'use client'

/**
 * Germany School Map Component
 *
 * Displays a choropleth map of Germany showing school density by state.
 * Uses react-simple-maps for SVG rendering.
 */

import { useState, useEffect, useCallback, memo } from 'react'
import {
  ComposableMap,
  Geographies,
  Geography,
  ZoomableGroup,
} from 'react-simple-maps'

// Germany GeoJSON - local file (simplified boundaries)
const GERMANY_GEO_URL = '/germany-states.json'

const STATE_NAMES: Record<string, string> = {
  'BW': 'Baden-Wuerttemberg',
  'BY': 'Bayern',
  'BE': 'Berlin',
  'BB': 'Brandenburg',
  'HB': 'Bremen',
  'HH': 'Hamburg',
  'HE': 'Hessen',
  'MV': 'Mecklenburg-Vorpommern',
  'NI': 'Niedersachsen',
  'NW': 'Nordrhein-Westfalen',
  'RP': 'Rheinland-Pfalz',
  'SL': 'Saarland',
  'SN': 'Sachsen',
  'ST': 'Sachsen-Anhalt',
  'SH': 'Schleswig-Holstein',
  'TH': 'Thueringen',
}

interface SchoolStats {
  total_schools: number
  by_state?: Record<string, number>
}

interface GermanySchoolMapProps {
  stats: SchoolStats | null
  onStateClick?: (stateCode: string) => void
  selectedState?: string
}

// Color scale for school density
const getStateColor = (count: number, maxCount: number): string => {
  if (count === 0) return '#f1f5f9' // slate-100
  const intensity = count / maxCount
  if (intensity < 0.2) return '#dbeafe' // blue-100
  if (intensity < 0.4) return '#93c5fd' // blue-300
  if (intensity < 0.6) return '#3b82f6' // blue-500
  if (intensity < 0.8) return '#1d4ed8' // blue-700
  return '#1e3a8a' // blue-900
}

function GermanySchoolMap({ stats, onStateClick, selectedState }: GermanySchoolMapProps) {
  const [tooltipContent, setTooltipContent] = useState('')
  const [tooltipPosition, setTooltipPosition] = useState({ x: 0, y: 0 })
  const [showTooltip, setShowTooltip] = useState(false)
  const [zoom, setZoom] = useState(1)
  const [center, setCenter] = useState<[number, number]>([10.5, 51.2])

  const maxSchools = stats?.by_state
    ? Math.max(...Object.values(stats.by_state))
    : 0

  const handleStateHover = useCallback((geo: { properties: { code?: string; name?: string } }, evt: React.MouseEvent) => {
    const stateCode = geo.properties.code || ''
    const stateName = geo.properties.name || STATE_NAMES[stateCode] || stateCode
    const schoolCount = stats?.by_state?.[stateCode] || 0

    setTooltipContent(`${stateName}: ${schoolCount.toLocaleString()} Schulen`)
    setTooltipPosition({ x: evt.clientX, y: evt.clientY })
    setShowTooltip(true)
  }, [stats])

  const handleStateLeave = useCallback(() => {
    setShowTooltip(false)
  }, [])

  const handleZoomIn = () => {
    if (zoom < 4) setZoom(zoom * 1.5)
  }

  const handleZoomOut = () => {
    if (zoom > 1) setZoom(zoom / 1.5)
  }

  const handleReset = () => {
    setZoom(1)
    setCenter([10.5, 51.2])
  }

  return (
    <div className="relative bg-white rounded-lg border p-4">
      {/* Map Controls */}
      <div className="absolute top-6 right-6 z-10 flex flex-col gap-2">
        <button
          onClick={handleZoomIn}
          className="w-8 h-8 bg-white border rounded shadow hover:bg-gray-50 flex items-center justify-center text-lg font-bold"
          title="Vergroessern"
        >
          +
        </button>
        <button
          onClick={handleZoomOut}
          className="w-8 h-8 bg-white border rounded shadow hover:bg-gray-50 flex items-center justify-center text-lg font-bold"
          title="Verkleinern"
        >
          -
        </button>
        <button
          onClick={handleReset}
          className="w-8 h-8 bg-white border rounded shadow hover:bg-gray-50 flex items-center justify-center text-xs"
          title="Zuruecksetzen"
        >
          Reset
        </button>
      </div>

      {/* Legend */}
      <div className="absolute bottom-6 left-6 z-10 bg-white/90 p-3 rounded border shadow-sm">
        <h4 className="text-xs font-medium text-slate-700 mb-2">Schulen pro Bundesland</h4>
        <div className="flex items-center gap-1">
          <div className="w-4 h-4 bg-blue-100 rounded-sm" />
          <div className="w-4 h-4 bg-blue-300 rounded-sm" />
          <div className="w-4 h-4 bg-blue-500 rounded-sm" />
          <div className="w-4 h-4 bg-blue-700 rounded-sm" />
          <div className="w-4 h-4 bg-blue-900 rounded-sm" />
        </div>
        <div className="flex justify-between text-xs text-slate-500 mt-1">
          <span>0</span>
          <span>{maxSchools.toLocaleString()}</span>
        </div>
      </div>

      {/* Tooltip */}
      {showTooltip && (
        <div
          className="fixed z-50 px-3 py-2 bg-slate-900 text-white text-sm rounded shadow-lg pointer-events-none"
          style={{
            left: tooltipPosition.x + 10,
            top: tooltipPosition.y - 30,
          }}
        >
          {tooltipContent}
        </div>
      )}

      {/* Map */}
      <ComposableMap
        projection="geoMercator"
        projectionConfig={{
          scale: 2800,
          center: [10.5, 51.2],
        }}
        className="w-full h-[500px]"
      >
        <ZoomableGroup
          zoom={zoom}
          center={center}
          onMoveEnd={({ coordinates, zoom: newZoom }: { coordinates: [number, number]; zoom: number }) => {
            setCenter(coordinates)
            setZoom(newZoom)
          }}
        >
          <Geographies geography={GERMANY_GEO_URL}>
            {({ geographies }: { geographies: any[] }) =>
              geographies.map((geo: any) => {
                const stateCode = geo.properties.code || ''
                const schoolCount = stats?.by_state?.[stateCode] || 0
                const isSelected = selectedState === stateCode

                return (
                  <Geography
                    key={geo.rsmKey}
                    geography={geo}
                    onMouseEnter={(evt: React.MouseEvent) => handleStateHover(geo, evt)}
                    onMouseLeave={handleStateLeave}
                    onClick={() => onStateClick?.(stateCode)}
                    style={{
                      default: {
                        fill: isSelected
                          ? '#f59e0b' // amber-500 for selected
                          : getStateColor(schoolCount, maxSchools),
                        stroke: '#ffffff',
                        strokeWidth: 0.5,
                        outline: 'none',
                      },
                      hover: {
                        fill: isSelected ? '#d97706' : '#60a5fa', // blue-400
                        stroke: '#ffffff',
                        strokeWidth: 1,
                        outline: 'none',
                        cursor: 'pointer',
                      },
                      pressed: {
                        fill: '#f59e0b',
                        stroke: '#ffffff',
                        strokeWidth: 1,
                        outline: 'none',
                      },
                    }}
                  />
                )
              })
            }
          </Geographies>
        </ZoomableGroup>
      </ComposableMap>

      {/* State List */}
      {stats?.by_state && (
        <div className="mt-4 pt-4 border-t">
          <h4 className="text-sm font-medium text-slate-700 mb-2">Schulen nach Bundesland</h4>
          <div className="grid grid-cols-2 md:grid-cols-4 gap-2 text-xs">
            {Object.entries(stats.by_state)
              .sort(([,a], [,b]) => b - a)
              .map(([code, count]) => (
                <button
                  key={code}
                  onClick={() => onStateClick?.(code)}
                  className={`flex justify-between items-center p-2 rounded hover:bg-slate-100 transition-colors ${
                    selectedState === code ? 'bg-amber-100 text-amber-800' : ''
                  }`}
                >
                  <span>{STATE_NAMES[code] || code}</span>
                  <span className="font-medium">{count.toLocaleString()}</span>
                </button>
              ))}
          </div>
        </div>
      )}
    </div>
  )
}

export default memo(GermanySchoolMap)