import { GenericId } from "../values/index.js";
import {
  DocumentByName,
  GenericDataModel,
  NamedTableInfo,
  TableNamesInDataModel,
} from "./data_model.js";
import { QueryInitializer } from "./query.js";
import { SystemDataModel } from "./schema.js";
import {
  WithOptionalSystemFields,
  WithoutSystemFields,
} from "./system_fields.js";

interface BaseDatabaseReader<DataModel extends GenericDataModel> {
  /**
   * Fetch a single document from the database by its {@link values.GenericId}.
   *
   * @param id - The {@link values.GenericId} of the document to fetch from the database.
   * @returns - The {@link GenericDocument} of the document at the given {@link values.GenericId}, or `null` if it no longer exists.
   */
  get<TableName extends TableNamesInDataModel<DataModel>>(
    id: GenericId<TableName>,
  ): Promise<DocumentByName<DataModel, TableName> | null>;

  /**
   * Begin a query for the given table name.
   *
   * Queries don't execute immediately, so calling this method and extending its
   * query are free until the results are actually used.
   *
   * @param tableName - The name of the table to query.
   * @returns - A {@link QueryInitializer} object to start building a query.
   */
  query<TableName extends TableNamesInDataModel<DataModel>>(
    tableName: TableName,
  ): QueryInitializer<NamedTableInfo<DataModel, TableName>>;

  /**
   * Returns the string ID format for the ID in a given table, or null if the ID
   * is from a different table or is not a valid ID.
   *
   * This accepts the string ID format as well as the `.toString()` representation
   * of the legacy class-based ID format.
   *
   * This does not guarantee that the ID exists (i.e. `db.get(id)` may return `null`).
   *
   * @param tableName - The name of the table.
   * @param id - The ID string.
   */
  normalizeId<TableName extends TableNamesInDataModel<DataModel>>(
    tableName: TableName,
    id: string,
  ): GenericId<TableName> | null;
}

/**
 * An interface to read from the database within Convex query functions.
 *
 * The two entry points are:
 *   - {@link GenericDatabaseReader.get}, which fetches a single document
 *     by its {@link values.GenericId}.
 *   - {@link GenericDatabaseReader.query}, which starts building a query.
 *
 * If you're using code generation, use the `DatabaseReader` type in
 * `convex/_generated/server.d.ts` which is typed for your data model.
 *
 * @public
 */
export interface GenericDatabaseReader<DataModel extends GenericDataModel>
  extends BaseDatabaseReader<DataModel> {
  /**
   * An interface to read from the system tables within Convex query functions
   *
   * The two entry points are:
   *   - {@link GenericDatabaseReader.get}, which fetches a single document
   *     by its {@link values.GenericId}.
   *   - {@link GenericDatabaseReader.query}, which starts building a query.
   *
   * @public
   */
  system: BaseDatabaseReader<SystemDataModel>;
}

/**
 * An interface to read from and write to the database within Convex mutation
 * functions.
 *
 * Convex guarantees that all writes within a single mutation are
 * executed atomically, so you never have to worry about partial writes leaving
 * your data in an inconsistent state. See [the Convex Guide](https://docs.convex.dev/understanding/convex-fundamentals/functions#atomicity-and-optimistic-concurrency-control)
 * for the guarantees Convex provides your functions.
 *
 *  If you're using code generation, use the `DatabaseReader` type in
 * `convex/_generated/server.d.ts` which is typed for your data model.
 *
 * @public
 */
export interface GenericDatabaseWriter<DataModel extends GenericDataModel>
  extends GenericDatabaseReader<DataModel> {
  /**
   * Insert a new document into a table.
   *
   * @param table - The name of the table to insert a new document into.
   * @param value - The {@link values.Value} to insert into the given table.
   * @returns - {@link values.GenericId} of the new document.
   */
  insert<TableName extends TableNamesInDataModel<DataModel>>(
    table: TableName,
    value: WithoutSystemFields<DocumentByName<DataModel, TableName>>,
  ): Promise<GenericId<TableName>>;

  /**
   * Patch an existing document, shallow merging it with the given partial
   * document.
   *
   * New fields are added. Existing fields are overwritten. Fields set to
   * `undefined` are removed.
   *
   * @param id - The {@link values.GenericId} of the document to patch.
   * @param value - The partial {@link GenericDocument} to merge into the specified document. If this new value
   * specifies system fields like `_id`, they must match the document's existing field values.
   */
  patch<TableName extends TableNamesInDataModel<DataModel>>(
    id: GenericId<TableName>,
    value: Partial<DocumentByName<DataModel, TableName>>,
  ): Promise<void>;

  /**
   * Replace the value of an existing document, overwriting its old value.
   *
   * @param id - The {@link values.GenericId} of the document to replace.
   * @param value - The new {@link GenericDocument} for the document. This value can omit the system fields,
   * and the database will fill them in.
   */
  replace<TableName extends TableNamesInDataModel<DataModel>>(
    id: GenericId<TableName>,
    value: WithOptionalSystemFields<DocumentByName<DataModel, TableName>>,
  ): Promise<void>;

  /**
   * Delete an existing document.
   *
   * @param id - The {@link values.GenericId} of the document to remove.
   */
  delete(id: GenericId<TableNamesInDataModel<DataModel>>): Promise<void>;
}