"use client";

import { useEffect, useMemo, useState } from "react";
import Link from "next/link";
import { useRouter } from "next/navigation";

import { SignInButton, SignedIn, SignedOut, useAuth } from "@clerk/nextjs";

import { DashboardSidebar } from "@/components/organisms/DashboardSidebar";
import { DashboardShell } from "@/components/templates/DashboardShell";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import SearchableSelect from "@/components/ui/searchable-select";
import { getApiBaseUrl } from "@/lib/api-base";

const apiBase = getApiBaseUrl();

type Board = {
  id: string;
  name: string;
  slug: string;
  gateway_id?: string | null;
};

type Gateway = {
  id: string;
  name: string;
  url: string;
  main_session_key: string;
  workspace_root: string;
};

const slugify = (value: string) =>
  value
    .toLowerCase()
    .trim()
    .replace(/[^a-z0-9]+/g, "-")
    .replace(/(^-|-$)/g, "") || "board";

export default function NewBoardPage() {
  const router = useRouter();
  const { getToken, isSignedIn } = useAuth();

  const [name, setName] = useState("");
  const [gateways, setGateways] = useState<Gateway[]>([]);
  const [gatewayId, setGatewayId] = useState<string>("");

  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const isFormReady = Boolean(name.trim() && gatewayId);

  const selectedGateway = useMemo(
    () => gateways.find((gateway) => gateway.id === gatewayId) || null,
    [gateways, gatewayId]
  );
  const gatewayOptions = useMemo(
    () => gateways.map((gateway) => ({ value: gateway.id, label: gateway.name })),
    [gateways]
  );

  const loadGateways = async () => {
    if (!isSignedIn) return;
    try {
      const token = await getToken();
      const response = await fetch(`${apiBase}/api/v1/gateways`, {
        headers: { Authorization: token ? `Bearer ${token}` : "" },
      });
      if (!response.ok) {
        throw new Error("Unable to load gateways.");
      }
      const data = (await response.json()) as Gateway[];
      setGateways(data);
      if (!gatewayId && data.length > 0) {
        setGatewayId(data[0].id);
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : "Something went wrong.");
    }
  };

  useEffect(() => {
    loadGateways();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [isSignedIn]);

  const handleSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
    event.preventDefault();
    if (!isSignedIn) return;
    const trimmedName = name.trim();
    if (!trimmedName) {
      setError("Board name is required.");
      return;
    }
    if (!gatewayId) {
      setError("Select a gateway before creating a board.");
      return;
    }

    setIsLoading(true);
    setError(null);
    try {
      const token = await getToken();

      const payload: Partial<Board> = {
        name: trimmedName,
        slug: slugify(trimmedName),
        gateway_id: gatewayId || null,
      };

      const response = await fetch(`${apiBase}/api/v1/boards`, {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          Authorization: token ? `Bearer ${token}` : "",
        },
        body: JSON.stringify(payload),
      });
      if (!response.ok) {
        throw new Error("Unable to create board.");
      }
      const created = (await response.json()) as Board;
      router.push(`/boards/${created.id}`);
    } catch (err) {
      setError(err instanceof Error ? err.message : "Something went wrong.");
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <DashboardShell>
      <SignedOut>
        <div className="col-span-2 flex min-h-[calc(100vh-64px)] items-center justify-center bg-slate-50 p-10 text-center">
          <div className="rounded-xl border border-slate-200 bg-white px-8 py-6 shadow-sm">
            <p className="text-sm text-slate-600">Sign in to create a board.</p>
            <SignInButton
              mode="modal"
              forceRedirectUrl="/boards/new"
              signUpForceRedirectUrl="/boards/new"
            >
              <Button className="mt-4">Sign in</Button>
            </SignInButton>
          </div>
        </div>
      </SignedOut>
      <SignedIn>
        <DashboardSidebar />
        <main className="flex-1 overflow-y-auto bg-slate-50">
          <div className="border-b border-slate-200 bg-white px-8 py-6">
            <div>
              <h1 className="font-heading text-2xl font-semibold text-slate-900 tracking-tight">
                Create board
              </h1>
              <p className="mt-1 text-sm text-slate-500">
                Boards organize tasks and agents by mission context.
              </p>
            </div>
          </div>

          <div className="p-8">
            <form
              onSubmit={handleSubmit}
              className="space-y-6 rounded-xl border border-slate-200 bg-white p-6 shadow-sm"
            >
              <div className="space-y-4">
                <div className="grid gap-6 md:grid-cols-2">
                  <div className="space-y-2">
                    <label className="text-sm font-medium text-slate-900">
                      Board name <span className="text-red-500">*</span>
                    </label>
                    <Input
                      value={name}
                      onChange={(event) => setName(event.target.value)}
                      placeholder="e.g. Release operations"
                      disabled={isLoading}
                    />
                  </div>
                  <div className="space-y-2">
                    <label className="text-sm font-medium text-slate-900">
                      Gateway <span className="text-red-500">*</span>
                    </label>
                    <SearchableSelect
                      ariaLabel="Select gateway"
                      value={gatewayId}
                      onValueChange={setGatewayId}
                      options={gatewayOptions}
                      placeholder="Select gateway"
                      searchPlaceholder="Search gateways..."
                      emptyMessage="No gateways found."
                      triggerClassName="w-full h-11 rounded-xl border border-slate-300 bg-white px-3 py-2 text-sm font-medium text-slate-900 shadow-sm focus:border-blue-500 focus:ring-2 focus:ring-blue-200"
                      contentClassName="rounded-xl border border-slate-200 shadow-lg"
                      itemClassName="px-4 py-3 text-sm text-slate-700 data-[selected=true]:bg-slate-50 data-[selected=true]:text-slate-900"
                    />
                  </div>
                </div>

              </div>

              {gateways.length === 0 ? (
                <div className="rounded-lg border border-slate-200 bg-slate-50 px-4 py-3 text-sm text-slate-600">
                  <p>
                    No gateways available. Create one in{" "}
                    <Link
                      href="/gateways"
                      className="font-medium text-blue-600 hover:text-blue-700"
                    >
                      Gateways
                    </Link>{" "}
                    to continue.
                  </p>
                </div>
              ) : null}

              {error ? <p className="text-sm text-red-500">{error}</p> : null}

              <div className="flex justify-end gap-3">
                <Button
                  type="button"
                  variant="ghost"
                  onClick={() => router.push("/boards")}
                  disabled={isLoading}
                >
                  Cancel
                </Button>
                <Button type="submit" disabled={isLoading || !isFormReady}>
                  {isLoading ? "Creating…" : "Create board"}
                </Button>
              </div>
            </form>
          </div>
        </main>
      </SignedIn>
    </DashboardShell>
  );
}