// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package storagenodedb

import (
	"context"
	"database/sql"
	"database/sql/driver"
	"fmt"
	"math/rand"
	"os"
	"path/filepath"
	"time"

	"github.com/zeebo/errs"
	"go.uber.org/zap"
	"gopkg.in/spacemonkeygo/monkit.v2"

	"storj.io/storj/internal/dbutil"
	"storj.io/storj/internal/dbutil/utccheck"
	"storj.io/storj/internal/migrate"
)

// ErrInfo is the default error class for InfoDB
var ErrInfo = errs.Class("infodb")

// SQLDB defines interface that matches *sql.DB
// this is such that we can use utccheck.DB for the backend
//
// TODO: wrap the connector instead of *sql.DB
type SQLDB interface {
	Begin() (*sql.Tx, error)
	BeginTx(ctx context.Context, opts *sql.TxOptions) (*sql.Tx, error)
	Close() error
	Conn(ctx context.Context) (*sql.Conn, error)
	Driver() driver.Driver
	Exec(query string, args ...interface{}) (sql.Result, error)
	ExecContext(ctx context.Context, query string, args ...interface{}) (sql.Result, error)
	Ping() error
	PingContext(ctx context.Context) error
	Prepare(query string) (*sql.Stmt, error)
	PrepareContext(ctx context.Context, query string) (*sql.Stmt, error)
	Query(query string, args ...interface{}) (*sql.Rows, error)
	QueryContext(ctx context.Context, query string, args ...interface{}) (*sql.Rows, error)
	QueryRow(query string, args ...interface{}) *sql.Row
	QueryRowContext(ctx context.Context, query string, args ...interface{}) *sql.Row
	SetConnMaxLifetime(d time.Duration)
	SetMaxIdleConns(n int)
	SetMaxOpenConns(n int)
}

// InfoDB implements information database for piecestore.
type InfoDB struct {
	db                SQLDB
	bandwidthdb       bandwidthdb
	v0PieceInfo       v0PieceInfo
	pieceExpirationDB pieceExpirationDB
	location          string
	pieceSpaceUsedDB  pieceSpaceUsedDB
}

// newInfo creates or opens InfoDB at the specified path.
func newInfo(path string) (*InfoDB, error) {
	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
		return nil, err
	}

	db, err := sql.Open("sqlite3", "file:"+path+"?_journal=WAL&_busy_timeout=10000")
	if err != nil {
		return nil, ErrInfo.Wrap(err)
	}

	dbutil.Configure(db, mon)

	infoDb := &InfoDB{db: db}
	infoDb.v0PieceInfo = v0PieceInfo{InfoDB: infoDb}
	infoDb.bandwidthdb = bandwidthdb{InfoDB: infoDb}
	infoDb.pieceExpirationDB = pieceExpirationDB{InfoDB: infoDb}
	infoDb.location = path
	infoDb.pieceSpaceUsedDB = pieceSpaceUsedDB{InfoDB: infoDb}

	return infoDb, nil
}

// NewInfoTest creates a new inmemory InfoDB.
func NewInfoTest() (*InfoDB, error) {
	// create memory DB with a shared cache and a unique name to avoid collisions
	db, err := sql.Open("sqlite3", fmt.Sprintf("file:memdb%d?mode=memory&cache=shared", rand.Int63()))
	if err != nil {
		return nil, ErrInfo.Wrap(err)
	}

	// Set max idle and max open to 1 to control concurrent access to the memory DB
	// Setting max open higher than 1 results in table locked errors
	db.SetMaxIdleConns(1)
	db.SetMaxOpenConns(1)
	db.SetConnMaxLifetime(-1)

	mon.Chain("db_stats", monkit.StatSourceFunc(
		func(cb func(name string, val float64)) {
			monkit.StatSourceFromStruct(db.Stats()).Stats(cb)
		}))

	infoDb := &InfoDB{db: utccheck.New(db)}
	infoDb.v0PieceInfo = v0PieceInfo{InfoDB: infoDb}
	infoDb.bandwidthdb = bandwidthdb{InfoDB: infoDb}
	infoDb.pieceExpirationDB = pieceExpirationDB{InfoDB: infoDb}
	infoDb.pieceSpaceUsedDB = pieceSpaceUsedDB{InfoDB: infoDb}

	return infoDb, nil
}

// Close closes any resources.
func (db *InfoDB) Close() error {
	return db.db.Close()
}

// CreateTables creates any necessary tables.
func (db *InfoDB) CreateTables(log *zap.Logger) error {
	migration := db.Migration()
	return migration.Run(log.Named("migration"), db)
}

// RawDB returns access to the raw database, only for migration tests.
func (db *InfoDB) RawDB() SQLDB { return db.db }

// Begin begins transaction
func (db *InfoDB) Begin() (*sql.Tx, error) { return db.db.Begin() }

// Rebind rebind parameters
func (db *InfoDB) Rebind(s string) string { return s }

// Schema returns schema
func (db *InfoDB) Schema() string { return "" }

// Migration returns table migrations.
func (db *InfoDB) Migration() *migrate.Migration {
	return &migrate.Migration{
		Table: "versions",
		Steps: []*migrate.Step{
			{
				Description: "Initial setup",
				Version:     0,
				Action: migrate.SQL{
					// table for keeping serials that need to be verified against
					`CREATE TABLE used_serial (
						satellite_id  BLOB NOT NULL,
						serial_number BLOB NOT NULL,
						expiration    TIMESTAMP NOT NULL
					)`,
					// primary key on satellite id and serial number
					`CREATE UNIQUE INDEX pk_used_serial ON used_serial(satellite_id, serial_number)`,
					// expiration index to allow fast deletion
					`CREATE INDEX idx_used_serial ON used_serial(expiration)`,

					// certificate table for storing uplink/satellite certificates
					`CREATE TABLE certificate (
						cert_id       INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
						node_id       BLOB        NOT NULL, -- same NodeID can have multiple valid leaf certificates
						peer_identity BLOB UNIQUE NOT NULL  -- PEM encoded
					)`,

					// table for storing piece meta info
					`CREATE TABLE pieceinfo (
						satellite_id     BLOB      NOT NULL,
						piece_id         BLOB      NOT NULL,
						piece_size       BIGINT    NOT NULL,
						piece_expiration TIMESTAMP, -- date when it can be deleted

						uplink_piece_hash BLOB    NOT NULL, -- serialized pb.PieceHash signed by uplink
						uplink_cert_id    INTEGER NOT NULL,

						FOREIGN KEY(uplink_cert_id) REFERENCES certificate(cert_id)
					)`,
					// primary key by satellite id and piece id
					`CREATE UNIQUE INDEX pk_pieceinfo ON pieceinfo(satellite_id, piece_id)`,

					// table for storing bandwidth usage
					`CREATE TABLE bandwidth_usage (
						satellite_id  BLOB    NOT NULL,
						action        INTEGER NOT NULL,
						amount        BIGINT  NOT NULL,
						created_at    TIMESTAMP NOT NULL
					)`,
					`CREATE INDEX idx_bandwidth_usage_satellite ON bandwidth_usage(satellite_id)`,
					`CREATE INDEX idx_bandwidth_usage_created   ON bandwidth_usage(created_at)`,

					// table for storing all unsent orders
					`CREATE TABLE unsent_order (
						satellite_id  BLOB NOT NULL,
						serial_number BLOB NOT NULL,

						order_limit_serialized BLOB      NOT NULL, -- serialized pb.OrderLimit
						order_serialized       BLOB      NOT NULL, -- serialized pb.Order
						order_limit_expiration TIMESTAMP NOT NULL, -- when is the deadline for sending it

						uplink_cert_id INTEGER NOT NULL,

						FOREIGN KEY(uplink_cert_id) REFERENCES certificate(cert_id)
					)`,
					`CREATE UNIQUE INDEX idx_orders ON unsent_order(satellite_id, serial_number)`,

					// table for storing all sent orders
					`CREATE TABLE order_archive (
						satellite_id  BLOB NOT NULL,
						serial_number BLOB NOT NULL,

						order_limit_serialized BLOB NOT NULL, -- serialized pb.OrderLimit
						order_serialized       BLOB NOT NULL, -- serialized pb.Order

						uplink_cert_id INTEGER NOT NULL,

						status      INTEGER   NOT NULL, -- accepted, rejected, confirmed
						archived_at TIMESTAMP NOT NULL, -- when was it rejected

						FOREIGN KEY(uplink_cert_id) REFERENCES certificate(cert_id)
					)`,
					`CREATE INDEX idx_order_archive_satellite ON order_archive(satellite_id)`,
					`CREATE INDEX idx_order_archive_status ON order_archive(status)`,
				},
			},
			{
				Description: "Network Wipe #2",
				Version:     1,
				Action: migrate.SQL{
					`UPDATE pieceinfo SET piece_expiration = '2019-05-09 00:00:00.000000+00:00'`,
				},
			},
			{
				Description: "Add tracking of deletion failures.",
				Version:     2,
				Action: migrate.SQL{
					`ALTER TABLE pieceinfo ADD COLUMN deletion_failed_at TIMESTAMP`,
				},
			},
			{
				Description: "Add vouchersDB for storing and retrieving vouchers.",
				Version:     3,
				Action: migrate.SQL{
					`CREATE TABLE vouchers (
						satellite_id BLOB PRIMARY KEY NOT NULL,
						voucher_serialized BLOB NOT NULL,
						expiration TIMESTAMP NOT NULL
					)`,
				},
			},
			{
				Description: "Add index on pieceinfo expireation",
				Version:     4,
				Action: migrate.SQL{
					`CREATE INDEX idx_pieceinfo_expiration ON pieceinfo(piece_expiration)`,
					`CREATE INDEX idx_pieceinfo_deletion_failed ON pieceinfo(deletion_failed_at)`,
				},
			},
			{
				Description: "Partial Network Wipe - Tardigrade Satellites",
				Version:     5,
				Action: migrate.SQL{
					`UPDATE pieceinfo SET piece_expiration = '2019-06-25 00:00:00.000000+00:00' WHERE satellite_id
						IN (x'84A74C2CD43C5BA76535E1F42F5DF7C287ED68D33522782F4AFABFDB40000000',
							x'A28B4F04E10BAE85D67F4C6CB82BF8D4C0F0F47A8EA72627524DEB6EC0000000',
							x'AF2C42003EFC826AB4361F73F9D890942146FE0EBE806786F8E7190800000000'
					)`,
				},
			},
			{
				Description: "Add creation date.",
				Version:     6,
				Action: migrate.SQL{
					`ALTER TABLE pieceinfo ADD COLUMN piece_creation TIMESTAMP NOT NULL DEFAULT 'epoch'`,
				},
			},
			{
				Description: "Drop certificate table.",
				Version:     7,
				Action: migrate.SQL{
					`DROP TABLE certificate`,
					`CREATE TABLE certificate (cert_id INTEGER)`,
				},
			},
			{
				Description: "Drop old used serials and remove pieceinfo_deletion_failed index.",
				Version:     8,
				Action: migrate.SQL{
					`DELETE FROM used_serial`,
					`DROP INDEX idx_pieceinfo_deletion_failed`,
				},
			},
			{
				Description: "Add order limit table.",
				Version:     9,
				Action: migrate.SQL{
					`ALTER TABLE pieceinfo ADD COLUMN order_limit BLOB NOT NULL DEFAULT X''`,
				},
			},
			{
				Description: "Optimize index usage.",
				Version:     10,
				Action: migrate.SQL{
					`DROP INDEX idx_pieceinfo_expiration`,
					`DROP INDEX idx_order_archive_satellite`,
					`DROP INDEX idx_order_archive_status`,
					`CREATE INDEX idx_pieceinfo_expiration ON pieceinfo(piece_expiration) WHERE piece_expiration IS NOT NULL`,
				},
			},
			{
				Description: "Create bandwidth_usage_rollup table.",
				Version:     11,
				Action: migrate.SQL{
					`CREATE TABLE bandwidth_usage_rollups (
										interval_start	TIMESTAMP NOT NULL,
										satellite_id  	BLOB    NOT NULL,
										action        	INTEGER NOT NULL,
										amount        	BIGINT  NOT NULL,
										PRIMARY KEY ( interval_start, satellite_id, action )
									)`,
				},
			},
			{
				Description: "Clear Tables from Alpha data",
				Version:     12,
				Action: migrate.SQL{
					`DROP TABLE pieceinfo`,
					`DROP TABLE used_serial`,
					`DROP TABLE order_archive`,
					`CREATE TABLE pieceinfo_ (
						satellite_id     BLOB      NOT NULL,
						piece_id         BLOB      NOT NULL,
						piece_size       BIGINT    NOT NULL,
						piece_expiration TIMESTAMP,

						order_limit       BLOB    NOT NULL,
						uplink_piece_hash BLOB    NOT NULL,
						uplink_cert_id    INTEGER NOT NULL,

						deletion_failed_at TIMESTAMP,
						piece_creation TIMESTAMP NOT NULL,

						FOREIGN KEY(uplink_cert_id) REFERENCES certificate(cert_id)
					)`,
					`CREATE UNIQUE INDEX pk_pieceinfo_ ON pieceinfo_(satellite_id, piece_id)`,
					`CREATE INDEX idx_pieceinfo__expiration ON pieceinfo_(piece_expiration) WHERE piece_expiration IS NOT NULL`,
					`CREATE TABLE used_serial_ (
						satellite_id  BLOB NOT NULL,
						serial_number BLOB NOT NULL,
						expiration    TIMESTAMP NOT NULL
					)`,
					`CREATE UNIQUE INDEX pk_used_serial_ ON used_serial_(satellite_id, serial_number)`,
					`CREATE INDEX idx_used_serial_ ON used_serial_(expiration)`,
					`CREATE TABLE order_archive_ (
						satellite_id  BLOB NOT NULL,
						serial_number BLOB NOT NULL,

						order_limit_serialized BLOB NOT NULL,
						order_serialized       BLOB NOT NULL,

						uplink_cert_id INTEGER NOT NULL,

						status      INTEGER   NOT NULL,
						archived_at TIMESTAMP NOT NULL,

						FOREIGN KEY(uplink_cert_id) REFERENCES certificate(cert_id)
					)`,
				},
			},
			{
				Description: "Free Storagenodes from trash data",
				Version:     13,
				Action: migrate.Func(func(log *zap.Logger, mgdb migrate.DB, tx *sql.Tx) error {
					// When using inmemory DB, skip deletion process
					if db.location == "" {
						return nil
					}

					err := os.RemoveAll(filepath.Join(filepath.Dir(db.location), "blob/ukfu6bhbboxilvt7jrwlqk7y2tapb5d2r2tsmj2sjxvw5qaaaaaa")) // us-central1
					if err != nil {
						log.Sugar().Debug(err)
					}
					err = os.RemoveAll(filepath.Join(filepath.Dir(db.location), "blob/v4weeab67sbgvnbwd5z7tweqsqqun7qox2agpbxy44mqqaaaaaaa")) // europe-west1
					if err != nil {
						log.Sugar().Debug(err)
					}
					err = os.RemoveAll(filepath.Join(filepath.Dir(db.location), "blob/qstuylguhrn2ozjv4h2c6xpxykd622gtgurhql2k7k75wqaaaaaa")) // asia-east1
					if err != nil {
						log.Sugar().Debug(err)
					}
					err = os.RemoveAll(filepath.Join(filepath.Dir(db.location), "blob/abforhuxbzyd35blusvrifvdwmfx4hmocsva4vmpp3rgqaaaaaaa")) // "tothemoon (stefan)"
					if err != nil {
						log.Sugar().Debug(err)
					}
					// To prevent the node from starting up, we just log errors and return nil
					return nil
				}),
			},
			{
				Description: "Free Storagenodes from orphaned tmp data",
				Version:     14,
				Action: migrate.Func(func(log *zap.Logger, mgdb migrate.DB, tx *sql.Tx) error {
					// When using inmemory DB, skip deletion process
					if db.location == "" {
						return nil
					}

					err := os.RemoveAll(filepath.Join(filepath.Dir(db.location), "tmp"))
					if err != nil {
						log.Sugar().Debug(err)
					}
					// To prevent the node from starting up, we just log errors and return nil
					return nil
				}),
			},
			{
				Description: "Start piece_expirations table, deprecate pieceinfo table",
				Version:     15,
				Action: migrate.SQL{
					// new table to hold expiration data (and only expirations. no other pieceinfo)
					`CREATE TABLE piece_expirations (
						satellite_id       BLOB      NOT NULL,
						piece_id           BLOB      NOT NULL,
						piece_expiration   TIMESTAMP NOT NULL, -- date when it can be deleted
						deletion_failed_at TIMESTAMP,
						PRIMARY KEY (satellite_id, piece_id)
					)`,
					`CREATE INDEX idx_piece_expirations_piece_expiration ON piece_expirations(piece_expiration)`,
					`CREATE INDEX idx_piece_expirations_deletion_failed_at ON piece_expirations(deletion_failed_at)`,
				},
			},
			{
				Description: "Add reputation and storage usage cache tables",
				Version:     16,
				Action: migrate.SQL{
					`CREATE TABLE reputation (
						satellite_id BLOB NOT NULL,
						uptime_success_count INTEGER NOT NULL,
						uptime_total_count INTEGER NOT NULL,
						uptime_reputation_alpha REAL NOT NULL,
						uptime_reputation_beta REAL NOT NULL,
						uptime_reputation_score REAL NOT NULL,
						audit_success_count INTEGER NOT NULL,
						audit_total_count INTEGER NOT NULL,
						audit_reputation_alpha REAL NOT NULL,
						audit_reputation_beta REAL NOT NULL,
						audit_reputation_score REAL NOT NULL,
						updated_at TIMESTAMP NOT NULL,
						PRIMARY KEY (satellite_id)
					)`,
					`CREATE TABLE storage_usage (
						satellite_id BLOB NOT NULL,
						at_rest_total REAL NOT NUll,
						timestamp TIMESTAMP NOT NULL,
						PRIMARY KEY (satellite_id, timestamp)
					)`,
				},
			},
			{
				Description: "Create piece_space_used table",
				Version:     17,
				Action: migrate.SQL{
					// new table to hold the most recent totals from the piece space used cache
					`CREATE TABLE piece_space_used (
						total INTEGER NOT NULL,
						satellite_id BLOB
					)`,
					`CREATE UNIQUE INDEX idx_piece_space_used_satellite_id ON piece_space_used(satellite_id)`,
				},
			},
		},
	}
}

// withTx is a helper method which executes callback in transaction scope
func (db *InfoDB) withTx(ctx context.Context, cb func(tx *sql.Tx) error) error {
	tx, err := db.Begin()
	if err != nil {
		return err
	}

	defer func() {
		if err != nil {
			err = errs.Combine(err, tx.Rollback())
			return
		}

		err = tx.Commit()
	}()

	return cb(tx)
}