/**
 * Terminal markdown renderer.
 * Converts markdown text to chalk-formatted terminal output.
 */
import chalk from "chalk"

interface RenderOptions {
  maxWidth?: number
  indent?: string
}

export function renderMarkdown(text: string, options?: RenderOptions): string {
  const lines = text.split("\n")
  const result: string[] = []

  for (const line of lines) {
    result.push(renderLine(line, options))
  }

  return result.join("\n")
}

function renderLine(line: string, options?: RenderOptions): string {
  const trimmed = line.trimStart()

  // Headings
  if (trimmed.startsWith("###### ")) return chalk.bold.cyan(trimmed.slice(7))
  if (trimmed.startsWith("##### "))  return chalk.bold.cyan(trimmed.slice(6))
  if (trimmed.startsWith("#### "))   return chalk.bold.cyan(trimmed.slice(5))
  if (trimmed.startsWith("### "))    return chalk.bold.cyan(trimmed.slice(4))
  if (trimmed.startsWith("## "))     return chalk.bold.blue(trimmed.slice(3))
  if (trimmed.startsWith("# "))      return chalk.bold.white(trimmed.slice(2))

  // Code blocks
  if (trimmed.startsWith("```")) {
    return chalk.dim(trimmed)
  }

  // Blockquotes
  if (trimmed.startsWith("> ")) {
    return chalk.dim("│ " + renderInline(trimmed.slice(2)))
  }

  // Lists
  if (/^[-*+]\s/.test(trimmed)) {
    return chalk.cyan("•") + " " + renderInline(trimmed.slice(2))
  }
  if (/^\d+\.\s/.test(trimmed)) {
    const match = trimmed.match(/^(\d+\.)\s(.*)$/)
    if (match) return chalk.cyan(match[1]) + " " + renderInline(match[2])
  }

  // Horizontal rule
  if (/^[-*_]{3,}\s*$/.test(trimmed)) {
    return chalk.dim("─".repeat(options?.maxWidth ?? 60))
  }

  return renderInline(line)
}

function renderInline(text: string): string {
  // Bold
  text = text.replace(/\*\*(.+?)\*\*/g, (_, content) => chalk.bold(content))
  // Italic
  text = text.replace(/(?<!\*)\*(?!\*)(.+?)(?<!\*)\*(?!\*)/g, (_, content) => chalk.italic(content))
  // Inline code
  text = text.replace(/`([^`]+)`/g, (_, content) => chalk.bgBlackBright(content))
  // Links
  text = text.replace(/\[([^\]]+)\]\(([^)]+)\)/g, (_, label, url) => chalk.blue.underline(label) + chalk.dim(` (${url})`))

  return text
}

export function renderCodeBlock(code: string, language?: string): string {
  const header = language ? chalk.dim(`─ ${language} ─`) : ""
  const lines = code.split("\n").map((line, i) => {
    const num = String(i + 1).padStart(4)
    return chalk.dim(`${num} │`) + ` ${line}`
  })
  return header + (header ? "\n" : "") + lines.join("\n")
}

export function renderTable(headers: string[], rows: string[][]): string {
  const colWidths = headers.map((h, i) => {
    const maxDataLen = Math.max(...rows.map((r) => (r[i] ?? "").length))
    return Math.max(h.length, maxDataLen) + 2
  })

  const headerLine = headers.map((h, i) => chalk.bold(h.padEnd(colWidths[i]))).join("")
  const separator = colWidths.map((w) => chalk.dim("─".repeat(w))).join(chalk.dim("─"))
  const dataLines = rows.map((row) =>
    row.map((cell, i) => (cell ?? "").padEnd(colWidths[i])).join(""),
  )

  return [headerLine, separator, ...dataLines].join("\n")
}