'use client';

import { useEffect, useState } from 'react';
import dynamic from 'next/dynamic';
import { ApexOptions } from 'apexcharts';
import { useTheme } from 'next-themes';
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";

// Dynamically import ApexCharts to avoid SSR issues
const Chart = dynamic(() => import('react-apexcharts'), { ssr: false });

interface JenisPendaftaranLulusData {
  tahun_angkatan: number;
  jenis_pendaftaran: string;
  jumlah_lulus_tepat_waktu: number;
}

interface Props {
  selectedYear: string;
}

export default function JenisPendaftaranLulusChart({ selectedYear }: Props) {
  const { theme } = useTheme();
  const [data, setData] = useState<JenisPendaftaranLulusData[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);

  useEffect(() => {
    const fetchData = async () => {
      try {
        setLoading(true);
        setError(null);
        
        const url = `/api/mahasiswa/jenis-pendaftaran-lulus?tahun_angkatan=${selectedYear}`;
        const response = await fetch(url);
        
        if (!response.ok) {
          throw new Error(`Failed to fetch data: ${response.status} ${response.statusText}`);
        }
        
        const result = await response.json();
        
        if (!Array.isArray(result)) {
          throw new Error('Invalid data format received from server');
        }
        
        // Sort data by tahun_angkatan
        const sortedData = result.sort((a: JenisPendaftaranLulusData, b: JenisPendaftaranLulusData) => 
          a.tahun_angkatan - b.tahun_angkatan
        );
        
        setData(sortedData);
      } catch (err) {
        setError(err instanceof Error ? err.message : 'An error occurred while fetching data');
      } finally {
        setLoading(false);
      }
    };

    fetchData();
  }, [selectedYear]);

  // Process data for series
  const processSeriesData = () => {
    if (!data.length) return [];

    const years = [...new Set(data.map(item => item.tahun_angkatan))].sort();
    const pendaftaranTypes = [...new Set(data.map(item => item.jenis_pendaftaran))];

    return pendaftaranTypes.map(type => ({
      name: type,
      data: years.map(year => {
        const item = data.find(d => d.tahun_angkatan === year && d.jenis_pendaftaran === type);
        return item ? item.jumlah_lulus_tepat_waktu : 0;
      })
    }));
  };

  const chartOptions: ApexOptions = {
    chart: {
      type: 'bar',
      stacked: false,
      toolbar: {
        show: true,
        tools: {
          download: true,
          selection: true,
          zoom: true,
          zoomin: true,
          zoomout: true,
          pan: true,
          reset: true
        }
      },
      background: theme === 'dark' ? '#0F172B' : '#fff',
    },
    plotOptions: {
      bar: {
        horizontal: false,
        columnWidth: '55%',
        borderRadius: 1,
      },
    },
    dataLabels: {
      enabled: true,
      formatter: function (val: number) {
        return val.toString();
      },
      style: {
        fontSize: '12px',
        colors: [theme === 'dark' ? '#fff' : '#000']
      }
    },
    stroke: {
      show: true,
      width: 2,
      colors: ['transparent']
    },
    xaxis: {
      categories: [...new Set(data.map(item => item.tahun_angkatan))].sort(),
      title: {
        text: 'Tahun Angkatan',
        style: {
          fontSize: '14px',
          fontWeight: 'bold',
          color: theme === 'dark' ? '#fff' : '#000'
        }
      },
      labels: {
        style: {
          fontSize: '12px',
          colors: theme === 'dark' ? '#fff' : '#000'
        }
      },
      axisBorder: {
        show: true,
        color: theme === 'dark' ? '#374151' : '#E5E7EB'
      },
      axisTicks: {
        show: true,
        color: theme === 'dark' ? '#374151' : '#E5E7EB'
      }
    },
    yaxis: {
      title: {
        text: 'Jumlah Mahasiswa',
        style: {
          fontSize: '14px',
          fontWeight: 'bold',
          color: theme === 'dark' ? '#fff' : '#000'
        }
      },
      labels: {
        style: {
          fontSize: '12px',
          colors: theme === 'dark' ? '#fff' : '#000'
        }
      },
      axisBorder: {
        show: true,
        color: theme === 'dark' ? '#374151' : '#E5E7EB'
      }
    },
    fill: {
      opacity: 1
    },
    colors: ['#008FFB', '#00E396', '#FEB019', '#FF4560', '#775DD0', '#8B5CF6', '#EC4899', '#06B6D4', '#F97316'],
    tooltip: {
      theme: theme === 'dark' ? 'dark' : 'light',
      y: {
        formatter: function (val: number) {
          return val + " mahasiswa";
        }
      }
    },
    legend: {
      position: 'top',
      fontSize: '14px',
      markers: {
        size: 12,
      },
      itemMargin: {
        horizontal: 10,
      },
      labels: {
        colors: theme === 'dark' ? '#fff' : '#000'
      }
    },
    grid: {
      borderColor: theme === 'dark' ? '#374151' : '#E5E7EB',
      strokeDashArray: 4,
      padding: {
        top: 20,
        right: 0,
        bottom: 0,
        left: 0
      }
    }
  };

  const series = processSeriesData();

  // Calculate the maximum value from all series for y-axis padding
  const maxValue = Math.max(
    ...series.flatMap(s => s.data)
  );
  
  // Add 20% padding to the maximum value
  const yAxisMax = Math.ceil(maxValue * 1.2);

  // Update chart options with y-axis max
  const updatedChartOptions: ApexOptions = {
    ...chartOptions,
    yaxis: {
      ...chartOptions.yaxis,
      max: yAxisMax
    }
  };

  if (loading) {
    return (
      <Card className="bg-white dark:bg-slate-900 shadow-lg">
        <CardHeader>
          <CardTitle className="text-xl font-bold dark:text-white">
            Loading...
          </CardTitle>
        </CardHeader>
      </Card>
    );
  }

  if (error) {
    return (
      <Card className="bg-white dark:bg-slate-900 shadow-lg">
        <CardHeader>
          <CardTitle className="text-xl font-bold text-red-500">
            Error: {error}
          </CardTitle>
        </CardHeader>
      </Card>
    );
  }

  if (data.length === 0) {
    return (
      <Card className="bg-white dark:bg-slate-900 shadow-lg">
        <CardHeader>
          <CardTitle className="text-xl font-bold dark:text-white">
            Tidak ada data yang tersedia
          </CardTitle>
        </CardHeader>
      </Card>
    );
  }

  return (
    <Card className="bg-white dark:bg-slate-900 shadow-lg">
      <CardHeader>
        <CardTitle className="text-xl font-bold dark:text-white">
          Jenis Pendaftaran Mahasiswa Lulus Tepat Waktu
          {selectedYear !== 'all' ? ` Angkatan ${selectedYear}` : ''}
        </CardTitle>
      </CardHeader>
      <CardContent>
        <div className="h-[300px] sm:h-[350px] md:h-[400px] w-full max-w-5xl mx-auto">
          {typeof window !== 'undefined' && series.length > 0 && (
            <Chart
              options={updatedChartOptions}
              series={series}
              type="bar"
              height="100%"
              width="90%"
            />
          )}
        </div>
      </CardContent>
    </Card>
  );
}