/**
 * Token generator — reads bytelyst.tokens.json, outputs 4 platform formats:
 *   1. CSS custom properties (tokens.css)
 *   2. TypeScript constants (tokens.ts)
 *   3. Kotlin object (MindLystTokens.kt) — for KMP shared module
 *   4. Swift structs (MindLystTheme.swift) — for iOS SwiftUI
 *
 * Output conventions match the hand-written originals in learning_multimodal_memory_agents:
 *   - Kotlin: SCREAMING_SNAKE_CASE, Palette/Dark/Light/BrainGradient/Typography/Motion/Layout
 *   - Swift:  Color(hex: UInt), dark/light prefixes, Gradient(colors:), MindLystMotion, Color ext
 *   - CSS:    [data-theme], --ml-fs-*, --ml-elevation-*, --ml-motion-*
 *
 * Usage: tsx scripts/generate.ts
 */

import { readFileSync, writeFileSync, mkdirSync } from "node:fs";
import { resolve, dirname } from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = dirname(fileURLToPath(import.meta.url));
const tokensPath = resolve(__dirname, "../tokens/bytelyst.tokens.json");
const outDir = resolve(__dirname, "../generated");

mkdirSync(outDir, { recursive: true });

const tokens = JSON.parse(readFileSync(tokensPath, "utf-8"));

// ── Helpers ──────────────────────────────────────────────────────────

function camelToKebab(str: string): string {
  return str.replace(/([a-z])([A-Z])/g, "$1-$2").toLowerCase();
}

function camelToScreamingSnake(str: string): string {
  return str.replace(/([a-z])([A-Z])/g, "$1_$2").toUpperCase();
}

function hexToUInt(hex: string): string {
  return `0x${hex.replace("#", "").toUpperCase()}`;
}

function capitalize(s: string): string {
  return s.charAt(0).toUpperCase() + s.slice(1);
}

// ── 1. CSS ───────────────────────────────────────────────────────────
function generateCSS(): string {
  const lines: string[] = [
    "/* Auto-generated from bytelyst.tokens.json — do not edit manually */",
    "",
    ":root,",
    '[data-theme="dark"] {',
  ];

  // Semantic colors (dark theme as default)
  for (const [key, value] of Object.entries(tokens.color.semantic.dark)) {
    lines.push(`  --ml-${camelToKebab(key)}: ${value};`);
  }
  lines.push("");

  // Typography
  for (const [key, value] of Object.entries(tokens.typography.fontFamily)) {
    // Swap single quotes → double quotes for CSS
    const cssVal = typeof value === "string" ? value.replace(/'/g, '"') : value;
    lines.push(`  --ml-font-${key}: ${cssVal};`);
  }
  lines.push("");

  // Font sizes (--ml-fs-* to match existing convention)
  for (const [key, value] of Object.entries(tokens.typography.fontSize)) {
    lines.push(`  --ml-fs-${key}: ${value}px;`);
  }
  lines.push("");

  // Spacing
  for (const [key, value] of Object.entries(tokens.spacing)) {
    lines.push(`  --ml-space-${key}: ${value === 0 ? "0" : `${value}px`};`);
  }
  lines.push("");

  // Radius
  for (const [key, value] of Object.entries(tokens.radius)) {
    lines.push(`  --ml-radius-${key}: ${value}px;`);
  }
  lines.push("");

  // Elevation (--ml-elevation-* to match existing)
  for (const [key, value] of Object.entries(tokens.elevation)) {
    if (key === "none") continue;
    lines.push(`  --ml-elevation-${key}: ${value};`);
  }
  lines.push("");

  // Motion
  for (const [key, value] of Object.entries(tokens.motion.duration)) {
    if (key === "instant") continue; // not used in CSS
    lines.push(`  --ml-motion-${key}: ${value}ms;`);
  }
  lines.push(`  --ml-easing-standard: ${tokens.motion.easing.standard};`);

  lines.push("}", "");

  // Light theme overrides
  lines.push('[data-theme="light"] {');
  for (const [key, value] of Object.entries(tokens.color.semantic.light)) {
    // Only emit overrides where light differs from dark
    const darkVal = tokens.color.semantic.dark[key];
    if (value !== darkVal) {
      lines.push(`  --ml-${camelToKebab(key)}: ${value};`);
    }
  }
  lines.push("}", "");

  return lines.join("\n");
}

// ── 2. TypeScript ────────────────────────────────────────────────────
function generateTS(): string {
  return [
    "// Auto-generated from bytelyst.tokens.json — do not edit manually",
    "",
    `export const tokens = ${JSON.stringify(tokens, null, 2)} as const;`,
    "",
    "export type Tokens = typeof tokens;",
    "",
  ].join("\n");
}

// ── 3. Kotlin ────────────────────────────────────────────────────────
function generateKotlin(): string {
  const lines: string[] = [
    "// Auto-generated from bytelyst.tokens.json — do not edit manually",
    "package com.mindlyst.shared.theme",
    "",
    "/**",
    " * Cross-platform design tokens from bytelyst.tokens.json.",
    " * Single source of truth consumed by both Android (Compose) and iOS (SwiftUI).",
    " */",
    "object MindLystTokens {",
    "",
  ];

  // ── Palette
  lines.push("    // ── Color Palette ────────────────────────────────────────────────");
  lines.push("    object Palette {");
  for (const [key, value] of Object.entries(tokens.color.palette.neutral)) {
    lines.push(`        const val NEUTRAL_${key} = 0xFF${(value as string).replace("#", "").toUpperCase()}`);
  }
  lines.push("");
  for (const [key, value] of Object.entries(tokens.color.palette.brand)) {
    lines.push(`        const val ${key.toUpperCase()} = 0xFF${(value as string).replace("#", "").toUpperCase()}`);
  }
  lines.push("    }", "");

  // ── Dark semantic
  lines.push("    // ── Semantic Colors (Dark Theme) ─────────────────────────────────");
  lines.push("    object Dark {");
  for (const [key, value] of Object.entries(tokens.color.semantic.dark)) {
    if (typeof value === "string" && value.startsWith("#")) {
      lines.push(`        const val ${camelToScreamingSnake(key)} = 0xFF${value.replace("#", "").toUpperCase()}`);
    }
  }
  lines.push("    }", "");

  // ── Light semantic
  lines.push("    // ── Semantic Colors (Light Theme) ────────────────────────────────");
  lines.push("    object Light {");
  for (const [key, value] of Object.entries(tokens.color.semantic.light)) {
    if (typeof value === "string" && value.startsWith("#")) {
      lines.push(`        const val ${camelToScreamingSnake(key)} = 0xFF${value.replace("#", "").toUpperCase()}`);
    }
  }
  lines.push("    }", "");

  // ── Brain gradients
  lines.push("    // ── Brain Identity Gradients ─────────────────────────────────────");
  lines.push("    data class BrainGradient(val from: Long, val to: Long)");
  lines.push("");
  for (const [name, grad] of Object.entries(tokens.color.brain) as [string, { from: string; to: string }][]) {
    lines.push(`    val BRAIN_${name.toUpperCase()} = BrainGradient(from = 0xFF${grad.from.replace("#", "").toUpperCase()}, to = 0xFF${grad.to.replace("#", "").toUpperCase()})`);
  }
  lines.push("");

  // ── Spacing
  lines.push("    // ── Spacing (8pt grid) ───────────────────────────────────────────");
  lines.push("    object Spacing {");
  for (const [key, value] of Object.entries(tokens.spacing)) {
    lines.push(`        const val X${key} = ${value}`);
  }
  lines.push("    }", "");

  // ── Radius
  lines.push("    // ── Radius ───────────────────────────────────────────────────────");
  lines.push("    object Radius {");
  for (const [key, value] of Object.entries(tokens.radius)) {
    lines.push(`        const val ${key.toUpperCase()} = ${value}`);
  }
  lines.push("    }", "");

  // ── Typography
  lines.push("    // ── Typography ───────────────────────────────────────────────────");
  lines.push("    object Typography {");
  for (const [key, value] of Object.entries(tokens.typography.fontFamily)) {
    // Extract just the primary font name (first in the list)
    const fontName = typeof value === "string" ? value.split(",")[0].replace(/'/g, "").trim() : value;
    lines.push(`        const val FONT_${key.toUpperCase()} = "${fontName}"`);
  }
  lines.push("");
  for (const [key, value] of Object.entries(tokens.typography.fontSize)) {
    const sizeKey = key.toUpperCase().replace("-", "");
    lines.push(`        const val SIZE_${sizeKey} = ${value}`);
  }
  lines.push("    }", "");

  // ── Motion
  lines.push("    // ── Motion ───────────────────────────────────────────────────────");
  lines.push("    object Motion {");
  for (const [key, value] of Object.entries(tokens.motion.duration)) {
    lines.push(`        const val ${key.toUpperCase()} = ${value}`);
  }
  lines.push("    }", "");

  // ── Layout
  lines.push("    // ── Layout ───────────────────────────────────────────────────────");
  lines.push("    object Layout {");
  lines.push(`        const val TOUCH_TARGET_MIN = ${tokens.layout.touchTargetMin}`);
  lines.push(`        const val MOBILE_GUTTER    = ${tokens.layout.mobileGutter}`);
  lines.push(`        const val MAX_WIDTH        = ${tokens.layout.maxContentWidth}`);
  lines.push("    }");

  lines.push("}", "");
  return lines.join("\n");
}

// ── 4. Swift ─────────────────────────────────────────────────────────
function generateSwift(): string {
  const lines: string[] = [
    "// Auto-generated from bytelyst.tokens.json — do not edit manually",
    "import SwiftUI",
    "",
    "// MARK: - MindLyst Design Tokens (from shared KMP MindLystTokens)",
    "// These values mirror MindLystTokens.kt exactly.",
    "",
    "struct MindLystColors {",
  ];

  // Dark colors
  lines.push("    // Dark");
  for (const [key, value] of Object.entries(tokens.color.semantic.dark)) {
    if (typeof value === "string" && value.startsWith("#")) {
      lines.push(`    static let dark${capitalize(key)} = Color(hex: ${hexToUInt(value)})`);
    } else if (typeof value === "string" && value.startsWith("rgba")) {
      // border/overlay → special handling
      if (key === "borderDefault") {
        lines.push("    static let darkBorder  = Color.white.opacity(0.12)");
      }
    }
  }
  lines.push("");

  // Light colors
  lines.push("    // Light");
  for (const [key, value] of Object.entries(tokens.color.semantic.light)) {
    if (typeof value === "string" && value.startsWith("#")) {
      if (value === "#FFFFFF") {
        lines.push(`    static let light${capitalize(key)} = Color.white`);
      } else {
        lines.push(`    static let light${capitalize(key)} = Color(hex: ${hexToUInt(value)})`);
      }
    }
  }
  lines.push("");

  // Brain gradients
  lines.push("    // Brain Gradients");
  for (const [name, grad] of Object.entries(tokens.color.brain) as [string, { from: string; to: string }][]) {
    lines.push(`    static let brain${capitalize(name)} = Gradient(colors: [Color(hex: ${hexToUInt(grad.from)}), Color(hex: ${hexToUInt(grad.to)})])`);
  }
  lines.push("}", "");

  // Spacing
  lines.push("struct MindLystSpacing {");
  for (const [key, value] of Object.entries(tokens.spacing)) {
    const pad = key.length === 1 ? " " : "";
    lines.push(`    static let x${key}: ${pad}CGFloat = ${value}`);
  }
  lines.push("}", "");

  // Radius
  lines.push("struct MindLystRadius {");
  for (const [key, value] of Object.entries(tokens.radius)) {
    const pad = key.length < 4 ? " ".repeat(4 - key.length) : "";
    lines.push(`    static let ${key}:${pad} CGFloat = ${value}`);
  }
  lines.push("}", "");

  // Motion (durations in seconds)
  lines.push("struct MindLystMotion {");
  for (const [key, value] of Object.entries(tokens.motion.duration)) {
    const seconds = (value as number) / 1000;
    const pad = key.length < 7 ? " ".repeat(7 - key.length) : "";
    lines.push(`    static let ${key}:${pad} Double = ${seconds.toFixed(2)}`);
  }
  lines.push("}", "");

  // Color hex extension
  lines.push("// MARK: - Color Hex Extension");
  lines.push("");
  lines.push("extension Color {");
  lines.push("    init(hex: UInt, alpha: Double = 1.0) {");
  lines.push("        self.init(");
  lines.push("            .sRGB,");
  lines.push("            red:   Double((hex >> 16) & 0xFF) / 255.0,");
  lines.push("            green: Double((hex >> 8)  & 0xFF) / 255.0,");
  lines.push("            blue:  Double(hex & 0xFF) / 255.0,");
  lines.push("            opacity: alpha");
  lines.push("        )");
  lines.push("    }");
  lines.push("}", "");

  return lines.join("\n");
}

// ── Write all ────────────────────────────────────────────────────────
writeFileSync(resolve(outDir, "tokens.css"), generateCSS());
writeFileSync(resolve(outDir, "tokens.ts"), generateTS());
writeFileSync(resolve(outDir, "MindLystTokens.kt"), generateKotlin());
writeFileSync(resolve(outDir, "MindLystTheme.swift"), generateSwift());

console.log("Generated 4 token files in generated/");