import {
  Component,
  For,
  onCleanup,
  createSignal,
  Show,
  untrack,
  onMount,
  type ParentComponent,
  children,
} from "solid-js";
import { useDocumentTitle } from "../utils";
import { useSessions } from "../masto/clients";
import { type mastodon } from "masto";
import Scaffold from "../material/Scaffold";
import {
  AppBar,
  Button,
  Fab,
  LinearProgress,
  ListItemSecondaryAction,
  ListItemText,
  MenuItem,
  Switch,
  Toolbar,
} from "@suid/material";
import { css } from "solid-styled";
import { TimeSourceProvider, createTimeSource } from "../platform/timesrc";
import TootThread from "./TootThread.js";
import { useAcctProfile } from "../masto/acct";
import ProfileMenuButton from "./ProfileMenuButton";
import Tabs from "../material/Tabs";
import Tab from "../material/Tab";
import { Create as CreateTootIcon } from "@suid/icons-material";
import { useTimeline } from "../masto/timelines";
import { makeEventListener } from "@solid-primitives/event-listener";
import BottomSheet from "../material/BottomSheet";
import { $settings } from "../settings/stores";
import { useStore } from "@nanostores/solid";

const TimelinePanel: Component<{
  client: mastodon.rest.Client;
  name: "home" | "public" | "trends";
  prefetch?: boolean;
}> = (props) => {
  const [timeline, { refetch: refetchTimeline, mutate: mutateTimeline }] =
    useTimeline(() =>
      props.name !== "trends"
        ? props.client.v1.timelines[props.name]
        : props.client.v1.trends.statuses,
    );

  const tlEndObserver = new IntersectionObserver(() => {
    if (untrack(() => props.prefetch) && !timeline.loading)
      refetchTimeline({ direction: "old" });
  });

  onCleanup(() => tlEndObserver.disconnect());

  const onBookmark = async (
    index: number,
    client: mastodon.rest.Client,
    status: mastodon.v1.Status,
  ) => {
    const result = await (status.bookmarked
      ? client.v1.statuses.$select(status.id).unbookmark()
      : client.v1.statuses.$select(status.id).bookmark());
    mutateTimeline((o) => {
      o[index] = result;
      return o;
    });
  };

  const onBoost = async (
    index: number,
    client: mastodon.rest.Client,
    status: mastodon.v1.Status,
  ) => {
    const reblogged = false;
    mutateTimeline((o) => {
      Object.assign(o[index].reblog ?? o[index], {
        reblogged: !reblogged,
      });
      return o;
    });
    const result = reblogged
      ? await client.v1.statuses.$select(status.id).unreblog()
      : (await client.v1.statuses.$select(status.id).reblog()).reblog!;
    mutateTimeline((o) => {
      Object.assign(o[index].reblog ?? o[index], {
        reblogged: result.reblogged,
        reblogsCount: result.reblogsCount,
      });
      return o;
    });
  };

  return (
    <>
      <div>
        <For each={timeline()}>
          {(item, index) => {
            return (
              <TootThread
                status={item}
                onBoost={(...args) => onBoost(index(), ...args)}
                onBookmark={(...args) => onBookmark(index(), ...args)}
                client={props.client}
              />
            );
          }}
        </For>
      </div>

      <div ref={(e) => tlEndObserver.observe(e)}></div>
      <Show when={timeline.loading}>
        <div class="loading-line" style={{ width: "100%" }}>
          <LinearProgress />
        </div>
      </Show>
      <Show when={timeline.error}>
        <div
          style={{
            display: "flex",
            padding: "20px 0 var(--safe-area-inset-bottom, 20px)",
            "align-items": "center",
            "justify-content": "center",
          }}
        >
          <Button variant="contained" onClick={[refetchTimeline, "old"]}>
            Retry
          </Button>
        </div>
      </Show>
      <Show when={!props.prefetch && !timeline.loading}>
        <div
          style={{
            display: "flex",
            padding: "20px 0 var(--safe-area-inset-bottom, 20px)",
            "align-items": "center",
            "justify-content": "center",
          }}
        >
          <Button variant="contained" onClick={[refetchTimeline, "old"]}>
            Load More
          </Button>
        </div>
      </Show>
    </>
  );
};

const Home: ParentComponent = (props) => {
  let panelList: HTMLDivElement;
  useDocumentTitle("Timelines");
  const now = createTimeSource();

  const settings$ = useStore($settings)
  const sessions = useSessions();
  const client = () => sessions()[0].client;
  const [profile] = useAcctProfile(client);

  const [panelOffset, setPanelOffset] = createSignal(0);
  const prefetching = () => !settings$().prefetchTootsDisabled
  const [currentFocusOn, setCurrentFocusOn] = createSignal<HTMLElement[]>([]);
  const [focusRange, setFocusRange] = createSignal([0, 0] as readonly [
    number,
    number,
  ]);

  const child = children(() => props.children)

  let scrollEventLockReleased = true;

  const recalculateTabIndicator = () => {
    scrollEventLockReleased = false;
    try {
      const { x: panelX, width: panelWidth } =
        panelList.getBoundingClientRect();
      let minIdx = +Infinity,
        maxIdx = -Infinity;
      const items = panelList.querySelectorAll(".tab-panel");
      const ranges = Array.from(items).map((x) => {
        const rect = x.getBoundingClientRect();
        const inlineStart = rect.x - panelX;
        const inlineEnd = rect.width + inlineStart;
        return [inlineStart, inlineEnd] as const;
      });
      for (let i = 0; i < items.length; i++) {
        const e = items.item(i);
        const [inlineStart, inlineEnd] = ranges[i];
        if (inlineStart >= 0 && inlineEnd <= panelWidth) {
          minIdx = Math.min(minIdx, i);
          maxIdx = Math.max(maxIdx, i);
          e.classList.add("active");
        } else {
          e.classList.remove("active");
        }
      }

      if (isFinite(minIdx) && isFinite(maxIdx)) {
        setFocusRange([minIdx, maxIdx]);
      }
    } finally {
      scrollEventLockReleased = true;
    }
  };

  onMount(() => {
    makeEventListener(panelList, "scroll", () => {
      if (scrollEventLockReleased) {
        requestAnimationFrame(recalculateTabIndicator);
      }
    });
    makeEventListener(window, "resize", () => {
      if (scrollEventLockReleased) {
        requestAnimationFrame(recalculateTabIndicator);
      }
    });
    requestAnimationFrame(recalculateTabIndicator);
  });

  const isTabFocus = (idx: number) => {
    const [start, end] = focusRange();
    if (!isFinite(start) || !isFinite(end)) return false;
    return idx >= start && idx <= end;
  };

  const onTabClick = (idx: number) => {
    const items = panelList.querySelectorAll(".tab-panel");
    if (items.length > idx) {
      items.item(idx).scrollIntoView({ block: "start", behavior: "smooth" });
    }
  };

  css`
    .tab-panel {
      overflow: visible auto;
      max-width: 560px;
      height: 100%;
      padding: 40px 16px;
      scroll-snap-align: center;

      @media (max-width: 600px) {
        padding: 0;
      }
    }

    .panel-list {
      display: grid;
      grid-auto-columns: 560px;
      grid-auto-flow: column;
      overflow-x: auto;
      scroll-snap-type: x mandatory;
      scroll-snap-stop: always;
      height: calc(100vh - var(--scaffold-topbar-height, 0px));
      height: calc(100dvh - var(--scaffold-topbar-height, 0px));
      padding-left: var(--safe-area-inset-left, 0);
      padding-right: var(--safe-area-inset-right, 0);

      @media (max-width: 600px) {
        grid-auto-columns: 100%;
      }
    }
  `;

  return (
    <>
      <Scaffold
        topbar={
          <AppBar position="static">
            <Toolbar variant="dense" class="responsive" sx={{ paddingTop: "var(--safe-area-inset-top, 0px)" }}>
              <Tabs onFocusChanged={setCurrentFocusOn} offset={panelOffset()}>
                <Tab focus={isTabFocus(0)} onClick={[onTabClick, 0]}>
                  Home
                </Tab>
                <Tab focus={isTabFocus(1)} onClick={[onTabClick, 1]}>
                  Trending
                </Tab>
                <Tab focus={isTabFocus(2)} onClick={[onTabClick, 2]}>
                  Public
                </Tab>
              </Tabs>
              <ProfileMenuButton profile={profile()}>
                <MenuItem onClick={(e) => $settings.setKey("prefetchTootsDisabled", !$settings.get().prefetchTootsDisabled)}>
                  <ListItemText>Prefetch Toots</ListItemText>
                  <ListItemSecondaryAction>
                    <Switch checked={prefetching()}></Switch>
                  </ListItemSecondaryAction>
                </MenuItem>
              </ProfileMenuButton>
            </Toolbar>
          </AppBar>
        }
        fab={
          <Fab color="secondary">
            <CreateTootIcon />
          </Fab>
        }
      >
        <TimeSourceProvider value={now}>
          <div class="panel-list" ref={panelList!}>
            <div class="tab-panel">
              <div>
                <TimelinePanel
                  client={client()}
                  name="home"
                  prefetch={prefetching()}
                />
              </div>
            </div>
            <div class="tab-panel">
              <div>
                <TimelinePanel
                  client={client()}
                  name="trends"
                  prefetch={prefetching()}
                />
              </div>
            </div>
            <div class="tab-panel">
              <div>
                <TimelinePanel
                  client={client()}
                  name="public"
                  prefetch={prefetching()}
                />
              </div>
            </div>
            <div></div>
          </div>
        </TimeSourceProvider>
        <BottomSheet open={!!child()}>{child()}</BottomSheet>
      </Scaffold>
    </>
  );
};

export default Home;