const output = document.querySelector("#run-output");

if (output) {
  let refreshTimer;
  const refresh = async () => {
    const response = await fetch(output.dataset.outputUrl, { cache: "no-store" });
    if (response.ok) {
      const nextOutput = (await response.json()).output;
      if (nextOutput !== output.textContent) {
        output.textContent = nextOutput;
      }
    }
    const status = document.querySelector("#run-status");
    if (status) {
      const stateResponse = await fetch(status.dataset.stateUrl, { cache: "no-store" });
      if (stateResponse.ok) {
        const state = await stateResponse.json();
        status.textContent = state.status;
        if (state.status !== "queued" && state.status !== "running") {
          window.clearInterval(refreshTimer);
        }
      }
    }
  };
  refresh();
  refreshTimer = window.setInterval(refresh, 2000);
}

const refreshArtifacts = async (container) => {
  const response = await fetch(container.dataset.artifactsUrl, { cache: "no-store" });
  if (!response.ok) {
    return [];
  }
  const artifacts = (await response.json()).artifacts;
  const list = container.querySelector("ul");
  list.replaceChildren();
  for (const artifact of artifacts) {
    const item = document.createElement("li");
    const link = document.createElement("a");
    link.href = artifact.url;
    link.textContent = artifact.name;
    item.append(link);
    list.append(item);
  }
  container.hidden = artifacts.length === 0;
  return artifacts;
};

for (const container of document.querySelectorAll("#run-artifacts")) {
  refreshArtifacts(container);
  window.setInterval(() => refreshArtifacts(container), 2000);
}

for (const form of document.querySelectorAll("form[data-wait-for-result]")) {
  const result = form.querySelector(".task-result");
  const controls = [...form.querySelectorAll("input, select, button")];
  let waiting = false;

  const warnBeforeLeaving = (event) => {
    event.preventDefault();
    event.returnValue = "";
  };

  const setWaiting = (value) => {
    waiting = value;
    form.classList.toggle("is-waiting", value);
    controls.forEach((control) => {
      control.disabled = value;
    });
    if (value) {
      window.addEventListener("beforeunload", warnBeforeLeaving);
    } else {
      window.removeEventListener("beforeunload", warnBeforeLeaving);
    }
  };

  const showResult = (message, kind, detailUrl) => {
    result.replaceChildren();
    result.className = `task-result ${kind}`;
    result.append(message);
    if (detailUrl) {
      const link = document.createElement("a");
      link.href = detailUrl;
      link.textContent = "View details";
      result.append(" ", link);
    }
  };

  const downloadArtifacts = async (run) => {
    const response = await fetch(run.artifacts_url, { cache: "no-store" });
    if (!response.ok) {
      return;
    }
    const artifacts = (await response.json()).artifacts;
    if (!artifacts.length) {
      return;
    }
    const link = document.createElement("a");
    link.href = artifacts[0].url;
    link.download = "";
    document.body.append(link);
    link.click();
    link.remove();
  };

  const waitForRun = async (run) => {
    while (true) {
      const response = await fetch(run.state_url, { cache: "no-store" });
      if (!response.ok) {
        throw new Error("Could not read task status.");
      }
      const state = await response.json();
      if (state.status !== "queued" && state.status !== "running") {
        if (state.status === "succeeded") {
          showResult("Completed successfully.", "succeeded", run.detail_url);
          if (form.dataset.downloadArtifacts !== undefined) {
            await downloadArtifacts(run);
          }
        } else {
          showResult(`Finished with status: ${state.status}.`, "failed", run.detail_url);
        }
        return;
      }
      await new Promise((resolve) => window.setTimeout(resolve, 500));
    }
  };

  form.addEventListener("submit", async (event) => {
    if (waiting) {
      event.preventDefault();
      return;
    }
    if (!form.reportValidity()) {
      return;
    }
    event.preventDefault();
    // Disabled fields are omitted from FormData, so collect values first.
    const formData = new FormData(form);
    setWaiting(true);
    showResult("Running...", "running");
    try {
      const response = await fetch(form.action, {
        method: "POST",
        body: formData,
        headers: { Accept: "application/json" },
      });
      const data = await response.json();
      if (!response.ok) {
        const messages = data.errors ? Object.values(data.errors).join(" ") : "Could not start task.";
        throw new Error(messages);
      }
      await waitForRun(data);
    } catch (error) {
      showResult(error instanceof Error ? error.message : "Could not run task.", "failed");
    } finally {
      setWaiting(false);
    }
  });
}