<script lang="ts">
	import { ScrollState } from "$lib/spells/scroll-state.svelte";
	import { type ConversationClass } from "$lib/state/conversations.svelte";
	import { watch } from "runed";
	import { tick } from "svelte";
	import CodeSnippets from "./code-snippets.svelte";
	import Message from "./message.svelte";

	interface Props {
		conversation: ConversationClass;
		viewCode: boolean;
		onCloseCode: () => void;
	}

	const { conversation, viewCode, onCloseCode }: Props = $props();

	let messageContainer: HTMLDivElement | null = $state(null);
	const scrollState = new ScrollState({
		element: () => messageContainer,
		offset: { bottom: 100 },
	});
	const atBottom = $derived(scrollState.arrived.bottom);

	watch(
		() => conversation.data.messages?.at(-1)?.content,
		() => {
			const shouldScroll = atBottom && !scrollState.isScrolling;
			if (!shouldScroll) return;
			try {
				tick().then(() => {
					scrollState.scrollToBottom();
				});
			} catch {
				// noop
			}
		}
	);

	async function regenMessage(idx: number) {
		// TODO: migrate to new logic
		const msg = conversation.data.messages?.[idx];
		if (!msg) return;
		if (msg.role === "user") {
			await conversation.deleteMessages(idx + 1);
		} else {
			await conversation.deleteMessages(idx);
		}

		conversation.stopGenerating();
		conversation.genNextMessage();
	}
</script>

<div
	class="@container flex h-full flex-col overflow-x-hidden overflow-y-auto"
	class:animate-pulse={conversation.generating && !conversation.data.streaming}
	bind:this={messageContainer}
>
	{#if !viewCode}
		{#if conversation.data.messages}
			{#each conversation.data.messages as message, index}
				<Message
					{message}
					{index}
					{conversation}
					onDelete={() => conversation.deleteMessage(index)}
					onRegen={() => regenMessage(index)}
				/>
			{:else}
				<div class="m-auto flex flex-col items-center gap-2 text-center px-4 text-balance">
					<h1 class="text-2xl font-semibold">Welcome to Hugging Face Inference Playground</h1>
					<p class="text-lg text-gray-500">Try hundreds of models on different providers</p>
				</div>
			{/each}
		{/if}
	{:else}
		<CodeSnippets {conversation} {onCloseCode} />
	{/if}
</div>
