export interface FrontmatterResult {
  frontmatter: Record<string, unknown>
  body: string
}

export function parseFrontmatter(content: string): FrontmatterResult {
  const trimmed = content.trimStart()

  if (!trimmed.startsWith("---")) {
    return { frontmatter: {}, body: content }
  }

  const endMatch = trimmed.indexOf("---", 3)
  if (endMatch === -1 || endMatch < 4) {
    return { frontmatter: {}, body: content }
  }

  const frontmatterStr = trimmed.slice(3, endMatch).trim()
  const body = trimmed.slice(endMatch + 3).trimStart()

  const frontmatter: Record<string, unknown> = {}
  for (const line of frontmatterStr.split("\n")) {
    const colonIdx = line.indexOf(":")
    if (colonIdx === -1) continue
    const key = line.slice(0, colonIdx).trim()
    let value: unknown = line.slice(colonIdx + 1).trim()

    if (typeof value === "string") {
      if (value === "true") value = true
      else if (value === "false") value = false
      else if (/^\d+$/.test(value)) value = Number(value)
      else if (value.startsWith("[") && value.endsWith("]")) {
        value = value
          .slice(1, -1)
          .split(",")
          .map((s) => s.trim())
          .filter(Boolean)
      } else {
        value = value.replace(/^["']|["']$/g, "")
      }
    }

    frontmatter[key] = value
  }

  return { frontmatter, body }
}