import { Signal } from "@char/aftercare";
import { assert, assertEquals, assertStringIncludes } from "@std/assert";
import { decodeBase64 } from "@std/encoding/base64";
import type { ImageContent } from "@earendil-works/pi-ai";
import { IDBFactory } from "fake-indexeddb";
import { PNG, until } from "@berry/util";
import { withDom } from "@berry/util/dom.ts";
import { composer } from "./composer.tsx";
import { imageDraft } from "./image-drafts.ts";
import type { CommandInfo } from "./conversation.tsx";
import { Scope } from "./ui.ts";

Deno.test("pasted images are durable route-specific drafts and sends retire only captured attachments", async (t) => {
  let decode = () => Promise.resolve({ width: 1, height: 1, close() {} });
  const globals = {
    indexedDB: new IDBFactory(),
    crypto: { getRandomValues: crypto.getRandomValues.bind(crypto) },
    createImageBitmap: () => decode(),
  };
  await withDom(async (window) => {
    const commands = new Signal<readonly CommandInfo[]>([]);
    const scopes: Scope[] = [];
    const errors: string[] = [];
    const calls: { text: string; followUp: boolean; images: readonly ImageContent[] }[] = [];
    let send = () => Promise.resolve();
    const file = (name = "screenshot.png") =>
      new File([decodeBase64(PNG)], name, { type: "image/png" });
    const open = async (route: string, busy = false) => {
      location.hash = `#/${route}`;
      const scope = new Scope();
      scopes.push(scope);
      const view = composer(scope, route, new Signal(busy), commands, (text, followUp, images) => {
        calls.push({ text, followUp, images });
        return send();
      }, (message) => errors.push(message));
      document.body.replaceChildren(view.element);
      await imageDraft(route).ready;
      const input = view.element.querySelector("textarea")!;
      return {
        ...view,
        input,
        paste(files: readonly File[], text = "") {
          const event = new window.Event("paste", { cancelable: true, bubbles: true });
          Object.defineProperty(event, "clipboardData", {
            value: {
              items: files.map((file) => ({
                kind: "file",
                type: file.type,
                getAsFile: () => file,
              })),
              getData: (format: string) => format === "text/plain" ? text : "",
            },
          });
          input.dispatchEvent(event as unknown as Event);
          return event.defaultPrevented;
        },
        async saved() {
          await until(() =>
            imageDraft(route).items.get().length > 0 &&
            imageDraft(route).items.get().every((image) => image.status !== "loading")
          );
        },
        async submit(followUp = false) {
          input.dispatchEvent(
            new window.KeyboardEvent("keydown", {
              key: "Enter",
              altKey: followUp,
            }) as unknown as Event,
          );
          await until(() => !imageDraft(route).submitting);
        },
        leave() {
          scope.dispose();
          view.element.remove();
        },
      };
    };
    let reloads = 0;
    const fresh = async (route: string) => {
      const module = await import(
        new URL(`./image-drafts.ts?reload=${++reloads}`, import.meta.url).href
      ) as typeof import("./image-drafts.ts");
      const draft = module.imageDraft(route);
      await draft.ready;
      assertEquals(draft.error.get(), null);
      return draft.items.get();
    };
    try {
      await t.step(
        "ordinary paste stays native and mixed paste preserves the text selection",
        async () => {
          const view = await open("mixed");
          assertEquals(view.paste([], "plain text"), false);
          view.setText("hello world");
          view.input.setSelectionRange(6, 11);
          assertEquals(view.paste([file()], "there"), true);
          assertEquals(view.input.value, "hello there");
          await view.saved();
          assertEquals(view.element.querySelector("img")!.alt, "screenshot.png");
          await view.submit();
          assertEquals(calls.at(-1), {
            text: "hello there",
            followUp: false,
            images: [{ type: "image", mimeType: "image/png", data: PNG }],
          });
          assertEquals(view.input.value, "");
          assertEquals(view.element.querySelectorAll(".attachment").length, 0);
          assertEquals(await fresh("mixed"), []);
        },
      );
      await t.step(
        "images survive navigation and a fresh frontend without crossing branch routes",
        async () => {
          for (const route of ["draft", "draft/fork@4"]) {
            const view = await open(route);
            view.paste([file(`${route}.png`)]);
            await view.saved();
            view.leave();
          }
          for (const route of ["draft", "draft/fork@4"]) {
            const restored = await fresh(route);
            assertEquals(restored.length, 1);
            assertEquals(restored[0].name, `${route}.png`);
            assertEquals(restored[0].blob.type, "image/png");
            assertEquals(new Uint8Array(await restored[0].blob.arrayBuffer()), decodeBase64(PNG));
            const view = await open(route);
            assertEquals(view.element.querySelector("img")!.alt, `${route}.png`);
            view.leave();
          }
          assertEquals((await open("unrelated")).element.querySelectorAll(".attachment").length, 0);
        },
      );
      await t.step(
        "failed sends retain images and image-only retries clear their durable draft",
        async () => {
          const view = await open("retry-images");
          view.paste([file()]);
          await view.saved();
          send = () => Promise.reject(new Error("offline"));
          await view.submit();
          assertEquals(errors.at(-1), "offline");
          assertEquals((await fresh("retry-images")).length, 1);
          assertEquals(view.element.querySelectorAll(".attachment").length, 1);
          send = () => Promise.resolve();
          await view.submit();
          assertEquals(calls.at(-1)!.text, "");
          assertEquals(calls.at(-1)!.images[0].data, PNG);
          assertEquals(await fresh("retry-images"), []);
        },
      );
      await t.step(
        "pending sends protect later pastes and edits, even after returning to the route",
        async () => {
          const pending = Promise.withResolvers<void>();
          send = () => pending.promise;
          const view = await open("pending-images");
          view.setText("old message");
          view.paste([file("old.png")]);
          await view.saved();
          const before = calls.length;
          const submitted = view.submit();
          await until(() => calls.length === before + 1);
          view.leave();
          const returned = await open("pending-images");
          const duplicate = returned.submit();
          assertEquals(calls.length, before + 1);
          returned.setText("next message");
          returned.paste([file("next.png")]);
          await returned.saved();
          pending.resolve();
          await submitted;
          await duplicate;
          assertEquals(returned.input.value, "next message");
          assertEquals([...returned.element.querySelectorAll("img")].map((img) => img.alt), [
            "next.png",
          ]);
          assertEquals((await fresh("pending-images")).map((image) => image.name), ["next.png"]);
          send = () => Promise.resolve();
        },
      );
      await t.step(
        "commands refuse attachments and busy sends preserve their delivery mode",
        async () => {
          let commandsRun = 0;
          commands.set([{
            name: "local",
            extension: "test",
            description: "local",
            run: () => {
              commandsRun++;
              return Promise.resolve();
            },
          }]);
          const view = await open("command-images");
          view.paste([file()]);
          await view.saved();
          view.setText("/local");
          const before = calls.length;
          await view.submit();
          assertEquals(commandsRun, 0);
          assertEquals(calls.length, before);
          assertEquals(errors.at(-1), "Slash commands cannot include images");
          assertEquals((await fresh("command-images")).length, 1);
          const busy = await open("busy-images", true);
          busy.paste([file()]);
          await busy.saved();
          await busy.submit(true);
          assertEquals(calls.at(-1)!.followUp, true);
          assertEquals(calls.at(-1)!.images[0].data, PNG);
        },
      );
      await t.step(
        "restored messages retain attachments and never replace text or image drafts",
        async () => {
          const view = await open("restored-images");
          const content = [
            { type: "text" as const, text: "Bring this back" },
            { type: "image" as const, mimeType: "image/png", data: PNG },
          ];
          view.setText(" ");
          assertEquals(await view.restore(content), false);
          assertEquals(view.input.value, " ");
          view.setText("");
          assertEquals(await view.restore(content), true);
          assertEquals(view.input.value, "Bring this back");
          assertEquals((await fresh("restored-images")).length, 1);
          view.setText("");
          assertEquals(await view.restore("must not replace the image"), false);
          assertEquals(view.input.value, "");
          view.setText("Bring this back");
          await view.submit();
          assertEquals(calls.at(-1), {
            text: "Bring this back",
            followUp: false,
            images: [{ type: "image", mimeType: "image/png", data: PNG }],
          });
          assertEquals(await fresh("restored-images"), []);
        },
      );
      await t.step("invalid and undecodable images cannot be sent and can be removed", async () => {
        const view = await open("invalid-images");
        const before = calls.length;
        view.paste([new File(["not an image"], "broken.png", { type: "image/png" })]);
        await view.saved();
        assertStringIncludes(
          view.element.querySelector(".attachment-status")!.textContent!,
          "declared format",
        );
        await view.submit();
        assertEquals(calls.length, before);
        assertEquals(await fresh("invalid-images"), []);
        view.element.querySelector<HTMLButtonElement>('[title="Remove image"]')!.click();
        await until(() => imageDraft("invalid-images").items.get().length === 0);
        decode = () => Promise.reject(new Error("Cannot decode image"));
        view.paste([file()]);
        await view.saved();
        assertStringIncludes(
          view.element.querySelector(".attachment-status")!.textContent!,
          "Cannot decode",
        );
        decode = () => Promise.resolve({ width: 1, height: 1, close() {} });
        const crowded = await open("crowded-images");
        crowded.paste(Array.from({ length: 5 }, () => file()));
        await until(() => errors.at(-1)?.includes("at most 4") === true);
        assertEquals(crowded.element.querySelectorAll(".attachment").length, 0);
      });
      assert(calls.length > 0);
    } finally {
      for (const scope of scopes) scope.dispose();
    }
  }, { globals });
});