<script lang="ts">
  import { createEventDispatcher, onMount } from "svelte";
  import { BlockLabel, Empty } from "@gradio/atoms";
  import { Video } from "@gradio/icons";

  import { start, stop } from "./webrtc_utils";

  export let value: string | null = null;
  export let label: string | undefined = undefined;
  export let show_label = true;
  export let rtc_configuration: Object | null = null;
  export let on_change_cb: (msg: "change" | "tick") => void;
  export let server: {
    offer: (body: any) => Promise<any>;
  };

  let video_element: HTMLVideoElement;

  let _webrtc_id = Math.random().toString(36).substring(2);

  let pc: RTCPeerConnection;

  const dispatch = createEventDispatcher<{
    error: string;
    tick: undefined;
  }>();

  let _on_change_cb = (msg: "change" | "tick" | "stopword" | any) => {
    if (msg.type === "end_stream") {
      on_change_cb(msg);
      stream_state = "closed";
      stop(pc);
    } else {
      console.debug("calling on_change_cb with msg", msg);
      on_change_cb(msg);
    }
  };

  let stream_state = "closed";

  $: if (value === "start_webrtc_stream") {
    _webrtc_id = Math.random().toString(36).substring(2);
    server
      .turn()
      .then((rtc_configuration_) => {
        rtc_configuration = rtc_configuration_;
      })
      .catch((error) => {
        dispatch("error", error);
      });
    value = _webrtc_id;
    pc = new RTCPeerConnection(rtc_configuration);
    pc.addEventListener("connectionstatechange", async (event) => {
      switch (pc.connectionState) {
        case "connected":
          stream_state = "open";
          dispatch("tick");
          break;
        case "disconnected":
          stop(pc);
          break;
        case "failed":
          stream_state = "closed";
          dispatch("error", "Connection failed!");
          stop(pc);
          break;
        default:
          break;
      }
    });

    const timeoutId = setTimeout(() => {
      // @ts-ignore
      on_change_cb({ type: "connection_timeout" });
    }, 5000);

    start(
      null,
      pc,
      video_element,
      server.offer,
      _webrtc_id,
      "video",
      _on_change_cb,
    )
      .then((connection) => {
        clearTimeout(timeoutId);
        pc = connection;
      })
      .catch(() => {
        clearTimeout(timeoutId);
        dispatch("error", "Too many concurrent users. Come back later!");
      });
  }
</script>

<BlockLabel {show_label} Icon={Video} label={label || "Video"} />

{#if value === "__webrtc_value__"}
  <Empty unpadded_box={true} size="large"><Video /></Empty>
{/if}
<div class="wrap">
  <video
    class:hidden={value === "__webrtc_value__"}
    bind:this={video_element}
    autoplay={true}
    on:loadeddata={dispatch.bind(null, "loadeddata")}
    on:click={dispatch.bind(null, "click")}
    on:play={dispatch.bind(null, "play")}
    on:pause={dispatch.bind(null, "pause")}
    on:ended={dispatch.bind(null, "ended")}
    on:mouseover={dispatch.bind(null, "mouseover")}
    on:mouseout={dispatch.bind(null, "mouseout")}
    on:focus={dispatch.bind(null, "focus")}
    on:blur={dispatch.bind(null, "blur")}
    on:load
    data-testid={$$props["data-testid"]}
    crossorigin="anonymous"
  >
    <track kind="captions" />
  </video>
</div>

<style>
  .hidden {
    display: none;
  }

  .wrap {
    position: relative;
    background-color: var(--background-fill-secondary);
    height: var(--size-full);
    width: var(--size-full);
    border-radius: var(--radius-xl);
  }
  .wrap :global(video) {
    height: var(--size-full);
    width: var(--size-full);
  }
</style>
