import fs from "node:fs";
import { resolveDataDir, resolveStoragePath } from "./data-dir.mjs";
import { ensureProviderSchema } from "./provider-store.mjs";
import { ensureSettingsSchema, hashManagementPassword, updateSettings } from "./settings-store.mjs";

async function loadBetterSqlite() {
  try {
    return (await import("better-sqlite3")).default;
  } catch {
    throw new Error("better-sqlite3 is not installed. Run npm install before using setup.");
  }
}

function createSqliteNativeError(error) {
  const message = error instanceof Error ? error.message : String(error);
  if (message.includes("NODE_MODULE_VERSION") || message.includes("ERR_DLOPEN_FAILED")) {
    return new Error(
      "better-sqlite3 native binding is incompatible with this Node.js runtime. " +
        "Run `npm rebuild better-sqlite3` in the OmniRoute project and try again."
    );
  }
  return error;
}

async function openSqliteDatabase(dbPath, options = {}) {
  const Database = await loadBetterSqlite();
  try {
    return new Database(dbPath, options);
  } catch (error) {
    throw createSqliteNativeError(error);
  }
}

export async function openOmniRouteDb() {
  const dataDir = resolveDataDir();
  const dbPath = resolveStoragePath(dataDir);
  fs.mkdirSync(dataDir, { recursive: true });

  const db = await openSqliteDatabase(dbPath);

  db.pragma("journal_mode = WAL");
  ensureSettingsSchema(db);
  ensureProviderSchema(db);

  return { db, dataDir, dbPath };
}

export async function withReadonlySqlite(dbPath, callback) {
  const db = await openSqliteDatabase(dbPath, { readonly: true, fileMustExist: true });
  try {
    return await callback(db);
  } finally {
    db.close();
  }
}

export async function backupSqliteFile(sourcePath, destPath) {
  const db = await openSqliteDatabase(sourcePath, { readonly: true });
  try {
    await db.backup(destPath);
  } finally {
    db.close();
  }
}

export async function readDatabaseHealth(dbPath) {
  return withReadonlySqlite(dbPath, (db) => {
    const quickCheck = db.prepare("PRAGMA quick_check").get();
    const quickCheckValue = Object.values(quickCheck || {})[0];
    const hasMigrationTable = !!db
      .prepare("SELECT name FROM sqlite_master WHERE type = 'table' AND name = ?")
      .get("_omniroute_migrations");
    const appliedMigrationVersions = hasMigrationTable
      ? db
          .prepare("SELECT version FROM _omniroute_migrations")
          .all()
          .map((row) => row.version)
      : [];

    return { quickCheckValue, hasMigrationTable, appliedMigrationVersions };
  });
}

export async function readEncryptedCredentialSamples(dbPath) {
  return withReadonlySqlite(dbPath, (db) => {
    const hasProviderTable = !!db
      .prepare("SELECT name FROM sqlite_master WHERE type = 'table' AND name = ?")
      .get("provider_connections");
    if (!hasProviderTable) {
      return { hasProviderTable: false, encryptedValues: [] };
    }

    const rows = db
      .prepare(
        `SELECT api_key, access_token, refresh_token, id_token
         FROM provider_connections
         WHERE api_key LIKE 'enc:v1:%'
            OR access_token LIKE 'enc:v1:%'
            OR refresh_token LIKE 'enc:v1:%'
            OR id_token LIKE 'enc:v1:%'
         LIMIT 20`
      )
      .all();

    const encryptedValues = rows.flatMap((row) =>
      ["api_key", "access_token", "refresh_token", "id_token"]
        .filter((key) => typeof row[key] === "string" && row[key].startsWith("enc:v1:"))
        .map((key) => row[key])
    );

    return { hasProviderTable: true, encryptedValues };
  });
}

export async function readManagementPasswordState(dbPath = resolveStoragePath(resolveDataDir())) {
  if (!fs.existsSync(dbPath)) {
    return { exists: false, hasPassword: false };
  }

  return withReadonlySqlite(dbPath, (db) => {
    const hasSettingsTable = !!db
      .prepare("SELECT name FROM sqlite_master WHERE type = 'table' AND name = ?")
      .get("key_value");
    if (!hasSettingsTable) {
      return { exists: true, hasPassword: false };
    }
    const row = db
      .prepare("SELECT value FROM key_value WHERE namespace = 'settings' AND key = ?")
      .get("password");
    let password = row?.value;
    if (typeof password === "string") {
      try {
        password = JSON.parse(password);
      } catch {}
    }
    return {
      exists: true,
      hasPassword: typeof password === "string" && password.length > 0,
    };
  });
}

export async function resetManagementPassword(
  password,
  dbPath = resolveStoragePath(resolveDataDir())
) {
  const db = await openSqliteDatabase(dbPath);
  try {
    db.pragma("journal_mode = WAL");
    ensureSettingsSchema(db);
    const hashedPassword = await hashManagementPassword(password);
    updateSettings(db, { password: hashedPassword, requireLogin: true });
  } finally {
    db.close();
  }
}