/**
 * Formats an A1C value with % sign.
 * @param val - A1C number
 * @returns A1C as string with percent
 */
declare function formatA1C(val: number): string;
/**
 * Validates if a value is a plausible A1C percentage.
 * @param value - Value to check
 * @returns True if valid A1C
 */
declare function isValidA1C(value: unknown): boolean;
/**
 * Returns a clinical category for an A1C value.
 * @param a1c - A1C value
 * @returns 'normal' | 'prediabetes' | 'diabetes' | 'invalid'
 */
declare function getA1CCategory(a1c: number): 'normal' | 'prediabetes' | 'diabetes' | 'invalid';
/**
 * Checks if an A1C value is within a target range.
 * @param a1c - A1C value
 * @param target - [min, max] range (default: [6.5, 7.0])
 * @returns True if in target range
 */
declare function isA1CInTarget(a1c: number, target?: [number, number]): boolean;
/**
 * Calculates the change (delta) between two A1C values.
 * @param current - Current A1C
 * @param previous - Previous A1C
 * @returns Delta (current - previous)
 * @throws If either value is invalid
 */
declare function a1cDelta(current: number, previous: number): number;
/**
 * Determines the trend of A1C values over time.
 * @param readings - Array of A1C values (chronological order)
 * @returns 'increasing' | 'decreasing' | 'stable' | 'insufficient data'
 */
declare function a1cTrend(readings: number[]): 'increasing' | 'decreasing' | 'stable' | 'insufficient data';

/**
 * Hypoglycemia threshold in mg/dL.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const HYPO_THRESHOLD_MGDL = 70;
/**
 * Hyperglycemia threshold in mg/dL.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const HYPER_THRESHOLD_MGDL = 180;
/**
 * Hypoglycemia threshold in mmol/L.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const HYPO_THRESHOLD_MMOLL = 3.9;
/**
 * Hyperglycemia threshold in mmol/L.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const HYPER_THRESHOLD_MMOLL = 10;
/**
 * Multiplier for converting A1C to estimated average glucose (eAG).
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare const A1C_TO_EAG_MULTIPLIER = 28.7;
/**
 * Constant for converting A1C to estimated average glucose (eAG).
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare const A1C_TO_EAG_CONSTANT = 46.7;
/**
 * Conversion factor between mg/dL and mmol/L.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare const MGDL_MMOLL_CONVERSION = 18.0182;
/**
 * String literal for mg/dL unit.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare const MG_DL: "mg/dL";
/**
 * String literal for mmol/L unit.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare const MMOL_L: "mmol/L";
/**
 * Color codes for glucose zones.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const GLUCOSE_COLOR_LOW = "#D32F2F";
declare const GLUCOSE_COLOR_NORMAL = "#388E3C";
declare const GLUCOSE_COLOR_NORMAL_UP = "#4CAF50";
declare const GLUCOSE_COLOR_NORMAL_DOWN = "#2E7D32";
declare const GLUCOSE_COLOR_ELEVATED = "#FBC02D";
declare const GLUCOSE_COLOR_HIGH = "#F57C00";
/**
 * Glucose zone color mapping for different statuses and trends.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const GLUCOSE_ZONE_COLORS: {
    LOW: string;
    NORMAL: string;
    ELEVATED: string;
    HIGH: string;
    NORMAL_UP: string;
    NORMAL_DOWN: string;
};
/**
 * Unicode arrows for glucose trend indication.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare const TREND_ARROWS: {
    STEADY: string;
    RISING: string;
    FALLING: string;
    RAPIDRISE: string;
    RAPIDFALL: string;
};

/**
 * Supported glucose units.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
type GlucoseUnit = typeof MG_DL | typeof MMOL_L;
/**
 * All allowed glucose units.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare const AllowedGlucoseUnits: GlucoseUnit[];
/**
 * Represents a single glucose reading with value, unit, and timestamp.
 * @see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7445493/
 */
interface GlucoseReading {
    readonly value: number;
    readonly unit: GlucoseUnit;
    readonly timestamp: string;
}
/**
 * Result of a Time-in-Range (TIR) calculation.
 * @see https://care.diabetesjournals.org/content/42/8/1593
 */
interface TIRResult {
    inRange: number;
    belowRange: number;
    aboveRange: number;
}
/**
 * Options for estimating GMI (Glucose Management Indicator).
 * @see https://diatribe.org/glucose-management-indicator-gmi
 */
interface EstimateGMIOptions {
    value: number;
    unit: GlucoseUnit;
}
/**
 * Options for Time-in-Range (TIR) calculations.
 */
interface TIROptions {
    readings: GlucoseReading[];
    unit: GlucoseUnit;
    range: [number, number];
}
/**
 * Represents a single A1C reading with value and date.
 */
interface A1CReading {
    value: number;
    date: string;
}
/**
 * Options for calculating glucose statistics.
 */
interface GlucoseStatsOptions {
    readings: GlucoseReading[];
    unit: GlucoseUnit;
    range: [number, number];
    gmi?: boolean;
    a1c?: boolean;
    tir?: boolean;
    tirRange?: [number, number];
    tirPercent?: boolean;
    tirPercentBelow?: boolean;
    tirPercentAbove?: boolean;
    tirPercentInRange?: boolean;
    tirPercentBelowRounded?: boolean;
    tirPercentAboveRounded?: boolean;
    tirPercentInRangeRounded?: boolean;
}

/**
 * Converts average glucose (mg/dL) to estimated A1C.
 * @param avgMgDl - Average glucose in mg/dL
 * @returns Estimated A1C value
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare function estimateA1CFromAvgGlucose(avgMgDl: number): number;
/**
 * Converts A1C value to estimated average glucose (mg/dL).
 * @param a1c - A1C value
 * @returns Estimated average glucose in mg/dL
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare function estimateAvgGlucoseFromA1C(a1c: number): number;
/**
 * Estimates eAG (estimated average glucose) from A1C.
 * @param a1c - A1C value
 * @returns Estimated average glucose (eAG) in mg/dL
 * @throws {Error} If a1c is negative.
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare function estimateEAG(a1c: number): number;
/**
 * Estimates A1C from average glucose.
 * @param avgGlucose - Average glucose value
 * @param unit - Glucose unit (mg/dL or mmol/L)
 * @returns Estimated A1C
 * @see https://www.cdc.gov/diabetes/managing/managing-blood-sugar/a1c.html
 */
declare function estimateA1CFromAverage(avgGlucose: number, unit?: GlucoseUnit): number;
/**
 * Converts A1C to Glucose Management Indicator (GMI).
 * @param a1c - A1C value
 * @returns GMI value
 * @see https://diatribe.org/glucose-management-indicator-gmi
 */
declare function a1cToGMI(a1c: number): number;
/**
 * Estimate Glucose Management Indicator (GMI) from average glucose.
 * @param valueOrOptions - Glucose value, string, or options object
 * @param unit - Glucose unit (if value is a number)
 * @returns GMI value
 * @throws {Error} If unit is required but not provided when input is a number.
 * @throws {Error} If the glucose unit is unsupported.
 * @throws {Error} If the glucose value is not a positive number.
 * @see https://diatribe.org/glucose-management-indicator-gmi
 */
declare function estimateGMI(valueOrOptions: number | string | EstimateGMIOptions, unit?: GlucoseUnit): number;
/**
 * Converts mg/dL to mmol/L.
 * @param val - Glucose value in mg/dL
 * @returns Value in mmol/L
 * @throws {Error} If val is not a finite number or is negative/zero.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function mgDlToMmolL(val: number): number;
/**
 * Converts mmol/L to mg/dL.
 * @param val - Glucose value in mmol/L
 * @returns Value in mg/dL
 * @throws {Error} If val is not a finite number or is negative/zero.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function mmolLToMgDl(val: number): number;
/**
 * Converts glucose value between mg/dL and mmol/L.
 * @param value - Glucose value
 * @param unit - Current glucose unit
 * @returns Object with converted value and new unit
 * @throws {Error} If value is not a finite number or is negative/zero.
 * @throws {Error} If unit is not a supported glucose unit.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function convertGlucoseUnit({ value, unit, }: {
    value: number;
    unit: GlucoseUnit;
}): {
    value: number;
    unit: GlucoseUnit;
};

/**
 * Formats a glucose value with its unit and optional rounding.
 * @param val - Glucose value to format.
 * @param unit - Unit of measurement (mg/dL or mmol/L).
 * @param options - Formatting options: number of digits and whether to include the unit suffix (default: { digits: 0, suffix: true }).
 * @returns Formatted glucose string, e.g., '5.5 mmol/L' or '120 mg/dL'.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function formatGlucose(val: number, unit: GlucoseUnit, options?: {
    digits?: number;
    suffix?: boolean;
}): string;
/**
 * Formats a number as a percentage string.
 * @param val - Value to format as a percentage (e.g., 0.85 or 85).
 * @param digits - Number of decimal places (default: 1).
 * @returns Formatted percentage string, e.g., '85.0%'.
 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/toFixed
 */
declare function formatPercentage(val: number, digits?: number): string;
/**
 * Formats a UTC ISO timestamp to a local-readable string.
 * @param iso - ISO 8601 timestamp string (e.g., '2024-03-20T10:00:00Z').
 * @param timeZone - Optional IANA time zone name (e.g., 'America/New_York').
 * @returns Localized date and time string, e.g., 'Mar 20, 2024, 06:00 AM'.
 * @throws {RangeError} If the ISO string is invalid or cannot be parsed by Date.
 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString
 * @see https://en.wikipedia.org/wiki/ISO_8601
 */
declare function formatDate(iso: string, timeZone?: string): string;

/**
 * Determines if a glucose value is below the hypoglycemia threshold for the given unit.
 * @param val - Glucose value to check.
 * @param unit - Unit of measurement (mg/dL or mmol/L). Defaults to mg/dL.
 * @returns True if the value is below the hypoglycemia threshold, otherwise false.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare function isHypo(val: number, unit?: GlucoseUnit): boolean;
/**
 * Determines if a glucose value is above the hyperglycemia threshold for the given unit.
 * @param val - Glucose value to check.
 * @param unit - Unit of measurement (mg/dL or mmol/L). Defaults to mg/dL.
 * @returns True if the value is above the hyperglycemia threshold, otherwise false.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare function isHyper(val: number, unit?: GlucoseUnit): boolean;
/**
 * Returns a glucose status label ('low', 'normal', or 'high') based on thresholds for the given unit.
 * @param val - Glucose value to label.
 * @param unit - Unit of measurement (mg/dL or mmol/L). Defaults to mg/dL.
 * @returns 'low' if below hypo threshold, 'high' if above hyper threshold, otherwise 'normal'.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
 */
declare function getGlucoseLabel(val: number, unit?: GlucoseUnit): 'low' | 'normal' | 'high';
/**
 * Parses a glucose string like "100 mg/dL" or "5.5 mmol/L" into a value and unit.
 * @param input - A string in the format "value unit" (e.g., "100 mg/dL").
 * @returns An object with numeric `value` and validated `unit`.
 * @throws {Error} If the input string is invalid or not in the expected format.
 * @example
 * parseGlucoseString("100 mg/dL") // { value: 100, unit: "mg/dL" }
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function parseGlucoseString(input: string): {
    value: number;
    unit: GlucoseUnit;
};
/**
 * Checks if a glucose value and unit are valid.
 * @param value - Glucose value to validate.
 * @param unit - Glucose unit to validate.
 * @returns True if the value is a positive finite number and the unit is supported, otherwise false.
 */
declare function isValidGlucoseValue(value: unknown, unit: unknown): boolean;

/**
 * Type guard to check if a value is a valid EstimateGMIOptions object.
 * @param input - The value to check for EstimateGMIOptions shape.
 * @returns True if the input is an object with numeric 'value' and string 'unit' properties, otherwise false.
 */
declare function isEstimateGMIOptions(input: unknown): input is EstimateGMIOptions;
/**
 * Checks if a string is in the format "100 mg/dL" or "5.5 mmol/L".
 * @param input - The value to validate as a glucose string.
 * @returns True if the input is a string matching the glucose value and unit format, otherwise false.
 * @see https://www.diabetes.co.uk/diabetes_care/blood-sugar-conversion.html
 */
declare function isValidGlucoseString(input: unknown): input is string;

/**
 * Calculates the percentage of time glucose readings are in, below, and above a target range.
 * @param readings - Array of glucose readings to analyze.
 * @param target - Object specifying the target range with { min, max } values.
 * @returns An object with the percentage of readings in range, below range, and above range.
 * @see https://care.diabetesjournals.org/content/42/8/1593
 */
declare function calculateTIR(readings: GlucoseReading[], target: {
    min: number;
    max: number;
}): TIRResult;
/**
 * Generates a human-readable summary string from a TIRResult object.
 * @param result - The TIR result breakdown to summarize.
 * @returns A string summarizing the in-range, below-range, and above-range percentages (e.g., 'In Range: 70%, Below: 10%, Above: 20%').
 */
declare function getTIRSummary(result: TIRResult): string;
/**
 * Groups glucose readings by date (YYYY-MM-DD).
 * @param readings - Array of glucose readings to group.
 * @returns An object mapping each date string to an array of readings for that day.
 */
declare function groupByDay(readings: GlucoseReading[]): Record<string, GlucoseReading[]>;
/**
 * Calculates the percentage of readings within a specified numeric range.
 * @param readings - Array of glucose values (numbers) to analyze.
 * @param lower - Lower bound of the target range (inclusive).
 * @param upper - Upper bound of the target range (inclusive).
 * @returns The percentage of readings within the specified range (0-100).
 */
declare function calculateTimeInRange(readings: number[], lower: number, upper: number): number;

export { type A1CReading, A1C_TO_EAG_CONSTANT, A1C_TO_EAG_MULTIPLIER, AllowedGlucoseUnits, type EstimateGMIOptions, GLUCOSE_COLOR_ELEVATED, GLUCOSE_COLOR_HIGH, GLUCOSE_COLOR_LOW, GLUCOSE_COLOR_NORMAL, GLUCOSE_COLOR_NORMAL_DOWN, GLUCOSE_COLOR_NORMAL_UP, GLUCOSE_ZONE_COLORS, type GlucoseReading, type GlucoseStatsOptions, type GlucoseUnit, HYPER_THRESHOLD_MGDL, HYPER_THRESHOLD_MMOLL, HYPO_THRESHOLD_MGDL, HYPO_THRESHOLD_MMOLL, MGDL_MMOLL_CONVERSION, MG_DL, MMOL_L, type TIROptions, type TIRResult, TREND_ARROWS, a1cDelta, a1cToGMI, a1cTrend, calculateTIR, calculateTimeInRange, convertGlucoseUnit, estimateA1CFromAverage, estimateA1CFromAvgGlucose, estimateAvgGlucoseFromA1C, estimateEAG, estimateGMI, formatA1C, formatDate, formatGlucose, formatPercentage, getA1CCategory, getGlucoseLabel, getTIRSummary, groupByDay, isA1CInTarget, isEstimateGMIOptions, isHyper, isHypo, isValidA1C, isValidGlucoseString, isValidGlucoseValue, mgDlToMmolL, mmolLToMgDl, parseGlucoseString };