frontend/src/lib/components/playground/Chat.svelte

<script lang="ts">
	import fileSaver from "file-saver";
	const { saveAs } = fileSaver;

	import { toast } from "svelte-sonner";

	import { goto } from "$app/navigation";
	import { onMount, tick, getContext } from "svelte";

	import {
		OLLAMA_API_BASE_URL,
		OPENAI_API_BASE_URL,
		REXPRO_API_BASE_URL,
		REXPRO_BASE_URL,
	} from "$lib/constants";
	import { REXPRO_NAME, config, user, models, settings } from "$lib/stores";

	import { chatCompletion } from "$lib/apis/openai";

	import { splitStream } from "$lib/utils";
	import Collapsible from "../common/Collapsible.svelte";
	import Dropdown from "../common/Dropdown.svelte";
	import DropdownSub from "../common/DropdownSub.svelte";

	import Messages from "$lib/components/playground/Chat/Messages.svelte";
	import AdvancedParams from "$lib/components/chat/Settings/Advanced/AdvancedParams.svelte";
	import ChevronUp from "../icons/ChevronUp.svelte";
	import ChevronDown from "../icons/ChevronDown.svelte";
	import Pencil from "../icons/Pencil.svelte";
	import Cog6 from "../icons/Cog6.svelte";
	import AdjustmentsHorizontal from "../icons/AdjustmentsHorizontal.svelte";
	import Modal from "../common/Modal.svelte";
	import XMark from "../icons/XMark.svelte";
	import Sidebar from "../common/Sidebar.svelte";
	import ArrowRight from "../icons/ArrowRight.svelte";
	import Download from "../icons/Download.svelte";
	import EllipsisHorizontal from "../icons/EllipsisHorizontal.svelte";

	const i18n = getContext("i18n");

	let loaded = false;

	let selectedModelId = "";
	let loading = false;
	let stopResponseFlag = false;

	let systemTextareaElement: HTMLTextAreaElement;
	let messagesContainerElement: HTMLDivElement;

	let showSystem = false;
	let showSettings = false;
	let showControls = false;

	let params: Record<string, any> = {};

	let system = "";

	let role = "user";
	let message = "";

	let messages = [];

	const scrollToBottom = () => {
		const element = messagesContainerElement;

		if (element) {
			element.scrollTop = element?.scrollHeight;
		}
	};

	const stopResponse = () => {
		stopResponseFlag = true;
		console.log("stopResponse");
	};

	const resizeSystemTextarea = async () => {
		await tick();
		if (systemTextareaElement) {
			systemTextareaElement.style.height = "";
			systemTextareaElement.style.height =
				Math.min(systemTextareaElement.scrollHeight, 555) + "px";
		}
	};

	$: if (showSystem) {
		resizeSystemTextarea();
	}

	const chatCompletionHandler = async () => {
		if (selectedModelId === "") {
			toast.error($i18n.t("Please select a model."));
			return;
		}

		const model = $models.find((model) => model.id === selectedModelId);
		if (!model) {
			selectedModelId = "";
			return;
		}

		// Build params object, filtering out null/undefined values
		const activeParams = Object.fromEntries(
			Object.entries(params).filter(
				([_, v]) => v !== null && v !== undefined,
			),
		);

		const [res, controller] = await chatCompletion(
			localStorage.token,
			{
				model: model.id,
				stream: true,
				messages: [
					system
						? {
								role: "system",
								content: system,
							}
						: undefined,
					...messages,
				].filter((message) => message),
				...(Object.keys(activeParams).length > 0 ? activeParams : {}),
			},
			`${REXPRO_BASE_URL}/api`,
		);

		let responseMessage;
		if (messages.at(-1)?.role === "assistant") {
			responseMessage = messages.at(-1);
		} else {
			responseMessage = {
				role: "assistant",
				content: "",
			};
			messages.push(responseMessage);
			messages = messages;
		}

		await tick();
		const textareaElement = document.getElementById(
			`assistant-${messages.length - 1}-textarea`,
		);

		if (res && res.ok) {
			const reader = res.body
				.pipeThrough(new TextDecoderStream())
				.pipeThrough(splitStream("\n"))
				.getReader();

			while (true) {
				const { value, done } = await reader.read();
				if (done || stopResponseFlag) {
					if (stopResponseFlag) {
						controller.abort("User: Stop Response");
					}
					break;
				}

				try {
					let lines = value.split("\n");

					for (const line of lines) {
						if (line !== "") {
							console.log(line);
							if (line === "data: [DONE]") {
								// responseMessage.done = true;
								messages = messages;
							} else {
								let data = JSON.parse(
									line.replace(/^data: /, ""),
								);
								console.log(data);

								if (
									responseMessage.content == "" &&
									data.choices[0].delta.content == "\n"
								) {
									continue;
								} else {
									textareaElement.style.height =
										textareaElement.scrollHeight + "px";

									responseMessage.content +=
										data.choices[0].delta.content ?? "";
									messages = messages;

									textareaElement.style.height =
										textareaElement.scrollHeight + "px";

									await tick();
								}
							}
						}
					}
				} catch (error) {
					console.log(error);
				}

				scrollToBottom();
			}
		}
	};

	const addHandler = async () => {
		if (message) {
			messages.push({
				role: role,
				content: message,
			});
			messages = messages;
			message = "";
			await tick();
			scrollToBottom();
		}
	};

	const submitHandler = async () => {
		if (selectedModelId) {
			await addHandler();

			loading = true;
			await chatCompletionHandler();

			loading = false;
			stopResponseFlag = false;
		}
	};

	const exportToJson = () => {
		const now = Math.floor(Date.now() / 1000);

		// Convert flat messages array to history map format
		const messagesMap: Record<string, any> = {};
		let currentId: string | null = null;
		let parentId: string | null = null;

		// Add system message if present
		if (system) {
			const systemId = crypto.randomUUID();
			messagesMap[systemId] = {
				id: systemId,
				parentId: null,
				childrenIds: [],
				role: "system",
				content: system,
				timestamp: now,
			};
			parentId = systemId;
		}

		// Add conversation messages
		for (const msg of messages) {
			const msgId = crypto.randomUUID();

			// Link parent to child
			if (parentId && messagesMap[parentId]) {
				messagesMap[parentId].childrenIds.push(msgId);
			}

			messagesMap[msgId] = {
				id: msgId,
				parentId: parentId,
				childrenIds: [],
				role: msg.role,
				content: msg.content,
				timestamp: now,
				...(msg.role === "assistant" && selectedModelId
					? { model: selectedModelId }
					: {}),
			};

			currentId = msgId;
			parentId = msgId;
		}

		const exportData = {
			chat: {
				title: "Playground Chat",
				models: [selectedModelId],
				params: system ? { system } : {},
				history: {
					messages: messagesMap,
					currentId,
				},
			},
			meta: {},
			pinned: false,
			created_at: now,
			updated_at: now,
		};

		const blob = new Blob([JSON.stringify([exportData], null, 2)], {
			type: "application/json",
		});
		saveAs(blob, `playground-chat-${Date.now()}.json`);
		toast.success($i18n.t("Chat exported successfully"));
	};

	const downloadTxt = () => {
		let chatText = "";

		// Add system message if present
		if (system) {
			chatText += `### SYSTEM\n${system}\n\n`;
		}

		// Add conversation messages
		for (const msg of messages) {
			chatText += `### ${msg.role.toUpperCase()}\n${msg.content}\n\n`;
		}

		const blob = new Blob([chatText.trim()], {
			type: "text/plain",
		});
		saveAs(blob, `playground-chat-${Date.now()}.txt`);
		toast.success($i18n.t("Chat exported successfully"));
	};

	onMount(async () => {
		if ($user?.role !== "admin") {
			await goto("/");
		}

		if ($settings?.models) {
			selectedModelId = $settings?.models[0];
		} else if ($config?.default_models) {
			selectedModelId = $config?.default_models.split(",")[0];
		} else {
			selectedModelId = "";
		}
		loaded = true;
	});
</script>

<Modal size="sm" bind:show={showControls}>
	<div class="text-gray-700 dark:text-gray-100">
		<div class="flex justify-between px-4.5 pt-4.5 pb-2">
			<div class="text-lg font-medium self-center">
				{$i18n.t("Controls")}
			</div>
			<button
				class="self-center"
				aria-label={$i18n.t("Close")}
				on:click={() => {
					showControls = false;
				}}
			>
				<XMark className="size-5" />
			</button>
		</div>
		<div class="px-4.5 pb-5 overflow-y-auto max-h-[70vh]">
			<AdvancedParams
				admin={$user?.role === "admin"}
				custom={true}
				bind:params
			/>
		</div>
	</div>
</Modal>

<div class=" flex flex-col justify-between w-full overflow-y-auto h-full">
	<div class="mx-auto w-full md:px-0 h-full relative">
		<div class=" flex flex-col h-full px-3.5">
			<div class="flex w-full items-center gap-1.5">
				<Collapsible
					className="w-full flex-1"
					bind:open={showSystem}
					buttonClassName="w-full rounded-lg text-sm border border-gray-100/30 dark:border-gray-850/30 w-full py-1 px-1.5"
					grow={true}
				>
					<div class="flex gap-2 justify-between items-center">
						<div class=" shrink-0 font-medium ml-1.5">
							{$i18n.t("System Instructions")}
						</div>

						{#if !showSystem && system.trim()}
							<div class=" flex-1 text-gray-500 line-clamp-1">
								{system}
							</div>
						{/if}

						<div class="shrink-0">
							<button
								class="p-1.5 bg-transparent hover:bg-white/5 transition rounded-lg"
							>
								{#if showSystem}
									<ChevronUp className="size-3.5" />
								{:else}
									<Pencil className="size-3.5" />
								{/if}
							</button>
						</div>
					</div>

					<div slot="content">
						<div class="pt-1 px-1.5">
							<textarea
								bind:this={systemTextareaElement}
								class="w-full h-full bg-transparent resize-none outline-hidden text-sm"
								bind:value={system}
								placeholder={$i18n.t(
									"You're a helpful assistant.",
								)}
								on:input={() => {
									resizeSystemTextarea();
								}}
								rows="4"
							/>
						</div>
					</div>
				</Collapsible>

				<Dropdown>
					<button
						class="p-1.5 text-sm font-medium bg-transparent hover:bg-gray-100 dark:hover:bg-gray-800 text-gray-500 dark:text-gray-400 transition rounded-lg"
						aria-label={$i18n.t("More options")}
					>
						<EllipsisHorizontal className="size-4" />
					</button>

					<div slot="content">
						<div
							class="min-w-[200px] rounded-2xl px-1 py-1 border border-gray-100 dark:border-gray-800 z-50 bg-white dark:bg-gray-850 dark:text-white shadow-lg"
						>
							<DropdownSub>
								<button
									slot="trigger"
									class="flex gap-2 items-center px-3 py-1.5 text-sm cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-800 rounded-xl select-none w-full"
								>
									<Download strokeWidth="1.5" />
									<div class="flex items-center">
										{$i18n.t("Download")}
									</div>
								</button>
								<button
									class="flex gap-2 items-center px-3 py-1.5 text-sm cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-800 rounded-xl select-none w-full"
									disabled={messages.length === 0}
									on:click={() => {
										exportToJson();
									}}
								>
									<div class="flex items-center line-clamp-1">
										{$i18n.t("Export chat (.json)")}
									</div>
								</button>
								<button
									class="flex gap-2 items-center px-3 py-1.5 text-sm cursor-pointer hover:bg-gray-50 dark:hover:bg-gray-800 rounded-xl select-none w-full"
									disabled={messages.length === 0}
									on:click={() => {
										downloadTxt();
									}}
								>
									<div class="flex items-center line-clamp-1">
										{$i18n.t("Plain text (.txt)")}
									</div>
								</button>
							</DropdownSub>
						</div>
					</div>
				</Dropdown>
			</div>

			<div
				class=" pb-2.5 flex flex-col justify-between w-full flex-auto overflow-auto h-0"
				id="messages-container"
				bind:this={messagesContainerElement}
			>
				<div class=" h-full w-full flex flex-col">
					<div class="flex-1 p-1">
						<Messages bind:messages />
					</div>
				</div>
			</div>

			<div class="pb-3">
				<div
					class="border border-gray-100/30 dark:border-gray-850/30 w-full px-3 py-2.5 rounded-xl"
				>
					<div class="py-0.5">
						<!-- $i18n.t('a user') -->
						<!-- $i18n.t('an assistant') -->
						<textarea
							bind:value={message}
							class=" w-full h-full bg-transparent resize-none outline-hidden text-sm"
							placeholder={$i18n.t(
								`Enter {{role}} message here`,
								{
									role:
										role === "user"
											? $i18n.t("a user")
											: $i18n.t("an assistant"),
								},
							)}
							on:input={(e) => {
								e.target.style.height = "";
								e.target.style.height =
									Math.min(e.target.scrollHeight, 150) + "px";
							}}
							on:focus={(e) => {
								e.target.style.height = "";
								e.target.style.height =
									Math.min(e.target.scrollHeight, 150) + "px";
							}}
							rows="2"
						/>
					</div>

					<div
						class="flex justify-between flex-col sm:flex-row items-start sm:items-center gap-2 mt-2"
					>
						<div class="shrink-0">
							<button
								type="button"
								class="px-3.5 py-1.5 text-sm font-medium bg-gray-50 hover:bg-gray-100 text-gray-900 dark:bg-gray-850 dark:hover:bg-gray-800 dark:text-gray-200 transition rounded-lg shrink-0 {($settings?.highContrastMode ??
								false)
									? ''
									: 'outline-hidden'}"
								aria-pressed={role === "assistant"}
								aria-label={$i18n.t(
									role === "user"
										? "Switch to Assistant role"
										: "Switch to User role",
								)}
								on:click={() => {
									role =
										role === "user" ? "assistant" : "user";
								}}
							>
								{#if role === "user"}
									{$i18n.t("User")}
								{:else}
									{$i18n.t("Assistant")}
								{/if}
							</button>
						</div>

						<div
							class="flex items-center justify-between gap-2 w-full sm:w-auto"
						>
							<div class="flex-1">
								<select
									class=" bg-transparent border border-gray-100/30 dark:border-gray-850/30 rounded-lg py-1 px-2 -mx-0.5 text-sm outline-hidden w-full"
									bind:value={selectedModelId}
								>
									{#each $models as model}
										<option
											value={model.id}
											class="bg-gray-50 dark:bg-gray-700"
											>{model.name}</option
										>
									{/each}
								</select>
							</div>

							<button
								class="p-1.5 text-sm font-medium bg-transparent hover:bg-gray-100 dark:hover:bg-gray-800 transition rounded-lg {showControls
									? 'text-black dark:text-white'
									: 'text-gray-500 dark:text-gray-400'}"
								aria-label={$i18n.t("Controls")}
								id="playground-controls-toggle"
								on:click={() => {
									showControls = !showControls;
								}}
							>
								<AdjustmentsHorizontal className="size-4" />
							</button>

							<div class="flex gap-2 shrink-0">
								{#if !loading}
									<button
										disabled={message === ""}
										class="px-3.5 py-1.5 text-sm font-medium disabled:bg-gray-50 dark:disabled:hover:bg-gray-850 disabled:cursor-not-allowed bg-gray-50 hover:bg-gray-100 text-gray-900 dark:bg-gray-850 dark:hover:bg-gray-800 dark:text-gray-200 transition rounded-lg"
										on:click={() => {
											addHandler();
											role =
												role === "user"
													? "assistant"
													: "user";
										}}
									>
										{$i18n.t("Add")}
									</button>

									<button
										class="px-3.5 py-1.5 text-sm font-medium bg-black hover:bg-gray-900 text-white dark:bg-white dark:text-black dark:hover:bg-gray-100 transition rounded-lg"
										on:click={() => {
											submitHandler();
										}}
									>
										{$i18n.t("Run")}
									</button>
								{:else}
									<button
										class="px-3 py-1.5 text-sm font-medium bg-gray-300 text-black transition rounded-lg"
										on:click={() => {
											stopResponse();
										}}
									>
										{$i18n.t("Cancel")}
									</button>
								{/if}
							</div>
						</div>
					</div>
				</div>
			</div>
		</div>
	</div>
</div>