// Copyright 2024 The Lynx Authors. All rights reserved.
// Licensed under the Apache License Version 2.0 that can be found in the
// LICENSE file in the root directory of this source tree.
import type { DataProcessorDefinition, InitData, InitDataRaw } from '../lynx-api.js';
import { profileEnd, profileStart } from '../shared/profile.js';

// `true` only while the default data processor is running. `defaultDataProcessor` is
// invoked by the native side as a separate call *before* `renderPage` / `updatePage`,
// so a `markFirstScreenSyncReady()` made inside it must not sync the *previous* tree
// (still latched ready) — a re-render of the data being processed is imminent. The
// first-screen sync backend reads this to defer such a mark. Lives here (not in the
// backend) so `core` does not depend on a runtime backend.
let processingDefaultData = false;

export function isProcessingDefaultData(): boolean {
  return processingDefaultData;
}

export function createProcessData(
  dataProcessorDefinition?: DataProcessorDefinition,
): (data: InitDataRaw, processorName?: string) => InitData | InitDataRaw {
  let hasDefaultDataProcessorExecuted = false;

  return (data, processorName) => {
    if (typeof __PROFILE__ !== 'undefined' && __PROFILE__) {
      profileStart('processData');
    }

    let result: InitData | InitDataRaw;
    try {
      if (processorName) {
        result = dataProcessorDefinition?.dataProcessors?.[processorName]?.(data) as InitData ?? data;
      } else {
        // a `markFirstScreenSyncReady()` made inside `defaultDataProcessor` must be
        // deferred until the data being processed renders (see `processingDefaultData`)
        processingDefaultData = true;
        try {
          result = dataProcessorDefinition?.defaultDataProcessor?.(data) ?? data;
        } finally {
          processingDefaultData = false;
        }
      }
    } catch (error: unknown) {
      lynx.reportError(error as Error);
      result = {};
    }

    if (typeof __PROFILE__ !== 'undefined' && __PROFILE__) {
      profileEnd();
    }

    if (!hasDefaultDataProcessorExecuted) {
      result = appendInitDataMetadata(result);
    }

    if (!processorName) {
      hasDefaultDataProcessorExecuted = true;
    }

    return result;
  };
}

function appendInitDataMetadata(result: InitData | InitDataRaw): InitData | InitDataRaw {
  // @ts-expect-error todo: add types to i18n logic
  const i18nResourceTranslation: unknown = globalThis.__I18N_RESOURCE_TRANSLATION__;
  if (i18nResourceTranslation) {
    result = {
      ...result,
      __I18N_RESOURCE_TRANSLATION__: i18nResourceTranslation,
    };
  }

  // @ts-expect-error todo: add types to __EXTRACT_STR__
  if (__EXTRACT_STR__) {
    // @ts-expect-error todo: add types to __EXTRACT_STR__
    const extractStrIdentFlag: unknown = __EXTRACT_STR_IDENT_FLAG__;
    result = {
      ...result,
      _EXTRACT_STR: extractStrIdentFlag,
    };
  }

  return result;
}