import fs from "node:fs";
import path from "node:path";
import { glob } from "glob";
import { TSESLint } from "@typescript-eslint/utils";
import {
  getCollectCatalogDefinitionsRule,
  type CatalogDef,
} from "@hi18n/eslint-plugin/internal-rules";
import { loadConfig } from "./config.ts";
import type { Hi18nCatalogData } from "@hi18n/tools-core";

export type Options = {
  cwd: string;
};

export async function export_(options: Options): Promise<void> {
  const { cwd } = options;
  const config = await loadConfig(cwd);
  const include = config.include;
  const exclude = config.exclude;
  if (include === undefined || include.length === 0) {
    throw new Error("No include specified");
  }

  if (!config.connector) {
    throw new Error("Connector not configured");
  }

  const catalogDefs: CatalogDef[] = [];
  const linterConfig: TSESLint.FlatConfig.Config = {
    languageOptions: {
      parser: config.parser as TSESLint.Parser.LooseParserModule,
      parserOptions: config.parserOptions,
    },
    plugins: {
      "@hi18n": {
        rules: {
          "collect-catalog-definitions": getCollectCatalogDefinitionsRule(
            (record) => catalogDefs.push(record),
          ),
        },
      },
    },
  };

  const linter = new TSESLint.Linter({ cwd });

  const files: string[] = [];
  for (const includeGlob of include) {
    files.push(
      ...(await glob(includeGlob, {
        cwd,
        nodir: true,
        ignore: exclude ?? [],
      })),
    );
  }
  for (const relative of files) {
    const filename = path.join(cwd, relative);
    const source = await fs.promises.readFile(filename, "utf-8");
    const messages = linter.verify(
      source,
      [
        { files: ["**"] },
        {
          ...linterConfig,
          rules: {
            "@hi18n/collect-catalog-definitions": [
              "error",
              {
                requestMessages: true,
              },
            ],
          },
        },
      ],
      { filename },
    );
    checkMessages(relative, messages);
  }
  const translations: Record<string, Hi18nCatalogData> = {};
  for (const catalogDef of catalogDefs) {
    if (!catalogDef.locale) {
      throw new Error(`No locale given in ${catalogDef.catalogLocation.path}`);
    }
    const locale = catalogDef.locale;
    const catalogData = (translations[locale] ??= {});
    for (const [key, messageDef] of Object.entries(catalogDef.messages)) {
      catalogData[key] = { raw: messageDef.value };
    }
  }
  const c = config.connector.connector(
    config.configPath,
    config.connectorOptions,
  );
  if (!c.exportData) {
    throw new Error("This connector doesn't support exporting");
  }

  await c.exportData({ translations });
}

function checkMessages(
  filepath: string,
  messages: TSESLint.Linter.LintMessage[],
) {
  for (const message of messages) {
    if (/^Definition for rule .* was not found\.$/.test(message.message)) {
      // We load ESLint with minimal rules. Ignore the "missing rule" error.
      continue;
    }
    if (message.severity >= 2)
      throw new Error(`Error on ${filepath}: ${message.message}`);
  }
}