using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Ink;
using Ink.Runtime;

namespace inklecate_wasm {
  class HackedCommandLinePlayer {
    public Story story { get; protected set; }
    public bool autoPlay { get; set; }
    public bool keepOpenAfterStoryFinish { get; set; }

    public HackedCommandLinePlayer(
        Story story,
        bool autoPlay = false,
        Compiler compiler = null,
        bool keepOpenAfterStoryFinish = false
    ) {
      this.story = story;
      this.autoPlay = autoPlay;
      _compiler = compiler;
      this.keepOpenAfterStoryFinish = keepOpenAfterStoryFinish;
    }

    public void Begin() {
      EvaluateStory();

      var rand = new Random();

      while (story.currentChoices.Count > 0 || this.keepOpenAfterStoryFinish) {
        var choices = story.currentChoices;

        var choiceIdx = 0;
        bool choiceIsValid = false;
        string userDivertedPath = null;

        if (autoPlay) {
          // autoPlay: Pick random choice
          choiceIdx = rand.Next() % choices.Count;
        } else {
          // Normal: Ask user for choice number
          Console.ForegroundColor = ConsoleColor.Blue;

          // Add extra newline to ensure that the choice is
          // on a separate line.
          Console.WriteLine();

          int i = 1;
          foreach (Choice choice in choices) {
            Console.WriteLine("{0}: {1}", i, choice.text);
            i++;
          } do {
            // Prompt
            Console.Write("?> ");
            string userInput = Console.ReadLine();

            // If we have null user input, it means that we're
            // "at the end of the stream", or in other words, the input
            // stream has closed, so there's nothing more we can do.
            // We return immediately, since otherwise we get into a busy
            // loop waiting for user input.
            if (userInput == null) {
              Console.WriteLine("<User input stream closed.>");
              return;
            }

            var result = _compiler.ReadCommandLineInput(userInput);

            if (result.output != null) {
              Console.WriteLine(result.output);
            }

            if (result.requestsExit) {
              return;
            } else if (result.divertedPath != null) {
              userDivertedPath = result.divertedPath;
            }

            if (result.choiceIdx >= 0) {
              if (result.choiceIdx >= choices.Count) {
                Console.WriteLine("Choice out of range");
              } else {
                choiceIdx = result.choiceIdx;
                choiceIsValid = true;
              }
            }
          } while (!choiceIsValid && userDivertedPath == null);
        }

        Console.ResetColor();

        if (choiceIsValid) {
          story.ChooseChoiceIndex(choiceIdx);
        } else if (userDivertedPath != null) {
          story.ChoosePathString(userDivertedPath);
          userDivertedPath = null;
        }

        EvaluateStory();
      }
    }

    void EvaluateStory() {
      while (story.canContinue) {
        story.Continue();

        _compiler.RetrieveDebugSourceForLatestContent();

        Console.Write(story.currentText);

        var tags = story.currentTags;
        if (tags.Count > 0) {
          Console.WriteLine("# tags: " + string.Join(", ", tags));
        }

        if (story.hasError) {
          foreach (var errorMsg in story.currentErrors) {
            Console.WriteLine(errorMsg, ConsoleColor.Red);
          }
        }

        if (story.hasWarning)  {
          foreach (var warningMsg in story.currentWarnings) {
            Console.WriteLine(warningMsg, ConsoleColor.Blue);
          }
        }

        story.ResetErrors();
      }

      if (story.currentChoices.Count == 0 && keepOpenAfterStoryFinish) {
        Console.WriteLine("--- End of story ---");
      }
    }
    Compiler _compiler;
  }
}