// Copyright 2017 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package wrap

import (
	"database/sql/driver"

	"sync/atomic"

	"github.com/30x/apid-core"
	"github.com/mattn/go-sqlite3"
)

type wrapConn struct {
	*sqlite3.SQLiteConn
	log         apid.LogService
	stmtCounter int64
	txCounter   int64
}

func (c *wrapConn) Swap(cc *sqlite3.SQLiteConn) {
	c.SQLiteConn = cc
}

func (c *wrapConn) Prepare(query string) (driver.Stmt, error) {
	stmtID := atomic.AddInt64(&c.stmtCounter, 1)
	log := c.log.WithField("stmt", stmtID)
	log.Debugf("begin prepare stmt: %s", query)

	stmt, err := c.SQLiteConn.Prepare(query)
	if err != nil {
		log.Errorf("prepare stmt failed: %s", err)
		return nil, err
	}

	log.Debug("end prepare stmt")
	s := stmt.(*sqlite3.SQLiteStmt)
	return &wrapStmt{s, log}, nil
}

func (c *wrapConn) Begin() (driver.Tx, error) {
	txID := atomic.AddInt64(&c.txCounter, 1)
	log := c.log.WithField("tx", txID)
	log.Debug("begin trans")

	tx, err := c.SQLiteConn.Begin()
	if err != nil {
		log.Errorf("begin trans failed: %s", err)
		return nil, err
	}

	log.Debug("end begin trans")
	t := tx.(*sqlite3.SQLiteTx)
	return &wrapTx{t, log}, nil
}

func (c *wrapConn) Close() (err error) {
	c.log.Debug("begin close conn")

	if err = c.SQLiteConn.Close(); err != nil {
		c.log.Errorf("close conn failed: %s", err)
		return
	}

	c.log.Debug("end close conn")
	return
}

func (c *wrapConn) Query(query string, args []driver.Value) (rows driver.Rows, err error) {
	c.log.Debugf("begin query: %s args: %#v", query, args)
	rows, err = c.SQLiteConn.Query(query, args)
	if err != nil {
		c.log.Debugf("query failed: %s", err)
		return
	}

	c.log.Debugf("end query: %#v", rows)
	return
}