// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'dart:async';
import 'dart:convert';

import 'package:convert/convert.dart';
import 'package:test/test.dart';

void main() {
  group("encoder", () {
    test("doesn't percent-encode unreserved characters", () {
      var safeChars = "abcdefghijklmnopqrstuvwxyz"
          "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
          "0123456789-._~";
      expect(percent.encode([...safeChars.codeUnits]), equals(safeChars));
    });

    test("percent-encodes reserved ASCII characters", () {
      expect(percent.encode([..." `{@[,/^}\x7f\x00%".codeUnits]),
          equals("%20%60%7B%40%5B%2C%2F%5E%7D%7F%00%25"));
    });

    test("percent-encodes non-ASCII characters", () {
      expect(percent.encode([0x80, 0xFF]), equals("%80%FF"));
    });

    test("mixes encoded and unencoded characters", () {
      expect(percent.encode([..."a+b=\x80".codeUnits]), equals("a%2Bb%3D%80"));
    });

    group("with chunked conversion", () {
      test("percent-encodes byte arrays", () {
        var results = <String>[];
        var controller = StreamController<String>(sync: true);
        controller.stream.listen(results.add);
        var sink = percent.encoder.startChunkedConversion(controller.sink);

        sink.add([..."a+b=\x80".codeUnits]);
        expect(results, equals(["a%2Bb%3D%80"]));

        sink.add([0x00, 0x01, 0xfe, 0xff]);
        expect(results, equals(["a%2Bb%3D%80", "%00%01%FE%FF"]));
      });

      test("handles empty and single-byte lists", () {
        var results = <String>[];
        var controller = StreamController<String>(sync: true);
        controller.stream.listen(results.add);
        var sink = percent.encoder.startChunkedConversion(controller.sink);

        sink.add([]);
        expect(results, equals([""]));

        sink.add([0x00]);
        expect(results, equals(["", "%00"]));

        sink.add([]);
        expect(results, equals(["", "%00", ""]));
      });
    });

    test("rejects non-bytes", () {
      expect(() => percent.encode([0x100]), throwsFormatException);

      var sink =
          percent.encoder.startChunkedConversion(StreamController(sync: true));
      expect(() => sink.add([0x100]), throwsFormatException);
    });
  });

  group("decoder", () {
    test("converts percent-encoded strings to byte arrays", () {
      expect(
          percent.decode("a%2Bb%3D%801"), equals([..."a+b=\x801".codeUnits]));
    });

    test("supports lowercase letters", () {
      expect(percent.decode("a%2bb%3d%80"), equals([..."a+b=\x80".codeUnits]));
    });

    test("supports more aggressive encoding", () {
      expect(percent.decode("%61%2E%5A"), equals([..."a.Z".codeUnits]));
    });

    test("supports less aggressive encoding", () {
      var chars = " `{@[,/^}\x7F\x00";
      expect(percent.decode(chars), equals([...chars.codeUnits]));
    });

    group("with chunked conversion", () {
      late List<List<int>> results;
      late StringConversionSink sink;
      setUp(() {
        results = [];
        var controller = StreamController<List<int>>(sync: true);
        controller.stream.listen(results.add);
        sink = percent.decoder.startChunkedConversion(controller.sink);
      });

      test("converts percent to byte arrays", () {
        sink.add("a%2Bb%3D%801");
        expect(
            results,
            equals([
              [..."a+b=\x801".codeUnits]
            ]));

        sink.add("%00%01%FE%FF");
        expect(
            results,
            equals([
              [..."a+b=\x801".codeUnits],
              [0x00, 0x01, 0xfe, 0xff]
            ]));
      });

      test("supports trailing percents and digits split across chunks", () {
        sink.add("ab%");
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));

        sink.add("2");
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));

        sink.add("0cd%2");
        expect(
            results,
            equals([
              [..."ab".codeUnits],
              [..." cd".codeUnits]
            ]));

        sink.add("0");
        expect(
            results,
            equals(([
              [..."ab".codeUnits],
              [..." cd".codeUnits],
              [..." ".codeUnits]
            ])));
      });

      test("supports empty strings", () {
        sink.add("");
        expect(results, isEmpty);

        sink.add("%");
        expect(results, equals([[]]));

        sink.add("");
        expect(results, equals([[]]));

        sink.add("2");
        expect(results, equals([[]]));

        sink.add("");
        expect(results, equals([[]]));

        sink.add("0");
        expect(
            results,
            equals([
              [],
              [0x20]
            ]));
      });

      test("rejects dangling % detected in close()", () {
        sink.add("ab%");
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));
        expect(() => sink.close(), throwsFormatException);
      });

      test("rejects dangling digit detected in close()", () {
        sink.add("ab%2");
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));
        expect(() => sink.close(), throwsFormatException);
      });

      test("rejects danging % detected in addSlice()", () {
        sink.addSlice("ab%", 0, 3, false);
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));

        expect(() => sink.addSlice("ab%", 0, 3, true), throwsFormatException);
      });

      test("rejects danging digit detected in addSlice()", () {
        sink.addSlice("ab%2", 0, 3, false);
        expect(
            results,
            equals([
              [..."ab".codeUnits]
            ]));

        expect(() => sink.addSlice("ab%2", 0, 3, true), throwsFormatException);
      });
    });

    group("rejects non-ASCII character", () {
      for (var char in ["\u0141", "\u{10041}"]) {
        test('"$char"', () {
          expect(() => percent.decode("a$char"), throwsFormatException);
          expect(() => percent.decode("${char}a"), throwsFormatException);

          var sink = percent.decoder
              .startChunkedConversion(StreamController(sync: true));
          expect(() => sink.add(char), throwsFormatException);
        });
      }
    });

    test("rejects % followed by non-hex", () {
      expect(() => percent.decode("%z2"), throwsFormatException);
      expect(() => percent.decode("%2z"), throwsFormatException);
    });

    test("rejects dangling % detected in convert()", () {
      expect(() => percent.decode("ab%"), throwsFormatException);
    });

    test("rejects dangling digit detected in convert()", () {
      expect(() => percent.decode("ab%2"), throwsFormatException);
    });
  });
}