import { mkdirSync } from 'node:fs';
import { homedir } from 'node:os';
import { join } from 'node:path';
import { Global, Inject, Module, type OnApplicationShutdown } from '@nestjs/common';
import { createDb, createPgliteDb, type Db, type DbHandle } from '@mosaicstack/db';
import { createStorageAdapter, type StorageAdapter } from '@mosaicstack/storage';
import type { MosaicConfig } from '@mosaicstack/config';
import { MOSAIC_CONFIG } from '../config/config.module.js';

export const DB_HANDLE = 'DB_HANDLE';
export const DB = 'DB';
export const STORAGE_ADAPTER = 'STORAGE_ADAPTER';

@Global()
@Module({
  providers: [
    {
      provide: DB_HANDLE,
      useFactory: (config: MosaicConfig): DbHandle => {
        if (config.tier === 'local') {
          const dataDir = join(homedir(), '.config', 'mosaic', 'gateway', 'pglite');
          mkdirSync(dataDir, { recursive: true });
          return createPgliteDb(dataDir);
        }
        return createDb(config.storage.type === 'postgres' ? config.storage.url : undefined);
      },
      inject: [MOSAIC_CONFIG],
    },
    {
      provide: DB,
      useFactory: (handle: DbHandle): Db => handle.db,
      inject: [DB_HANDLE],
    },
    {
      provide: STORAGE_ADAPTER,
      useFactory: (config: MosaicConfig): StorageAdapter => createStorageAdapter(config.storage),
      inject: [MOSAIC_CONFIG],
    },
  ],
  exports: [DB, STORAGE_ADAPTER],
})
export class DatabaseModule implements OnApplicationShutdown {
  constructor(
    @Inject(DB_HANDLE) private readonly handle: DbHandle,
    @Inject(STORAGE_ADAPTER) private readonly storageAdapter: StorageAdapter,
  ) {}

  async onApplicationShutdown(): Promise<void> {
    await Promise.all([this.handle.close(), this.storageAdapter.close()]);
  }
}