"use client";

import { HTMLAttributes } from "react";
import { clsx } from "clsx";

// =============================================================================
// Skeleton Types
// =============================================================================

export type SkeletonVariant = 
  | "text"
  | "heading"
  | "paragraph"
  | "card"
  | "button"
  | "avatar"
  | "image"
  | "list"
  | "circular";

export interface SkeletonProps extends HTMLAttributes<HTMLDivElement> {
  variant?: SkeletonVariant;
  lines?: number;
  width?: string | number;
  height?: string | number;
  animated?: boolean;
}

// =============================================================================
// SharedSkeleton Component
// =============================================================================

export function SharedSkeleton({
  variant = "text",
  lines = 1,
  width,
  height,
  animated = true,
  className,
  ...props
}: SkeletonProps) {
  // Default dimensions for each variant
  const defaults: Record<SkeletonVariant, { width: string; height: string }> = {
    text: { width: "100%", height: "1em" },
    heading: { width: "60%", height: "1.5em" },
    paragraph: { width: "100%", height: "1em" },
    card: { width: "100%", height: "120px" },
    button: { width: "120px", height: "40px" },
    avatar: { width: "40px", height: "40px" },
    image: { width: "100%", height: "200px" },
    list: { width: "100%", height: "40px" },
    circular: { width: "40px", height: "40px" },
  };

  const d = defaults[variant];
  const w = width || d.width;
  const h = height || d.height;

  // Build style object
  const style: React.CSSProperties = {
    width: typeof w === "number" ? `${w}px` : w,
    height: typeof h === "number" ? `${h}px` : h,
  };

  // Animation classes
  const animationClasses = animated ? "animate-skeleton-pulse" : "";

  // Variant-specific classes (reserved)
  const _variantClasses = clsx({
    circular: "rounded-full",
    card: "rounded-lg",
    button: "rounded-lg",
    avatar: "rounded-full",
    image: "rounded-lg",
    // Default to rounded for text/paragraph/heading/list
  });

  if (variant === "paragraph" && lines > 1) {
    return (
      <div className={clsx("space-y-2", className)} {...props}>
        {Array.from({ length: lines }).map((_, i) => (
          <SharedSkeleton
            key={i}
            variant="text"
            animated={animated}
            width={i === 0 ? "80%" : i === lines - 1 ? "60%" : "100%"}
          />
        ))}
      </div>
    );
  }

  if (variant === "list" && lines > 1) {
    return (
      <div className={clsx("space-y-2", className)} {...props}>
        {Array.from({ length: lines }).map((_, i) => (
          <SharedSkeleton key={i} variant="list" animated={animated} />
        ))}
      </div>
    );
  }

  return (
    <div
      className={clsx(
        "bg-[var(--bg-elevated)]",
        "border",
        "border-[var(--border-subtle)]",
        variant !== "circular" && variant !== "avatar" && "rounded-md",
        variant === "circular" && "rounded-full",
        variant === "avatar" && "rounded-full",
        animationClasses,
        className,
      )}
      style={style}
      {...props}
    />
  );
}

// =============================================================================
// Skeleton Containers
// =============================================================================

// Card skeleton (matching SharedCard)
export function SkeletonCard({
  lines = 3,
  className,
  ...props
}: { lines?: number } & Omit<SkeletonProps, "variant">) {
  return (
    <SharedSkeleton
      variant="card"
      className={clsx("rounded-xl", className)}
      {...props}
    >
      <div className="space-y-3 p-7">
        <SharedSkeleton variant="heading" animated={props.animated} />
        {Array.from({ length: lines }).map((_, i) => (
          <SharedSkeleton
            key={i}
            variant="text"
            animated={props.animated}
            width={i === lines - 1 ? "75%" : "100%"}
          />
        ))}
      </div>
    </SharedSkeleton>
  );
}

// Button skeleton
export function SkeletonButton({ className, ...props }: Omit<SkeletonProps, "variant">) {
  return (
    <SharedSkeleton
      variant="button"
      className={clsx("rounded-lg", className)}
      {...props}
    />
  );
}

// Input skeleton
export function SkeletonInput({ className, ...props }: Omit<SkeletonProps, "variant">) {
  return (
    <SharedSkeleton
      variant="text"
      height="44px"
      className={clsx("rounded-lg w-full", className)}
      {...props}
    />
  );
}

// Avatar skeleton
export function SkeletonAvatar({
  size = 40,
  className,
  ...props
}: { size?: number } & Omit<SkeletonProps, "variant" | "width" | "height">) {
  return (
    <SharedSkeleton
      variant="circular"
      width={size}
      height={size}
      className={className}
      {...props}
    />
  );
}