import 'dart:convert';

import 'package:easy_localization/easy_localization.dart';
import 'package:html/parser.dart';
import 'package:http/http.dart';
import 'package:obtainium/components/generated_form.dart';
import 'package:obtainium/custom_errors.dart';
import 'package:obtainium/providers/source_provider.dart';

class FDroid extends AppSource {
  FDroid() {
    host = 'f-droid.org';
    name = tr('fdroid');
    canSearch = true;
    additionalSourceAppSpecificSettingFormItems = [
      [
        GeneratedFormTextField('filterVersionsByRegEx',
            label: tr('filterVersionsByRegEx'),
            required: false,
            additionalValidators: [
              (value) {
                return regExValidator(value);
              }
            ])
      ],
      [
        GeneratedFormSwitch('trySelectingSuggestedVersionCode',
            label: tr('trySelectingSuggestedVersionCode'))
      ],
      [
        GeneratedFormSwitch('autoSelectHighestVersionCode',
            label: tr('autoSelectHighestVersionCode'))
      ],
    ];
  }

  @override
  String sourceSpecificStandardizeURL(String url) {
    RegExp standardUrlRegExB =
        RegExp('^https?://$host/+[^/]+/+packages/+[^/]+');
    RegExpMatch? match = standardUrlRegExB.firstMatch(url.toLowerCase());
    if (match != null) {
      url =
          'https://${Uri.parse(url.substring(0, match.end)).host}/packages/${Uri.parse(url).pathSegments.last}';
    }
    RegExp standardUrlRegExA = RegExp('^https?://$host/+packages/+[^/]+');
    match = standardUrlRegExA.firstMatch(url.toLowerCase());
    if (match == null) {
      throw InvalidURLError(name);
    }
    return url.substring(0, match.end);
  }

  @override
  Future<String?> tryInferringAppId(String standardUrl,
      {Map<String, dynamic> additionalSettings = const {}}) async {
    return Uri.parse(standardUrl).pathSegments.last;
  }

  @override
  Future<APKDetails> getLatestAPKDetails(
    String standardUrl,
    Map<String, dynamic> additionalSettings,
  ) async {
    String? appId = await tryInferringAppId(standardUrl);
    String host = Uri.parse(standardUrl).host;
    return getAPKUrlsFromFDroidPackagesAPIResponse(
        await sourceRequest('https://$host/api/v1/packages/$appId'),
        'https://$host/repo/$appId',
        standardUrl,
        name,
        autoSelectHighestVersionCode:
            additionalSettings['autoSelectHighestVersionCode'] == true,
        trySelectingSuggestedVersionCode:
            additionalSettings['trySelectingSuggestedVersionCode'] == true,
        filterVersionsByRegEx:
            (additionalSettings['filterVersionsByRegEx'] as String?)
                        ?.isNotEmpty ==
                    true
                ? additionalSettings['filterVersionsByRegEx']
                : null);
  }

  @override
  Future<Map<String, List<String>>> search(String query,
      {Map<String, dynamic> querySettings = const {}}) async {
    Response res = await sourceRequest(
        'https://search.$host/?q=${Uri.encodeQueryComponent(query)}');
    if (res.statusCode == 200) {
      Map<String, List<String>> urlsWithDescriptions = {};
      parse(res.body).querySelectorAll('.package-header').forEach((e) {
        String? url = e.attributes['href'];
        if (url != null) {
          try {
            standardizeUrl(url);
          } catch (e) {
            url = null;
          }
        }
        if (url != null) {
          urlsWithDescriptions[url] = [
            e.querySelector('.package-name')?.text.trim() ?? '',
            e.querySelector('.package-summary')?.text.trim() ??
                tr('noDescription')
          ];
        }
      });
      return urlsWithDescriptions;
    } else {
      throw getObtainiumHttpError(res);
    }
  }
}

APKDetails getAPKUrlsFromFDroidPackagesAPIResponse(
    Response res, String apkUrlPrefix, String standardUrl, String sourceName,
    {bool autoSelectHighestVersionCode = false,
    bool trySelectingSuggestedVersionCode = false,
    String? filterVersionsByRegEx}) {
  if (res.statusCode == 200) {
    var response = jsonDecode(res.body);
    List<dynamic> releases = response['packages'] ?? [];
    if (releases.isEmpty) {
      throw NoReleasesError();
    }
    String? version;
    Iterable<dynamic> releaseChoices = [];
    // Grab the versionCode suggested if the user chose to do that
    // Only do so at this stage if the user has no release filter
    if (trySelectingSuggestedVersionCode &&
        response['suggestedVersionCode'] != null &&
        filterVersionsByRegEx == null) {
      var suggestedReleases = releases.where((element) =>
          element['versionCode'] == response['suggestedVersionCode']);
      if (suggestedReleases.isNotEmpty) {
        releaseChoices = suggestedReleases;
        version = suggestedReleases.first['versionName'];
      }
    }
    // Apply the release filter if any
    if (filterVersionsByRegEx != null) {
      version = null;
      releaseChoices = [];
      for (var i = 0; i < releases.length; i++) {
        if (RegExp(filterVersionsByRegEx)
            .hasMatch(releases[i]['versionName'])) {
          version = releases[i]['versionName'];
        }
      }
      if (version == null) {
        throw NoVersionError();
      }
    }
    // Default to the highest version
    version ??= releases[0]['versionName'];
    if (version == null) {
      throw NoVersionError();
    }
    // If a suggested release was not already picked, pick all those with the selected version
    if (releaseChoices.isEmpty) {
      releaseChoices =
          releases.where((element) => element['versionName'] == version);
    }
    // For the remaining releases, use the toggles to auto-select one if possible
    if (releaseChoices.length > 1) {
      if (autoSelectHighestVersionCode) {
        releaseChoices = [releaseChoices.first];
      } else if (trySelectingSuggestedVersionCode &&
          response['suggestedVersionCode'] != null) {
        var suggestedReleases = releaseChoices.where((element) =>
            element['versionCode'] == response['suggestedVersionCode']);
        if (suggestedReleases.isNotEmpty) {
          releaseChoices = suggestedReleases;
        }
      }
    }
    if (releaseChoices.isEmpty) {
      throw NoReleasesError();
    }
    List<String> apkUrls = releaseChoices
        .map((e) => '${apkUrlPrefix}_${e['versionCode']}.apk')
        .toList();
    return APKDetails(version, getApkUrlsFromUrls(apkUrls),
        AppNames(sourceName, Uri.parse(standardUrl).pathSegments.last));
  } else {
    throw getObtainiumHttpError(res);
  }
}