package tick

import "log"
import "database/sql"
import _ "github.com/go-sql-driver/mysql"
import "fmt"
import "time"
import "errors"

var db *sql.DB
var tserver *TickServer
var serverconf *ServerConf

type newDs func(conf *DsConf) (DataSource, error)

var drivers = make(map[string]newDs)

//设置数据库连接
func initdb(dbconf *DBConf) {
	var err error
	db, err = sql.Open(dbconf.DBDriver, dbconf.DSN)
	if err != nil {
		panic(err)
	}
}

func getDriver(name string) (newDs, error) {
	if ret, ok := drivers[name]; ok {
		return ret, nil
	}
	return nil, errors.New("getDriver " + name + " error.")
}

func SetConf(conf *ServerConf) {
	serverconf = conf
}

func InitDb() {
	initdb(&serverconf.DBConf)
}

func Init() {
	//parse
	//log.Println("initdb")
	initdb(&serverconf.DBConf)
	var err error
	//getdblock,global 获取一个数据库的锁，这个锁可以证明没有其他的实例运行，操作数据库
	tserver, err = NewTickServer()
	if err != nil {
		panic(err)
	}
	//log.Println("run datasource...")
	runDataSource(serverconf)
}

func getFilePath(ty string) (string, error) {
	if conf, ok := serverconf.DsMap[ty]; ok {
		return conf.SaveDir, nil
	}
	return "", ErrDataSourceType
}

func runDataSource(conf *ServerConf) {
	for name, dsConf := range conf.DsMap {
		if dsConf.Run {
			ds := NewDataSource(name, dsConf)
			if ds != nil {
				tserver.AddDataSource(ds, dsConf.Download)
				go ds.Run()
			}
			//log.Println("run", name)
		}
	}
}

func NewDataSource(name string, conf *DsConf) DataSource {
	driver, err := getDriver(name)
	if err != nil {
		log.Fatal(err)
	}
	ds, err := driver(conf)
	if err != nil {
		log.Fatal(err)
	}
	return ds
}

func lockDb(name string) bool {
	//setLock
	q := "UPDATE system_lock SET flag=1 WHERE name='%s' AND flag <> 1"
	q = fmt.Sprintf(q, name)
	result, err := db.Exec(q)
	if err != nil {
		//log.Println("[lockdb]", err)
		return false
	}
	n, err := result.RowsAffected()
	if err != nil {
		//log.Println("[lockdb]", err)
		return false
	}
	if n == 1 {
		return true
	}
	//log.Println("[lockdb]", "lock an locked lock")
	return false
}

func LockDb(name string, wait bool) bool {
	for {
		ok := lockDb(name)
		if !ok && wait {
			time.Sleep(time.Millisecond * 100)
			continue
		}
		return ok
	}
}

func UnlockDb(name string) bool {
	q := "UPDATE system_lock SET flag=0 WHERE name='%s' AND flag <> 0"
	q = fmt.Sprintf(q, name)
	result, err := db.Exec(q)
	if err != nil {
		//log.Println("[unlockdb]", err)
		return false
	}
	n, err := result.RowsAffected()
	if err != nil {
		//log.Println("[unlockdb]", err)
		return false
	}
	if n == 1 {
		return true
	}
	panic("unlock a unlocked lock")
}