import {
  Component,
  For,
  onCleanup,
  createSignal,
  createEffect,
  Show,
  untrack,
  onMount,
} from "solid-js";
import { $accounts } from "../accounts/stores";
import { useDocumentTitle } from "../utils";
import { useStore } from "@nanostores/solid";
import { useMastoClientFor } from "../masto/clients";
import { type mastodon } from "masto";
import Scaffold from "../material/Scaffold";
import {
  AppBar,
  Button,
  Fab,
  LinearProgress,
  ListItemSecondaryAction,
  ListItemText,
  MenuItem,
  Switch,
  Toolbar,
  Typography,
} 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";

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",
            "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",
            "align-items": "center",
            "justify-content": "center",
          }}
        >
          <Button variant="contained" onClick={[refetchTimeline, "old"]}>
            Load More
          </Button>
        </div>
      </Show>
    </>
  );
};

const Home: Component = () => {
  let panelList: HTMLDivElement;
  useDocumentTitle("Timelines");
  const accounts = useStore($accounts);
  const now = createTimeSource();

  const client = useMastoClientFor(() => accounts()[0]);
  const [profile] = useAcctProfile(() => accounts()[0]);

  const [panelOffset, setPanelOffset] = createSignal(0);
  const [prefetching, setPrefetching] = createSignal(true);
  const [currentFocusOn, setCurrentFocusOn] = createSignal<HTMLElement[]>([]);
  const [focusRange, setFocusRange] = createSignal([0, 0] as readonly [
    number,
    number,
  ]);

  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({ behavior: "smooth" });
    }
  };

  css`
    .tab-panel {
      overflow: visible auto;
      max-width: 560px;
      height: 100%;
      padding: 40px 16px;
      max-height: calc(100vh - var(--scaffold-topbar-height, 0px));
      max-height: calc(100dvh - var(--scaffold-topbar-height, 0px));
      scroll-snap-align: center;

      &:not(.active) {
        overflow: hidden;
      }

      @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));

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

  return (
    <Scaffold
      topbar={
        <AppBar position="static">
          <Toolbar variant="dense" class="responsive">
            <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) => setPrefetching((x) => !x)}>
                <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>
    </Scaffold>
  );
};

export default Home;