// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.

package models

import (
	"database/sql"
	"errors"
	"fmt"
	"net/url"
	"os"
	"path"
	"strings"

	_ "github.com/go-sql-driver/mysql"
	"github.com/go-xorm/core"
	"github.com/go-xorm/xorm"
	_ "github.com/lib/pq"

	"github.com/go-gitea/gitea/models/migrations"
	"github.com/go-gitea/gitea/modules/setting"
)

// Engine represents a xorm engine or session.
type Engine interface {
	Delete(interface{}) (int64, error)
	Exec(string, ...interface{}) (sql.Result, error)
	Find(interface{}, ...interface{}) error
	Get(interface{}) (bool, error)
	Id(interface{}) *xorm.Session
	In(string, ...interface{}) *xorm.Session
	Insert(...interface{}) (int64, error)
	InsertOne(interface{}) (int64, error)
	Iterate(interface{}, xorm.IterFunc) error
	Sql(string, ...interface{}) *xorm.Session
	Where(interface{}, ...interface{}) *xorm.Session
}

func sessionRelease(sess *xorm.Session) {
	if !sess.IsCommitedOrRollbacked {
		sess.Rollback()
	}
	sess.Close()
}

var (
	x         *xorm.Engine
	tables    []interface{}
	HasEngine bool

	DbCfg struct {
		Type, Host, Name, User, Passwd, Path, SSLMode string
	}

	EnableSQLite3 bool
	EnableTiDB    bool
)

func init() {
	tables = append(tables,
		new(User), new(PublicKey), new(AccessToken),
		new(Repository), new(DeployKey), new(Collaboration), new(Access), new(Upload),
		new(Watch), new(Star), new(Follow), new(Action),
		new(Issue), new(PullRequest), new(Comment), new(Attachment), new(IssueUser),
		new(Label), new(IssueLabel), new(Milestone),
		new(Mirror), new(Release), new(LoginSource), new(Webhook),
		new(UpdateTask), new(HookTask),
		new(Team), new(OrgUser), new(TeamUser), new(TeamRepo),
		new(Notice), new(EmailAddress))

	gonicNames := []string{"SSL"}
	for _, name := range gonicNames {
		core.LintGonicMapper[name] = true
	}
}

func LoadConfigs() {
	sec := setting.Cfg.Section("database")
	DbCfg.Type = sec.Key("DB_TYPE").String()
	switch DbCfg.Type {
	case "sqlite3":
		setting.UseSQLite3 = true
	case "mysql":
		setting.UseMySQL = true
	case "postgres":
		setting.UsePostgreSQL = true
	case "tidb":
		setting.UseTiDB = true
	}
	DbCfg.Host = sec.Key("HOST").String()
	DbCfg.Name = sec.Key("NAME").String()
	DbCfg.User = sec.Key("USER").String()
	if len(DbCfg.Passwd) == 0 {
		DbCfg.Passwd = sec.Key("PASSWD").String()
	}
	DbCfg.SSLMode = sec.Key("SSL_MODE").String()
	DbCfg.Path = sec.Key("PATH").MustString("data/gogs.db")
}

// parsePostgreSQLHostPort parses given input in various forms defined in
// https://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING
// and returns proper host and port number.
func parsePostgreSQLHostPort(info string) (string, string) {
	host, port := "127.0.0.1", "5432"
	if strings.Contains(info, ":") && !strings.HasSuffix(info, "]") {
		idx := strings.LastIndex(info, ":")
		host = info[:idx]
		port = info[idx+1:]
	} else if len(info) > 0 {
		host = info
	}
	return host, port
}

func getEngine() (*xorm.Engine, error) {
	connStr := ""
	var Param string = "?"
	if strings.Contains(DbCfg.Name, Param) {
		Param = "&"
	}
	switch DbCfg.Type {
	case "mysql":
		if DbCfg.Host[0] == '/' { // looks like a unix socket
			connStr = fmt.Sprintf("%s:%s@unix(%s)/%s%scharset=utf8&parseTime=true",
				DbCfg.User, DbCfg.Passwd, DbCfg.Host, DbCfg.Name, Param)
		} else {
			connStr = fmt.Sprintf("%s:%s@tcp(%s)/%s%scharset=utf8&parseTime=true",
				DbCfg.User, DbCfg.Passwd, DbCfg.Host, DbCfg.Name, Param)
		}
	case "postgres":
		host, port := parsePostgreSQLHostPort(DbCfg.Host)
		if host[0] == '/' { // looks like a unix socket
			connStr = fmt.Sprintf("postgres://%s:%s@:%s/%s%ssslmode=%s&host=%s",
				url.QueryEscape(DbCfg.User), url.QueryEscape(DbCfg.Passwd), port, DbCfg.Name, Param, DbCfg.SSLMode, host)
		} else {
			connStr = fmt.Sprintf("postgres://%s:%s@%s:%s/%s%ssslmode=%s",
				url.QueryEscape(DbCfg.User), url.QueryEscape(DbCfg.Passwd), host, port, DbCfg.Name, Param, DbCfg.SSLMode)
		}
	case "sqlite3":
		if !EnableSQLite3 {
			return nil, errors.New("This binary version does not build support for SQLite3.")
		}
		if err := os.MkdirAll(path.Dir(DbCfg.Path), os.ModePerm); err != nil {
			return nil, fmt.Errorf("Fail to create directories: %v", err)
		}
		connStr = "file:" + DbCfg.Path + "?cache=shared&mode=rwc"
	case "tidb":
		if !EnableTiDB {
			return nil, errors.New("This binary version does not build support for TiDB.")
		}
		if err := os.MkdirAll(path.Dir(DbCfg.Path), os.ModePerm); err != nil {
			return nil, fmt.Errorf("Fail to create directories: %v", err)
		}
		connStr = "goleveldb://" + DbCfg.Path
	default:
		return nil, fmt.Errorf("Unknown database type: %s", DbCfg.Type)
	}
	return xorm.NewEngine(DbCfg.Type, connStr)
}

func NewTestEngine(x *xorm.Engine) (err error) {
	x, err = getEngine()
	if err != nil {
		return fmt.Errorf("Connect to database: %v", err)
	}

	x.SetMapper(core.GonicMapper{})
	return x.StoreEngine("InnoDB").Sync2(tables...)
}

func SetEngine() (err error) {
	x, err = getEngine()
	if err != nil {
		return fmt.Errorf("Fail to connect to database: %v", err)
	}

	x.SetMapper(core.GonicMapper{})

	// WARNING: for serv command, MUST remove the output to os.stdout,
	// so use log file to instead print to stdout.
	logPath := path.Join(setting.LogRootPath, "xorm.log")
	os.MkdirAll(path.Dir(logPath), os.ModePerm)

	f, err := os.Create(logPath)
	if err != nil {
		return fmt.Errorf("Fail to create xorm.log: %v", err)
	}
	x.SetLogger(xorm.NewSimpleLogger(f))
	x.ShowSQL(true)
	return nil
}

func NewEngine() (err error) {
	if err = SetEngine(); err != nil {
		return err
	}

	if err = migrations.Migrate(x); err != nil {
		return fmt.Errorf("migrate: %v", err)
	}

	if err = x.StoreEngine("InnoDB").Sync2(tables...); err != nil {
		return fmt.Errorf("sync database struct error: %v\n", err)
	}

	return nil
}

type Statistic struct {
	Counter struct {
		User, Org, PublicKey,
		Repo, Watch, Star, Action, Access,
		Issue, Comment, Oauth, Follow,
		Mirror, Release, LoginSource, Webhook,
		Milestone, Label, HookTask,
		Team, UpdateTask, Attachment int64
	}
}

func GetStatistic() (stats Statistic) {
	stats.Counter.User = CountUsers()
	stats.Counter.Org = CountOrganizations()
	stats.Counter.PublicKey, _ = x.Count(new(PublicKey))
	stats.Counter.Repo = CountRepositories(true)
	stats.Counter.Watch, _ = x.Count(new(Watch))
	stats.Counter.Star, _ = x.Count(new(Star))
	stats.Counter.Action, _ = x.Count(new(Action))
	stats.Counter.Access, _ = x.Count(new(Access))
	stats.Counter.Issue, _ = x.Count(new(Issue))
	stats.Counter.Comment, _ = x.Count(new(Comment))
	stats.Counter.Oauth = 0
	stats.Counter.Follow, _ = x.Count(new(Follow))
	stats.Counter.Mirror, _ = x.Count(new(Mirror))
	stats.Counter.Release, _ = x.Count(new(Release))
	stats.Counter.LoginSource = CountLoginSources()
	stats.Counter.Webhook, _ = x.Count(new(Webhook))
	stats.Counter.Milestone, _ = x.Count(new(Milestone))
	stats.Counter.Label, _ = x.Count(new(Label))
	stats.Counter.HookTask, _ = x.Count(new(HookTask))
	stats.Counter.Team, _ = x.Count(new(Team))
	stats.Counter.UpdateTask, _ = x.Count(new(UpdateTask))
	stats.Counter.Attachment, _ = x.Count(new(Attachment))
	return
}

func Ping() error {
	return x.Ping()
}

// DumpDatabase dumps all data from database to file system.
func DumpDatabase(filePath string) error {
	return x.DumpAllToFile(filePath)
}