import type {
	BackgroundLayerSpecification,
	CircleLayerSpecification,
	FillExtrusionLayerSpecification,
	FillLayerSpecification,
	HeatmapLayerSpecification,
	HillshadeLayerSpecification,
	LayerSpecification,
	LineLayerSpecification,
	Map,
	MapLayerEventType,
	RasterLayerSpecification,
	Source,
	SymbolLayerSpecification
} from 'maplibre-gl';
import { type PropType, unref, type VNode } from 'vue';

export class LayerLib {

	static readonly SOURCE_OPTS: Array<keyof (Omit<FillLayerSpecification & LineLayerSpecification & SymbolLayerSpecification & CircleLayerSpecification & HeatmapLayerSpecification & FillExtrusionLayerSpecification & RasterLayerSpecification & HillshadeLayerSpecification & BackgroundLayerSpecification, 'source-layer'> & {
		sourceLayer?: string
	})> = [
		'metadata', 'ref', 'source', 'sourceLayer', 'minzoom', 'maxzoom', 'interactive', 'filter', 'layout', 'paint'
	];

	static readonly LAYER_EVENTS: Array<keyof MapLayerEventType> = [
		'click', 'dblclick', 'mousedown', 'mouseup', 'mousemove', 'mouseenter', 'mouseleave', 'mouseover', 'mouseout', 'contextmenu', 'touchstart', 'touchend',
		'touchcancel'
	];

	static readonly SHARED = {
		props: {
			layerId    : {
				type    : String as PropType<string>,
				required: true
			},
			source     : [ String, Object ] as PropType<string | Source>,
			metadata   : [ Object, Array, String, Number ] as PropType<any>,
			sourceLayer: String as PropType<string>,
			minzoom    : Number as PropType<number>,
			maxzoom    : Number as PropType<number>,
			interactive: Boolean as PropType<boolean>,
			before     : String as PropType<string>
		},
		emits: [
			'click', 'dblclick', 'mousedown', 'mouseup', 'mousemove', 'mouseenter', 'mouseleave', 'mouseover', 'mouseout', 'contextmenu', 'touchstart', 'touchend',
			'touchcancel'
		]
	};

	static genLayerOpts<T = LayerSpecification>(id: string, type: string, props: any, source: any): T {

		return Object.keys(props)
					 .filter(opt => (props as any)[ opt ] !== undefined && LayerLib.SOURCE_OPTS.indexOf(opt as any) !== -1)
					 .reduce((obj, opt) => {
						 (obj as any)[ opt === 'sourceLayer' ? 'source-layer' : opt ] = unref((props as any)[ opt ]);
						 return obj;
					 }, { type, source: props.source || source, id } as T);

	}

	static registerLayerEvents(map: Map, layerId: string, vn: VNode) {

		if (!vn.props) {
			return;
		}

		for (let i = 0, len = LayerLib.LAYER_EVENTS.length; i < len; i++) {
			const evProp = 'on' + LayerLib.LAYER_EVENTS[ i ].charAt(0).toUpperCase() + LayerLib.LAYER_EVENTS[ i ].substr(1);
			if (vn.props[ evProp ]) {
				map.on(LayerLib.LAYER_EVENTS[ i ], layerId, vn.props[ evProp ]);
			}
		}

	}

	static unregisterLayerEvents(map: Map, layerId: string, vn: VNode) {

		if (!vn.props) {
			return;
		}

		for (let i = 0, len = LayerLib.LAYER_EVENTS.length; i < len; i++) {
			const evProp = 'on' + LayerLib.LAYER_EVENTS[ i ].charAt(0).toUpperCase() + LayerLib.LAYER_EVENTS[ i ].substr(1);
			if (vn.props[ evProp ]) {
				map.off(LayerLib.LAYER_EVENTS[ i ], layerId, vn.props[ evProp ]);
			}
		}

	}

}