package database

import (
	"net/url"
	"path/filepath"
	"strings"
	"sync"

	u "git.eeqj.de/sneak/goutil"
	"github.com/golang/groupcache/lru"
	"github.com/jinzhu/gorm"
	_ "github.com/jinzhu/gorm/dialects/postgres"
	_ "github.com/jinzhu/gorm/dialects/sqlite"
	"github.com/rs/zerolog/log"
	"github.com/spf13/viper"
)

const cacheEntries = 1000000

// Manager coordinates database and cache reads and writes
type Manager struct {
	db                            *gorm.DB
	cachelock                     sync.Mutex
	recentlyInsertedTootHashCache *lru.Cache
}

// New creates new Manager
func New() *Manager {
	m := new(Manager)
	m.init()
	return m
}

func (m *Manager) init() {
	m.open(viper.GetString("DBURL"))
	// breaks stuff, do not use:
	//m.db.SingularTable(true)
	m.db.LogMode(false)
	if viper.GetBool("Debug") {
		m.db.LogMode(true)
	}
	m.recentlyInsertedTootHashCache = lru.New(cacheEntries)
}

func (m *Manager) open(dbURL string) {
	log.Info().Msg("opening database")
	dsn, err := url.Parse(dbURL)
	if err != nil {
		log.Panic().
			Err(err).
			Msg("error parsing dbURL")
	}
	log.Info().
		Str("scheme", dsn.Scheme).
		Str("user", dsn.User.Username()).
		Str("host", dsn.Host).
		Str("db", dsn.Path).
		Str("args", dsn.RawQuery).
		Msg("db connection values")
	switch {
	case strings.HasPrefix(dbURL, "postgres://"):
		log.Info().Msg("using postgres db")
		db, err := gorm.Open("postgres", dbURL)
		if err != nil {
			log.Panic().
				Err(err).
				Msg("failed to open database")
		}
		m.db = db
	case strings.HasPrefix(dbURL, "sqlite://"):
		log.Info().Msg("using sqlite db")
		if !strings.HasSuffix(dbURL, ":memory:") {
			dirname := filepath.Dir(strings.TrimPrefix(dbURL, "sqlite://"))
			err := u.Mkdirp(dirname)
			if err != nil {
				log.Panic().
					Err(err).
					Msg("db path error")
			}
		}
		db, err := gorm.Open("sqlite3", strings.TrimPrefix(dbURL, "sqlite://"))
		if err != nil {
			log.Panic().
				Err(err).
				Str("dbURL", dbURL).
				Msg("failed to open database")
		}
		m.db = db
	default:
		log.Panic().
			Str("driver", dsn.Scheme).
			Msg("unsupported driver in database url, must be 'postgres' or 'sqlite'")
	}

	m.doMigrations()
}