import type { ModuleDatabaseExecutor, ModuleId } from "@ekklesia/contracts";
import {
  type AuthorizationDrizzleDatabase,
  createAuthorizationDrizzleView,
} from "@ekklesia/core/authorization";
import {
  createDashboardDrizzleView,
  type DashboardDrizzleDatabase,
} from "@ekklesia/core/dashboard";
import { createValidatedPostgresPool, type PostgresPoolOptions } from "@ekklesia/core/database";
import { createDeviceDrizzleView, type DeviceDrizzleDatabase } from "@ekklesia/core/devices";
import { createIdentityDrizzleView, type IdentityDrizzleDatabase } from "@ekklesia/core/identity";
import {
  createModuleConfigurationView,
  createModuleDatabaseExecutor,
  createModuleDatabaseView,
  createModuleLifecycleView,
  type ModuleConfigurationDrizzleDatabase,
  type ModuleDatabase,
  type ModuleLifecycleDrizzleDatabase,
} from "@ekklesia/core/modules";

export interface ApiDatabaseHandle {
  readonly authorization: AuthorizationDrizzleDatabase;
  readonly devices: DeviceDrizzleDatabase;
  readonly dashboard: DashboardDrizzleDatabase;
  readonly identity: IdentityDrizzleDatabase;
  readonly module: ModuleDatabase;
  /** Builds one ABI-v1 executor attributed to exactly one module, over this handle's shared pool. */
  readonly moduleExecutor: (moduleId: ModuleId) => ModuleDatabaseExecutor;
  readonly moduleConfiguration: ModuleConfigurationDrizzleDatabase;
  readonly moduleLifecycle: ModuleLifecycleDrizzleDatabase;
  /**
   * One trivial round trip on the shared pool, for readiness (`./health-routes.js`). The `SELECT 1`
   * runs in a read-only transaction carrying its own `SET LOCAL statement_timeout`, so PostgreSQL
   * cancels a stalled statement itself rather than the caller merely abandoning it; the pool's
   * session-wide `statement_timeout`/`query_timeout` remain the outer bound. The four statements
   * travel as one simple-protocol message, so the check costs a single round trip. On any failure
   * the pool discards that connection instead of returning it, so a transaction left open by a
   * cancelled statement never reaches another caller. Rejects with whatever the driver raised; no
   * caller may surface it.
   */
  readonly ping: (statementTimeoutMs: number) => Promise<void>;
  /** Closes the one shared pool exactly once, regardless of how many typed views were created
   * over it. Safe to call from both a startup-failure cleanup path and normal shutdown. */
  readonly close: () => Promise<void>;
}

function pingStatement(statementTimeoutMs: number): string {
  // Interpolated rather than bound: neither SET nor a multi-statement simple query accepts
  // parameters. Only a positive safe integer can ever reach the SQL text.
  if (!Number.isSafeInteger(statementTimeoutMs) || statementTimeoutMs <= 0) {
    throw new RangeError("The ping statement timeout must be a positive integer.");
  }
  return `BEGIN READ ONLY; SET LOCAL statement_timeout = ${statementTimeoutMs}; SELECT 1; COMMIT`;
}

/**
 * Composes the one physical PostgreSQL pool this process uses for Core's identity and
 * authorization schemas plus the module database facade: one validated, timeout-bounded
 * `pg.Pool` (`createValidatedPostgresPool`, `@ekklesia/core/database`), wrapped by independent
 * typed Drizzle views (`createIdentityDrizzleView`, `createAuthorizationDrizzleView`,
 * `createDashboardDrizzleView`, `createModuleLifecycleView`, `createModuleConfigurationView`,
 * `createModuleDatabaseView`). No domain
 * owns or closes the pool in this composition — `close()`
 * here is the only thing that ever calls `pool.end()`. `createIdentityDrizzleDatabase`/
 * `createAuthorizationDrizzleDatabase` remain available, unaffected, and independently testable
 * for callers that only need one domain.
 */
export function createApiDatabase(
  databaseUrl: string,
  options: PostgresPoolOptions = {},
): ApiDatabaseHandle {
  const { close, pool } = createValidatedPostgresPool(databaseUrl, options);

  return Object.freeze({
    authorization: createAuthorizationDrizzleView(pool),
    close,
    devices: createDeviceDrizzleView(pool),
    dashboard: createDashboardDrizzleView(pool),
    identity: createIdentityDrizzleView(pool),
    module: createModuleDatabaseView(pool),
    moduleExecutor: (moduleId: ModuleId) => createModuleDatabaseExecutor(pool, { moduleId }),
    moduleConfiguration: createModuleConfigurationView(pool),
    moduleLifecycle: createModuleLifecycleView(pool),
    ping: async (statementTimeoutMs: number) => {
      await pool.query(pingStatement(statementTimeoutMs));
    },
  });
}