package db

import (
	"code.hoteas.com/golang/hotime/cache"
	. "code.hoteas.com/golang/hotime/common"
	"database/sql"
	"strings"
	"sync"

	_ "github.com/go-sql-driver/mysql"
	_ "github.com/mattn/go-sqlite3"
	"github.com/sirupsen/logrus"
)

// HoTimeDB 数据库操作核心结构体
type HoTimeDB struct {
	*sql.DB
	ContextBase
	DBName string
	*cache.HoTimeCache
	Log         *logrus.Logger
	Type        string // 数据库类型: mysql, sqlite3, postgres
	Prefix      string
	LastQuery   string
	LastData    []interface{}
	ConnectFunc func(err ...*Error) (*sql.DB, *sql.DB)
	LastErr     *Error
	limit       Slice
	*sql.Tx             //事务对象
	SlaveDB     *sql.DB // 从数据库
	Mode        int     // mode为0生产模式,1为测试模式,2为开发模式
	mu          sync.RWMutex
	limitMu     sync.Mutex
	Dialect     Dialect // 数据库方言适配器
}

// SetConnect 设置数据库配置连接
func (that *HoTimeDB) SetConnect(connect func(err ...*Error) (master, slave *sql.DB), err ...*Error) {
	that.ConnectFunc = connect
	_ = that.InitDb(err...)
}

// InitDb 初始化数据库连接
func (that *HoTimeDB) InitDb(err ...*Error) *Error {
	if len(err) != 0 {
		that.LastErr = err[0]
	}
	that.DB, that.SlaveDB = that.ConnectFunc(that.LastErr)
	if that.DB == nil {
		return that.LastErr
	}
	e := that.DB.Ping()

	that.LastErr.SetError(e)

	if that.SlaveDB != nil {
		e := that.SlaveDB.Ping()
		that.LastErr.SetError(e)
	}

	// 根据数据库类型初始化方言适配器
	if that.Dialect == nil {
		that.initDialect()
	}

	return that.LastErr
}

// initDialect 根据数据库类型初始化方言
func (that *HoTimeDB) initDialect() {
	switch that.Type {
	case "postgres", "postgresql":
		that.Dialect = &PostgreSQLDialect{}
	case "sqlite3", "sqlite":
		that.Dialect = &SQLiteDialect{}
	default:
		that.Dialect = &MySQLDialect{}
	}
}

// GetDialect 获取当前方言适配器
func (that *HoTimeDB) GetDialect() Dialect {
	if that.Dialect == nil {
		that.initDialect()
	}
	return that.Dialect
}

// SetDialect 设置方言适配器
func (that *HoTimeDB) SetDialect(dialect Dialect) {
	that.Dialect = dialect
}

// GetType 获取数据库类型
func (that *HoTimeDB) GetType() string {
	return that.Type
}

// GetPrefix 获取表前缀
func (that *HoTimeDB) GetPrefix() string {
	return that.Prefix
}

// GetProcessor 获取标识符处理器
// 用于处理表名、字段名的前缀添加和引号转换
func (that *HoTimeDB) GetProcessor() *IdentifierProcessor {
	return NewIdentifierProcessor(that.GetDialect(), that.Prefix)
}

// T 辅助方法：获取带前缀和引号的表名
// 用于手动构建 SQL 时使用
// 示例: db.T("order") 返回 "`app_order`" (MySQL) 或 "\"app_order\"" (PostgreSQL)
func (that *HoTimeDB) T(table string) string {
	return that.GetProcessor().ProcessTableName(table)
}

// C 辅助方法：获取带前缀和引号的 table.column
// 支持两种调用方式:
//   - db.C("order", "name") 返回 "`app_order`.`name`"
//   - db.C("order.name") 返回 "`app_order`.`name`"
func (that *HoTimeDB) C(args ...string) string {
	if len(args) == 0 {
		return ""
	}
	if len(args) == 1 {
		return that.GetProcessor().ProcessColumn(args[0])
	}
	// 两个参数: table, column
	dialect := that.GetDialect()
	table := args[0]
	column := args[1]
	// 去除已有引号
	table = trimQuotes(table)
	column = trimQuotes(column)
	return dialect.QuoteIdentifier(that.Prefix+table) + "." + dialect.QuoteIdentifier(column)
}

// trimQuotes 去除字符串两端的引号
func trimQuotes(s string) string {
	s = strings.TrimSpace(s)
	if len(s) >= 2 {
		if (s[0] == '`' && s[len(s)-1] == '`') || (s[0] == '"' && s[len(s)-1] == '"') {
			return s[1 : len(s)-1]
		}
	}
	return s
}