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import { Schema, IMemoryDb, ISchema, TableEvent, GlobalEvent, QueryError, IBackup, MemoryDbOptions, ISubscription, LanguageCompiler, nil } from './interfaces.ts';import { _IDb, _ISelection, _ITable, _Transaction, _ISchema, _FunctionDefinition, GLOBAL_VARS, _IType, _OperatorDefinition, IValue } from './interfaces-private.ts';import { DbSchema } from './schema/schema.ts';import { initialize } from './transforms/transform-base.ts';import { buildSelection } from './transforms/selection.ts';import { buildAlias } from './transforms/alias.ts';import { buildFilter } from './transforms/build-filter.ts';import { Adapters } from './adapters/index.ts';import { Transaction } from './transaction.ts';import { buildGroupBy } from './transforms/aggregation.ts';import { buildLimit } from './transforms/limit.ts';import { buildUnion } from './transforms/union.ts';import { buildDistinct } from './transforms/distinct.ts';import { buildOrderBy } from './transforms/order-by.ts';import { setupPgCatalog } from './schema/pg-catalog/index.ts';import { setupInformationSchema } from './schema/information-schema/index.ts';import { QName, BinaryOperator } from 'https://deno.land/x/pgsql_ast_parser@12.0.1/mod.ts';import { asSingleQName } from './utils.ts';
export function newDb(opts?: MemoryDbOptions): IMemoryDb {    initialize({        buildSelection,        buildAlias,        buildFilter,        buildGroupBy,        buildLimit,        buildUnion,        buildOrderBy,        buildDistinct,    });    // root transaction    const root = Transaction.root();    const globals = root.getMap(GLOBAL_VARS)        .set('server_version', '12.2 (pg-mem)');    root.set(GLOBAL_VARS, globals);
    // create db    return new MemoryDb(root, undefined, opts ?? {});}
class MemoryDb implements _IDb {
    private handlers = new Map<TableEvent | GlobalEvent, Set<(...args: any[]) => any>>();    private schemas = new Map<string, _ISchema>();
    schemaVersion = 1;
    readonly adapters: Adapters = new Adapters(this);    private extensions: { [name: string]: (schema: ISchema) => void } = {};    private languages: { [name: string]: LanguageCompiler } = {};    readonly searchPath = ['pg_catalog', 'public'];
    get public() {        return this.getSchema(null)    }
    onSchemaChange() {        this.schemaVersion++;        this.raiseGlobal('schema-change', this);    }
    constructor(public data: Transaction, schemas?: Map<string, _ISchema>, readonly options: MemoryDbOptions = {}) {        if (!schemas) {            this.createSchema('public');        } else {            this.schemas = schemas;        }        setupPgCatalog(this);        setupInformationSchema(this);    }
    backup(): IBackup {        return new Backup(this);    }
    registerExtension(name: string, install: (schema: ISchema) => void): this {        this.extensions[name] = install;        return this;    }
    registerLanguage(languageName: string, compiler: LanguageCompiler): this {        this.languages[languageName.toLowerCase()] = compiler;        return this;    }
    getLanguage(name: string): LanguageCompiler {        const ret = this.languages[name.toLowerCase()];        if (!ret) {            throw new QueryError(`Unkonwn language "${name}". If you plan to use a script language, you must declare it to pg-mem via ".registerLanguage()"`);        }        return ret;    }

    getExtension(name: string): (schema: ISchema) => void {        const ret = this.extensions[name];        if (!ret) {            throw new Error('Extension does not exist: ' + name);        }        return ret;    }

    createSchema(name: string): DbSchema {        if (this.schemas.has(name)) {            throw new Error('Schema exists: ' + name);        }        this.onSchemaChange();        const ret = new DbSchema(name, this);        this.schemas.set(name, ret);        return ret;    }
    getTable(name: string): _ITable;    getTable(name: string, nullIfNotExists?: boolean): _ITable | null {        return this.public.getTable(name, nullIfNotExists);    }
    resolveFunction(name: string | QName, types: IValue[]): _FunctionDefinition | nil {        const asSingle = asSingleQName(name);        if (asSingle) {            for (const sp of this.searchPath) {                const found = this.getSchema(sp).resolveFunction(name, types, true);                if (found) {                    return found;                }            }            return null;        } else {            const q = name as QName;            return this.getSchema(q.schema!).resolveFunction(q.name, types, true);        }    }
    resolveOperator(name: BinaryOperator, left: IValue, right: IValue): _OperatorDefinition | nil {        for (const sp of this.searchPath) {            const found = this.getSchema(sp).resolveOperator(name, left, right, true);            if (found) {                return found;            }        }        return null;    }


    on(event: GlobalEvent | TableEvent, handler: (...args: any[]) => any): ISubscription {        let lst = this.handlers.get(event);        if (!lst) {            this.handlers.set(event, lst = new Set());        }        lst.add(handler);        return {            unsubscribe: () => lst?.delete(handler),        };    }
    raiseTable(table: string, event: TableEvent): void {        const got = this.handlers.get(event);        for (const h of got ?? []) {            h(table);        }    }
    raiseGlobal(event: GlobalEvent, ...data: any[]): void {        const got = this.handlers.get(event);        for (const h of got ?? []) {            h(...data);        }    }

    getSchema(db?: string | null, nullIfNotFound?: false): _ISchema;    getSchema(db: string, nullIfNotFound: true): _ISchema | null;    getSchema(db?: string | null, nullIfNotFound?: boolean): _ISchema | null {        db = db ?? 'public';        const got = this.schemas.get(db);        if (!got) {            if (nullIfNotFound) {                return null;            }            throw new QueryError('schema not found: ' + db);        }        return got;    }
    listSchemas() {        return [...this.schemas.values()];    }
}
class Backup implements IBackup {    private readonly data: Transaction;    private readonly schemaVersion: number;    constructor(private db: MemoryDb) {        this.data = db.data.clone();        this.schemaVersion = db.schemaVersion;    }
    restore() {        if (this.schemaVersion !== this.db.schemaVersion) {            throw new Error('You cannot restore this backup: schema has been changed since this backup has been created => prefer .clone() in this kind of cases.');        }        this.db.data = this.data.clone();    }}