"use client";

import * as React from "react";
import { useRouter, useSearchParams } from "next/navigation";
import { toast } from "sonner";
import { Loader2, ArrowLeft, Plug, Plus } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import {
  Card,
  CardContent,
  CardHeader,
  CardTitle,
  CardDescription,
} from "@/components/ui/card";

type ProviderInfo = {
  id: string;
  name: string;
  description: string;
  configFields: ConfigField[];
  supportsOAuth: boolean;
};

type ConfigField = {
  key: string;
  label: string;
  type: string;
  placeholder?: string;
  required?: boolean;
  helpText?: string;
  options?: { value: string; label: string }[];
};

export default function NewIntegrationPage() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const preselectedProvider = searchParams.get("provider") || "";

  const [providers, setProviders] = React.useState<ProviderInfo[]>([]);
  const [selectedProvider, setSelectedProvider] = React.useState(preselectedProvider);
  const [name, setName] = React.useState("");
  const [config, setConfig] = React.useState<Record<string, string>>({});
  const [loading, setLoading] = React.useState(true);
  const [creating, setCreating] = React.useState(false);

  React.useEffect(() => {
    fetch("/api/integrations")
      .then((r) => r.json())
      .then((data) => {
        setProviders(data.providers || []);
        setLoading(false);
      })
      .catch(() => setLoading(false));
  }, []);

  React.useEffect(() => {
    if (selectedProvider) {
      const p = providers.find((pr) => pr.id === selectedProvider);
      if (p && !name) {
        setName(p.name);
      }
    }
  }, [selectedProvider, providers, name]);

  const provider = providers.find((p) => p.id === selectedProvider);

  const handleCreate = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!selectedProvider) {
      toast.error("Select a provider");
      return;
    }

    setCreating(true);
    try {
      const res = await fetch("/api/integrations", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({
          provider: selectedProvider,
          name: name || provider?.name || selectedProvider,
          config,
        }),
      });

      if (res.ok) {
        const data = await res.json();
        toast.success("Integration created");

        if (provider?.supportsOAuth) {
          window.location.href = `/api/integrations/oauth/${selectedProvider}/authorize?integrationId=${data.integration.id}`;
        } else {
          router.push(`/settings/integrations/${data.integration.id}`);
        }
      } else {
        const data = await res.json();
        toast.error(data.error || "Failed to create integration");
      }
    } catch {
      toast.error("Failed to create integration");
    } finally {
      setCreating(false);
    }
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center py-20">
        <Loader2 className="size-6 animate-spin text-muted-foreground" />
      </div>
    );
  }

  return (
    <div className="space-y-6">
      <Button
        variant="ghost"
        size="sm"
        onClick={() => router.push("/settings/integrations")}
      >
        <ArrowLeft className="mr-1.5 size-3.5" />
        Back to Integrations
      </Button>

      {!selectedProvider ? (
        <div className="space-y-4">
          <h2 className="text-lg font-semibold">Choose a provider</h2>
          <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
            {providers.map((p) => (
              <button
                key={p.id}
                onClick={() => setSelectedProvider(p.id)}
                className="flex flex-col items-center gap-2 rounded-xl border border-border/50 p-5 text-center transition-colors hover:border-primary/50 hover:bg-primary/5"
              >
                <Plug className="size-6 text-muted-foreground" />
                <span className="text-sm font-medium">{p.name}</span>
                <span className="text-xs text-muted-foreground">
                  {p.description}
                </span>
              </button>
            ))}
          </div>
        </div>
      ) : (
        <Card className="glass-card">
          <CardHeader>
            <CardTitle className="flex items-center gap-2 text-base">
              <Plug className="size-4" />
              Configure {provider?.name}
            </CardTitle>
            <CardDescription>{provider?.description}</CardDescription>
          </CardHeader>
          <CardContent>
            <form onSubmit={handleCreate} className="space-y-4">
              <div className="space-y-2">
                <Label>Integration Name</Label>
                <Input
                  value={name}
                  onChange={(e) => setName(e.target.value)}
                  placeholder={provider?.name || "My Integration"}
                />
              </div>

              {provider?.configFields.map((field) => (
                <div key={field.key} className="space-y-2">
                  <Label>
                    {field.label}
                    {field.required && (
                      <span className="text-destructive"> *</span>
                    )}
                  </Label>
                  {field.type === "select" && field.options ? (
                    <select
                      value={config[field.key] || ""}
                      onChange={(e) =>
                        setConfig((c) => ({
                          ...c,
                          [field.key]: e.target.value,
                        }))
                      }
                      className="flex h-10 w-full rounded-md border border-input bg-background px-3 py-2 text-sm"
                    >
                      <option value="">Select...</option>
                      {field.options.map((opt) => (
                        <option key={opt.value} value={opt.value}>
                          {opt.label}
                        </option>
                      ))}
                    </select>
                  ) : (
                    <Input
                      type={field.type === "password" ? "password" : "text"}
                      value={config[field.key] || ""}
                      onChange={(e) =>
                        setConfig((c) => ({
                          ...c,
                          [field.key]: e.target.value,
                        }))
                      }
                      placeholder={field.placeholder}
                      required={field.required}
                    />
                  )}
                  {field.helpText && (
                    <p className="text-xs text-muted-foreground">
                      {field.helpText}
                    </p>
                  )}
                </div>
              ))}

              {provider?.supportsOAuth && (
                <p className="text-sm text-muted-foreground">
                  After creating, you&apos;ll be redirected to authorize with{" "}
                  {provider.name}.
                </p>
              )}

              <div className="flex gap-3">
                <Button
                  type="button"
                  variant="outline"
                  onClick={() => setSelectedProvider("")}
                >
                  Change Provider
                </Button>
                <Button type="submit" disabled={creating} className="flex-1">
                  {creating ? (
                    <Loader2 className="mr-2 size-4 animate-spin" />
                  ) : (
                    <Plus className="mr-2 size-4" />
                  )}
                  {provider?.supportsOAuth
                    ? "Create & Connect"
                    : "Create Integration"}
                </Button>
              </div>
            </form>
          </CardContent>
        </Card>
      )}
    </div>
  );
}