gistfile1.txt

import SwiftUI
import MapboxMaps

/// Generic contour layer - minimal, self-contained, renders from ContourLayerState
/// Works for SST, Chlorophyll, Salinity, Water Clarity, and other dataset types
struct SSTContourLayer: MapContent {
    let state: ContourLayerState
    
    var body: some MapContent { 
        let _ = print("🌊 [ContourLayer] Creating \(state.datasetType.rawValue) layer")
        let _ = print("🌊 [ContourLayer] DatasetType: \(state.datasetType)")

        // Major contour lines (whole degrees) with range filtering
        let _ = print("🌊 [ContourLayer] Range filter: min=\(state.minValue), max=\(state.maxValue)")
        let _ = print("🌊 [ContourLayer] Field name: \(state.fieldName)")
        
        LineLayer(id: "\(state.layerId)-major", source: state.sourceId)
            .sourceLayer("contours")
            .filter(combinedFilter(
                baseFilter: Exp(.eq) { Exp(.get) { "is_major" }; true },
                rangeFilter: state.rangeFilter
            ))
            .lineColor(state.styleColor)
            .lineWidth(2.5)
            .lineOpacity(state.opacity)
            .lineCap(.round)
            .lineJoin(.round)
            .slot(.top)

        // Decimal contour lines (0.5 degree intervals) with range filtering
        LineLayer(id: "\(state.layerId)-decimal", source: state.sourceId)
            .sourceLayer("contours")
            .filter(combinedFilter(
                baseFilter: Exp(.eq) { Exp(.get) { "is_major" }; false },
                rangeFilter: state.rangeFilter
            ))
            .lineColor(state.styleColor)
            .lineWidth(1.5)
            .lineOpacity(state.opacity * 0.7)
            .lineCap(.round)
            .lineJoin(.round)
            .slot(.top)
            .minZoom(9)

        // Labels for major lines with range filtering
        SymbolLayer(id: "\(state.layerId)-labels", source: state.sourceId)
            .sourceLayer("contours")
            .filter(combinedFilter(
                baseFilter: Exp(.eq) { Exp(.get) { "is_major" }; true },
                rangeFilter: state.rangeFilter
            ))
            .textColor(StyleColor(.black))
            .textHaloColor(StyleColor(.white))
            .textHaloWidth(2.0)
            .textFont(["League Mono Regular"])
            .symbolPlacement(.line)
            .textField(Exp(.concat) {
                Exp(.get) { ContourFilterExpression.getContourLabelFieldName(for: state.datasetType) }
            })
            .textSize(12)
            .textMaxAngle(45.0)
            .textAllowOverlap(false)
            .symbolSpacing(150)
            .textPadding(8)
            .textOpacity(state.opacity)
            .slot(.top)
            .minZoom(7)
    }
    
    // MARK: - Filter Helpers
    
    /// Creates contour filter expression if filtering is active
    private func createContourFilter() -> Exp? {
        guard let filterState = state.filter,
              filterState.effectiveIsActive else {
            return nil
        }
        
        return ContourFilterExpression.createFilter(
            for: state.datasetType,
            filterState: filterState
        )
    }
    
    /// Combines base filter with range filter
    private func combinedFilter(baseFilter: Exp, rangeFilter: Exp) -> Exp {
        Exp(.all) {
            baseFilter
            rangeFilter
        }
    }
}