import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const repoRoot = path.resolve(__dirname, "..");
const sourcePath = path.join(repoRoot, "ndView.tsx");
const outputDir = path.join(repoRoot, "docs", "generated");
const outputPath = path.join(outputDir, "jrshikoku-operation-info.user.js");

const source = fs.readFileSync(sourcePath, "utf8");
const match = source.match(/return String\.raw`([\s\S]*?)`;\n};/);
if (!match) {
  throw new Error("Failed to locate buildOperationPageScript body in ndView.tsx");
}

let scriptBody = match[1];

scriptBody = scriptBody.replace(
  "  window.__jrsNativeOperationLayout = ${nativeLayout};",
  [
    "  window.__jrsNativeOperationLayout = Object.assign({",
    "    forceSignage: true,",
    "    safeAreaLeft: 0,",
    "    safeAreaRight: 0,",
    "    lineBadges: []",
    "  }, window.__TM_OPERATION_INFO_LAYOUT || {});"
  ].join("\n")
);

const nativePostMessageBlock = [
  "  function postMessage(payload) {",
  "    if (!window.ReactNativeWebView) return;",
  "    payload.type = 'operationInfoCapture';",
  "    window.ReactNativeWebView.postMessage(JSON.stringify(payload));",
  "  }"
].join("\n");

const tampermonkeyPostMessageBlock = [
  "  function downloadCapture(dataUrl, fileName) {",
  "    if (!dataUrl) return;",
  "    if (typeof GM_download === 'function') {",
  "      try {",
  "        GM_download({ url: dataUrl, name: fileName, saveAs: true });",
  "        return;",
  "      } catch (error) {",
  "        console.warn('[JRShikoku TM] GM_download failed, falling back to anchor download.', error);",
  "      }",
  "    }",
  "",
  "    var link = document.createElement('a');",
  "    link.href = dataUrl;",
  "    link.download = fileName || ('operation-info-' + Date.now() + '.png');",
  "    link.rel = 'noopener';",
  "    document.body.appendChild(link);",
  "    link.click();",
  "    link.remove();",
  "  }",
  "",
  "  function postMessage(payload) {",
  "    if (!payload) return;",
  "    if (payload.error) {",
  "      console.error('[JRShikoku TM] capture failed', payload);",
  "      window.alert('運行情報の画像生成に失敗しました。');",
  "      return;",
  "    }",
  "    downloadCapture(payload.dataUrl, payload.fileName);",
  "  }"
].join("\n");

if (!scriptBody.includes(nativePostMessageBlock)) {
  throw new Error("Failed to locate React Native postMessage block in ndView.tsx");
}
scriptBody = scriptBody.replace(nativePostMessageBlock, tampermonkeyPostMessageBlock);

const header = [
  "// ==UserScript==",
  "// @name         JR四国 運行情報 Inject",
  "// @namespace    https://github.com/harukin/jrshikoku",
  "// @version      0.1.0",
  "// @description  Run the JR Shikoku operation-info injection on desktop browsers via Tampermonkey.",
  "// @match        https://www.jr-shikoku.co.jp/info/*",
  "// @run-at       document-idle",
  "// @grant        GM_download",
  "// ==/UserScript==",
  "",
  "/* Generated from ndView.tsx by scripts/generate-operation-info-userscript.mjs. */",
  "",
  "window.__TM_OPERATION_INFO_LAYOUT = Object.assign({",
  "  forceSignage: true,",
  "  safeAreaLeft: 0,",
  "  safeAreaRight: 0,",
  "  lineBadges: []",
  "}, window.__TM_OPERATION_INFO_LAYOUT || {});",
  ""
].join("\n");

fs.mkdirSync(outputDir, { recursive: true });
fs.writeFileSync(outputPath, header + scriptBody.trimStart() + "\n", "utf8");
console.log(path.relative(repoRoot, outputPath));