import { stat } from "node:fs/promises";
import { dbPath } from "./db.mjs";
import { backupSummary } from "./backup.mjs";

function envValue(name) {
  return String(process.env[name] || "").trim();
}

function configuredCheck(key, label, envName, detail) {
  const value = envValue(envName);
  return {
    key,
    label,
    status: value ? "configured" : "not-configured",
    severity: value ? "info" : "warning",
    blocking: false,
    detail: value ? `${detail}：已读取 ${envName}` : `${detail}：未设置 ${envName}`,
    envName
  };
}

async function databaseCheck() {
  try {
    const file = await stat(dbPath);
    return {
      key: "business-database",
      label: "业务数据库",
      status: "active-local",
      severity: "warning",
      blocking: false,
      provider: "Node 24 node:sqlite",
      detail: "当前业务真源是本地 SQLite；尚未切换 PostgreSQL 高可用运行时。",
      path: dbPath,
      bytes: Number(file.size || 0),
      modifiedAt: file.mtime?.toISOString?.() || null
    };
  } catch (error) {
    return {
      key: "business-database",
      label: "业务数据库",
      status: "failed",
      severity: "critical",
      blocking: true,
      provider: "Node 24 node:sqlite",
      detail: `数据库文件不可读：${error.message}`,
      path: dbPath
    };
  }
}

export async function systemReadiness() {
  const backups = await backupSummary();
  const allowDevContext = process.env.AI_DRAMA_ALLOW_DEV_CONTEXT === "1";
  const sessionSecret = envValue("AI_DRAMA_SESSION_SECRET");
  const mfaKey = envValue("AI_DRAMA_MFA_ENCRYPTION_KEY");
  const oidcKey = envValue("AI_DRAMA_OIDC_STORAGE_KEY");
  const checks = [
    await databaseCheck(),
    configuredCheck("postgres-target", "PostgreSQL 目标", "PLATFORM_POSTGRES_URL", "目标数据库连接"),
    configuredCheck("redis-target", "Redis 目标", "PLATFORM_REDIS_URL", "目标队列/分布式锁连接"),
    configuredCheck("object-storage-target", "对象存储目标", "PLATFORM_OBJECT_STORAGE_ENDPOINT", "S3-compatible 存储端点"),
    {
      key: "security-secrets",
      label: "生产密钥",
      status: sessionSecret.length >= 32 && mfaKey.length >= 16 && oidcKey.length >= 16 ? "ready" : "needs-config",
      severity: sessionSecret.length >= 32 && mfaKey.length >= 16 && oidcKey.length >= 16 ? "info" : "critical",
      blocking: sessionSecret.length < 32 || mfaKey.length < 16 || oidcKey.length < 16,
      detail: "Session、MFA 和 OIDC 存储密钥必须通过环境变量注入，不写入数据库。",
      configured: { sessionSecret: sessionSecret.length >= 32, mfaKey: mfaKey.length >= 16, oidcKey: oidcKey.length >= 16 }
    },
    {
      key: "dev-context",
      label: "开发上下文旁路",
      status: allowDevContext ? "unsafe" : "ready",
      severity: allowDevContext ? "critical" : "info",
      blocking: allowDevContext,
      detail: allowDevContext ? "AI_DRAMA_ALLOW_DEV_CONTEXT=1，生产部署禁止启用。" : "请求头上下文旁路已关闭，使用真实 session/API client。"
    },
    {
      key: "database-backup",
      label: "数据库快照",
      status: backups.count ? "ready" : "missing",
      severity: backups.count ? "info" : "warning",
      blocking: false,
      detail: backups.count ? `已有 ${backups.count} 个本地快照，最近一次 ${backups.latest?.modifiedAt || "未知"}。` : "还没有本地 SQLite 快照；上线前应先创建并验证备份。"
    }
  ];
  const blocking = checks.filter((check) => check.blocking && !["ready", "configured"].includes(check.status)).length;
  const attention = checks.filter((check) => check.severity === "warning" || check.severity === "critical").length;
  return {
    profile: process.env.NODE_ENV === "production" ? "production" : "local-development",
    activeRuntime: { database: "node:sqlite", queue: "database-lease-worker", objectStorage: "local-filesystem" },
    summary: { status: blocking ? "blocked" : attention ? "attention" : "ready", blocking, attention, ready: checks.length - attention },
    checks,
    backups,
    checkedAt: new Date().toISOString()
  };
}