import noScientificNotation from "../format/helpers/noScientificNotation.js"

/**
 * Returns the OpenGIS Styled Layer Descriptor encoded for an URL. The required parameters are the layer and the color scale.
 * 
 * @example
 * Basic usage
 * ```ts
 * // Returns the SLD for the GDPS.ETA_TT layer with a color scale going from blue to red.
 * const sdl = styledLayerDescriptor("GDPS.ETA_TT", [
 *   { color: "#550c24", value: 100 },
 *   { color: "#7f2e34", value: 30 },
 *   { color: "#c26847", value: 20 },
 *   { color: "#bdbb7a", value: 10 },
 *   { color: "#e0e9f0", value: 0 },
 *   { color: "#97b4cd", value: -10 },
 *   { color: "#5881a1", value: -20 },
 *   { color: "#334f60", value: -30 },
 *   { color: "#21353f", value: -100 },
 * ])

 * // The sdl can now be used in a WMS request as SLD_BODY
 * const url = `https://geo.weather.gc.ca/geomet?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&BBOX=-90,-180,90,180&CRS=EPSG:4326&WIDTH=2400&HEIGHT=1200&LAYERS=GDPS.ETA_TT&FORMAT=image/jpeg&SLD_BODY=${sld}`
 * ```
 * 
 * @param layer The name of the layer.
 * @param colorScale An array of objects containing color and value properties.
 * 
 * @category Geo
 */
export default function styledLayerDescriptor(
    layer: string,
    colorScale: { color: string; value: number }[]
): string {
    // Color map entrie need to be in ascending order.
    colorScale.sort((a, b) => (a.value < b.value ? -1 : 1))

    const xml = `<?xml version="1.0" encoding="UTF-8"?><StyledLayerDescriptor version="1.0.0" xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.0.0/StyledLayerDescriptor.xsd"><NamedLayer><se:Name>${layer}</se:Name><UserStyle><Title>Custom style</Title><se:FeatureTypeStyle><se:Rule><se:RasterSymbolizer><se:Opacity>1.0</se:Opacity><ColorMap>${colorScale
        .map(
            (item) =>
                `<ColorMapEntry color="${item.color}" quantity="${noScientificNotation(item.value)}"/>`
        )
        .join(
            ""
        )}</ColorMap></se:RasterSymbolizer></se:Rule></se:FeatureTypeStyle></UserStyle></NamedLayer></StyledLayerDescriptor>`

    return encodeURIComponent(xml)
}