import process from "node:process"
import type { NewsItem } from "@shared/types"
import type { Database } from "db0"
import type { CacheInfo } from "../types"

export class Cache {
  private db
  constructor(db: Database) {
    this.db = db
  }

  async init() {
    await this.db.prepare(`
      CREATE TABLE IF NOT EXISTS cache (
        id TEXT PRIMARY KEY,
        updated INTEGER,
        data TEXT
      );
    `).run()
    logger.success(`init cache table`)
  }

  async set(key: string, value: NewsItem[]) {
    const now = Date.now()
    await this.db.prepare(
      `INSERT OR REPLACE INTO cache (id, data, updated) VALUES (?, ?, ?)`,
    ).run(key, JSON.stringify(value), now)
    logger.success(`set ${key} cache`)
  }

  async get(key: string): Promise<CacheInfo> {
    const row: any = await this.db.prepare(`SELECT id, data, updated FROM cache WHERE id = ?`).get(key)
    const r = row
      ? {
          ...row,
          data: JSON.parse(row.data),
        }
      : undefined
    logger.success(`get ${key} cache`)
    return r
  }

  async getEntries(keys: string[]) {
    const keysStr = keys.map(k => `id = '${k}'`).join(" or ")
    const res = await this.db.prepare(`SELECT id, data, updated FROM cache WHERE ${keysStr}`).all() as any

    const rows = (res.results ?? res) as {
      id: SourceID
      data: string
      updated: number
    }[]

    /**
     * https://developers.cloudflare.com/d1/build-with-d1/d1-client-api/#return-object
     * cloudflare d1 .all() will return
     * {
     *   success: boolean
     *   meta:
     *   results:
     * }
     */
    if (rows?.length) {
      logger.success(`get entries cache`)
      return Object.fromEntries(rows.map(row => [row.id, {
        id: row.id,
        updatedTime: row.updated,
        items: JSON.parse(row.data) as NewsItem[],
      }]))
    }
  }

  async delete(key: string) {
    return await this.db.prepare(`DELETE FROM cache WHERE id = ?`).run(key)
  }
}

export async function getCacheTable() {
  try {
    // 如果没有数据库，这里不会报错，只会在第一次访问的时候报错
    const db = useDatabase()
    if (process.env.ENABLE_CACHE === "false") return
    const cacheTable = new Cache(db)
    if (process.env.INIT_TABLE !== "false") await cacheTable.init()
    return cacheTable
  } catch {
    // logger.error("failed to init database ", e)
  }
}