/** Time ranges offered above CloudWatch charts. */
export const RANGES = [{label: '1 hour', minutes: 60}, {label: '3 hours', minutes: 180}, {label: '24 hours', minutes: 1440}, {label: '7 days', minutes: 10080}]

/** About five round ticks covering [min, max], always including zero when the range does. */
export function niceTicks(min: number, max: number, count = 5): number[] {
    const span = max - min
    const raw = span / (count - 1)
    const magnitude = 10 ** Math.floor(Math.log10(raw))
    const step = [1, 2, 2.5, 5, 10].map((factor) => factor * magnitude).find((candidate) => candidate >= raw) ?? 10 * magnitude
    const start = Math.floor(min / step) * step
    const end = Math.ceil(max / step) * step
    const ticks: number[] = []
    for (let value = start; value <= end + step / 2; value += step) ticks.push(Number(value.toPrecision(12)))
    return ticks
}

export function timeTicks(start: number, end: number, count: number): number[] {
    if (end <= start) return [start]
    const step = (end - start) / count
    return Array.from({length: count + 1}, (_, index) => start + index * step)
}

export function formatValue(value: number): string {
    const abs = Math.abs(value)
    if (abs >= 1e9) return `${trim(value / 1e9)}B`
    if (abs >= 1e6) return `${trim(value / 1e6)}M`
    if (abs >= 1e3) return `${trim(value / 1e3)}K`
    return trim(value)
}

function trim(value: number): string {
    return Number.isInteger(value) ? String(value) : value.toFixed(Math.abs(value) < 10 ? 2 : 1).replace(/\.?0+$/, '')
}