import { clsx, type ClassValue } from "clsx";
import { twMerge } from "tailwind-merge";
import { cva } from "class-variance-authority";
import calculateReadingTime from 'reading-time';
import { fromMarkdown } from 'mdast-util-from-markdown';
import { toString } from 'mdast-util-to-string';

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

export function capitalizeFirstLetter(sentence: string): string {
  return `${sentence.charAt(0).toUpperCase()}${sentence.slice(1)}`;
}

export const buttonVariants = cva(
  "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium ring-offset-background transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0",
  {
    variants: {
      variant: {
        default: "bg-primary text-primary-foreground hover:bg-primary/90",
        destructive:
          "bg-destructive text-destructive-foreground hover:bg-destructive/90",
        outline:
          "border border-input bg-background hover:bg-accent hover:text-accent-foreground",
        secondary:
          "bg-secondary text-secondary-foreground hover:bg-secondary/80",
        ghost: "hover:bg-accent hover:text-accent-foreground",
        link: "text-primary underline-offset-4 hover:underline",
      },
      size: {
        default: "h-10 px-4 py-2",
        sm: "h-9 rounded-md px-3",
        lg: "h-11 rounded-md px-8",
        icon: "h-10 w-10",
      },
    },
    defaultVariants: {
      variant: "default",
      size: "default",
    },
  }
);


export const getReadingTime = (text: string): string | undefined => {
  if (!text || !text.length) return undefined;
  try {
    const { minutes } = calculateReadingTime(toString(fromMarkdown(text)));
    if (minutes && minutes > 0) {
      return `${Math.ceil(minutes)} min read`;
    }
    return undefined;
  } catch (e) {
    return undefined;
  }
};