import { cva, type VariantProps } from "class-variance-authority";

import { cn } from "@/lib/utils";

/**
 * Site-wide typography scale optimized for Persian (RTL) readability.
 * Use via `typography({ variant })`, `type.*` shorthand, or `<Typography>`.
 */
export const typographyVariants = cva("tracking-normal", {
  variants: {
    variant: {
      /** Large marketing hero titles */
      display:
        "text-3xl font-semibold leading-relaxed text-balance sm:text-4xl lg:text-5xl",
      /** Main page titles */
      h1: "text-3xl font-bold leading-snug text-balance md:text-4xl lg:text-5xl",
      /** Major section headings */
      h2: "text-2xl font-semibold leading-snug text-balance md:text-3xl lg:text-4xl",
      /** Subsection / feature block headings */
      h3: "text-lg font-semibold leading-snug md:text-xl",
      /** Compact block headings, mini sections */
      h4: "text-base font-semibold leading-snug md:text-lg",
      /** Prominent intro paragraphs */
      "body-lg": "text-lg leading-relaxed md:text-xl",
      /** Standard paragraphs */
      body: "text-base leading-relaxed",
      /** Secondary / denser copy */
      "body-sm": "text-sm leading-relaxed",
      /** Metadata, timestamps, footnotes */
      caption: "text-xs leading-normal text-muted-foreground",
      /** Section eyebrow / badge labels */
      eyebrow: "text-sm font-medium leading-normal text-muted-foreground",
      /** Form labels, settings labels */
      label: "text-sm font-medium leading-none",
      /** Header / menu items (desktop) */
      nav: "text-sm font-medium",
      /** Mobile navigation items */
      "nav-mobile": "text-base font-medium",
      /** Titles inside cards and panels */
      "card-title": "text-base font-semibold leading-snug",
      /** Supporting copy inside cards */
      "card-desc": "text-sm leading-relaxed text-muted-foreground",
      /** Chat message bubbles */
      chat: "text-sm leading-relaxed",
      /** Log panels, JSON, technical output */
      code: "font-mono text-xs leading-relaxed",
      /** Large stat numbers */
      stat: "text-4xl font-bold leading-none text-primary md:text-5xl",
      /** Inline nav / footer links */
      link: "text-sm text-muted-foreground",
      /** Section intro paragraphs (muted) */
      "section-intro": "text-lg leading-relaxed text-muted-foreground",
      /** Pull quotes / emphasis blocks */
      emphasis: "text-base font-medium leading-relaxed text-foreground",
      /** Accordion / list item titles */
      "list-title": "text-base font-medium leading-snug",
      /** CTA section headings (slightly larger than h2) */
      "cta-title":
        "text-2xl font-semibold leading-snug text-balance md:text-3xl lg:text-4xl",
      /** Decorative error page numbers */
      "display-mono":
        "text-[5rem] font-black leading-none sm:text-[6rem] md:text-[8rem]",
    },
  },
  defaultVariants: {
    variant: "body",
  },
});

export type TypographyVariant = NonNullable<
  VariantProps<typeof typographyVariants>["variant"]
>;

/** Shorthand class strings for inline use: `className={type.h2}` */
export const type: Record<TypographyVariant, string> = {
  display:
    "text-3xl font-semibold leading-relaxed tracking-normal text-balance sm:text-4xl lg:text-5xl",
  h1: "text-3xl font-bold leading-snug tracking-normal text-balance md:text-4xl lg:text-5xl",
  h2: "text-2xl font-semibold leading-snug tracking-normal text-balance md:text-3xl lg:text-4xl",
  h3: "text-lg font-semibold leading-snug tracking-normal md:text-xl",
  h4: "text-base font-semibold leading-snug tracking-normal md:text-lg",
  "body-lg": "text-lg leading-relaxed tracking-normal md:text-xl",
  body: "text-base leading-relaxed tracking-normal",
  "body-sm": "text-sm leading-relaxed tracking-normal",
  caption: "text-xs leading-normal tracking-normal text-muted-foreground",
  eyebrow: "text-sm font-medium leading-normal tracking-normal text-muted-foreground",
  label: "text-sm font-medium leading-none tracking-normal",
  nav: "text-sm font-medium tracking-normal",
  "nav-mobile": "text-base font-medium tracking-normal",
  "card-title": "text-base font-semibold leading-snug tracking-normal",
  "card-desc": "text-sm leading-relaxed tracking-normal text-muted-foreground",
  chat: "text-sm leading-relaxed tracking-normal",
  code: "font-mono text-xs leading-relaxed tracking-normal",
  stat: "text-4xl font-bold leading-none tracking-normal text-primary md:text-5xl",
  link: "text-sm tracking-normal text-muted-foreground",
  "section-intro": "text-lg leading-relaxed tracking-normal text-muted-foreground",
  emphasis: "text-base font-medium leading-relaxed tracking-normal text-foreground",
  "list-title": "text-base font-medium leading-snug tracking-normal",
  "cta-title":
    "text-2xl font-semibold leading-snug tracking-normal text-balance md:text-3xl lg:text-4xl",
  "display-mono":
    "text-[5rem] font-black leading-none tracking-tighter sm:text-[6rem] md:text-[8rem]",
};

/** Text-related spacing tied to typography hierarchy */
export const typeSpacing = {
  /** Eyebrow → heading */
  eyebrowToHeading: "mt-2",
  /** Heading → supporting paragraph */
  headingToBody: "mt-3",
  /** Section title block */
  sectionStack: "space-y-4",
  /** Page hero block */
  heroStack: "space-y-6",
  /** Card title → description */
  cardStack: "gap-1.5",
  /** Stacked paragraphs */
  paragraphStack: "space-y-4",
  /** Label → input */
  labelToControl: "gap-1.5",
  /** Message → timestamp in chat */
  chatMeta: "space-y-1",
} as const;

export function typography(
  variant: TypographyVariant,
  className?: string
): string {
  return cn(typographyVariants({ variant }), className);
}