#!/bin/bash
"""
Advanced Minecraft Snapshot Downloader
マルチスレッドダウンロード、リトライ機能付き
"""

# 設定
MINECRAFT_DIR="/opt/minecraft-snapshot"
BACKUP_DIR="/opt/minecraft-snapshots-backup"
LOG_FILE="/var/log/minecraft-snapshot-downloader.log"
MAX_RETRIES=3
RETRY_DELAY=5

# ログ関数
log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') - $1" | tee -a "$LOG_FILE"
}

# User-Agent ランダマイザー（MS側のBL対策）
generate_user_agent() {
    local rand_num=$((1 + RANDOM % 5000))
    echo "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.33 (KHTML, like Gecko) Chrome/90.0.$rand_num.212 Safari/537.33"
}

# snapshots.jsonを取得
get_snapshots_manifest() {
    local user_agent=$(generate_user_agent)
    local url="https://piston-meta.mojang.com/mc/game/version_manifest.json"
    
    log "Fetching snapshots manifest..."
    
    for i in $(seq 1 $MAX_RETRIES); do
        if curl -s -H "Accept-Encoding: identity" \
                -H "Accept-Language: en" \
                -A "$user_agent" \
                -o "/tmp/snapshots.json" \
                "$url"; then
            log "Successfully fetched snapshots manifest"
            return 0
        else
            log "Failed to fetch snapshots manifest (attempt $i/$MAX_RETRIES)"
            sleep $RETRY_DELAY
        fi
    done
    
    log "ERROR: Failed to fetch snapshots manifest after $MAX_RETRIES attempts"
    return 1
}

# 最新Snapshotバージョンを取得
get_latest_snapshot() {
    if [ ! -f "/tmp/snapshots.json" ]; then
        log "ERROR: snapshots.json not found"
        return 1
    fi
    
    python3 -c "
import json
with open('/tmp/snapshots.json', 'r') as f:
    data = json.load(f)
    print(data['latest']['snapshot'])
"
}

# 特定バージョンの情報を取得
get_version_info() {
    local version="$1"
    
    if [ ! -f "/tmp/snapshots.json" ]; then
        log "ERROR: snapshots.json not found"
        return 1
    fi
    
    python3 -c "
import json
import sys

version = sys.argv[1]
with open('/tmp/snapshots.json', 'r') as f:
    data = json.load(f)
    
for v in data['versions']:
    if v['id'] == version:
        print(v['url'])
        break
else:
    sys.exit(1)
" "$version"
}

# サーバーjarをダウンロード
download_server_jar() {
    local version="$1"
    local version_url="$2"
    local user_agent=$(generate_user_agent)
    
    log "Getting version info for $version..."
    
    # バージョン情報を取得
    local version_info_file="/tmp/version_info_$version.json"
    
    for i in $(seq 1 $MAX_RETRIES); do
        if curl -s -A "$user_agent" \
                -o "$version_info_file" \
                "$version_url"; then
            log "Successfully fetched version info for $version"
            break
        else
            log "Failed to fetch version info (attempt $i/$MAX_RETRIES)"
            if [ $i -eq $MAX_RETRIES ]; then
                log "ERROR: Failed to fetch version info after $MAX_RETRIES attempts"
                return 1
            fi
            sleep $RETRY_DELAY
        fi
    done
    
    # サーバーjarのURLを取得
    local server_url=$(python3 -c "
import json
with open('$version_info_file', 'r') as f:
    data = json.load(f)
    print(data['downloads']['server']['url'])
")
    
    if [ -z "$server_url" ]; then
        log "ERROR: Server URL not found in version info"
        return 1
    fi
    
    log "Downloading server jar for $version..."
    
    # サーバーjarをダウンロード
    local jar_file="$MINECRAFT_DIR/server-$version.jar"
    local temp_jar_file="/tmp/server-$version.jar"
    
    for i in $(seq 1 $MAX_RETRIES); do
        if curl -A "$user_agent" \
                -o "$temp_jar_file" \
                "$server_url"; then
            
            # ファイルサイズをチェック
            local file_size=$(stat -c%s "$temp_jar_file")
            if [ "$file_size" -gt 1000000 ]; then  # 1MB以上
                mv "$temp_jar_file" "$jar_file"
                log "Successfully downloaded server jar: $jar_file"
                return 0
            else
                log "Downloaded file seems too small (${file_size} bytes)"
            fi
        else
            log "Failed to download server jar (attempt $i/$MAX_RETRIES)"
        fi
        
        if [ $i -lt $MAX_RETRIES ]; then
            sleep $RETRY_DELAY
        fi
    done
    
    log "ERROR: Failed to download server jar after $MAX_RETRIES attempts"
    return 1
}

# バックアップ作成
create_backup() {
    local version="$1"
    local timestamp=$(date +%Y%m%d_%H%M%S)
    local backup_path="$BACKUP_DIR/backup_${version}_${timestamp}"
    
    log "Creating backup: $backup_path"
    
    mkdir -p "$backup_path"
    
    # 重要なファイルをバックアップ
    if [ -d "$MINECRAFT_DIR/world" ]; then
        cp -r "$MINECRAFT_DIR/world" "$backup_path/"
    fi
    
    if [ -f "$MINECRAFT_DIR/server.properties" ]; then
        cp "$MINECRAFT_DIR/server.properties" "$backup_path/"
    fi
    
    if [ -f "$MINECRAFT_DIR/server.jar" ]; then
        cp "$MINECRAFT_DIR/server.jar" "$backup_path/"
    fi
    
    log "Backup created successfully: $backup_path"
}

# サーバー更新
update_server() {
    local version="$1"
    local jar_file="$MINECRAFT_DIR/server-$version.jar"
    local current_jar="$MINECRAFT_DIR/server.jar"
    
    if [ ! -f "$jar_file" ]; then
        log "ERROR: Server jar not found: $jar_file"
        return 1
    fi
    
    log "Updating server to version $version..."
    
    # サーバー停止
    if systemctl is-active --quiet minecraft-snapshot; then
        log "Stopping Minecraft server..."
        systemctl stop minecraft-snapshot
        sleep 5
    fi
    
    # バックアップ作成
    create_backup "$version"
    
    # 新しいjarファイルをリンク
    if [ -L "$current_jar" ] || [ -f "$current_jar" ]; then
        rm "$current_jar"
    fi
    
    ln -s "$jar_file" "$current_jar"
    
    # サーバー起動
    log "Starting Minecraft server..."
    systemctl start minecraft-snapshot
    
    # 起動確認
    sleep 10
    if systemctl is-active --quiet minecraft-snapshot; then
        log "Server successfully updated to version $version"
        return 0
    else
        log "ERROR: Server failed to start after update"
        return 1
    fi
}

# 最後に処理したバージョンを保存/読み込み
save_last_version() {
    echo "$1" > "/tmp/last_snapshot_version.txt"
}

load_last_version() {
    if [ -f "/tmp/last_snapshot_version.txt" ]; then
        cat "/tmp/last_snapshot_version.txt"
    else
        echo ""
    fi
}

# メイン処理
main() {
    log "Starting Minecraft Snapshot Downloader..."
    
    # snapshots.jsonを取得
    if ! get_snapshots_manifest; then
        log "ERROR: Failed to get snapshots manifest"
        exit 1
    fi
    
    # 最新Snapshotバージョンを取得
    local latest_version=$(get_latest_snapshot)
    if [ -z "$latest_version" ]; then
        log "ERROR: Failed to get latest snapshot version"
        exit 1
    fi
    
    log "Latest snapshot version: $latest_version"
    
    # 最後に処理したバージョンと比較
    local last_version=$(load_last_version)
    if [ "$latest_version" = "$last_version" ]; then
        log "No new snapshot version found"
        exit 0
    fi
    
    log "New snapshot version detected: $latest_version (previous: $last_version)"
    
    # バージョン情報URLを取得
    local version_url=$(get_version_info "$latest_version")
    if [ -z "$version_url" ]; then
        log "ERROR: Failed to get version info URL"
        exit 1
    fi
    
    # サーバーjarをダウンロード
    if download_server_jar "$latest_version" "$version_url"; then
        # サーバー更新
        if update_server "$latest_version"; then
            save_last_version "$latest_version"
            log "Successfully updated to snapshot version: $latest_version"
        else
            log "ERROR: Failed to update server"
            exit 1
        fi
    else
        log "ERROR: Failed to download server jar"
        exit 1
    fi
}

# スクリプト実行
main "$@"
                    

# docker-compose.yml for Beta Testing
version: '3.8'

services:
  minecraft-snapshot-test:
    image: itzg/minecraft-server
    container_name: minecraft-snapshot-test
    environment:
      EULA: "TRUE"
      TYPE: "VANILLA"
      VERSION: "SNAPSHOT"
      MEMORY: "4G"
      MOTD: "§6[BETA] Snapshot Testing Server"
      MAX_PLAYERS: 10
      DIFFICULTY: "easy"
      GAMEMODE: "survival"
      PVP: "false"
      ONLINE_MODE: "false"
      ENABLE_COMMAND_BLOCK: "true"
      SPAWN_PROTECTION: 0
      VIEW_DISTANCE: 16
      SIMULATION_DISTANCE: 10
      # 自動アップデート設定
      CHECK_VERSION: "true"
      FORCE_REDOWNLOAD: "false"
      # テスト用設定
      ENABLE_RCON: "true"
      RCON_PASSWORD: "test123"
      RCON_PORT: 25575
      # デバッグ設定
      DEBUG: "true"
      LOG_LEVEL: "DEBUG"
    ports:
      - "25565:25565"
      - "25575:25575"
    volumes:
      - ./test-data:/data
      - ./test-logs:/logs
      - ./test-backups:/backups
    restart: unless-stopped
    depends_on:
      - test-monitor
    
  test-monitor:
    image: prom/prometheus
    container_name: test-monitor
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml
      - ./prometheus-data:/prometheus
    restart: unless-stopped
    
  test-grafana:
    image: grafana/grafana
    container_name: test-grafana
    ports:
      - "3000:3000"
    volumes:
      - ./grafana-data:/var/lib/grafana
      - ./grafana-config:/etc/grafana
    environment:
      - GF_SECURITY_ADMIN_PASSWORD=admin
    restart: unless-stopped
    depends_on:
      - test-monitor
      
  test-backup:
    image: alpine:latest
    container_name: test-backup
    volumes:
      - ./test-data:/minecraft-data:ro
      - ./test-backups:/backups
    command: >
      sh -c "
      while true; do
        echo 'Creating backup...'
        timestamp=$$(date +%Y%m%d_%H%M%S)
        tar -czf /backups/snapshot_backup_$$timestamp.tar.gz -C /minecraft-data .
        # 7日以上古いバックアップを削除
        find /backups -name '*.tar.gz' -mtime +7 -delete
        sleep 3600
      done"
    restart: unless-stopped
    
  test-logger:
    image: fluent/fluent-bit
    container_name: test-logger
    volumes:
      - ./test-logs:/logs:ro
      - ./fluent-bit.conf:/fluent-bit/etc/fluent-bit.conf
    depends_on:
      - minecraft-snapshot-test
    restart: unless-stopped

networks:
  default:
    name: minecraft-snapshot-test
                    

# 推奨JVMパラメータ（Snapshot用）
java -Xms4G -Xmx4G \
     -XX:+UseG1GC \
     -XX:+ParallelRefProcEnabled \
     -XX:MaxGCPauseMillis=200 \
     -XX:+UnlockExperimentalVMOptions \
     -XX:+DisableExplicitGC \
     -XX:+AlwaysPreTouch \
     -XX:G1NewSizePercent=30 \
     -XX:G1MaxNewSizePercent=40 \
     -XX:G1HeapRegionSize=8M \
     -XX:G1ReservePercent=20 \
     -XX:G1HeapWastePercent=5 \
     -XX:G1MixedGCCountTarget=4 \
     -XX:InitiatingHeapOccupancyPercent=15 \
     -XX:G1MixedGCLiveThresholdPercent=90 \
     -XX:G1RSetUpdatingPauseTimePercent=5 \
     -XX:SurvivorRatio=32 \
     -XX:+PerfDisableSharedMem \
     -XX:MaxTenuringThreshold=1 \
     -Dusing.aikars.flags=https://mcflags.emc.gs \
     -Daikars.new.flags=true \
     -jar server.jar nogui