import { BaseLayer } from './base_layer'
import { RouteSegmenter } from '../utils/route_segmenter'

/**
 * Routes layer showing travel paths
 * Connects points chronologically with solid color
 * Uses RouteSegmenter for route processing logic
 */
export class RoutesLayer extends BaseLayer {
  constructor(map, options = {}) {
    super(map, { id: 'routes', ...options })
    this.maxGapHours = options.maxGapHours || 5 // Max hours between points to connect
    this.hoverSourceId = 'routes-hover-source'
  }

  getSourceConfig() {
    return {
      type: 'geojson',
      data: this.data || {
        type: 'FeatureCollection',
        features: []
      }
    }
  }

  /**
   * Override add() to create both main and hover sources
   */
  add(data) {
    this.data = data

    // Add main source
    if (!this.map.getSource(this.sourceId)) {
      this.map.addSource(this.sourceId, this.getSourceConfig())
    }

    // Add hover source (initially empty)
    if (!this.map.getSource(this.hoverSourceId)) {
      this.map.addSource(this.hoverSourceId, {
        type: 'geojson',
        data: { type: 'FeatureCollection', features: [] }
      })
    }

    // Add layers
    const layers = this.getLayerConfigs()
    layers.forEach(layerConfig => {
      if (!this.map.getLayer(layerConfig.id)) {
        this.map.addLayer(layerConfig)
      }
    })

    this.setVisibility(this.visible)
  }

  getLayerConfigs() {
    return [
      {
        id: this.id,
        type: 'line',
        source: this.sourceId,
        layout: {
          'line-join': 'round',
          'line-cap': 'round'
        },
        paint: {
          // Use color from feature properties if available, otherwise default blue
          'line-color': [
            'case',
            ['has', 'color'],
            ['get', 'color'],
            '#0000ff'  // Default blue color (matching v1)
          ],
          'line-width': 3,
          'line-opacity': 0.8
        }
      },
      {
        id: 'routes-hover',
        type: 'line',
        source: this.hoverSourceId,
        layout: {
          'line-join': 'round',
          'line-cap': 'round'
        },
        paint: {
          'line-color': '#ffff00',  // Yellow highlight
          'line-width': 8,
          'line-opacity': 1.0
        }
      }
      // Note: routes-hit layer is added separately in LayerManager after points layer
      // for better interactivity (see _addRoutesHitLayer method)
    ]
  }

  /**
   * Override setVisibility to also control routes-hit layer
   * @param {boolean} visible - Show/hide layer
   */
  setVisibility(visible) {
    // Call parent to handle main routes and routes-hover layers
    super.setVisibility(visible)

    // Also control routes-hit layer if it exists
    if (this.map.getLayer('routes-hit')) {
      const visibility = visible ? 'visible' : 'none'
      this.map.setLayoutProperty('routes-hit', 'visibility', visibility)
    }
  }

  /**
   * Update hover layer with route geometry
   * @param {Object|null} feature - Route feature, FeatureCollection, or null to clear
   */
  setHoverRoute(feature) {
    const hoverSource = this.map.getSource(this.hoverSourceId)
    if (!hoverSource) return

    if (feature) {
      // Handle both single feature and FeatureCollection
      if (feature.type === 'FeatureCollection') {
        hoverSource.setData(feature)
      } else {
        hoverSource.setData({
          type: 'FeatureCollection',
          features: [feature]
        })
      }
    } else {
      hoverSource.setData({ type: 'FeatureCollection', features: [] })
    }
  }

  /**
   * Override remove() to clean up hover source and hit layer
   */
  remove() {
    // Remove layers
    this.getLayerIds().forEach(layerId => {
      if (this.map.getLayer(layerId)) {
        this.map.removeLayer(layerId)
      }
    })

    // Remove routes-hit layer if it exists
    if (this.map.getLayer('routes-hit')) {
      this.map.removeLayer('routes-hit')
    }

    // Remove main source
    if (this.map.getSource(this.sourceId)) {
      this.map.removeSource(this.sourceId)
    }

    // Remove hover source
    if (this.map.getSource(this.hoverSourceId)) {
      this.map.removeSource(this.hoverSourceId)
    }

    this.data = null
  }

  /**
   * Calculate haversine distance between two points in kilometers
   * Delegates to RouteSegmenter utility
   * @deprecated Use RouteSegmenter.haversineDistance directly
   * @param {number} lat1 - First point latitude
   * @param {number} lon1 - First point longitude
   * @param {number} lat2 - Second point latitude
   * @param {number} lon2 - Second point longitude
   * @returns {number} Distance in kilometers
   */
  static haversineDistance(lat1, lon1, lat2, lon2) {
    return RouteSegmenter.haversineDistance(lat1, lon1, lat2, lon2)
  }

  /**
   * Convert points to route LineStrings with splitting
   * Delegates to RouteSegmenter utility for processing
   * @param {Array} points - Points from API
   * @param {Object} options - Splitting options
   * @returns {Object} GeoJSON FeatureCollection
   */
  static pointsToRoutes(points, options = {}) {
    return RouteSegmenter.pointsToRoutes(points, options)
  }
}