offline-twitter/persistence/versions.go

package persistence

import (
	"fmt"

	sql "github.com/jmoiron/sqlx"

	"offline_twitter/terminal_utils"
)

const ENGINE_DATABASE_VERSION = 13

type VersionMismatchError struct {
	EngineVersion   int
	DatabaseVersion int
}

func (e VersionMismatchError) Error() string {
	return fmt.Sprintf(
		`This profile was created with database schema version %d, which is newer than this application's database schema version, %d.
Please upgrade this application to a newer version to use this profile.  Or downgrade the profile's schema version, somehow.`,
		e.DatabaseVersion, e.EngineVersion,
	)
}

/**
 * The Nth entry is the migration that moves you from version N to version N+1.
 * `len(MIGRATIONS)` should always equal `ENGINE_DATABASE_VERSION`.
 */
var MIGRATIONS = []string{
	`create table polls (rowid integer primary key,
    id integer unique not null check(typeof(id) = 'integer'),
    tweet_id integer not null,
    num_choices integer not null,

    choice1 text,
    choice1_votes integer,
    choice2 text,
    choice2_votes integer,
    choice3 text,
    choice3_votes integer,
    choice4 text,
    choice4_votes integer,

    voting_duration integer not null,  -- in seconds
    voting_ends_at integer not null,

    last_scraped_at integer not null,

    foreign key(tweet_id) references tweets(id)
	);`,
	`alter table tweets add column is_conversation_scraped boolean default 0;
	alter table tweets add column last_scraped_at integer not null default 0`,
	`update tombstone_types set tombstone_text = 'This Tweet is from a suspended account' where rowid = 2;
	insert into tombstone_types (rowid, short_name, tombstone_text)
	                     values (5, 'violated', 'This Tweet violated the Twitter Rules'),
	                            (6, 'no longer exists', 'This Tweet is from an account that no longer exists')`,
	`alter table videos add column thumbnail_remote_url text not null default "missing";
	alter table videos add column thumbnail_local_filename text not null default "missing"`,
	`alter table videos add column duration integer not null default 0;
	alter table videos add column view_count integer not null default 0`,
	`alter table users add column is_banned boolean default 0`,
	`alter table urls add column short_text text not null default ""`,
	`insert into tombstone_types (rowid, short_name, tombstone_text) values (7, 'age-restricted', 'Age-restricted adult content. '
	|| 'This content might not be appropriate for people under 18 years old. To view this media, you’ll need to log in to Twitter')`,
	`alter table users add column is_followed boolean default 0`,
	`create table fake_user_sequence(latest_fake_id integer not null);
	insert into fake_user_sequence values(0x4000000000000000);
	alter table users add column is_id_fake boolean default 0;`,
	`delete from urls where rowid in (select urls.rowid from tweets join urls on tweets.id = urls.tweet_id where urls.text like
	'https://twitter.com/%/status/' || tweets.quoted_tweet_id || "%")`,
	`create table spaces(rowid integer primary key,
	    id text unique not null,
	    short_url text not null
	);
	alter table tweets add column space_id text references spaces(id)`,
	`alter table videos add column is_blocked_by_dmca boolean not null default 0`,
}

/**
 * This should only get called on a newly created Profile.
 * Subsequent updates should change the number, not insert a new row.
 */
func InitializeDatabaseVersion(db *sql.DB) {
	db.MustExec("insert into database_version (version_number) values (?)", ENGINE_DATABASE_VERSION)
}

func (p Profile) GetDatabaseVersion() (int, error) {
	row := p.DB.QueryRow("select version_number from database_version")

	var version int

	err := row.Scan(&version)
	if err != nil {
		return 0, fmt.Errorf("Error checking database version:\n  %w", err)
	}
	return version, nil
}

func (p Profile) check_and_update_version() error {
	version, err := p.GetDatabaseVersion()
	if err != nil {
		return err
	}

	if version > ENGINE_DATABASE_VERSION {
		return VersionMismatchError{ENGINE_DATABASE_VERSION, version}
	}

	if ENGINE_DATABASE_VERSION > version {
		fmt.Printf(terminal_utils.COLOR_YELLOW)
		fmt.Printf("================================================\n")
		fmt.Printf("Database version is out of date.  Upgrading database from version %d to version %d!\n", version,
			ENGINE_DATABASE_VERSION)
		fmt.Printf(terminal_utils.COLOR_RESET)
		return p.UpgradeFromXToY(version, ENGINE_DATABASE_VERSION)
	}

	return nil
}

/**
 * Run all the migrations from version X to version Y, and update the `database_version` table's `version_number`
 */
func (p Profile) UpgradeFromXToY(x int, y int) error {
	for i := x; i < y; i++ {
		fmt.Printf(terminal_utils.COLOR_CYAN)
		fmt.Println(MIGRATIONS[i])
		fmt.Printf(terminal_utils.COLOR_RESET)

		p.DB.MustExec(MIGRATIONS[i])
		p.DB.MustExec("update database_version set version_number = ?", i+1)

		fmt.Printf(terminal_utils.COLOR_YELLOW)
		fmt.Printf("Now at database schema version %d.\n", i+1)
		fmt.Printf(terminal_utils.COLOR_RESET)
	}
	fmt.Printf(terminal_utils.COLOR_GREEN)
	fmt.Printf("================================================\n")
	fmt.Printf("Database version has been upgraded to version %d.\n", y)
	fmt.Printf(terminal_utils.COLOR_RESET)
	return nil
}