#!/usr/bin/env python
# coding: utf-8

#===================================================
from config import Log
#---------------------------------------------------
import pymysql
import threading
import traceback
#===================================================

def array_join(arr, c):
    t = ''
    for a in arr:
        t += "'%s'" % str(a).replace("'","\\\'") + c
    return t[:-len(c)]

class MysqlDB(object):
    """
    修改服务器上的配置文件/etc/my.cnf，在对应位置添加以下设置:
    [client]
    default-character-set = utf8mb4

    [mysql]
    default-character-set = utf8mb4

    [mysqld]
    character-set-client-handshake = FALSE
    character-set-server = utf8mb4
    collation-server = utf8mb4_unicode_ci
    init_connect='SET NAMES utf8mb4'
    """

    def __init__(self, conf):
        self.conf = conf
        config = {
            'host': conf['host'],
            'port': conf['port'],
            'user': conf['user'],
            'passwd': conf['passwd'],
            'charset':'utf8mb4', # 支持1-4个字节字符
            'cursorclass': pymysql.cursors.DictCursor
        }
        self.conn = pymysql.connect(**config)
        self.conn.autocommit(1)
        # for thread-save
        self.lock = threading.Lock()

        self.create_db(conf['database'])
        self.conn.select_db(conf['database'])

        # cache table cols
        self.table_cols = {}
        for t in self.show_tables():
            self.table_cols[t] = self.get_table_column_name(t)

    def show_database(self):
        c = self.conn.cursor()
        sql = 'SHOW DATABASES'
        Log.debug('DB -> %s' % sql)
        c.execute(sql)
        return [r['Database'] for r in c.fetchall()]

    def show_tables(self):
        c = self.conn.cursor()
        sql = 'SHOW TABLES'
        Log.debug('DB -> %s' % sql)
        c.execute(sql)
        return [r['Tables_in_'+self.conf['database']] for r in c.fetchall()]

    def create_db(self, db_name):
        """
        @brief      Creates a database
        @param      db_name  String
        """
        if self.conf['database'] not in self.show_database():
            sql = 'CREATE DATABASE IF NOT EXISTS %s CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci' % db_name
            Log.debug('DB -> %s' % sql)
            self.execute(sql)

    def create_table(self, table, cols):
        """
        @brief      Creates a table in database
        @param      table  String
        @param      cols   String, the cols in table
        """
        if table not in self.table_cols:
            sql = 'CREATE TABLE IF NOT EXISTS %s(id int primary key auto_increment, %s) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci' % (table, cols)
            Log.debug('DB -> %s' % sql)
            self.execute(sql)
            self.table_cols[table] = ['id'] + [c.strip().split(' ')[0] for c in cols.split(',')]

    def delete_table(self, table):
        """
        @brief      Delete a table in database
        @param      table  String
        """
        if table in self.table_cols:
            sql = "DROP TABLE IF EXISTS %s" % table
            Log.debug('DB -> %s' % sql)
            self.execute(sql)
            self.table_cols.pop(table)

    def insert(self, table, value):
        """
        @brief      Insert a row in table
        @param      table  String
        @param      value  Tuple
        """
        col_name = self.table_cols[table][1:]
        sql = "INSERT INTO %s(%s) VALUES (%s)" % (table, str(','.join(col_name)), array_join(value, ','))
        Log.debug('DB -> %s' % sql)
        self.execute(sql)

    def insertmany(self, table, values):
        """
        @brief      Insert many rows in table
        @param      table  String
        @param      values  Array of tuple
        """
        col_name = self.table_cols[table][1:]
        sql = 'INSERT INTO %s(%s) VALUES (%s)' % (table, ','.join(col_name), ','.join(['%s'] * len(values[0])))
        Log.debug('DB -> %s' % sql)
        self.execute(sql, values)

    def select(self, table, field='', condition=''):
        """
        @brief      select all result from table
        @param      table  String
        @param      field  String
        @param      condition  String
        @return     result  Tuple
        """
        sql = "SELECT * FROM %s" % table
        if field and condition:
            sql += " WHERE %s='%s'" % (field, condition)
        Log.debug('DB -> %s' % sql)
        return self.execute(sql)

    def get_table_column_name(self, table):
        """
        @brief      select all result from table
        @param      table  String
        @return     result  Array
        """
        c = self.conn.cursor()
        c.execute("SELECT * FROM %s" % table)
        names = list(map(lambda x: x[0], c.description))
        return names

    def execute(self, sql, values=None):
        """
        @brief      execute sql commands, return result if it has
        @param      sql  String
        @param      value  Tuple
        @return     result  Array
        """
        c = self.conn.cursor()
        self.lock.acquire()
        hasReturn = sql.lstrip().upper().startswith("SELECT")

        result = []
        try:
            if values:
                c.executemany(sql, values)
            else:
                c.execute(sql)

            if hasReturn:
                result = c.fetchall()

        except Exception, e:
            Log.error(traceback.format_exc())
            self.conn.rollback()
        finally:
            self.lock.release()

        if hasReturn:
            return result

    def delete(self, table, field='', condition=''):
        """
        @brief      execute sql commands, return result if it has
        @param      table  String
        @param      field  String
        @param      condition  String
        """
        sql = "DELETE FROM %s WHERE %s=%s" % (table, field, condition)
        Log.debug('DB -> %s' % sql)
        self.execute(sql)

    def close(self):
        """
        @brief      close connection to database
        """
        Log.debug('DB -> close')
        # 关闭数据库连接
        self.conn.close()