#!/bin/bash
# =============================================================================
# Gitea 备份脚本 (套件版 / Docker 版 通用)
# =============================================================================
# 用途: 定期备份 Gitea 数据,防再次出现"卸载清空"惨案
#
# 备份内容:
#   - Gitea 配置文件 (app.ini)
#   - SQLite 数据库
#   - 所有仓库 (git bare repos)
#   - LFS 数据
#   - 附件 / avatars
#
# 用法:
#   sudo bash scripts/backup-gitea.sh                    # 默认备份到 /volume1/backups/gitea/
#   sudo bash scripts/backup-gitea.sh /path/to/backup    # 自定义备份目录
#   sudo bash scripts/backup-gitea.sh --keep 30          # 保留 30 天
#   sudo bash scripts/backup-gitea.sh --restore latest   # 恢复最新备份(谨慎)
#
# Cron 建议 (每天凌晨 3 点):
#   0 3 * * * /volume1/docker/wecom-it-desk/scripts/backup-gitea.sh >> /var/log/gitea-backup.log 2>&1
# =============================================================================

set -e

# 颜色
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

info()  { echo -e "${BLUE}[INFO]${NC}  $1"; }
ok()    { echo -e "${GREEN}[OK]${NC}    $1"; }
warn()  { echo -e "${YELLOW}[WARN]${NC}  $1"; }
error() { echo -e "${RED}[ERROR]${NC} $1"; exit 1; }

# 默认参数
BACKUP_DIR="${1:-/volume1/backups/gitea}"
KEEP_DAYS=7
RESTORE=""

for arg in "$@"; do
    case $arg in
        --keep) KEEP_DAYS="$2"; shift 2 ;;
        --restore) RESTORE="$2"; shift 2 ;;
    esac
done

TIMESTAMP=$(date +%Y%m%d-%H%M%S)
BACKUP_NAME="gitea-backup-${TIMESTAMP}"
BACKUP_PATH="${BACKUP_DIR}/${BACKUP_NAME}"

# =============================================================================
# 路径探测
# =============================================================================
detect_gitea_paths() {
    info "探测 Gitea 数据目录..."

    # 套件版默认路径
    if [ -d "/volume1/@appdata/gitea" ]; then
        GITEA_HOME="/volume1/@appdata/gitea"
        info "  套件版: $GITEA_HOME"
    # Docker 版常见路径
    elif [ -d "/volume1/docker/gitea" ]; then
        GITEA_HOME="/volume1/docker/gitea"
        info "  Docker 版: $GITEA_HOME"
    else
        error "未找到 Gitea 数据目录,请手动指定 GITEA_HOME 环境变量"
    fi

    # 找配置和数据子目录
    for sub in gitea data config repos lfs avatars; do
        if [ -d "$GITEA_HOME/$sub" ]; then
            declare -g "GITEA_${sub^^}=$GITEA_HOME/$sub"
        fi
    done

    # 找 SQLite 数据库
    for db in "$GITEA_HOME/gitea/data/gitea.db" "$GITEA_HOME/data/gitea.db"; do
        [ -f "$db" ] && GITEA_DB="$db" && break
    done

    if [ -z "$GITEA_DB" ]; then
        warn "未找到 SQLite 数据库,可能用 MySQL/Postgres(此脚本不备份 DB)"
    else
        info "  数据库: $GITEA_DB"
    fi
}

# =============================================================================
# 备份模式
# =============================================================================
do_backup() {
    info "=== Gitea 备份开始 ==="
    info "时间: $TIMESTAMP"
    info "目标: $BACKUP_PATH"

    mkdir -p "$BACKUP_PATH"
    detect_gitea_paths

    # 1. 备份 app.ini 配置
    if [ -f "$GITEA_HOME/gitea/conf/app.ini" ]; then
        mkdir -p "$BACKUP_PATH/conf"
        cp "$GITEA_HOME/gitea/conf/app.ini" "$BACKUP_PATH/conf/"
        ok "备份配置 app.ini"
    fi

    # 2. 备份 SQLite(必须先停 Gitea,或用 .backup 命令)
    if [ -n "$GITEA_DB" ] && [ -f "$GITEA_DB" ]; then
        # 用 sqlite3 .backup(支持热备)
        if command -v sqlite3 &> /dev/null; then
            sqlite3 "$GITEA_DB" ".backup '$BACKUP_PATH/gitea.db'"
            ok "SQLite 热备完成 (sqlite3 .backup)"
        else
            warn "无 sqlite3 命令,改用文件复制(可能不一致)"
            cp "$GITEA_DB" "$BACKUP_PATH/gitea.db"
        fi
    fi

    # 3. 备份仓库 (bare git)
    if [ -d "$GITEA_HOME/gitea/repos" ]; then
        info "备份仓库目录(可能大)..."
        tar -czf "$BACKUP_PATH/repos.tar.gz" \
            -C "$GITEA_HOME/gitea" repos 2>/dev/null || \
        warn "仓库备份失败(可能权限不足,需 sudo)"
        ok "仓库 tar 完成: $(du -h "$BACKUP_PATH/repos.tar.gz" 2>/dev/null | cut -f1)"
    fi

    # 4. 备份 LFS
    if [ -d "$GITEA_HOME/gitea/lfs" ]; then
        tar -czf "$BACKUP_PATH/lfs.tar.gz" \
            -C "$GITEA_HOME/gitea" lfs 2>/dev/null || warn "LFS 备份失败"
    fi

    # 5. 备份附件 / avatars
    if [ -d "$GITEA_HOME/gitea/avatars" ]; then
        cp -r "$GITEA_HOME/gitea/avatars" "$BACKUP_PATH/" 2>/dev/null || true
    fi

    # 6. 备份元信息
    cat > "$BACKUP_PATH/backup.meta" <<EOF
# Gitea 备份元信息
timestamp=$TIMESTAMP
hostname=$(hostname)
gitea_home=$GITEA_HOME
db_path=$GITEA_DB
backup_size=$(du -sh "$BACKUP_PATH" | cut -f1)
git_rev=$(cd "$GITEA_HOME" 2>/dev/null && git rev-parse HEAD 2>/dev/null || echo "N/A")
EOF

    # 7. 打包成单文件(方便转存)
    info "打包最终备份..."
    tar -czf "${BACKUP_PATH}.tar.gz" -C "$BACKUP_DIR" "$BACKUP_NAME"
    rm -rf "$BACKUP_PATH"
    ok "最终备份: ${BACKUP_PATH}.tar.gz"
    ok "  大小: $(du -h "${BACKUP_PATH}.tar.gz" | cut -f1)"

    # 8. 清理旧备份
    info "清理 $KEEP_DAYS 天前的旧备份..."
    local cleaned=0
    while IFS= read -r old; do
        rm -f "$old"
        cleaned=$((cleaned+1))
    done < <(find "$BACKUP_DIR" -maxdepth 1 -name "gitea-backup-*.tar.gz" -mtime +$KEEP_DAYS)
    ok "清理旧备份: $cleaned 个"

    info "=== 备份完成 ==="
    info "建议: 把 ${BACKUP_PATH}.tar.gz scp 到异地(例 NAS2 / 阿里云 OSS / 本地电脑)"
}

# =============================================================================
# 恢复模式
# =============================================================================
do_restore() {
    if [ -z "$RESTORE" ]; then
        error "未指定要恢复的备份名(--restore latest|YYYYMMDD-HHMMSS)"
    fi

    if [ "$RESTORE" = "latest" ]; then
        RESTORE_FILE=$(ls -t "$BACKUP_DIR"/gitea-backup-*.tar.gz 2>/dev/null | head -1)
        [ -z "$RESTORE_FILE" ] && error "找不到备份文件"
    else
        RESTORE_FILE="$BACKUP_DIR/gitea-backup-${RESTORE}.tar.gz"
        [ -f "$RESTORE_FILE" ] || error "备份文件不存在: $RESTORE_FILE"
    fi

    warn "!!! 恢复操作会覆盖当前 Gitea 数据 !!!"
    warn "    备份文件: $RESTORE_FILE"
    warn "    按 Ctrl+C 取消,或 5 秒后继续"
    sleep 5

    info "解压备份..."
    TMP_DIR=$(mktemp -d)
    tar -xzf "$RESTORE_FILE" -C "$TMP_DIR"
    BACKUP_CONTENT=$(ls "$TMP_DIR" | head -1)
    [ -z "$BACKUP_CONTENT" ] && error "备份文件内容为空"

    detect_gitea_paths
    EXTRACT_DIR="$TMP_DIR/$BACKUP_CONTENT"

    # 停 Gitea(套件 / Docker)
    info "停 Gitea..."
    if command -v synopkg &> /dev/null; then
        sudo synopkg stop Gitea 2>/dev/null || true
    fi
    docker stop gitea 2>/dev/null || true

    # 恢复 app.ini
    if [ -f "$EXTRACT_DIR/conf/app.ini" ]; then
        cp "$EXTRACT_DIR/conf/app.ini" "$GITEA_HOME/gitea/conf/app.ini"
        ok "恢复 app.ini"
    fi

    # 恢复 DB
    if [ -f "$EXTRACT_DIR/gitea.db" ]; then
        cp "$EXTRACT_DIR/gitea.db" "$GITEA_DB"
        ok "恢复 SQLite"
    fi

    # 恢复 repos
    if [ -f "$EXTRACT_DIR/repos.tar.gz" ]; then
        rm -rf "$GITEA_HOME/gitea/repos"
        tar -xzf "$EXTRACT_DIR/repos.tar.gz" -C "$GITEA_HOME/gitea/"
        ok "恢复 repos"
    fi

    # 启动 Gitea
    info "启动 Gitea..."
    if command -v synopkg &> /dev/null; then
        sudo synopkg start Gitea
    fi
    docker start gitea 2>/dev/null || true

    rm -rf "$TMP_DIR"
    ok "恢复完成"
}

# =============================================================================
# 入口
# =============================================================================
if [ -n "$RESTORE" ]; then
    do_restore
else
    do_backup
fi