contourLineExpression.swift

import UIKit
import MapboxMaps

class SSTColorUtil {
    private static let colors = DatasetType.sst.config.colorScale
    
    static func getContourLineExpression(min minTemp: Double, max maxTemp: Double) -> Exp {
        let range = maxTemp - minTemp
        var stops: [Exp.Argument] = []
       
        for (index, color) in colors.enumerated() {
            let temp = minTemp + (range * Double(index) / Double(colors.count - 1))
            stops.append(.number(temp))
            stops.append(.string(color))
        }

        return Exp(operator: .interpolate, arguments: [
            .expression(Exp(operator: .linear, arguments: [])),
            .expression(Exp(operator: .get, arguments: [.string("temperature")])),
        ] + stops)
    }

    static func getLineWidth(isHovered: Bool = false, strength: String? = nil) -> Double {
        if isHovered { return 5.0 }
        switch strength {
        case "strong": return 2.0
        case "moderate": return 1.0
        default: return 0.75
        }
    }
}

// Helper for string chunking
extension StringProtocol {
    func chunks(ofCount count: Int) -> [SubSequence] {
        var chunks: [SubSequence] = []
        var i = startIndex
        while i < endIndex {
            let j = index(i, offsetBy: count, limitedBy: endIndex) ?? endIndex
            chunks.append(self[i..<j])
            i = j
        }
        return chunks
    }
}