yoyo-project/yoyo

package reverse

import (
    "fmt"

    "github.com/yoyo-project/yoyo/env"
    "github.com/yoyo-project/yoyo/internal/dbms/dialect"
    "github.com/yoyo-project/yoyo/internal/schema"
    "github.com/yoyo-project/yoyo/internal/yoyo"
)

type AdapterLoader func(dia string) (adapter Adapter, err error)
type DatabaseReader func(config yoyo.Config) (db schema.Database, err error)
type AdapterBuilder func(host, userName, dbName, password, port string) (Adapter, error)

// Adapter is the yoyo interface for reverse-engineering databases to a schema.Database for creating diff migrations
// and for creating a yoyo.yml from an existing database.
type Adapter interface {
    ListTables() ([]string, error)

    // ListColumns returns a []string of column names for the given table
    // It MUST NOT return any columns which are foreign key columns. These will instead come from ListReferences
    ListColumns(table string) ([]string, error)

    // ListIndices returns a []string of index names for the given table.
    // It MUST NOT return information referring to PrimaryKey or Foreign Keys, which will instead come from GetColumn and
    // ListReferences respectively
    ListIndices(table string) ([]string, error)

    // ListReferences returns a []string of tables referenced from the given table.
    ListReferences(table string) ([]string, error)

    // GetColumn returns a schema.Column representing the given tableName and colName.
    GetColumn(table, column string) (schema.Column, error)

    // GetIndex returns a schema.Index representing the given tableName and indexName.
    GetIndex(table, column string) (schema.Index, error)

    // GetReference returns a schema.Reference representing the given tableName and indexName.
    GetReference(table, column string) (schema.Reference, error)
}

func InitAdapterSelector(newMysqlReverser, newPostgresReverser AdapterBuilder) func(dia string) (adapter Adapter, err error) {
    return func(dia string) (adapter Adapter, err error) {
        switch dia {
        case dialect.MySQL:
            adapter, err = newMysqlReverser(env.DBHost(), env.DBUser(), env.DBName(), env.DBPassword(), env.DBPort())
        case dialect.PostgreSQL:
            adapter, err = newPostgresReverser(env.DBHost(), env.DBUser(), env.DBName(), env.DBPassword(), env.DBPort())
        default:
            err = fmt.Errorf("unknown dialect `%s`", dia)
        }

        return adapter, err
    }
}