dev/null
}

install_component() {
    local name="$1"
    local pattern="$2"
    local extract_dir="$3"
    local parent_dir="$4"

    local tar_file
    tar_file=$(find "$parent_dir" -maxdepth 1 -type f -name "$pattern" | head -n 1)

    if [ -z "$tar_file" ]; then
        log "⚠️ No $name tar.gz found. Skipping."
        return 0
    fi

    mkdir -p "$extract_dir"
    log "Extracting $tar_file into $extract_dir"

    if ! tar -xzf "$tar_file" -C "$extract_dir" >> "$LOG_FILE" 2>&1; then
        log "❌ Extraction of $name failed."
        return 1
    fi
    log "✅ $name extracted successfully."

    local install_sh
    install_sh=$(find "$extract_dir" -type f -name "install.sh" | head -n 1)

    if [ -z "$install_sh" ]; then
        log "⚠️ install.sh not found in $name folder. Skipping."
        return 0
    fi

    local install_folder
    install_folder=$(dirname "$install_sh")
    chmod +x "$install_sh"
    log "Running $name install.sh with automatic EULA acceptance..."

    if (cd "$install_folder" && echo "1" | ./install.sh >> "$LOG_FILE" 2>&1); then
        log "✅ $name install completed successfully."
    else
        log "❌ $name install failed. Check $LOG_FILE for details."
        return 1
    fi
}

log "====== Starting Redgate update check ======"

exec 9>"$LOCK_FILE"
flock -n 9 || { log "⚠️ Another instance is running. Exiting."; exit 0; }

touch "$LOG_FILE" && chmod 640 "$LOG_FILE"
chmod 600 "$STATE_FILE" 2>/dev/null || true

base_monitor_present=false
website_present=false

if is_installed "$BASE_MONITOR_SERVICE"; then
    base_monitor_present=true
    log "ℹ️ BaseMonitor detected on this server."
fi

if is_installed "$WEBSITE_SERVICE"; then
    website_present=true
    log "ℹ️ Website detected on this server."
fi

if ! $base_monitor_present && ! $website_present; then
    log "⚠️ No Redgate components detected on this server. Exiting."
    exit 0
fi

log "Querying S3 for latest available build..."
latest_found=$(curl -s "${S3_BUCKET}/?prefix=${S3_PREFIX}/&delimiter=/" | grep -oP "(?<=<Prefix>${S3_PREFIX}/)\d{4}-\d{2}-\d{2}(?=/)" | sort | tail -1)

if [ -z "$latest_found" ]; then
    log "❌ Could not determine latest build from S3. Exiting."
    exit 1
fi

log "✅ Latest available build: $latest_found"

if [[ ! "$latest_found" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
    log "❌ Unexpected date format: $latest_found. Exiting."
    exit 1
fi

last_stored=""
[ -f "$STATE_FILE" ] && last_stored=$(cat "$STATE_FILE")
log "Last stored build: ${last_stored:-none}"

if [ "$latest_found" == "$last_stored" ]; then
    log "No new build found. Last known: $last_stored"
    log "====== Redgate update check completed ======"
    exit 0
fi

log "🚩 New build detected: $latest_found (previous: ${last_stored:-none})"

download_dir="$DOWNLOAD_BASE/$latest_found"
mkdir -p "$download_dir" && chmod 700 "$download_dir"
output_path="$download_dir/$FILENAME"
download_url="$URL_BASE/$latest_found/$FILENAME"

log "Downloading $download_url"
if ! curl -L --fail --ssl-reqd --tlsv1.2 -o "$output_path" "$download_url"; then
    log "❌ Download failed."
    exit 1
fi
log "✅ Download completed: $output_path"

log "Unzipping into $download_dir"
if ! unzip -o "$output_path" -d "$download_dir" >> "$LOG_FILE" 2>&1; then
    log "❌ Unzip failed."
    exit 1
fi
log "✅ Unzip completed."
log "Removing downloaded zip to save disk space..."
rm -f "$output_path"
log "✅ Zip removed."

install_failed=false

if $base_monitor_present; then
    install_component "BaseMonitor" "*BaseMonitor*.tar.gz" "$download_dir/bm" "$download_dir" || install_failed=true
else
    log "ℹ️ Skipping BaseMonitor — not installed on this server."
fi

if $website_present; then
    install_component "Website" "*Website*.tar.gz" "$download_dir/web" "$download_dir" || install_failed=true
else
    log "ℹ️ Skipping Website — not installed on this server."
fi

if $install_failed; then
    log "⚠️ One or more components failed. State file NOT updated — will retry on next run."
else
    echo "$latest_found" > "$STATE_FILE"
    log "✅ State updated to $latest_found"
    log "Cleaning up download directories older than 7 days..."
    find "$DOWNLOAD_BASE" -mindepth 1 -maxdepth 1 -type d -mtime +7 -exec rm -rf {} + && log "✅ Old directories removed." || log "⚠️ Cleanup encountered an issue — continuing."
fi

log "====== Redgate update check completed ======"
echo ""