import { ObservableSeedBase, ObservableSeedImpl } from "./observable"

export function toString(obj: any): string {
  var hasProp = {}.hasOwnProperty
  try {
    recursionDepth++
    if (obj instanceof ObservableSeedBase) {
      return toString(obj.desc)
    } else if (obj == null) {
      return "undefined"
    } else if (obj instanceof Function) {
      return "fn"
    } else if (obj instanceof Array) {
      if (recursionDepth > 5) {
        return "[..]"
      }
      return "[" + obj.map(toString).toString() + "]"
    } else if (obj.toString && obj.constructor !== Object) {
      return obj.toString()
    } else if (typeof obj === "object") {
      if (recursionDepth > 5) {
        return "{..}"
      }
      var results: string[] = []
      for (var key in obj) {
        if (!hasProp.call(obj, key)) continue
        let value = (function () {
          try {
            return obj[key]
          } catch (error) {
            return error
          }
        })()
        results.push(toString(key) + ":" + toString(value))
      }
      return "{" + results + "}"
    } else {
      return obj
    }
  } finally {
    recursionDepth--
  }
}

let recursionDepth = 0