import { useState } from "react";
import { json } from "@remix-run/node";
import { useLoaderData } from "@remix-run/react";
import { type LoaderFunctionArgs } from "@remix-run/server-runtime";
import { requireUserId, requireWorkpace } from "~/services/session.server";
import { getIntegrationDefinitions } from "~/services/integrationDefinition.server";
import { getIntegrationAccounts } from "~/services/integrationAccount.server";

import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from "~/components/ui/card";
import { Button } from "~/components/ui/button";
import { Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle, DialogTrigger } from "~/components/ui/dialog";
import { Input } from "~/components/ui/input";
import { FormButtons } from "~/components/ui/FormButtons";
import { Plus, Search } from "lucide-react";
import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "~/components/ui/select";

// Loader to fetch integration definitions and existing accounts
export async function loader({ request }: LoaderFunctionArgs) {
  const userId = await requireUserId(request);
  const workspace = await requireWorkpace(request);
  
  const [integrationDefinitions, integrationAccounts] = await Promise.all([
    getIntegrationDefinitions(workspace.id),
    getIntegrationAccounts(userId),
  ]);

  return json({
    integrationDefinitions,
    integrationAccounts,
    userId,
  });
}

export default function Integrations() {
  const { integrationDefinitions, integrationAccounts, userId } = useLoaderData<typeof loader>();
  const [selectedCategory, setSelectedCategory] = useState<string>("all");
  const [selectedIntegration, setSelectedIntegration] = useState<any>(null);
  const [apiKey, setApiKey] = useState("");
  const [isLoading, setIsLoading] = useState(false);
  const [isConnecting, setIsConnecting] = useState(false);

  // Extract categories from integration definitions
  const categories = Array.from(
    new Set(integrationDefinitions.map((integration) => {
      const specData = typeof integration.spec === 'string' 
        ? JSON.parse(integration.spec) 
        : integration.spec;
      return specData?.category || "Uncategorized";
    }))
  );

  // Filter integrations by selected category
  const filteredIntegrations = selectedCategory === "all"
    ? integrationDefinitions
    : integrationDefinitions.filter(
        (integration) => {
          const specData = typeof integration.spec === 'string' 
            ? JSON.parse(integration.spec) 
            : integration.spec;
          return specData?.category === selectedCategory;
        }
      );

  // Check if user has an active account for an integration
  const hasActiveAccount = (integrationDefinitionId: string) => {
    return integrationAccounts.some(
      (account) => account.integrationDefinitionId === integrationDefinitionId && account.isActive
    );
  };

  // Handle connection with API key
  const handleApiKeyConnect = async () => {
    if (!selectedIntegration || !apiKey.trim()) return;
    
    setIsLoading(true);
    try {
      const response = await fetch("/api/v1/integration_account", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          integrationDefinitionId: selectedIntegration.id,
          apiKey,
        }),
      });
      
      if (!response.ok) {
        const errorData = await response.json();
        throw new Error(errorData.error || "Failed to connect integration");
      }
      
      // Refresh the page to show the new integration account
      window.location.reload();
    } catch (error) {
      console.error("Error connecting integration:", error);
      // Handle error (could add error state and display message)
    } finally {
      setIsLoading(false);
    }
  };

  // Handle OAuth connection
  const handleOAuthConnect = async () => {
    if (!selectedIntegration) return;
    
    setIsConnecting(true);
    try {
      const response = await fetch("/api/v1/oauth", {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          integrationDefinitionId: selectedIntegration.id,
          userId,
        }),
      });
      
      if (!response.ok) {
        const errorData = await response.json();
        throw new Error(errorData.error || "Failed to start OAuth flow");
      }
      
      const { url } = await response.json();
      // Redirect to OAuth authorization URL
      window.location.href = url;
    } catch (error) {
      console.error("Error starting OAuth flow:", error);
      // Handle error
    } finally {
      setIsConnecting(false);
    }
  };

  return (
    <div className="home flex h-full flex-col overflow-y-auto p-3">
      <div className="flex items-center justify-between">
        <div className="space-y-1 text-base">
          <h2 className="text-lg font-semibold">Integrations</h2>
          <p className="text-muted-foreground">Connect your tools and services</p>
        </div>
        <div className="flex items-center gap-2">
          {/* Category filter */}
          <Select 
            value={selectedCategory} 
            onValueChange={setSelectedCategory}
          >
            <SelectTrigger className="w-[180px]">
              <SelectValue placeholder="Category" />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="all">All Categories</SelectItem>
              {categories.map((category) => (
                <SelectItem key={category} value={category}>{category}</SelectItem>
              ))}
            </SelectContent>
          </Select>
          
          {/* Add integration button */}
          <Button variant="default" size="sm">
            <Plus className="mr-1 h-3.5 w-3.5" />
            Add integration
          </Button>
        </div>
      </div>
      
      {/* Integration cards grid */}
      <div className="mt-6 grid grid-cols-1 gap-4 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4 xl:grid-cols-5">
        {filteredIntegrations.map((integration) => {
          const isConnected = hasActiveAccount(integration.id);
          const authType = integration.spec?.auth?.type || "unknown";
          
          return (
            <Dialog key={integration.id} onOpenChange={(open) => {
              if (open) {
                setSelectedIntegration(integration);
                setApiKey("");
              } else {
                setSelectedIntegration(null);
              }
            }}>
              <DialogTrigger asChild>
                <Card className="cursor-pointer transition-all hover:shadow-md">
                  <CardHeader className="p-4">
                    <div className="mb-2 flex h-10 w-10 items-center justify-center rounded bg-background-2">
                      {integration.icon ? (
                        <img 
                          src={integration.icon} 
                          alt={integration.name} 
                          className="h-6 w-6" 
                        />
                      ) : (
                        <div className="h-6 w-6 rounded-full bg-gray-300" />
                      )}
                    </div>
                    <CardTitle className="text-base">{integration.name}</CardTitle>
                    <CardDescription className="line-clamp-2 text-xs">
                      {integration.description || "Connect to " + integration.name}
                    </CardDescription>
                  </CardHeader>
                  <CardFooter className="border-t p-3">
                    <div className="flex w-full items-center justify-between">
                      <span className="text-xs text-muted-foreground">
                        {(() => {
                          const specData = typeof integration.spec === 'string' 
                            ? JSON.parse(integration.spec) 
                            : integration.spec;
                          return specData?.category || "Uncategorized";
                        })()}
                      </span>
                      {isConnected ? (
                        <span className="rounded-full bg-green-100 px-2 py-0.5 text-xs text-green-800">
                          Connected
                        </span>
                      ) : (
                        <span className="text-xs text-muted-foreground">Not connected</span>
                      )}
                    </div>
                  </CardFooter>
                </Card>
              </DialogTrigger>
              
              <DialogContent className="sm:max-w-md">
                <DialogHeader>
                  <DialogTitle>Connect to {integration.name}</DialogTitle>
                  <DialogDescription>
                    {integration.description || `Connect your ${integration.name} account to enable integration.`}
                  </DialogDescription>
                </DialogHeader>
                
                {/* API Key Authentication */}
                {(() => {
                  const specData = typeof integration.spec === 'string' 
                    ? JSON.parse(integration.spec) 
                    : integration.spec;
                  return specData?.auth?.api_key;
                })() && (
                  <div className="space-y-4 py-4">
                    <div className="space-y-2">
                      <label htmlFor="apiKey" className="text-sm font-medium">
                        {(() => {
                        const specData = typeof integration.spec === 'string' 
                          ? JSON.parse(integration.spec) 
                          : integration.spec;
                        return specData?.auth?.api_key?.label || "API Key";
                      })()}
                      </label>
                      <Input
                        id="apiKey"
                        type="password"
                        placeholder="Enter your API key"
                        value={apiKey}
                        onChange={(e) => setApiKey(e.target.value)}
                      />
                      {(() => {
                        const specData = typeof integration.spec === 'string' 
                          ? JSON.parse(integration.spec) 
                          : integration.spec;
                        return specData?.auth?.api_key?.description;
                      })() && (
                        <p className="text-xs text-muted-foreground">
                          {(() => {
                            const specData = typeof integration.spec === 'string' 
                              ? JSON.parse(integration.spec) 
                              : integration.spec;
                            return specData?.auth?.api_key?.description;
                          })()}
                        </p>
                      )}
                    </div>
                    
                    <FormButtons>
                      <Button
                        type="button"
                        variant="default"
                        disabled={isLoading || !apiKey.trim()}
                        onClick={handleApiKeyConnect}
                      >
                        {isLoading ? "Connecting..." : "Connect"}
                      </Button>
                    </FormButtons>
                  </div>
                )}
                
                {/* OAuth Authentication */}
                {(() => {
                  const specData = typeof integration.spec === 'string' 
                    ? JSON.parse(integration.spec) 
                    : integration.spec;
                  return specData?.auth?.oauth2;
                })() && (
                  <div className="flex justify-center py-8">
                    <Button
                      type="button"
                      variant="default"
                      size="lg"
                      disabled={isConnecting}
                      onClick={handleOAuthConnect}
                    >
                      {isConnecting ? "Connecting..." : `Connect to ${integration.name}`}
                    </Button>
                  </div>
                )}
                
                {/* No authentication method found */}
                {(() => {
                  const specData = typeof integration.spec === 'string' 
                    ? JSON.parse(integration.spec) 
                    : integration.spec;
                  return !specData?.auth?.api_key && !specData?.auth?.oauth2;
                })() && (
                  <div className="py-4 text-center text-muted-foreground">
                    This integration doesn't specify an authentication method.
                  </div>
                )}
                
                <DialogFooter className="sm:justify-start">
                  <div className="w-full text-xs text-muted-foreground">
                    By connecting, you agree to the {integration.name} terms of service.
                  </div>
                </DialogFooter>
              </DialogContent>
            </Dialog>
          );
        })}
      </div>
      
      {/* Empty state */}
      {filteredIntegrations.length === 0 && (
        <div className="mt-20 flex flex-col items-center justify-center">
          <Search className="mb-2 h-12 w-12 text-muted-foreground" />
          <h3 className="text-lg font-medium">No integrations found</h3>
          <p className="text-muted-foreground">
            {selectedCategory === "all"
              ? "No integrations are available at this time."
              : `No integrations found in the "${selectedCategory}" category.`}
          </p>
        </div>
      )}
    </div>
  );
}