initial commit

database.ts

@@ -0,0 +1,62 @@
+import { Entry, Table } from "./table.ts";
+
+type Tables = Record<string, Table<Entry>>;
+
+export class Database {
+  private constructor(private filePath: string, private tables: Tables) {}
+
+  static async load(
+    filePath: string,
+    ifEmpty: (database: Database) => Promise<void>,
+  ): Promise<Database> {
+    const database = new Database(filePath, {});
+
+    try {
+      const data = await Deno.readTextFile(filePath);
+      const parsedData = JSON.parse(data);
+      for (const tableName in parsedData) {
+        const table = new Table(() => database.saveDatabase());
+        table.entries = parsedData[tableName].entries;
+        table.autoIncrementId = parsedData[tableName].autoIncrementId;
+        database.tables[tableName] = table;
+      }
+    } catch (_) {
+      // File doesn't exists already
+      await ifEmpty(database);
+    }
+
+    return database;
+  }
+
+  private async saveDatabase() {
+    const dataToSave: {
+      [name: string]: { entries: Entry[]; autoIncrementId: number };
+    } = {};
+    for (const tableName in this.tables) {
+      dataToSave[tableName] = {
+        entries: this.tables[tableName].entries,
+        autoIncrementId: this.tables[tableName].autoIncrementId,
+      };
+    }
+    await Deno.writeTextFile(
+      this.filePath,
+      JSON.stringify(dataToSave),
+    );
+  }
+
+  async createTable(name: string) {
+    if (this.tables[name]) {
+      throw new Error(`Table ${name} already exists.`);
+    }
+    this.tables[name] = new Table(this.saveDatabase.bind(this));
+    await this.saveDatabase();
+  }
+
+  getTable(name: string): Table<Entry> {
+    const table = this.tables[name];
+    if (!table) {
+      throw new Error(`Table ${name} does not exist.`);
+    }
+    return table;
+  }
+}