"use strict";

/** A DokployClient stand-in that records calls and replays canned answers. */
class FakeApi {
  /**
   * @param {object} handlers Procedure name -> value, or (input, call) => value.
   *   A value may be a function returning a promise, or an array consumed one
   *   entry per call so a poller can see a status change.
   */
  constructor(handlers = {}) {
    this.handlers = handlers;
    this.calls = [];
    this.counts = {};
  }

  #dispatch(kind, procedure, input) {
    this.calls.push({ kind, procedure, input });
    const index = (this.counts[procedure] = (this.counts[procedure] ?? 0) + 1) - 1;

    if (!(procedure in this.handlers)) {
      throw new Error(`FakeApi: unexpected ${kind} ${procedure}`);
    }
    const handler = this.handlers[procedure];
    if (typeof handler === "function") return Promise.resolve(handler(input, index));
    if (Array.isArray(handler) && handler.__sequence) {
      return Promise.resolve(handler[Math.min(index, handler.length - 1)]);
    }
    return Promise.resolve(handler);
  }

  query(procedure, input) {
    return this.#dispatch("query", procedure, input);
  }

  mutate(procedure, input) {
    return this.#dispatch("mutate", procedure, input);
  }

  procedures() {
    return this.calls.map((call) => call.procedure);
  }

  find(procedure) {
    return this.calls.find((call) => call.procedure === procedure);
  }
}

/** Marks an array as "one entry per call" rather than a literal return value. */
function sequence(values) {
  const copy = [...values];
  copy.__sequence = true;
  return copy;
}

/** A clock that only moves when something sleeps, so tests never really wait. */
function fakeClock(start = 0) {
  let current = start;
  return {
    now: () => current,
    sleep: async (ms) => {
      current += Math.max(ms, 1);
    },
    advance: (ms) => {
      current += ms;
    },
  };
}

function collectingLog() {
  const lines = [];
  return {
    lines,
    info: (message) => lines.push(`info: ${message}`),
    warning: (message) => lines.push(`warning: ${message}`),
  };
}

module.exports = { FakeApi, sequence, fakeClock, collectingLog };