import {
  damaskPattern,
  confettiPattern,
  leafPattern,
  polkaDotPattern,
  snowflakePattern,
  starPattern,
  scratchPattern,
  pixelGridPattern,
  floralLacePattern,
  palmLeafPattern,
  wheatPattern,
  gradCapPattern,
  texturePattern,
  combinePatterns,
  type Pattern,
} from '@/lib/patterns';
import { deriveThemeColors, type ThemeColors } from '@/lib/color';

export type Theme = {
  id: string;
  name: string;
  emoji: string;
  /** Light card vs. dark card - drives how resolveTheme derives a full
   * palette from a host's custom primary/accent choice (see color.ts). */
  mode: 'light' | 'dark';
  colors: ThemeColors;
  pattern: Pattern;
  /** Rebuilds this theme's pattern for an arbitrary color set - used by
   * resolveTheme when a host overrides the default colors. */
  buildPattern: (colors: ThemeColors) => Pattern;
};

type ThemeDefinition = Omit<Theme, 'pattern'>;

function defineTheme(def: ThemeDefinition): Theme {
  return { ...def, pattern: def.buildPattern(def.colors) };
}

// Colors applied via CSS custom properties (see ThemedInviteLayout).
// Fonts are mapped separately in src/lib/fonts.ts since next/font classes
// must be static imports, not computed dynamically. `pattern` is a tileable
// inline-SVG background (see src/lib/patterns.ts) that gives each theme a
// distinct texture, not just a color/font swap. `buildPattern` regenerates
// that same pattern for a different color set - see resolveTheme below.
export const THEMES: Theme[] = [
  defineTheme({
    id: 'classic-elegant',
    name: 'Classic Elegant',
    emoji: '🥂',
    mode: 'light',
    colors: {
      bg: '#f5f1ea',
      surface: '#ffffff',
      primary: '#4b3b2a',
      accent: '#b08d57',
      text: '#2b2118',
    },
    buildPattern: (c) => combinePatterns(damaskPattern(c.accent), texturePattern('/textures/exclusive-paper.png', 560, 420)),
  }),
  defineTheme({
    id: 'birthday-confetti',
    name: 'Birthday Confetti',
    emoji: '🎉',
    mode: 'light',
    colors: {
      bg: '#fff3f8',
      surface: '#ffffff',
      primary: '#e0218a',
      accent: '#ffb703',
      text: '#3a1030',
    },
    buildPattern: (c) => confettiPattern([c.primary, c.accent, '#3dd6c2']),
  }),
  defineTheme({
    id: 'garden-party',
    name: 'Garden Party',
    emoji: '🌿',
    mode: 'light',
    colors: {
      bg: '#f1f7ee',
      surface: '#ffffff',
      primary: '#3f6b3a',
      accent: '#e0a458',
      text: '#233720',
    },
    buildPattern: (c) => leafPattern(c.primary, c.accent),
  }),
  defineTheme({
    id: 'modern-minimal',
    name: 'Modern Minimal',
    emoji: '⬛',
    mode: 'light',
    colors: {
      bg: '#fafafa',
      surface: '#ffffff',
      primary: '#111827',
      accent: '#2563eb',
      text: '#111827',
    },
    buildPattern: (c) => polkaDotPattern(c.accent, 1.75),
  }),
  defineTheme({
    id: 'holiday-festive',
    name: 'Holiday Festive',
    emoji: '❄️',
    mode: 'dark',
    colors: {
      bg: '#0f2d24',
      surface: '#153a2e',
      primary: '#e63946',
      accent: '#f1c40f',
      text: '#fdf6ec',
    },
    buildPattern: (c) => combinePatterns(snowflakePattern(c.accent), texturePattern('/textures/fresh-snow.png', 500, 500)),
  }),
  defineTheme({
    id: 'baby-shower-pastel',
    name: 'Baby Shower Pastel',
    emoji: '🍼',
    mode: 'light',
    colors: {
      bg: '#f4f1fb',
      surface: '#ffffff',
      primary: '#8e7cc3',
      accent: '#f6b6c1',
      text: '#3a3350',
    },
    buildPattern: (c) => starPattern([c.primary, c.accent]),
  }),
  defineTheme({
    id: 'goth-grunge',
    name: 'Goth Grunge',
    emoji: '💀',
    mode: 'dark',
    colors: {
      bg: '#121212',
      surface: '#1c1c1c',
      primary: '#b91c1c',
      accent: '#9333ea',
      text: '#e5e5e5',
    },
    buildPattern: (c) => combinePatterns(scratchPattern(c.accent), texturePattern('/textures/dark-leather.png', 398, 484)),
  }),
  defineTheme({
    id: 'retro-arcade',
    name: 'Retro Arcade',
    emoji: '🕹️',
    mode: 'dark',
    colors: {
      bg: '#0d0221',
      surface: '#1a0b3d',
      primary: '#ff2e88',
      accent: '#00e5ff',
      text: '#eafffb',
    },
    buildPattern: (c) => pixelGridPattern(c.accent, [c.primary, c.accent]),
  }),
  defineTheme({
    id: 'wedding-romance',
    name: 'Wedding Romance',
    emoji: '💍',
    mode: 'light',
    colors: {
      bg: '#fdf5f2',
      surface: '#ffffff',
      primary: '#8c5b6b',
      accent: '#c9a45c',
      text: '#3a2a2e',
    },
    buildPattern: (c) => combinePatterns(floralLacePattern(c.accent), texturePattern('/textures/white-linen.png', 400, 300)),
  }),
  defineTheme({
    id: 'tropical-luau',
    name: 'Tropical Luau',
    emoji: '🌺',
    mode: 'light',
    colors: {
      bg: '#e6fbf7',
      surface: '#ffffff',
      primary: '#0f766e',
      accent: '#f59e0b',
      text: '#0b3d3a',
    },
    buildPattern: (c) => palmLeafPattern(c.primary, c.accent),
  }),
  defineTheme({
    id: 'rustic-harvest',
    name: 'Rustic Harvest',
    emoji: '🍂',
    mode: 'light',
    colors: {
      bg: '#f7ecd9',
      surface: '#fffaf1',
      primary: '#7a4a24',
      accent: '#c1622d',
      text: '#3d2812',
    },
    buildPattern: (c) => combinePatterns(wheatPattern(c.accent), texturePattern('/textures/cardboard.png', 600, 600)),
  }),
  defineTheme({
    id: 'graduation-grad',
    name: 'Graduation',
    emoji: '🎓',
    mode: 'dark',
    colors: {
      bg: '#0b1f3a',
      surface: '#122a4d',
      primary: '#f2c14e',
      accent: '#f2c14e',
      text: '#f5f5f0',
    },
    buildPattern: (c) => gradCapPattern(c.accent),
  }),
];

export const DEFAULT_THEME_ID = THEMES[0].id;

export function getTheme(id: string): Theme {
  return THEMES.find((t) => t.id === id) ?? THEMES[0];
}

/**
 * Resolves a theme for rendering, with optional host-chosen primary/accent
 * overrides (Event.themePrimaryColor / themeAccentColor). With no overrides,
 * returns the theme's own hand-tuned default palette and pattern completely
 * unchanged. With one or both overrides, derives a full contrast-safe
 * palette (see deriveThemeColors) and rebuilds the pattern to match, so a
 * customized theme never ends up illegible.
 */
export function resolveTheme(
  id: string,
  primaryOverride?: string | null,
  accentOverride?: string | null
): Theme {
  const base = getTheme(id);
  if (!primaryOverride && !accentOverride) return base;

  const colors = deriveThemeColors(
    base.mode,
    primaryOverride || base.colors.primary,
    accentOverride || base.colors.accent
  );
  return { ...base, colors, pattern: base.buildPattern(colors) };
}