import chalk from 'chalk';
import fs from 'node:fs';
import path from 'node:path';
import { documentsToRender } from '../actions/render';
import { TopLevelDirectoryName } from '../domain/file-names';
import { RootConfigWrite } from '../domain/root-config';
import { generateDocument } from './generate-document';
import { getErrorMessage } from './get-error-message';
import { validateDocument } from './validate-document';

const maxDocumentSizeString = '6291556 bytes (6MB)';

export const validateDocuments = async (params: { apiKey: string; productModuleConfig: RootConfigWrite }) => {
  const { apiKey, productModuleConfig } = params;

  for await (const documentToRender of documentsToRender) {
    const [fileName, extension] = documentToRender.split('.');
    const pathToFile = path.join('./', TopLevelDirectoryName.Documents, `${fileName}.${extension}`);
    const { host } = productModuleConfig;
    if (fs.existsSync(pathToFile)) {
      const content = fs.readFileSync(pathToFile, { encoding: 'utf-8' });

      const validationResult = await validateDocument({
        apiKey,
        content,
        host,
      });

      if (validationResult.result === 'error') {
        console.log(`\nThere was an error validating ${chalk.yellow(documentToRender)}`);
        throw new Error(validationResult.message);
      }

      try {
        await generateDocument({ apiKey, host, merge: false, content, mergeVars: {} });
      } catch (error) {
        const errorMessage = getErrorMessage(error);
        if (errorMessage.includes('entity_too_large_error')) {
          throw new Error(
            `The document ${documentToRender} is too large. Please ensure the size of the rendered document is less than ${maxDocumentSizeString}.`,
          );
        }

        if (errorMessage.includes('request_timeout_error')) {
          throw new Error(
            `Validation of document ${documentToRender} timed out. If the problem persists, please ensure the rendered document is less than ${maxDocumentSizeString}.`,
          );
        }

        // Preserve the underlying error so the user can act on it. Without this, every
        // platform-side failure (template syntax error, missing merge var, 5xx, etc.)
        // collapses into the same opaque "Error validating document X" line.
        throw new Error(
          [
            `Error validating document ${chalk.yellow(documentToRender)}`,
            `File: ${chalk.yellow(pathToFile)}`,
            '',
            'Underlying error:',
            errorMessage
              .split('\n')
              .map((line) => `  ${line}`)
              .join('\n'),
            '',
            `Tip: open ${chalk.yellow(pathToFile)} and check for unmatched template tags, malformed HTML, or merge-var references that the renderer cannot resolve.`,
          ].join('\n'),
        );
      }
    }
  }
};