/**
 * Timeline coordinate conversion and formatting utilities
 */

/**
 * Base pixels per second at zoom level 1
 * zoom=1: 5 pixels per second
 * zoom=2: 10 pixels per second, etc.
 */
const PIXELS_PER_SECOND_BASE = 5;

/**
 * Convert time (in seconds) to pixel position
 */
export function timeToPixel(time: number, duration: number, zoom: number): number {
  if (duration === 0) return 0;
  const totalWidth = duration * zoom * PIXELS_PER_SECOND_BASE;
  return (time / duration) * totalWidth;
}

/**
 * Convert pixel position to time (in seconds)
 */
export function pixelToTime(pixel: number, duration: number, zoom: number): number {
  if (duration === 0) return 0;
  const totalWidth = duration * zoom * PIXELS_PER_SECOND_BASE;
  return (pixel / totalWidth) * duration;
}

/**
 * Calculate appropriate tick interval based on visible duration
 * Returns interval in seconds
 */
export function calculateTickInterval(visibleDuration: number): {
  major: number;
  minor: number;
} {
  // Very zoomed in: show sub-second intervals
  if (visibleDuration < 5) {
    return { major: 1, minor: 0.5 };
  }
  // Zoomed in: show every second
  if (visibleDuration < 20) {
    return { major: 5, minor: 1 };
  }
  // Medium zoom: show every 5 seconds
  if (visibleDuration < 60) {
    return { major: 10, minor: 5 };
  }
  // Zoomed out: show every 10 seconds
  if (visibleDuration < 300) {
    return { major: 30, minor: 10 };
  }
  // Very zoomed out: show every minute
  return { major: 60, minor: 30 };
}

/**
 * Format time in seconds to display format
 * Returns format like "0:00", "1:23", "12:34.5"
 */
export function formatTimeLabel(seconds: number, showMillis: boolean = false): string {
  const mins = Math.floor(seconds / 60);
  const secs = seconds % 60;

  if (showMillis) {
    const wholeSecs = Math.floor(secs);
    const decimalPart = Math.floor((secs - wholeSecs) * 10);
    return `${mins}:${wholeSecs.toString().padStart(2, '0')}.${decimalPart}`;
  }

  return `${mins}:${Math.floor(secs).toString().padStart(2, '0')}`;
}

/**
 * Calculate visible time range based on scroll position
 */
export function getVisibleTimeRange(
  scrollLeft: number,
  viewportWidth: number,
  duration: number,
  zoom: number
): { start: number; end: number } {
  const totalWidth = duration * zoom * 100;

  const start = pixelToTime(scrollLeft, duration, zoom);
  const end = pixelToTime(scrollLeft + viewportWidth, duration, zoom);

  return {
    start: Math.max(0, start),
    end: Math.min(duration, end),
  };
}