#!/bin/bash

# CCDI 数据库迁移自动化脚本
# 功能：数据库导出和导入自动化

set -e  # 遇到错误立即退出

# 颜色定义
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# 日志函数
log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

log_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# 脚本目录
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIG_FILE="${SCRIPT_DIR}/db_config.conf"

# 检查配置文件
check_config() {
    if [ ! -f "$CONFIG_FILE" ]; then
        log_error "配置文件不存在: $CONFIG_FILE"
        log_info "请先复制配置模板: cp db_config.conf.template db_config.conf"
        log_info "然后编辑 db_config.conf 填写实际数据库连接信息"
        exit 1
    fi

    # 加载配置文件
    source "$CONFIG_FILE"
    log_info "配置文件加载成功"
}

# 检查 mysqldump 命令
check_mysqldump() {
    if ! command -v mysqldump &> /dev/null; then
        log_error "mysqldump 命令未找到"
        log_info "请安装 MySQL 客户端工具"
        exit 1
    fi
    log_info "mysqldump 命令检查通过"
}

# 创建备份目录
create_backup_dir() {
    if [ ! -d "$BACKUP_DIR" ]; then
        mkdir -p "$BACKUP_DIR"
        log_info "创建备份目录: $BACKUP_DIR"
    fi
}

# 导出表结构
export_structure() {
    log_info "开始导出表结构..."

    local output_file="${BACKUP_DIR}/${STRUCTURE_FILE}"

    # 创建临时文件
    local temp_file=$(mktemp)

    # 导出表结构到临时文件
    mysqldump -h "$SOURCE_DB_HOST" \
        -P "$SOURCE_DB_PORT" \
        -u "$SOURCE_DB_USER" \
        -p"$SOURCE_DB_PASS" \
        --no-data \
        --skip-triggers \
        --skip-add-drop-table \
        --default-character-set=$CHARACTER_SET \
        --single-transaction \
        --max_allowed_packet=$MAX_ALLOWED_PACKET \
        "$SOURCE_DB_NAME" > "$temp_file" 2>/dev/null

    if [ $? -eq 0 ]; then
        # 添加字符集声明到文件头部
        {
            echo "-- CCDI 数据库表结构"
            echo "-- 导出时间: $(date '+%Y-%m-%d %H:%M:%S')"
            echo "-- 源数据库: ${SOURCE_DB_HOST}:${SOURCE_DB_PORT}/${SOURCE_DB_NAME}"
            echo "-- 字符集: ${CHARACTER_SET}"
            echo ""
            echo "SET NAMES utf8mb4;"
            echo "SET CHARACTER SET utf8mb4;"
            echo "SET GLOBAL character_set_client=utf8mb4;"
            echo "SET GLOBAL character_set_connection=utf8mb4;"
            echo "SET GLOBAL character_set_results=utf8mb4;"
            echo ""
            cat "$temp_file"
        } > "$output_file"

        rm -f "$temp_file"
        log_info "表结构导出成功: $output_file"
        log_info "文件大小: $(du -h "$output_file" | cut -f1)"
    else
        rm -f "$temp_file"
        log_error "表结构导出失败"
        exit 1
    fi
}

# 导出数据
export_data() {
    log_info "开始导出数据..."

    local output_file="${BACKUP_DIR}/${DATA_FILE}"

    # 创建临时文件
    local temp_file=$(mktemp)

    # 导出数据到临时文件
    mysqldump -h "$SOURCE_DB_HOST" \
        -P "$SOURCE_DB_PORT" \
        -u "$SOURCE_DB_USER" \
        -p"$SOURCE_DB_PASS" \
        --no-create-info \
        --skip-triggers \
        --default-character-set=$CHARACTER_SET \
        --single-transaction \
        --complete-insert \
        --extended-insert \
        --max_allowed_packet=$MAX_ALLOWED_PACKET \
        "$SOURCE_DB_NAME" > "$temp_file" 2>/dev/null

    if [ $? -eq 0 ]; then
        # 添加字符集声明到文件头部
        {
            echo "-- CCDI 数据库数据"
            echo "-- 导出时间: $(date '+%Y-%m-%d %H:%M:%S')"
            echo "-- 源数据库: ${SOURCE_DB_HOST}:${SOURCE_DB_PORT}/${SOURCE_DB_NAME}"
            echo "-- 字符集: ${CHARACTER_SET}"
            echo ""
            echo "SET NAMES utf8mb4;"
            echo "SET CHARACTER SET utf8mb4;"
            echo "SET GLOBAL character_set_client=utf8mb4;"
            echo "SET GLOBAL character_set_connection=utf8mb4;"
            echo "SET GLOBAL character_set_results=utf8mb4;"
            echo "SET FOREIGN_KEY_CHECKS=0;"
            echo ""
            cat "$temp_file"
            echo ""
            echo "SET FOREIGN_KEY_CHECKS=1;"
        } > "$output_file"

        rm -f "$temp_file"
        log_info "数据导出成功: $output_file"
        log_info "文件大小: $(du -h "$output_file" | cut -f1)"
    else
        rm -f "$temp_file"
        log_error "数据导出失败"
        exit 1
    fi
}

# 验证导出文件
verify_export() {
    log_info "验证导出文件..."

    local structure_file="${BACKUP_DIR}/${STRUCTURE_FILE}"
    local data_file="${BACKUP_DIR}/${DATA_FILE}"

    # 检查文件是否存在
    if [ ! -f "$structure_file" ]; then
        log_error "表结构文件不存在: $structure_file"
        exit 1
    fi

    if [ ! -f "$data_file" ]; then
        log_error "数据文件不存在: $data_file"
        exit 1
    fi

    # 检查字符集声明
    if ! grep -q "SET NAMES utf8mb4" "$structure_file"; then
        log_error "表结构文件缺少字符集声明"
        exit 1
    fi

    if ! grep -q "SET NAMES utf8mb4" "$data_file"; then
        log_error "数据文件缺少字符集声明"
        exit 1
    fi

    log_info "导出文件验证通过"
    log_info "表结构文件: $structure_file ($(du -h "$structure_file" | cut -f1))"
    log_info "数据文件: $data_file ($(du -h "$data_file" | cut -f1))"
}

# 导入表结构
import_structure() {
    local env_type=$1
    local db_host db_port db_user db_pass db_name

    case "$env_type" in
        production|prod)
            db_host="$PROD_DB_HOST"
            db_port="$PROD_DB_PORT"
            db_user="$PROD_DB_USER"
            db_pass="$PROD_DB_PASS"
            db_name="$PROD_DB_NAME"
            ;;
        test)
            db_host="$TEST_DB_HOST"
            db_port="$TEST_DB_PORT"
            db_user="$TEST_DB_USER"
            db_pass="$TEST_DB_PASS"
            db_name="$TEST_DB_NAME"
            ;;
        *)
            log_error "未知的环境类型: $env_type"
            exit 1
            ;;
    esac

    log_info "导入表结构到 ${env_type} 环境: ${db_host}:${db_port}/${db_name}"

    local structure_file="${BACKUP_DIR}/${STRUCTURE_FILE}"

    if [ ! -f "$structure_file" ]; then
        log_error "表结构文件不存在: $structure_file"
        log_info "请先执行导出: ./export_database.sh export"
        exit 1
    fi

    # 导入表结构
    mysql -h "$db_host" \
        -P "$db_port" \
        -u "$db_user" \
        -p"$db_pass" \
        --default-character-set=$CHARACTER_SET \
        "$db_name" < "$structure_file" 2>/dev/null

    if [ $? -eq 0 ]; then
        log_info "表结构导入成功"
    else
        log_error "表结构导入失败"
        exit 1
    fi
}

# 导入数据
import_data() {
    local env_type=$1
    local db_host db_port db_user db_pass db_name

    case "$env_type" in
        production|prod)
            db_host="$PROD_DB_HOST"
            db_port="$PROD_DB_PORT"
            db_user="$PROD_DB_USER"
            db_pass="$PROD_DB_PASS"
            db_name="$PROD_DB_NAME"
            ;;
        test)
            db_host="$TEST_DB_HOST"
            db_port="$TEST_DB_PORT"
            db_user="$TEST_DB_USER"
            db_pass="$TEST_DB_PASS"
            db_name="$TEST_DB_NAME"
            ;;
        *)
            log_error "未知的环境类型: $env_type"
            exit 1
            ;;
    esac

    log_info "导入数据到 ${env_type} 环境: ${db_host}:${db_port}/${db_name}"

    local data_file="${BACKUP_DIR}/${DATA_FILE}"

    if [ ! -f "$data_file" ]; then
        log_error "数据文件不存在: $data_file"
        log_info "请先执行导出: ./export_database.sh export"
        exit 1
    fi

    # 导入数据
    mysql -h "$db_host" \
        -P "$db_port" \
        -u "$db_user" \
        -p"$db_pass" \
        --default-character-set=$CHARACTER_SET \
        "$db_name" < "$data_file" 2>/dev/null

    if [ $? -eq 0 ]; then
        log_info "数据导入成功"
    else
        log_error "数据导入失败"
        exit 1
    fi
}

# 验证导入结果
verify_import() {
    local env_type=$1
    local db_host db_port db_user db_pass db_name

    case "$env_type" in
        production|prod)
            db_host="$PROD_DB_HOST"
            db_port="$PROD_DB_PORT"
            db_user="$PROD_DB_USER"
            db_pass="$PROD_DB_PASS"
            db_name="$PROD_DB_NAME"
            ;;
        test)
            db_host="$TEST_DB_HOST"
            db_port="$TEST_DB_PORT"
            db_user="$TEST_DB_USER"
            db_pass="$TEST_DB_PASS"
            db_name="$TEST_DB_NAME"
            ;;
        *)
            log_error "未知的环境类型: $env_type"
            exit 1
            ;;
    esac

    log_info "验证导入结果..."

    # 查询表数量
    local table_count=$(mysql -h "$db_host" \
        -P "$db_port" \
        -u "$db_user" \
        -p"$db_pass" \
        --default-character-set=$CHARACTER_SET \
        -N -e "SELECT COUNT(*) FROM information_schema.tables WHERE table_schema='$db_name';" "$db_name" 2>/dev/null)

    log_info "目标数据库表数量: $table_count"

    # 查询关键表行数（示例：sys_user 表）
    local user_count=$(mysql -h "$db_host" \
        -P "$db_port" \
        -u "$db_user" \
        -p"$db_pass" \
        --default-character-set=$CHARACTER_SET \
        -N -e "SELECT COUNT(*) FROM sys_user;" "$db_name" 2>/dev/null)

    log_info "sys_user 表数据行数: $user_count"

    # 检查数据库字符集
    local db_charset=$(mysql -h "$db_host" \
        -P "$db_port" \
        -u "$db_user" \
        -p"$db_pass" \
        --default-character-set=$CHARACTER_SET \
        -N -e "SELECT DEFAULT_CHARACTER_SET_NAME FROM information_schema.schemata WHERE schema_name='$db_name';" 2>/dev/null)

    log_info "数据库字符集: $db_charset"
}

# 导入数据库
import_database() {
    local env_type=$1

    if [ -z "$env_type" ]; then
        log_error "请指定目标环境: production 或 test"
        log_info "用法: $0 import [production|test]"
        exit 1
    fi

    log_info "========== 开始导入数据库到 ${env_type} 环境 =========="

    check_config
    import_structure "$env_type"
    import_data "$env_type"
    verify_import "$env_type"

    log_info "========== 数据库导入完成 =========="
}

# 导出数据库
export_database() {
    log_info "========== 开始导出数据库 =========="

    check_config
    check_mysqldump
    create_backup_dir
    export_structure
    export_data
    verify_export

    log_info "========== 数据库导出完成 =========="
}

# 使用帮助
show_usage() {
    echo "用法: $0 <command> [options]"
    echo ""
    echo "命令:"
    echo "  export              导出数据库"
    echo "  import <env>        导入数据库到指定环境"
    echo "  help                显示帮助信息"
    echo ""
    echo "环境:"
    echo "  production, prod    生产环境"
    echo "  test                测试环境"
    echo ""
    echo "示例:"
    echo "  $0 export           # 导出数据库到 doc/database/backup/ 目录"
    echo "  $0 import test      # 导入数据库到测试环境"
    echo "  $0 import prod      # 导入数据库到生产环境"
}

# 主函数
main() {
    case "$1" in
        export)
            export_database
            ;;
        import)
            import_database "$2"
            ;;
        help|--help|-h)
            show_usage
            ;;
        *)
            log_error "未知命令: $1"
            show_usage
            exit 1
            ;;
    esac
}

# 执行主函数
main "$@"