/* Core of picomath: generates an instance */
import poortf from './poortf.js'

export default function picomathInstance (instName, config) {
   /* Since we have to do it all the time, when we call a picomath instance
    * as a function, it takes a name and 0 or more implementations add adds
    * them to its poortf property named name, returning that property value.
    */
   function fn (name, imps, author, data) {
      if (name in fn) {
         fn[name].addImps(imps, author, data)
      } else {
         fn[name] = poortf(name, imps, author, data)
      }
      /* For PoC, just assume only reason to provide author info
       * is to be invalidated when config changes
       */
      if (author) {
         if (!fn.configUsers.has(author)) {
            fn.configUsers.set(author, new Set())
         }
         fn.configUsers.get(author).add(name)
      }
      return fn[name]
   }

   Object.defineProperty(fn, 'name', {value: instName})
   // There is an issue below of possible collision between the following
   // property names and operation names. Since it would not be too hard to
   // solve, we won't worry about it in this PoC.
   fn.config = config || { resolveComplex: false } // primitive default for POC
   fn.configUsers = new Map()
   fn.reconfigure = config => {
      for (const [author, names] of fn.configUsers.entries()) {
         for (const name of names) {
            fn[name].invalidate(author)
         }
      }
      fn.config = config
   }
   return fn
}