import React, { useState, useEffect } from "react";
import { Card, CardContent } from "@/components/ui/card";
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { GitCompare, BarChart3, Eye } from "lucide-react";

import { api } from "@/lib/api";
import { LoadingSpinner } from "@/components/shared/LoadingSpinner";
import { GraphSelector } from "./GraphSelector";
import { ComparisonResults } from "./ComparisonResults";
import { VisualComparison } from "./VisualComparison";
import { AvailableGraph, GraphComparisonResults } from "@/types";

export const GraphComparisonView: React.FC = () => {
  const [activeTab, setActiveTab] = useState("selection");
  const [availableGraphs, setAvailableGraphs] = useState<AvailableGraph[]>([]);
  const [selectedGraph1, setSelectedGraph1] = useState<AvailableGraph | null>(
    null
  );
  const [selectedGraph2, setSelectedGraph2] = useState<AvailableGraph | null>(
    null
  );
  const [comparisonResults, setComparisonResults] =
    useState<GraphComparisonResults | null>(null);
  const [isLoading, setIsLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  // Load available graphs on component mount
  useEffect(() => {
    loadAvailableGraphs();
  }, []);

  // Auto-refresh available graphs every 15 seconds
  useEffect(() => {
    const interval = setInterval(() => {
      if (!isLoading) {
        loadAvailableGraphs();
      }
    }, 15000); // 15 seconds

    return () => clearInterval(interval);
  }, [isLoading]);

  const loadAvailableGraphs = async () => {
    try {
      setIsLoading(true);
      setError(null);
      const response = await api.graphComparison.listAvailableGraphs();
      setAvailableGraphs(response.final_graphs);
    } catch (err) {
      setError(err instanceof Error ? err.message : "Failed to load graphs");
    } finally {
      setIsLoading(false);
    }
  };

  const handleGraphSelection = (
    graph1: AvailableGraph | null,
    graph2: AvailableGraph | null
  ) => {
    setSelectedGraph1(graph1);
    setSelectedGraph2(graph2);
    // Remove auto-navigation - let users control when to switch tabs
  };

  const handleCompareGraphs = async () => {
    if (!selectedGraph1 || !selectedGraph2) return;

    try {
      setIsLoading(true);
      setError(null);

      const results = await api.graphComparison.compareGraphs(
        selectedGraph1.id,
        selectedGraph2.id,
        { similarity_threshold: 0.7, use_cache: true }
      );

      setComparisonResults(results);
      setActiveTab("results");
    } catch (err) {
      setError(err instanceof Error ? err.message : "Failed to compare graphs");
    } finally {
      setIsLoading(false);
    }
  };

  const canCompare = selectedGraph1 && selectedGraph2;

  return (
    <div className="flex flex-col h-screen bg-background">
      {/* Error Display */}
      {error && (
        <div className="mx-4 mt-4 p-4 bg-destructive/10 border border-destructive/20 rounded-lg">
          <p className="text-destructive text-sm">{error}</p>
        </div>
      )}

      {/* Content */}
      <div className="flex-1 overflow-hidden">
        <Tabs
          value={activeTab}
          onValueChange={setActiveTab}
          className="h-full flex flex-col"
        >
          <div className="border-b enhanced-tabs px-4">
            <TabsList className="grid w-full grid-cols-3 h-10 bg-transparent p-1 gap-1">
              <TabsTrigger
                value="selection"
                className="flex items-center gap-2 h-8 px-3 rounded-md text-sm font-medium transition-all duration-200 data-[state=active]:bg-white data-[state=active]:text-primary data-[state=active]:shadow-sm data-[state=active]:border data-[state=active]:border-primary/20 hover:bg-white/60 hover:text-foreground text-muted-foreground"
              >
                <GitCompare className="h-3.5 w-3.5" />
                Selection
              </TabsTrigger>
              <TabsTrigger
                value="results"
                disabled={!comparisonResults}
                className="flex items-center gap-2 h-8 px-3 rounded-md text-sm font-medium transition-all duration-200 data-[state=active]:bg-white data-[state=active]:text-primary data-[state=active]:shadow-sm data-[state=active]:border data-[state=active]:border-primary/20 hover:bg-white/60 hover:text-foreground text-muted-foreground disabled:opacity-50 disabled:cursor-not-allowed"
              >
                <BarChart3 className="h-3.5 w-3.5" />
                Results
              </TabsTrigger>
              <TabsTrigger
                value="visual"
                disabled={!canCompare}
                className="flex items-center gap-2 h-8 px-3 rounded-md text-sm font-medium transition-all duration-200 data-[state=active]:bg-white data-[state=active]:text-primary data-[state=active]:shadow-sm data-[state=active]:border data-[state=active]:border-primary/20 hover:bg-white/60 hover:text-foreground text-muted-foreground disabled:opacity-50 disabled:cursor-not-allowed"
              >
                <Eye className="h-3.5 w-3.5" />
                Visual
              </TabsTrigger>
            </TabsList>
          </div>

          <div className="flex-1 overflow-y-auto">
            <TabsContent value="selection" className="h-full m-0 p-4">
              {isLoading && !availableGraphs.length ? (
                <div className="flex items-center justify-center h-64">
                  <LoadingSpinner size="lg" />
                </div>
              ) : (
                <GraphSelector
                  availableGraphs={availableGraphs}
                  selectedGraph1={selectedGraph1}
                  selectedGraph2={selectedGraph2}
                  onSelectionChange={handleGraphSelection}
                  onCompareGraphs={handleCompareGraphs}
                  isLoading={isLoading}
                />
              )}
            </TabsContent>

            <TabsContent value="results" className="h-full m-0 p-4">
              {comparisonResults ? (
                <ComparisonResults results={comparisonResults} />
              ) : (
                <Card>
                  <CardContent className="p-8 text-center">
                    <p className="text-muted-foreground">
                      No comparison results available
                    </p>
                  </CardContent>
                </Card>
              )}
            </TabsContent>

            <TabsContent value="visual" className="h-full m-0">
              {canCompare ? (
                <VisualComparison
                  graph1={selectedGraph1!}
                  graph2={selectedGraph2!}
                  comparisonResults={comparisonResults}
                />
              ) : (
                <Card className="m-4">
                  <CardContent className="p-8 text-center">
                    <p className="text-muted-foreground">
                      Select 2 graphs to view visual comparison
                    </p>
                  </CardContent>
                </Card>
              )}
            </TabsContent>
          </div>
        </Tabs>
      </div>
    </div>
  );
};