/* Copyright Azareal 2017 - 2018 */
package main

import (
	"fmt"
	"bytes"
	"strings"
	"strconv"
	"io/ioutil"
	"path/filepath"
	"database/sql"

	"../query_gen/lib"
	_ "github.com/go-sql-driver/mysql"
)

//var db_collation string = "utf8mb4_general_ci"

func _set_mysql_adapter() {
	db_port = "3306"
	init_database = _init_mysql
	table_defs = _table_defs_mysql
	initial_data = _initial_data_mysql
}

func _init_mysql() (err error) {
	_db_password := db_password
	if _db_password != "" {
		_db_password = ":" + _db_password
	}
	db, err = sql.Open("mysql",db_username + _db_password + "@tcp(" + db_host + ":" + db_port + ")/")
	if err != nil {
		return err
	}

	// Make sure that the connection is alive..
	err = db.Ping()
	if err != nil {
		return err
	}
	fmt.Println("Successfully connected to the database")

	var waste string
	err = db.QueryRow("SHOW DATABASES LIKE '" + db_name + "'").Scan(&waste)
	if err != nil && err != sql.ErrNoRows {
		return err
	}

	if err == sql.ErrNoRows {
		fmt.Println("Unable to find the database. Attempting to create it")
		_,err = db.Exec("CREATE DATABASE IF NOT EXISTS " + db_name + "")
		if err != nil {
			return err
		}
		fmt.Println("The database was successfully created")
	}

	fmt.Println("Switching to database " + db_name)
	_, err = db.Exec("USE " + db_name)
	if err != nil {
		return err
	}

	// Ready the query builder
	qgen.Builder.SetConn(db)
	err = qgen.Builder.SetAdapter("mysql")
	if err != nil {
		return err
	}

	return nil
}

func _table_defs_mysql() error {
	//fmt.Println("Creating the tables")
	files, _ := ioutil.ReadDir("./schema/mysql/")
	for _, f := range files {
		if !strings.HasPrefix(f.Name(),"query_") {
			continue
		}

		var table string
		var ext string
		table = strings.TrimPrefix(f.Name(),"query_")
		ext = filepath.Ext(table)
		if ext != ".sql" {
			continue
		}
		table = strings.TrimSuffix(table,ext)

		fmt.Println("Creating table '" + table + "'")
		data, err := ioutil.ReadFile("./schema/mysql/" + f.Name())
		if err != nil {
			return err
		}
		data = bytes.TrimSpace(data)

		_, err = db.Exec(string(data))
		if err != nil {
			fmt.Println("Failed query:",string(data))
			return err
		}
	}
	//fmt.Println("Finished creating the tables")
	return nil
}

func _initial_data_mysql() error {
	return nil // Coming Soon

	fmt.Println("Seeding the tables")
	data, err := ioutil.ReadFile("./schema/mysql/inserts.sql")
	if err != nil {
		return err
	}
	data = bytes.TrimSpace(data)

	fmt.Println("Executing query",string(data))
	_, err = db.Exec(string(data))
	if err != nil {
		return err
	}

	//fmt.Println("Finished inserting the database data")
	return nil
}

func _mysql_seed_database() error {
	fmt.Println("Opening the database seed file")
	sqlContents, err := ioutil.ReadFile("./mysql.sql")
	if err != nil {
		return err
	}

	fmt.Println("Preparing installation queries")
	sqlContents = bytes.TrimSpace(sqlContents)
	statements := bytes.Split(sqlContents, []byte(";"))
	for key, statement := range statements {
		if len(statement) == 0 {
			continue
		}

		fmt.Println("Executing query #" + strconv.Itoa(key) + " " + string(statement))
		_, err = db.Exec(string(statement))
		if err != nil {
			return err
		}
	}
	fmt.Println("Finished inserting the database data")
	return nil
}