#!/usr/bin/env bash
set -euo pipefail

# ============================================
# Gitea 迁移脚本（旧服务器 → 新服务器）
# 用法：
#   bash migrate.sh export              # 旧服务器：导出迁移包
#   bash migrate.sh import <迁移包路径>  # 新服务器：导入迁移包
#   bash migrate.sh verify              # 迁移后：验证完整性
#
# 迁移流程：
#   旧服务器 → export → scp 传输 → 新服务器 → import → verify
# ============================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
NC='\033[0m'

log()     { echo -e "${GREEN}[INFO]${NC} $*"; }
warn()    { echo -e "${YELLOW}[WARN]${NC} $*"; }
error()   { echo -e "${RED}[ERROR]${NC} $*" >&2; }
step()    { echo -e "\n${CYAN}========== $* ==========${NC}"; }
confirm() {
    echo -en "${YELLOW}[确认]${NC} $* [y/N]: "
    read -r reply
    [[ "$reply" =~ ^[Yy]$ ]]
}

# ===== 前置检查 =====
preflight() {
    if [ "$(id -u)" -ne 0 ]; then
        error "请使用 root 用户运行: sudo bash migrate.sh"
        exit 1
    fi
}

load_env() {
    if [ ! -f .env ]; then
        error ".env 文件不存在"
        exit 1
    fi
    set -a
    source .env
    set +a
}

# =============================================================
#  导出模式 — 在旧服务器执行
# =============================================================
do_export() {
    step "迁移导出 — 旧服务器"

    load_env

    GITEA_DATA_DIR="${GITEA_DATA_DIR:-/var/lib/gitea}"
    MYSQL_DATA_DIR="${MYSQL_DATA_DIR:-/var/lib/mysql/gitea}"
    BACKUP_DIR="${BACKUP_DIR:-/var/backups/gitea}"
    DATE=$(date +%Y%m%d_%H%M%S)
    EXPORT_DIR="${BACKUP_DIR}/migrate_${DATE}"
    EXPORT_ARCHIVE="${BACKUP_DIR}/gitea_migrate_${DATE}.tar.gz"

    mkdir -p "$EXPORT_DIR"

    # --- 1. 显示当前状态 ---
    step "1/6 当前环境信息"
    log "域名: ${GITEA_DOMAIN:-未设置}"
    log "数据目录: ${GITEA_DATA_DIR}"
    log "MySQL 数据: ${MYSQL_DATA_DIR}"

    if docker compose ps --status running 2>/dev/null | grep -q gitea; then
        GITEA_VER=$(curl -sf http://127.0.0.1:3000/api/v1/version 2>/dev/null | grep -oP '"version"\s*:\s*"\K[^"]+' || echo "未知")
        log "Gitea 版本: ${GITEA_VER}"
    fi

    MYSQL_VER=$(docker compose exec -T db mysql --version 2>/dev/null | grep -oP 'Distrib \K[0-9.]+' || echo "未知")
    log "MySQL 版本: ${MYSQL_VER}"

    echo ""
    warn "导出过程中 Gitea 将停止服务，以保证数据一致性。"
    if ! confirm "是否继续？"; then
        log "已取消"
        rm -rf "$EXPORT_DIR"
        exit 0
    fi

    # --- 2. 停止 Gitea，保留 MySQL 用于导出 ---
    step "2/6 停止 Gitea 容器"
    docker compose stop server 2>/dev/null || true
    log "Gitea 已停止"

    # --- 3. 导出 MySQL 数据库 ---
    step "3/6 导出 MySQL 数据库"
    log "使用 mysqldump 导出（比 gitea dump 的 XORM 更可靠）..."
    docker compose exec -T db mysqldump \
        -u root -p"${DB_ROOT_PASSWORD}" \
        --single-transaction \
        --routines \
        --triggers \
        --databases gitea \
        > "${EXPORT_DIR}/gitea-db.sql"

    DB_SIZE=$(du -h "${EXPORT_DIR}/gitea-db.sql" | cut -f1)
    log "数据库导出完成: gitea-db.sql (${DB_SIZE})"

    # --- 4. 停止所有容器 ---
    step "4/6 停止全部容器"
    docker compose down
    log "全部容器已停止"

    # --- 5. 打包 Gitea 数据 ---
    step "5/6 打包 Gitea 数据目录"
    if [ -d "$GITEA_DATA_DIR" ]; then
        log "正在打包 ${GITEA_DATA_DIR} ..."
        tar czf "${EXPORT_DIR}/gitea-data.tar.gz" \
            -C "$(dirname "$GITEA_DATA_DIR")" \
            "$(basename "$GITEA_DATA_DIR")"
        DATA_SIZE=$(du -h "${EXPORT_DIR}/gitea-data.tar.gz" | cut -f1)
        log "数据打包完成: gitea-data.tar.gz (${DATA_SIZE})"
    else
        warn "数据目录 ${GITEA_DATA_DIR} 不存在，跳过"
    fi

    # --- 5b. 打包部署配置 ---
    log "正在打包部署配置..."
    tar czf "${EXPORT_DIR}/gitea-config.tar.gz" \
        -C "$SCRIPT_DIR" \
        --exclude='.git' \
        --exclude='data' \
        --exclude='backups' \
        .env docker-compose.yml .env.example \
        $([ -d nginx ] && echo "nginx/") \
        $([ -f backup.sh ] && echo "backup.sh") \
        $([ -f deploy.sh ] && echo "deploy.sh") \
        $([ -f upgrade.sh ] && echo "upgrade.sh") \
        $([ -f migrate.sh ] && echo "migrate.sh") \
        $([ -f .gitignore ] && echo ".gitignore") \
        $([ -f README.md ] && echo "README.md") \
        2>/dev/null || true
    log "配置打包完成: gitea-config.tar.gz"

    # --- 5c. 记录元信息 ---
    cat > "${EXPORT_DIR}/migrate-meta.txt" <<EOF
# Gitea 迁移元信息
export_date=${DATE}
gitea_version=${GITEA_VER:-unknown}
mysql_version=${MYSQL_VER:-unknown}
gitea_domain=${GITEA_DOMAIN:-}
gitea_data_dir=${GITEA_DATA_DIR}
mysql_data_dir=${MYSQL_DATA_DIR}
source_hostname=$(hostname)
EOF

    # --- 6. 生成最终迁移包 ---
    step "6/6 生成迁移包"
    tar czf "$EXPORT_ARCHIVE" -C "$BACKUP_DIR" "migrate_${DATE}"
    TOTAL_SIZE=$(du -h "$EXPORT_ARCHIVE" | cut -f1)

    # 清理临时目录
    rm -rf "$EXPORT_DIR"

    # 重启服务（旧服务器可继续运行）
    echo ""
    if confirm "导出完成。是否重启旧服务器的 Gitea？"; then
        docker compose up -d
        log "服务已重启"
    fi

    echo ""
    log "===== 导出完成 ====="
    log "迁移包: ${EXPORT_ARCHIVE} (${TOTAL_SIZE})"
    echo ""
    log "下一步：将迁移包传输到新服务器并执行导入"
    echo -e "${CYAN}  scp ${EXPORT_ARCHIVE} root@新服务器IP:/opt/gitea/${NC}"
    echo -e "${CYAN}  # 在新服务器上:${NC}"
    echo -e "${CYAN}  cd /opt/gitea${NC}"
    echo -e "${CYAN}  bash migrate.sh import $(basename "$EXPORT_ARCHIVE")${NC}"
}

# =============================================================
#  导入模式 — 在新服务器执行
# =============================================================
do_import() {
    local archive="$1"

    if [ ! -f "$archive" ]; then
        error "迁移包不存在: $archive"
        echo "用法: bash migrate.sh import <迁移包路径>"
        exit 1
    fi

    step "迁移导入 — 新服务器"

    # --- 1. 解压迁移包 ---
    step "1/9 解压迁移包"
    WORK_DIR=$(mktemp -d)
    tar xzf "$archive" -C "$WORK_DIR"
    MIGRATE_DIR=$(find "$WORK_DIR" -maxdepth 1 -type d -name 'migrate_*' | head -1)

    if [ -z "$MIGRATE_DIR" ]; then
        error "无效的迁移包格式"
        rm -rf "$WORK_DIR"
        exit 1
    fi

    # 显示元信息
    if [ -f "${MIGRATE_DIR}/migrate-meta.txt" ]; then
        log "迁移包信息:"
        grep -v '^#' "${MIGRATE_DIR}/migrate-meta.txt" | while IFS='=' read -r key val; do
            printf "  %-20s %s\n" "$key:" "$val"
        done
    fi

    # --- 2. 检查必要文件 ---
    step "2/9 检查迁移包内容"
    local has_db=false has_data=false has_config=false

    [ -f "${MIGRATE_DIR}/gitea-db.sql" ] && has_db=true
    [ -f "${MIGRATE_DIR}/gitea-data.tar.gz" ] && has_data=true
    [ -f "${MIGRATE_DIR}/gitea-config.tar.gz" ] && has_config=true

    log "数据库导出: $(${has_db} && echo '✓' || echo '✗')"
    log "数据目录:   $(${has_data} && echo '✓' || echo '✗')"
    log "部署配置:   $(${has_config} && echo '✓' || echo '✗')"

    if ! $has_db || ! $has_data; then
        error "迁移包缺少必要文件（需要 gitea-db.sql 和 gitea-data.tar.gz）"
        rm -rf "$WORK_DIR"
        exit 1
    fi

    echo ""
    warn "导入将覆盖当前服务器上的 Gitea 数据。"
    if ! confirm "是否继续？"; then
        log "已取消"
        rm -rf "$WORK_DIR"
        exit 0
    fi

    # --- 3. 恢复配置文件 ---
    step "3/9 恢复部署配置"
    if $has_config; then
        tar xzf "${MIGRATE_DIR}/gitea-config.tar.gz" -C "$SCRIPT_DIR"
        log "配置文件已恢复到 ${SCRIPT_DIR}/"
    fi

    # 加载 .env
    load_env
    GITEA_DATA_DIR="${GITEA_DATA_DIR:-/var/lib/gitea}"
    MYSQL_DATA_DIR="${MYSQL_DATA_DIR:-/var/lib/mysql/gitea}"

    # --- 4. 提示修改配置 ---
    step "4/9 检查配置"
    echo ""
    warn "如果新服务器的域名或 IP 与旧服务器不同，请先修改 .env："
    echo -e "  ${CYAN}vi ${SCRIPT_DIR}/.env${NC}"
    echo ""
    echo "  当前配置："
    echo "    GITEA_DOMAIN=${GITEA_DOMAIN:-未设置}"
    echo "    GITEA_DATA_DIR=${GITEA_DATA_DIR}"
    echo "    MYSQL_DATA_DIR=${MYSQL_DATA_DIR}"
    echo ""

    if ! confirm "配置正确，继续导入？（如需修改请选 N，改完后重新运行 import）"; then
        log "已暂停。修改 .env 后重新运行:"
        echo -e "  ${CYAN}bash migrate.sh import ${archive}${NC}"
        rm -rf "$WORK_DIR"
        exit 0
    fi

    # --- 5. 停止现有服务 ---
    step "5/9 停止现有服务"
    docker compose down 2>/dev/null || true

    # --- 6. 安装基础设施（如新服务器未部署过） ---
    step "6/9 检查基础设施"
    if ! command -v docker &>/dev/null; then
        warn "Docker 未安装。请先运行 deploy.sh 安装基础设施，或手动安装 Docker。"
        echo -e "  ${CYAN}bash deploy.sh${NC}"
        rm -rf "$WORK_DIR"
        exit 1
    fi

    if ! docker compose version &>/dev/null; then
        error "Docker Compose V2 未安装"
        rm -rf "$WORK_DIR"
        exit 1
    fi
    log "Docker 和 Compose 已就绪"

    # --- 7. 恢复 Gitea 数据目录 ---
    step "7/9 恢复 Gitea 数据"
    mkdir -p "$(dirname "$GITEA_DATA_DIR")"
    if [ -d "$GITEA_DATA_DIR" ] && [ "$(ls -A "$GITEA_DATA_DIR" 2>/dev/null)" ]; then
        warn "数据目录 ${GITEA_DATA_DIR} 非空"
        if confirm "是否清空后恢复？（选 N 则覆盖合并）"; then
            rm -rf "${GITEA_DATA_DIR:?}/"*
        fi
    fi
    tar xzf "${MIGRATE_DIR}/gitea-data.tar.gz" -C "$(dirname "$GITEA_DATA_DIR")"
    chown -R 1000:1000 "$GITEA_DATA_DIR"
    log "Gitea 数据已恢复到 ${GITEA_DATA_DIR}"

    # --- 8. 恢复数据库 ---
    step "8/9 恢复 MySQL 数据库"

    # 确保 MySQL 数据目录存在
    mkdir -p "$MYSQL_DATA_DIR"

    # 启动 MySQL（清空后让其自动初始化）
    log "启动 MySQL 容器..."
    docker compose up -d db

    # 等待 MySQL 就绪
    log "等待 MySQL 就绪..."
    local retries=0
    while ! docker compose exec -T db mysqladmin ping -h localhost -u root -p"${DB_ROOT_PASSWORD}" --silent 2>/dev/null; do
        retries=$((retries + 1))
        if [ "$retries" -ge 60 ]; then
            error "MySQL 启动超时（60 次重试）"
            rm -rf "$WORK_DIR"
            exit 1
        fi
        sleep 2
    done
    log "MySQL 已就绪"

    # 导入数据库
    log "正在导入数据库（这可能需要几分钟）..."
    docker compose exec -T db mysql \
        -u root -p"${DB_ROOT_PASSWORD}" \
        --default-character-set=utf8mb4 \
        < "${MIGRATE_DIR}/gitea-db.sql"
    log "数据库导入完成"

    # --- 9. 启动 Gitea 并执行迁移后操作 ---
    step "9/9 启动 Gitea 并验证"
    docker compose up -d
    log "容器已启动，等待 Gitea 就绪..."

    local retries=0
    while ! curl -sf http://127.0.0.1:3000/api/v1/version &>/dev/null; do
        retries=$((retries + 1))
        if [ "$retries" -ge 60 ]; then
            warn "Gitea 启动超时，请手动检查: docker compose logs server"
            break
        fi
        sleep 2
    done

    if curl -sf http://127.0.0.1:3000/api/v1/version &>/dev/null; then
        GITEA_VER=$(curl -sf http://127.0.0.1:3000/api/v1/version | grep -oP '"version"\s*:\s*"\K[^"]+')
        log "Gitea ${GITEA_VER} 启动成功"
    fi

    # 重新生成 Git Hooks（迁移后必须执行）
    log "重新生成 Git Hooks..."
    docker compose exec -u git server \
        /usr/local/bin/gitea -c /data/gitea/conf/app.ini admin regenerate hooks || \
        warn "regenerate hooks 失败，请手动执行"

    # 运行 doctor 检查
    log "运行 doctor 诊断..."
    docker compose exec -u git server \
        /usr/local/bin/gitea -c /data/gitea/conf/app.ini doctor check --all --fix 2>&1 | \
        tail -5 || warn "doctor check 返回异常，请检查日志"

    # 清理
    rm -rf "$WORK_DIR"

    echo ""
    log "===== 导入完成 ====="
    log "Gitea 已在新服务器运行"
    echo ""
    warn "迁移后请检查以下事项:"
    echo "  1. 访问 https://${GITEA_DOMAIN:-你的域名} 确认页面正常"
    echo "  2. 如域名/IP 变更，需更新 DNS 解析"
    echo "  3. 如需 HTTPS，需重新申请 SSL 证书:"
    echo -e "     ${CYAN}certbot certonly --webroot -w /var/www/certbot -d ${GITEA_DOMAIN:-你的域名}${NC}"
    echo "  4. 测试 Git clone / push 操作"
    echo "  5. 测试 SSH 克隆: git clone ssh://git@${GITEA_DOMAIN:-你的域名}:${SSH_PORT:-2222}/用户/仓库.git"
    echo ""
    log "运行验证命令检查完整性: bash migrate.sh verify"
}

# =============================================================
#  验证模式 — 迁移后验证完整性
# =============================================================
do_verify() {
    step "迁移后验证"

    load_env
    GITEA_DATA_DIR="${GITEA_DATA_DIR:-/var/lib/gitea}"
    local pass=0 fail=0

    check() {
        if eval "$2" &>/dev/null; then
            echo -e "  ${GREEN}✓${NC} $1"
            pass=$((pass + 1))
        else
            echo -e "  ${RED}✗${NC} $1"
            fail=$((fail + 1))
        fi
    }

    echo ""
    log "检查服务状态:"
    check "Gitea 容器运行中" "docker compose ps --status running | grep -q gitea"
    check "MySQL 容器运行中" "docker compose ps --status running | grep -q gitea-db"

    log "检查 API:"
    check "Gitea API 可达" "curl -sf http://127.0.0.1:3000/api/v1/version"

    if curl -sf http://127.0.0.1:3000/api/v1/version &>/dev/null; then
        GITEA_VER=$(curl -sf http://127.0.0.1:3000/api/v1/version | grep -oP '"version"\s*:\s*"\K[^"]+')
        log "  Gitea 版本: ${GITEA_VER}"
    fi

    log "检查数据库:"
    check "MySQL 连接正常" "docker compose exec -T db mysqladmin ping -h localhost -u root -p'${DB_ROOT_PASSWORD}' --silent"

    # 检查仓库数量
    REPO_COUNT=$(docker compose exec -T db mysql -u root -p"${DB_ROOT_PASSWORD}" -N -e \
        "SELECT COUNT(*) FROM gitea.repository;" 2>/dev/null || echo "0")
    log "  仓库数量: ${REPO_COUNT}"

    USER_COUNT=$(docker compose exec -T db mysql -u root -p"${DB_ROOT_PASSWORD}" -N -e \
        "SELECT COUNT(*) FROM gitea.user;" 2>/dev/null || echo "0")
    log "  用户数量: ${USER_COUNT}"

    log "检查数据目录:"
    check "Gitea 数据目录存在" "[ -d '${GITEA_DATA_DIR}/gitea' ]"
    check "仓库目录存在" "[ -d '${GITEA_DATA_DIR}/gitea/repositories' ] || [ -d '${GITEA_DATA_DIR}/git/repositories' ]"
    check "app.ini 存在" "[ -f '${GITEA_DATA_DIR}/gitea/conf/app.ini' ]"

    # 统计仓库目录下的裸仓库数量
    if [ -d "${GITEA_DATA_DIR}/gitea/repositories" ]; then
        DISK_REPOS=$(find "${GITEA_DATA_DIR}/gitea/repositories" -name "*.git" -type d -maxdepth 3 2>/dev/null | wc -l)
        log "  磁盘上的仓库目录: ${DISK_REPOS}"
    fi

    log "检查网络:"
    check "SSH 端口可监听" "docker compose port server 2222"

    if command -v nginx &>/dev/null; then
        check "Nginx 运行中" "systemctl is-active nginx"
        check "Nginx 配置正确" "nginx -t"
    else
        warn "  Nginx 未安装（如需 HTTPS 请运行 deploy.sh 或手动安装）"
    fi

    echo ""
    log "===== 验证结果: ${pass} 通过, ${fail} 失败 ====="
    if [ "$fail" -gt 0 ]; then
        warn "存在失败项，请检查上方输出并排查问题"
        echo "  查看日志: docker compose logs"
        return 1
    else
        log "所有检查通过！迁移成功。"
    fi
}

# =============================================================
#  主入口
# =============================================================
usage() {
    echo "Gitea 迁移脚本"
    echo ""
    echo "用法:"
    echo "  bash migrate.sh export                # 旧服务器：导出迁移包"
    echo "  bash migrate.sh import <迁移包路径>    # 新服务器：导入迁移包"
    echo "  bash migrate.sh verify                # 迁移后：验证完整性"
    echo ""
    echo "迁移流程:"
    echo "  1. 旧服务器: bash migrate.sh export"
    echo "  2. 传输: scp gitea_migrate_xxx.tar.gz root@新服务器:/opt/gitea/"
    echo "  3. 新服务器: bash migrate.sh import gitea_migrate_xxx.tar.gz"
    echo "  4. 新服务器: bash migrate.sh verify"
}

main() {
    preflight

    case "${1:-}" in
        export)
            do_export
            ;;
        import)
            if [ -z "${2:-}" ]; then
                error "请指定迁移包路径"
                echo "用法: bash migrate.sh import <迁移包路径>"
                exit 1
            fi
            do_import "$2"
            ;;
        verify)
            do_verify
            ;;
        -h|--help|help)
            usage
            ;;
        *)
            usage
            exit 1
            ;;
    esac
}

main "$@"