"use client";

import { ArrowLeft, CheckCircle, Loader2, XCircle } from "lucide-react";
import { useRouter, useSearchParams } from "next/navigation";
import { Suspense, useEffect, useState } from "react";
import AnimatedProcessingIcon from "@/components/icons/animated-processing-icon";
import { Button } from "@/components/ui/button";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { useAuth } from "@/contexts/auth-context";

function AuthCallbackContent() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const { refreshAuth } = useAuth();
  const [status, setStatus] = useState<"processing" | "success" | "error">(
    "processing",
  );
  const [error, setError] = useState<string | null>(null);
  const [purpose, setPurpose] = useState<string>("app_auth");

  useEffect(() => {
    const code = searchParams.get("code");
    const callbackKey = `callback_processed_${code}`;

    // Prevent double execution across component remounts
    if (sessionStorage.getItem(callbackKey)) {
      return;
    }
    sessionStorage.setItem(callbackKey, "true");

    const handleCallback = async () => {
      try {
        // Get parameters from URL
        const state = searchParams.get("state");
        const errorParam = searchParams.get("error");

        // Get stored auth info
        const connectorId = localStorage.getItem("connecting_connector_id");
        const storedConnectorType = localStorage.getItem(
          "connecting_connector_type",
        );
        const authPurpose = localStorage.getItem("auth_purpose");

        // Determine purpose - default to app_auth for login, data_source for connectors
        const detectedPurpose =
          authPurpose ||
          (storedConnectorType?.includes("drive") ? "data_source" : "app_auth");
        setPurpose(detectedPurpose);

        // Debug logging
        console.log("OAuth Callback Debug:", {
          urlParams: { code: !!code, state: !!state, error: errorParam },
          localStorage: { connectorId, storedConnectorType, authPurpose },
          detectedPurpose,
          fullUrl: window.location.href,
        });

        // Use state parameter as connection_id if localStorage is missing
        const finalConnectorId = connectorId || state;

        if (errorParam) {
          throw new Error(`OAuth error: ${errorParam}`);
        }

        if (!code || !state || !finalConnectorId) {
          console.error("Missing OAuth callback parameters:", {
            code: !!code,
            state: !!state,
            finalConnectorId: !!finalConnectorId,
          });
          throw new Error("Missing required parameters for OAuth callback");
        }

        // Send callback data to backend
        const response = await fetch("/api/auth/callback", {
          method: "POST",
          headers: {
            "Content-Type": "application/json",
          },
          body: JSON.stringify({
            connection_id: finalConnectorId,
            authorization_code: code,
            state: state,
          }),
        });

        const result = await response.json();

        if (response.ok) {
          setStatus("success");

          if (result.purpose === "app_auth" || detectedPurpose === "app_auth") {
            // App authentication - refresh auth context and redirect to home/original page
            await refreshAuth();

            // Get redirect URL from login page
            const redirectTo = searchParams.get("redirect") || "/chat";

            // Clean up localStorage
            localStorage.removeItem("connecting_connector_id");
            localStorage.removeItem("connecting_connector_type");
            localStorage.removeItem("auth_purpose");

            // Redirect to the original page or home
            setTimeout(() => {
              router.push(redirectTo);
            }, 2000);
          } else {
            // Connector authentication - redirect to connectors page

            // Clean up localStorage
            localStorage.removeItem("connecting_connector_id");
            localStorage.removeItem("connecting_connector_type");
            localStorage.removeItem("auth_purpose");

            // Redirect to settings page with success indicator
            setTimeout(() => {
              router.push("/settings?oauth_success=true");
            }, 2000);
          }
        } else {
          throw new Error(result.error || "Authentication failed");
        }
      } catch (err) {
        console.error("OAuth callback error:", err);
        setError(err instanceof Error ? err.message : "Unknown error occurred");
        setStatus("error");

        // Clean up localStorage on error too
        localStorage.removeItem("connecting_connector_id");
        localStorage.removeItem("connecting_connector_type");
        localStorage.removeItem("auth_purpose");
      }
    };

    handleCallback();
  }, [searchParams, router, refreshAuth]);

  // Dynamic UI content based on purpose
  const isAppAuth = purpose === "app_auth";

  const getTitle = () => {
    if (status === "processing") {
      return isAppAuth ? "Signing you in..." : "Connecting...";
    }
    if (status === "success") {
      return isAppAuth ? "Welcome to OpenRAG!" : "Connection Successful!";
    }
    if (status === "error") {
      return isAppAuth ? "Sign In Failed" : "Connection Failed";
    }
  };

  const getDescription = () => {
    if (status === "processing") {
      return isAppAuth
        ? "Please wait while we complete your sign in..."
        : "Please wait while we complete the connection...";
    }
    if (status === "success") {
      return "You will be redirected shortly.";
    }
    if (status === "error") {
      return isAppAuth
        ? "There was an issue signing you in."
        : "There was an issue with the connection.";
    }
  };

  return (
    <div className="min-h-screen flex items-center justify-center bg-card rounded-lg m-4">
      <Card className="w-full max-w-md bg-card rounded-lg m-4">
        <CardHeader className="text-center">
          <CardTitle className="flex items-center justify-center gap-2">
            {status === "processing" && (
              <>
                <AnimatedProcessingIcon className="h-5 w-5 text-current" />
                {getTitle()}
              </>
            )}
            {status === "success" && (
              <>
                <CheckCircle className="h-5 w-5 text-green-500" />
                {getTitle()}
              </>
            )}
            {status === "error" && (
              <>
                <XCircle className="h-5 w-5 text-red-500" />
                {getTitle()}
              </>
            )}
          </CardTitle>
          <CardDescription>{getDescription()}</CardDescription>
        </CardHeader>
        <CardContent>
          {status === "error" && (
            <div className="space-y-4">
              <div className="p-3 bg-red-500/10 border border-red-500/20 rounded-lg">
                <p className="text-sm text-red-600">{error}</p>
              </div>
              <Button
                onClick={() => router.push(isAppAuth ? "/login" : "/settings")}
                variant="outline"
                className="w-full"
              >
                <ArrowLeft className="h-4 w-4 mr-2" />
                {isAppAuth ? "Back to Login" : "Back to Settings"}
              </Button>
            </div>
          )}
          {status === "success" && (
            <div className="text-center">
              <div className="p-3 bg-green-500/10 border border-green-500/20 rounded-lg">
                <p className="text-sm text-green-600">
                  {isAppAuth
                    ? "Redirecting you to the app..."
                    : "Redirecting to settings..."}
                </p>
              </div>
            </div>
          )}
        </CardContent>
      </Card>
    </div>
  );
}

export default function AuthCallbackPage() {
  return (
    <Suspense
      fallback={
        <div className="min-h-screen flex items-center justify-center bg-background">
          <Card className="w-full max-w-md">
            <CardHeader className="text-center">
              <CardTitle className="flex items-center justify-center gap-2">
                <Loader2 className="h-5 w-5 animate-spin" />
                Loading...
              </CardTitle>
              <CardDescription>
                Please wait while we process your request...
              </CardDescription>
            </CardHeader>
          </Card>
        </div>
      }
    >
      <AuthCallbackContent />
    </Suspense>
  );
}