import 'dart:convert';
import 'dart:io';
import 'dart:math';

import 'package:dio/dio.dart' as dio_lib;

var dio = dio_lib.Dio();

// Load mastodon instance url from env
final instanceUrl = Platform.environment['INSTANCE_URL'];
// Load mastodon auth token from env
final authToken = Platform.environment['MASTODON_TOKEN'];

Future<void> _postOnMastodon(String postText, bool isHorny) async {
  await dio.post('$instanceUrl/api/v1/statuses',
      data: {
        'status': postText,
        if (isHorny) 'sensitive': true,
        if (isHorny) 'spoiler_text': 'NSFW'
      },
      options:
          dio_lib.Options(headers: {'Authorization': 'Bearer $authToken'}));
}

/// Reads a file [fileUri] and adds posts to posts.json
///
/// If [fileUri] does not exist, do nothing.
/// [fileUri] is a plain text file where the posts are separated by empty lines.
/// posts.json is an array of posts
Future<void> _importPosts(String fileUri, String outputFile) async {
  if (!File(fileUri).existsSync()) {
    return;
  }

  final file = File(fileUri);
  final lines = await file.readAsLines();

  final List<String> posts = [];
  String post = '';

  for (final line in lines) {
    if (line.isEmpty && post != '') {
      posts.add(post);
      print('Added post: $post');
      post = '';
    } else {
      post += '$line\n';
    }
  }

  if (post != '') {
    posts.add(post);
    print('Added post: $post');
  }

  // Read posts.json and add posts to it
  final postsJson = json.decode(await File('/data/$outputFile').readAsString());
  postsJson.addAll(posts);

  // Write posts.json
  await File('/data/$outputFile').writeAsString(json.encode(postsJson));

  // Delete file
  await file.delete();

  return;
}

/// Posts a random string from posts.json to mastodon
///
/// If posts.json does not exist, do nothing.
/// posts.json is an array of posts
/// If an array is empty, do nothing.
/// Delete posted post from posts.json
Future<void> _postRandomPost() async {
  if (!File('/data/posts.json').existsSync()) {
    return;
  }
  if (!File('/data/horny.json').existsSync()) {
    return;
  }

  bool isHorny = false;

  final postsJson = json.decode(await File('/data/posts.json').readAsString());
  final hornyPostsJson =
      json.decode(await File('/data/horny.json').readAsString());

  if (postsJson.isEmpty && hornyPostsJson.isEmpty) {
    return;
  }
  if (postsJson.isEmpty) {
    isHorny = true;
  } else if (hornyPostsJson.isEmpty) {
    isHorny = false;
  } else {
    // 30% chance of being horny
    isHorny = Random().nextInt(3) == 0;
  }

  final post = isHorny
      ? hornyPostsJson.removeAt(Random().nextInt(hornyPostsJson.length))
      : postsJson.removeAt(Random().nextInt(postsJson.length));

  if (isHorny) {
    await File('/data/horny.json').writeAsString(json.encode(hornyPostsJson));
  } else {
    await File('/data/posts.json').writeAsString(json.encode(postsJson));
  }

  await _postOnMastodon(post, isHorny);

  return;
}

void main(List<String> args) async {
  // If posts.json does not exist, create it and write an empty array
  if (!File('/data/posts.json').existsSync()) {
    await File('/data/posts.json').writeAsString(json.encode([]));
  }

  if (!File('/data/horny.json').existsSync()) {
    await File('/data/horny.json').writeAsString(json.encode([]));
  }

  // Import posts from files
  await _importPosts('/data/posts.txt', 'posts.json');
  await _importPosts('/data/horny.txt', 'horny.json');

  // Post a random post
  await _postRandomPost();

  // Post a random post at random time
  // Random time is between 1 and 8 hours
  // Random time is choosen after every post
  while (true) {
    await Future.delayed(Duration(minutes: Random().nextInt(60 * 5) + 10));
    await _importPosts('/data/posts.txt', 'posts.json');
    await _importPosts('/data/horny.txt', 'horny.json');
    await _postRandomPost();
  }
}