import type { DesktopArticleContent } from "@geo/shared-types";
import type { Session, WebContents, WebContentsView } from "electron/main";
import { marked } from "marked";

import { STANDARD_ACCEPT_LANGUAGES, STANDARD_USER_AGENT } from "../user-agent";

export function normalizeText(value: unknown): string | null {
  if (typeof value !== "string") {
    return null;
  }
  const trimmed = value.trim();
  return trimmed ? trimmed : null;
}

export function normalizeRemoteUrl(value?: string | null): string | null {
  const trimmed = value?.trim();
  if (!trimmed) {
    return null;
  }
  if (/^(data|blob):/i.test(trimmed)) {
    return trimmed;
  }
  if (/^https?:\/\//i.test(trimmed)) {
    return trimmed;
  }
  if (/^\/\//.test(trimmed)) {
    return `https:${trimmed}`;
  }
  if (/^[a-z][a-z\d+\-.]*:/i.test(trimmed)) {
    return trimmed;
  }
  return `https://${trimmed.replace(/^\/+/, "")}`;
}

export interface NormalizeArticleHtmlOptions {
  prepareMarkdown?: (markdown: string) => string;
}

export function normalizeArticleHtml(article: DesktopArticleContent, options: NormalizeArticleHtmlOptions = {}): string {
  const markdown = article.markdown_content?.trim();
  const source = markdown ? markdownToHtml(options.prepareMarkdown?.(markdown) ?? markdown) : article.html_content?.trim() || "";
  let next = source.trim();
  next = next.replace(/<section\b/gi, "<div").replace(/<\/section>/gi, "</div>");
  next = next.replace(/<(script|style)[^>]*>[\s\S]*?<\/\1>/gi, "");
  next = next.replace(/\sstyle="[^"]*"/gi, "");
  next = next.replace(/\sdata-[a-z-]+="[^"]*"/gi, "");
  next = next.replace(/<figure[^>]*>\s*(<img[\s\S]*?>)\s*<\/figure>/gi, "$1");
  return next.trim();
}

function markdownToHtml(markdown: string): string {
  const source = markdown.trim();
  if (!source) {
    return "";
  }
  return marked.parse(source, {
    async: false,
    gfm: true,
    breaks: false,
  }) as string;
}

export function extractImageSources(html: string): string[] {
  const sources = new Set<string>();
  for (const match of html.matchAll(/<img\b[^>]*src=(['"])(.*?)\1[^>]*>/gi)) {
    const src = match[2]?.trim();
    if (src) {
      sources.add(src);
    }
  }
  return [...sources];
}

export async function fetchImageBlob(sourceUrl: string): Promise<Blob | null> {
  const normalizedUrl = normalizeRemoteUrl(sourceUrl);
  if (!normalizedUrl) {
    return null;
  }

  const response = await fetch(normalizedUrl).catch(() => null);
  if (!response?.ok) {
    return null;
  }

  const blob = await response.blob().catch(() => null);
  if (!blob || !blob.type.startsWith("image/")) {
    return null;
  }

  return blob;
}

export async function uploadHtmlImages(
  html: string,
  uploader: (sourceUrl: string) => Promise<string | null>,
): Promise<{ html: string; uploaded: Map<string, string> }> {
  const sources = extractImageSources(html);
  if (!sources.length) {
    return {
      html,
      uploaded: new Map(),
    };
  }

  const uploaded = new Map<string, string>();
  for (const source of sources) {
    const target = await uploader(source);
    if (target) {
      uploaded.set(source, target);
    }
  }

  let next = html;
  for (const [from, to] of uploaded.entries()) {
    next = next.split(from).join(to);
  }

  return { html: next, uploaded };
}

export async function sessionFetchText(
  session: Session,
  input: string,
  init?: RequestInit,
): Promise<string> {
  const headers = new Headers(init?.headers);
  if (!headers.has("user-agent")) {
    headers.set("user-agent", STANDARD_USER_AGENT);
  }
  if (!headers.has("accept-language")) {
    headers.set("accept-language", STANDARD_ACCEPT_LANGUAGES);
  }

  const response = await session.fetch(input, {
    ...init,
    headers,
  });
  const text = await response.text();
  if (!response.ok) {
    throw new Error(text || `request_failed_${response.status}`);
  }
  return text;
}

export async function sessionFetchJson<T>(
  session: Session,
  input: string,
  init?: RequestInit,
): Promise<T> {
  const text = await sessionFetchText(session, input, init);
  if (!text) {
    return {} as T;
  }
  return JSON.parse(text) as T;
}

export interface PageFetchInit {
  method?: string;
  headers?: Record<string, string>;
  body?: string;
  credentials?: "include" | "same-origin" | "omit";
}

export async function sessionCookieFetchJson<T>(
  session: Session,
  url: string,
  init?: { method?: string; headers?: Record<string, string>; body?: string },
): Promise<T | null> {
  let parsedURL: URL;
  try {
    parsedURL = new URL(url);
  } catch {
    return null;
  }

  let cookieHeader = "";
  try {
    const cookies = await session.cookies.get({ url });
    cookieHeader = cookies.map((cookie) => `${cookie.name}=${cookie.value}`).join("; ");
  } catch {
    cookieHeader = "";
  }

  const headers: Record<string, string> = {
    "user-agent": STANDARD_USER_AGENT,
    "accept-language": STANDARD_ACCEPT_LANGUAGES,
    accept: "application/json, text/plain, */*",
    referer: `${parsedURL.protocol}//${parsedURL.host}/`,
    origin: `${parsedURL.protocol}//${parsedURL.host}`,
  };
  if (cookieHeader) {
    headers.cookie = cookieHeader;
  }
  if (init?.headers) {
    for (const [key, value] of Object.entries(init.headers)) {
      headers[key.toLowerCase()] = value;
    }
  }

  let response: Response;
  try {
    response = await fetch(url, {
      method: init?.method ?? "GET",
      headers,
      body: init?.body,
    });
  } catch {
    return null;
  }

  if (!response.ok) {
    return null;
  }

  let text: string;
  try {
    text = await response.text();
  } catch {
    return null;
  }

  if (!text) {
    return {} as T;
  }
  try {
    return JSON.parse(text) as T;
  } catch {
    return null;
  }
}

export async function pageFetchJson<T>(
  webContents: WebContents,
  url: string,
  init?: PageFetchInit,
): Promise<T | null> {
  if (!webContents || webContents.isDestroyed()) {
    return null;
  }

  const effectiveInit: PageFetchInit = {
    credentials: "include",
    ...init,
  };

  const script = `(async () => {
    try {
      const response = await fetch(${JSON.stringify(url)}, ${JSON.stringify(effectiveInit)});
      if (!response.ok) {
        return JSON.stringify({ __ok: false, status: response.status });
      }
      const text = await response.text();
      if (!text) {
        return JSON.stringify({ __ok: true, empty: true });
      }
      return JSON.stringify({ __ok: true, body: text });
    } catch (error) {
      return JSON.stringify({ __ok: false, error: String(error && error.message || error) });
    }
  })()`;

  let serialized: string;
  try {
    serialized = (await webContents.executeJavaScript(script, true)) as string;
  } catch {
    return null;
  }

  if (typeof serialized !== "string" || !serialized) {
    return null;
  }

  let envelope: { __ok: boolean; body?: string; empty?: boolean; status?: number; error?: string };
  try {
    envelope = JSON.parse(serialized);
  } catch {
    return null;
  }

  if (!envelope.__ok) {
    return null;
  }
  if (envelope.empty) {
    return {} as T;
  }
  if (!envelope.body) {
    return null;
  }

  try {
    return JSON.parse(envelope.body) as T;
  } catch {
    return null;
  }
}

export async function sessionCookieValue(
  session: Session,
  domain: string,
  name: string,
): Promise<string> {
  const cookies = await session.cookies.get({ domain });
  return cookies.find((item) => item.name === name)?.value ?? "";
}

export async function sessionCookieHeader(session: Session, domain: string): Promise<string> {
  const cookies = await session.cookies.get({ domain });
  return cookies.map((item) => `${item.name}=${item.value}`).join("; ");
}

export async function ensureViewLoaded(
  view: WebContentsView,
  url: string,
  signal?: AbortSignal,
): Promise<void> {
  if (signal?.aborted) {
    throw new Error("adapter_aborted");
  }

  if (view.webContents.isLoading()) {
    await waitForLoadStop(view, signal);
  }

  const currentURL = view.webContents.getURL();
  if (currentURL === url) {
    return;
  }

  await view.webContents.loadURL(url);
  await waitForLoadStop(view, signal);
}

async function waitForLoadStop(view: WebContentsView, signal?: AbortSignal): Promise<void> {
  if (!view.webContents.isLoading()) {
    return;
  }

  while (view.webContents.isLoading()) {
    if (signal?.aborted) {
      throw new Error("adapter_aborted");
    }
    await new Promise((resolve) => {
      setTimeout(resolve, 120);
    });
  }
}