remove echarts, use canvas

src/lib/charts/data.ts

@@ -0,0 +1,106 @@
+/**
+ * Chart Data Helpers
+ *
+ * Shared color palette and data-processing helpers used by the chart pages.
+ * Ported from the previous ECharts utilities so the visual identity and
+ * calculations stay identical.
+ */
+
+// ─── Color Palette ───────────────────────────────────────────────────────────
+
+/** Default series color palette matching the application's design system */
+export const SERIES_COLORS = [
+	'#5470c6',
+	'#91cc75',
+	'#fac858',
+	'#ee6666',
+	'#73c0de',
+	'#3ba272',
+	'#fc8452',
+	'#9a60b4',
+	'#ea7ccc',
+	'#4dc9f6'
+] as const;
+
+/** Semantic colors used for specific chart elements */
+export const CHART_COLORS = {
+	average: '#5e5e5e',
+	currentTimeLine: '#ef4444',
+	daylight: 'rgba(255, 255, 194, 0.3)',
+	memberLine: 'rgba(115, 192, 222, 0.45)'
+} as const;
+
+// ─── Utility: Detect column-type variables ───────────────────────────────────
+
+/** Units that should be rendered as bar/column charts instead of lines. */
+const COLUMN_UNITS = new Set(['mm', 'cm', 'inch', 'MJ/m²']);
+
+/**
+ * Returns true if the given unit should be rendered as a bar chart.
+ */
+export function isColumnUnit(unit: string): boolean {
+	return COLUMN_UNITS.has(unit);
+}
+
+// ─── Data Processing Helpers ─────────────────────────────────────────────────
+
+export interface AverageResult {
+	average: number[];
+	averageCount: number[];
+}
+
+/**
+ * Calculates per-timestep average and count from hourly model data.
+ *
+ * @param hourlyData - The `data.hourly` object from the API response
+ * @param variable   - The variable prefix to filter on (e.g. 'temperature_2m')
+ * @param timeLength - Number of timesteps
+ * @returns Object containing running average and count arrays
+ */
+export function calculateAverage(
+	hourlyData: Record<string, unknown>,
+	variable: string,
+	timeLength: number
+): AverageResult {
+	const average = new Array<number>(timeLength).fill(0);
+	const averageCount = new Array<number>(timeLength).fill(0);
+
+	for (const [model, values] of Object.entries(hourlyData)) {
+		if (model === 'time') continue;
+		if (!model.startsWith(variable)) continue;
+
+		for (const [index, val] of (values as number[]).entries()) {
+			if (val !== null && val !== undefined && isFinite(val)) {
+				average[index] += val;
+				averageCount[index]++;
+			}
+		}
+	}
+
+	// Finalize average values
+	for (let i = 0; i < timeLength; i++) {
+		if (averageCount[i] > 0) {
+			average[i] = Math.round((average[i] / averageCount[i]) * 10) / 10;
+		}
+	}
+
+	return { average, averageCount };
+}
+
+/**
+ * Finds the unit string for a given variable from the hourly_units map.
+ * Returns an empty string if the variable is not found.
+ */
+export function findUnit(
+	hourlyUnits: Record<string, string>,
+	hourlyData: Record<string, unknown>,
+	variable: string
+): string {
+	for (const model of Object.keys(hourlyData)) {
+		if (model === 'time') continue;
+		if (model.startsWith(variable) && hourlyUnits[model]) {
+			return hourlyUnits[model];
+		}
+	}
+	return '';
+}