// Name: Replace Colors with Hex
// Description: Finds colors in text (rgb, rgba, hsl, lab, lch, oklab, oklch, color(), hex) and replaces them with closest #RRGGBB.
// Author: ScottGuthart
// GitHub: ScottGuthart

import "@johnlindquist/kit"
import Color from "colorjs.io"

const compositeOnWhite = (srgb: Color) => {
  // srgb coords in [0..1]
  const a = typeof srgb.alpha === "number" ? srgb.alpha : 1
  const c = srgb.to("srgb").toGamut({ space: "srgb" })
  const [r, g, b] = c.coords as [number, number, number]
  const blend = (v: number) => Math.max(0, Math.min(1, a * v + (1 - a) * 1))
  const toHex = (v: number) => {
    const i = Math.round(blend(v) * 255)
    return i.toString(16).padStart(2, "0")
  }
  return `#${toHex(r)}${toHex(g)}${toHex(b)}`.toLowerCase()
}

const tryToHex = (raw: string): string | null => {
  try {
    // Normalize common typo "okch(" -> "oklch("
    const s = raw.replace(/\bokch\s*\(/i, "oklch(")
    const parsed = Color.parse(s)
    if (!parsed) return null
    // Convert to srgb and then composite any alpha over white
    const srgb = parsed.to("srgb")
    return compositeOnWhite(srgb)
  } catch {
    return null
  }
}

// Match common CSS color notations and hexes
// Note: Simple, pragmatic matcher (not a full CSS parser)
const colorRegex =
  /#[0-9a-fA-F]{3,8}\b|\b(?:rgb|rgba|hsl|hsla|hwb|lab|lch|oklab|oklch|okch|color)\((?:[^)(]|\((?:[^)(]|\([^)(]*\))*\))*\)/g

let selected = ""
try {
  selected = await getSelectedText()
} catch {}

/**
 * Get input text from selection or editor
 */
let input = selected?.trim()
if (!input) {
  input = await editor({
    value: "",
    language: "md",
    hint: "Paste text to convert colors to hex, then press Cmd+S or Enter",
    footer: "All detected colors will be converted to #RRGGBB (alpha composited over white)",
  })
}

let count = 0
const output = input.replace(colorRegex, m => {
  const hex = tryToHex(m)
  if (hex) {
    count++
    return hex
  }
  return m
})

if (selected) {
  await setSelectedText(output)
  await toast(`Converted ${count} color${count === 1 ? "" : "s"} to hex`)
} else {
  await editor({
    value: output,
    language: "md",
    hint: `Converted ${count} color${count === 1 ? "" : "s"} to hex`,
    footer: "Result shown above. Copy/paste as needed.",
  })
}