(() => {
	const $messages = document.getElementById("messages"),
		$chat = document.getElementById("chat"),
		$message = document.getElementById("message"),
		$bottom = document.getElementById("bottom"),
		$role = document.getElementById("role"),
		$model = document.getElementById("model"),
		$prompt = document.getElementById("prompt"),
		$temperature = document.getElementById("temperature"),
		$add = document.getElementById("add"),
		$send = document.getElementById("send"),
		$clear = document.getElementById("clear");

	const messages = [];

	function uid() {
		return `${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 8)}`;
	}

	function make(tag, ...classes) {
		const el = document.createElement(tag);

		el.classList.add(...classes);

		return el;
	}

	function render(markdown) {
		return marked.parse(DOMPurify.sanitize(markdown), {
			gfm: true,
		});
	}

	function scroll() {
		$messages.scroll({
			top: $messages.scrollHeight + 200,
			behavior: "smooth",
		});
	}

	class Message {
		#id;
		#role;
		#reasoning;
		#text;

		#editing = false;
		#expanded = false;
		#state = false;

		#_message;
		#_role;
		#_reasoning;
		#_text;
		#_edit;

		constructor(role, reasoning, text) {
			this.#id = uid();
			this.#role = role;
			this.#reasoning = reasoning || "";
			this.#text = text || "";

			this.#build();
			this.#render();

			messages.push(this);
		}

		#build() {
			// main message div
			this.#_message = make("div", "message", this.#role);

			// message role
			this.#_role = make("div", "role", this.#role);

			this.#_message.appendChild(this.#_role);

			// message reasoning (wrapper)
			const _reasoning = make("div", "reasoning", "markdown");

			this.#_message.appendChild(_reasoning);

			// message reasoning (toggle)
			const _toggle = make("button", "toggle");

			_toggle.textContent = "Reasoning";

			_reasoning.appendChild(_toggle);

			_toggle.addEventListener("click", () => {
				this.#expanded = !this.#expanded;

				if (this.#expanded) {
					this.#_message.classList.add("expanded");
				} else {
					this.#_message.classList.remove("expanded");
				}
			});

			// message reasoning (content)
			this.#_reasoning = make("div", "reasoning-text");

			_reasoning.appendChild(this.#_reasoning);

			// message content
			this.#_text = make("div", "text", "markdown");

			this.#_message.appendChild(this.#_text);

			// message edit textarea
			this.#_edit = make("textarea", "text");

			this.#_message.appendChild(this.#_edit);

			// message options
			const _opts = make("div", "options");

			this.#_message.appendChild(_opts);

			// copy option
			const _optCopy = make("button", "copy");

			_optCopy.title = "Copy message content";

			_opts.appendChild(_optCopy);

			let timeout;

			_optCopy.addEventListener("click", () => {
				clearTimeout(timeout);

				navigator.clipboard.writeText(this.#text);

				_optCopy.classList.add("copied");

				timeout = setTimeout(() => {
					_optCopy.classList.remove("copied");
				}, 1000);
			});

			// edit option
			const _optEdit = make("button", "edit");

			_optEdit.title = "Edit message content";

			_opts.appendChild(_optEdit);

			_optEdit.addEventListener("click", () => {
				this.toggleEdit();
			});

			// delete option
			const _optDelete = make("button", "delete");

			_optDelete.title = "Delete message";

			_opts.appendChild(_optDelete);

			_optDelete.addEventListener("click", () => {
				this.delete();
			});

			$messages.appendChild(this.#_message);

			scroll();
		}

		#render(only = false) {
			if (!only || only === "role") {
				this.#_role.textContent = this.#role;
			}

			if (!only || only === "reasoning") {
				this.#_reasoning.innerHTML = render(this.#reasoning);

				if (this.#reasoning) {
					this.#_message.classList.add("has-reasoning");
				} else {
					this.#_message.classList.remove("has-reasoning");
				}
			}

			if (!only || only === "text") {
				this.#_text.innerHTML = render(this.#text);
			}

			scroll();
		}

		#save() {
			const data = messages.map((message) => message.getData(true));

			console.log("save", data);

			localStorage.setItem("messages", JSON.stringify(data));
		}

		getData(includeReasoning = false) {
			const data = {
				role: this.#role,
				text: this.#text,
			};

			if (this.#reasoning && includeReasoning) {
				data.reasoning = this.#reasoning;
			}

			return data;
		}

		setState(state) {
			if (this.#state === state) {
				return;
			}

			if (this.#state) {
				this.#_message.classList.remove(this.#state);
			}

			if (state) {
				this.#_message.classList.add(state);
			}

			this.#state = state;
		}

		addReasoning(chunk) {
			this.#reasoning += chunk;

			this.#render("reasoning");
			this.#save();
		}

		addText(text) {
			this.#text += text;

			this.#render("text");
			this.#save();
		}

		stopEdit() {
			if (!this.#editing) {
				return;
			}

			this.toggleEdit();
		}

		toggleEdit() {
			this.#editing = !this.#editing;

			if (this.#editing) {
				this.#_edit.value = this.#text;

				this.#_edit.style.height = `${this.#_text.offsetHeight}px`;
				this.#_edit.style.width = `${this.#_text.offsetWidth}px`;

				this.setState("editing");

				this.#_edit.focus();
			} else {
				this.#text = this.#_edit.value;

				this.setState(false);

				this.#render();
				this.#save();
			}
		}

		delete() {
			const index = messages.findIndex((msg) => msg.#id === this.#id);

			if (index === -1) {
				return;
			}

			console.log("delete", index);

			messages.splice(index, 1);

			this.#_message.remove();

			this.#save();
		}
	}

	let controller;

	async function json(url) {
		try {
			const response = await fetch(url);

			if (!response.ok) {
				throw new Error(response.statusText);
			}

			return await response.json();
		} catch (err) {
			console.error(err);

			return false;
		}
	}

	async function stream(url, options, callback) {
		try {
			const response = await fetch(url, options);

			if (!response.ok) {
				throw new Error(response.statusText);
			}

			const reader = response.body.getReader(),
				decoder = new TextDecoder();

			let buffer = "";

			while (true) {
				const { value, done } = await reader.read();

				if (done) break;

				buffer += decoder.decode(value, {
					stream: true,
				});

				while (true) {
					const idx = buffer.indexOf("\n\n");

					if (idx === -1) {
						break;
					}

					const frame = buffer.slice(0, idx).trim();
					buffer = buffer.slice(idx + 2);

					if (!frame) {
						continue;
					}

					try {
						const chunk = JSON.parse(frame);

						if (!chunk) {
							throw new Error("invalid chunk");
						}

						callback(chunk);
					} catch (err) {
						console.warn("bad frame", frame);
						console.warn(err);
					}
				}
			}
		} catch (err) {
			if (err.name !== "AbortError") {
				callback({
					type: "error",
					text: err.message,
				});
			}
		} finally {
			callback(false);
		}
	}

	async function loadModels() {
		const models = await json("/-/models");

		if (!models) {
			alert("Failed to load models.");

			return;
		}

		models.sort((a, b) => a.name > b.name);

		$model.innerHTML = "";

		for (const model of models) {
			const el = document.createElement("option");

			el.value = model.id;
			el.textContent = model.name;

			$model.appendChild(el);
		}
	}

	function restore(models) {
		$role.value = localStorage.getItem("role") || "user";
		$model.value = localStorage.getItem("model") || models[0].id;
		$prompt.value = localStorage.getItem("prompt") || "normal";
		$temperature.value = localStorage.getItem("temperature") || 0.85;

		try {
			JSON.parse(localStorage.getItem("messages") || "[]").forEach(
				(message) =>
					new Message(
						message.role,
						message.reasoning,
						message.text,
					),
			);
		} catch {}
	}

	function pushMessage() {
		const text = $message.value.trim();

		if (!text) {
			return false;
		}

		$message.value = "";

		return new Message($role.value, "", text);
	}

	$messages.addEventListener("scroll", () => {
		const bottom =
			$messages.scrollHeight - ($messages.scrollTop + $messages.offsetHeight);

		if (bottom >= 80) {
			$bottom.classList.remove("hidden");
		} else {
			$bottom.classList.add("hidden");
		}
	});

	$bottom.addEventListener("click", () => {
		$messages.scroll({
			top: $messages.scrollHeight,
			behavior: "smooth",
		});
	});

	$role.addEventListener("change", () => {
		localStorage.setItem("role", $role.value);
	});

	$model.addEventListener("change", () => {
		localStorage.setItem("model", $model.value);
	});

	$prompt.addEventListener("change", () => {
		localStorage.setItem("prompt", $prompt.value);
	});

	$temperature.addEventListener("input", () => {
		localStorage.setItem("temperature", $temperature.value);
	});

	$message.addEventListener("input", () => {
		localStorage.setItem("message", $message.value);
	});

	$add.addEventListener("click", () => {
		pushMessage();
	});

	$clear.addEventListener("click", () => {
		if (!confirm("Are you sure you want to delete all messages?")) {
			return;
		}

		for (const message of messages) {
			message.delete();
		}
	});

	$send.addEventListener("click", () => {
		if (controller) {
			controller.abort();

			return;
		}

		const temperature = parseFloat($temperature.value);

		if (Number.isNaN(temperature) || temperature < 0 || temperature > 1) {
			return;
		}

		pushMessage();

		controller = new AbortController();

		$chat.classList.add("completing");

		const body = {
			prompt: $prompt.value,
			model: $model.value,
			temperature: temperature,
			messages: messages.map((message) => message.getData()),
		};

		const message = new Message("assistant", "", "");

		message.setState("waiting");

		stream(
			"/-/chat",
			{
				method: "POST",
				headers: {
					"Content-Type": "application/json",
				},
				body: JSON.stringify(body),
				signal: controller.signal,
			},
			(chunk) => {
				if (!chunk) {
					controller = null;

					message.setState(false);

					$chat.classList.remove("completing");

					return;
				}

				console.log(chunk);

				switch (chunk.type) {
					case "reason":
						message.setState("reasoning");
						message.addReasoning(chunk.text);

						break;
					case "text":
						message.setState("receiving");
						message.addText(chunk.text);

						break;
				}
			},
		);
	});

	$message.addEventListener("keydown", (event) => {
		if (!event.ctrlKey || event.key !== "Enter") {
			return;
		}

		$send.click();
	});

	loadModels().then(restore);
})();