import dedent from "dedent"

import type { Formatters } from "../types"

export const isObject = (v: unknown): boolean =>
  typeof v === "object" && v !== null && !Array.isArray(v) && !(v instanceof Date)

export const formatObject = (
  value: unknown,
  llml: (data: unknown, formatters: Formatters) => string,
  formatters: Formatters,
): string => {
  // Check if object has a custom toString method (not the default Object.prototype.toString)
  if (value && typeof value.toString === "function" && value.toString !== Object.prototype.toString) {
    return value.toString()
  }

  const entries = Object.entries(value as Record<string, unknown>)
  if (entries.length === 0) {
    // Plain empty objects should return empty string
    // Other objects with no enumerable properties should use String(value)
    if (Object.getPrototypeOf(value) === Object.prototype) {
      return ""
    }
    return String(value)
  }
  const results: string[] = []

  for (let i = 0; i < entries.length; i++) {
    const [key, val] = entries[i]

    if (i > 0) results.push("\n")

    // Format key-value pair with proper XML structure
    const formattedContent = formatKeyValue(key, val, llml, formatters)
    results.push(formattedContent)
  }

  return results.join("")
}

/**
 * Helper function to format key-value pairs in VibeXML style
 */
function formatKeyValue(
  key: string,
  value: unknown,
  llml: (data: unknown, formatters: Formatters) => string,
  formatters: Formatters,
): string {
  if (Array.isArray(value)) {
    if (value.length === 0) return ""

    const wrapperTag = key
    let result = `<${wrapperTag}>\n`

    for (let i = 0; i < value.length; i++) {
      const item = value[i]
      const itemTag = `${key}-${i + 1}`

      if (typeof item === "object" && item !== null && !Array.isArray(item)) {
        const itemFormatted = llml(item, formatters)
        if (itemFormatted.includes("\n")) {
          result += `  <${itemTag}>\n`
          const indentedContent = itemFormatted
            .split("\n")
            .map(line => (line ? `    ${line}` : ""))
            .join("\n")
          result += indentedContent
          result += `\n  </${itemTag}>\n`
        } else {
          result += `  <${itemTag}>${itemFormatted}</${itemTag}>\n`
        }
      } else {
        if (typeof item === "string" && item.includes("\n")) {
          const cleanText = dedent(item).trim()
          const lines = cleanText.split("\n")
          result += `  <${itemTag}>`
          for (let j = 0; j < lines.length; j++) {
            if (j > 0) {
              result += "\n  "
            } else {
              result += "  "
            }
            result += lines[j]
          }
          result += `</${itemTag}>\n`
        } else {
          const formatted = llml(item, formatters)
          result += `  <${itemTag}>${formatted}</${itemTag}>\n`
        }
      }
    }

    result += `</${wrapperTag}>`
    return result
  }

  if (typeof value === "object" && value !== null) {
    const formatted = llml(value, formatters)
    if (formatted.includes("\n")) {
      const indentedContent = formatted
        .split("\n")
        .map(line => (line ? `  ${line}` : ""))
        .join("\n")
      return `<${key}>\n${indentedContent}\n</${key}>`
    }

    return `<${key}>${formatted}</${key}>`
  }

  if (typeof value === "string" && value.includes("\n")) {
    const cleanText = dedent(value).trim()
    const lines = cleanText.split("\n")
    const formattedLines = lines.map(line => `  ${line}`)
    const formattedContent = formattedLines.join("\n")
    return `<${key}>\n${formattedContent}\n</${key}>`
  }

  const formatted = llml(value, formatters)
  return `<${key}>${formatted}</${key}>`
}