/**

* Core Database Service

* Provides database connection, core utilities, and base operations∂ƒ

*/

import { drizzle } from 'drizzle-orm/d1';

import * as Sentry from '@sentry/cloudflare';

import * as schema from './schema';

import type { DrizzleD1Database } from 'drizzle-orm/d1';

import type { HealthStatusResult } from './types';

// ========================================

// TYPE DEFINITIONS AND INTERFACES

// ========================================

export type {

User, NewUser, Session, NewSession,

App, NewApp,

AppLike, NewAppLike, AppComment, NewAppComment,

AppView, NewAppView, OAuthState, NewOAuthState,

SystemSetting, NewSystemSetting,

UserModelConfig, NewUserModelConfig,

} from './schema';

/**

* Core Database Service - Connection and Base Operations

*

* Provides database connection, shared utilities, and core operations.

* Domain-specific operations are handled by dedicated service classes.

*/

export class DatabaseService {

public readonly db: DrizzleD1Database<typeof schema>;

private readonly d1: D1Database;

private readonly enableReplicas: boolean;

constructor(env: Env) {

const instrumented = Sentry.instrumentD1WithSentry(env.DB);

this.d1 = instrumented;

this.db = drizzle(instrumented, { schema });

this.enableReplicas = env.ENABLE_READ_REPLICAS === 'true';

}

/**

* Get a read-optimized database connection using D1 Sessions API

* This routes queries to read replicas for lower global latency

*

* @param strategy - Session strategy:

* - 'fast' (default): Routes to any replica for lowest latency

* - 'fresh': Routes first query to primary for latest data

* @returns Drizzle database instance configured for read operations

*/

public getReadDb(strategy: 'fast' | 'fresh' = 'fast'): DrizzleD1Database<typeof schema> {

// Return regular db if replicas are disabled

if (!this.enableReplicas) {

return this.db;

}

const sessionType = strategy === 'fresh' ? 'first-primary' : 'first-unconstrained';

const session = this.d1.withSession(sessionType);

// D1DatabaseSession is compatible with D1Database for Drizzle operations

return drizzle(session as unknown as D1Database, { schema });

}

// ========================================

// UTILITY METHODS

// ========================================

async getHealthStatus(): Promise<HealthStatusResult> {

try {

await this.db.select().from(schema.systemSettings).limit(1);

return {

healthy: true,

timestamp: new Date().toISOString(),

};

} catch (error) {

return {

healthy: false,

timestamp: new Date().toISOString(),

};

}

}

}

/**

* Factory function to create database service instance

*/

export function createDatabaseService(env: Env): DatabaseService {

return new DatabaseService(env);

}