// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Linq;
using System.Text.RegularExpressions;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Rewrite.Internal;
using Microsoft.AspNetCore.Rewrite.Internal.IISUrlRewrite;
using Microsoft.AspNetCore.Rewrite.Internal.PatternSegments;
using Microsoft.Extensions.Logging.Abstractions;
using Xunit;

namespace Microsoft.AspNetCore.Rewrite.Tests.UrlRewrite
{
    public class InputParserTests
    {
        [Fact]
        public void InputParser_ParseLiteralString()
        {
            var testString = "hello/hey/what";
            var result = new InputParser().ParseInputString(testString, UriMatchPart.Path);
            Assert.Equal(1, result.PatternSegments.Count);
        }

        [Theory]
        [InlineData("foo/bar/{R:1}/what", 3)]
        [InlineData("foo/{R:1}", 2)]
        [InlineData("foo/{R:1}/{C:2}", 4)]
        [InlineData("foo/{R:1}{C:2}", 3)]
        [InlineData("foo/", 1)]
        public void InputParser_ParseStringWithBackReference(string testString, int expected)
        {
            var result = new InputParser().ParseInputString(testString, UriMatchPart.Path);
            Assert.Equal(expected, result.PatternSegments.Count);
        }

        // Test actual evaluation of the types, verifying the correct string comes from the evalation
        [Theory]
        [InlineData("hey/hello/what", "hey/hello/what")]
        [InlineData("hey/{R:1}/what", "hey/foo/what")]
        [InlineData("hey/{R:2}/what", "hey/bar/what")]
        [InlineData("hey/{R:3}/what", "hey/baz/what")]
        [InlineData("hey/{C:1}/what", "hey/foo/what")]
        [InlineData("hey/{C:2}/what", "hey/bar/what")]
        [InlineData("hey/{C:3}/what", "hey/baz/what")]
        [InlineData("hey/{R:1}/{C:1}", "hey/foo/foo")]
        public void EvaluateBackReferenceRule(string testString, string expected)
        {
            var middle = new InputParser().ParseInputString(testString, UriMatchPart.Path);
            var result = middle.Evaluate(CreateTestRewriteContext(), CreateTestRuleBackReferences(), CreateTestCondBackReferences());
            Assert.Equal(expected, result);
        }

        [Theory]
        [InlineData("hey/{ToLower:HEY}", "hey/hey")]
        [InlineData("hey/{ToLower:{R:1}}", "hey/foo")]
        [InlineData("hey/{ToLower:{C:1}}", "hey/foo")]
        [InlineData("hey/{ToLower:{C:1}/what}", "hey/foo/what")]
        [InlineData("hey/ToLower:/what", "hey/ToLower:/what")]
        public void EvaluatToLowerRule(string testString, string expected)
        {
            var middle = new InputParser().ParseInputString(testString, UriMatchPart.Path);
            var result = middle.Evaluate(CreateTestRewriteContext(), CreateTestRuleBackReferences(), CreateTestCondBackReferences());
            Assert.Equal(expected, result);
        }

        [Theory]
        [InlineData("hey/{UrlEncode:<hey>}", "hey/%3Chey%3E")]
        public void EvaluatUriEncodeRule(string testString, string expected)
        {
            var middle = new InputParser().ParseInputString(testString, UriMatchPart.Path);
            var result = middle.Evaluate(CreateTestRewriteContext(), CreateTestRuleBackReferences(), CreateTestCondBackReferences());
            Assert.Equal(expected, result);
        }

        [Theory]
        [InlineData("{")]
        [InlineData("{:}")]
        [InlineData("{R:")]
        [InlineData("{R:1")]
        [InlineData("{R:A}")]
        [InlineData("{R:10}")]
        [InlineData("{R:-1}")]
        [InlineData("{foo:1")]
        [InlineData("{UrlEncode:{R:}}")]
        [InlineData("{UrlEncode:{R:1}")]
        [InlineData("{HTTPS")]
        public void FormatExceptionsOnBadSyntax(string testString)
        {
            Assert.Throws<FormatException>(() => new InputParser().ParseInputString(testString, UriMatchPart.Path));
        }

        [Fact]
        public void Should_throw_FormatException_if_no_rewrite_maps_are_defined()
        {
            Assert.Throws<FormatException>(() => new InputParser(null).ParseInputString("{apiMap:{R:1}}", UriMatchPart.Path));
        }

        [Fact]
        public void Should_throw_FormatException_if_rewrite_map_not_found()
        {
            const string definedMapName = "testMap";
            const string undefinedMapName = "apiMap";
            var map = new IISRewriteMap(definedMapName);
            var maps = new IISRewriteMapCollection { map };
            Assert.Throws<FormatException>(() => new InputParser(maps).ParseInputString($"{{{undefinedMapName}:{{R:1}}}}", UriMatchPart.Path));
        }

        [Fact]
        public void Should_parse_RewriteMapSegment_and_successfully_evaluate_result()
        {
            const string expectedMapName = "apiMap";
            const string expectedKey = "api.test.com";
            const string expectedValue = "test.com/api";
            var map = new IISRewriteMap(expectedMapName);
            map[expectedKey] = expectedValue;
            var maps = new IISRewriteMapCollection { map };

            var inputString = $"{{{expectedMapName}:{{R:1}}}}";
            var pattern = new InputParser(maps).ParseInputString(inputString, UriMatchPart.Path);
            Assert.Equal(1, pattern.PatternSegments.Count);

            var segment = pattern.PatternSegments.Single();
            var rewriteMapSegment = segment as RewriteMapSegment;
            Assert.NotNull(rewriteMapSegment);

            var result = rewriteMapSegment.Evaluate(CreateTestRewriteContext(), CreateRewriteMapRuleMatch(expectedKey).BackReferences, CreateRewriteMapConditionMatch(inputString).BackReferences);
            Assert.Equal(expectedValue, result);
        }

        private RewriteContext CreateTestRewriteContext()
        {
            var context = new DefaultHttpContext();
            return new RewriteContext { HttpContext = context, StaticFileProvider = null, Logger = NullLogger.Instance };
        }

        private BackReferenceCollection CreateTestRuleBackReferences()
        {
            var match = Regex.Match("foo/bar/baz", "(.*)/(.*)/(.*)");
            return new BackReferenceCollection(match.Groups);
        }

        private BackReferenceCollection CreateTestCondBackReferences()
        {
            var match = Regex.Match("foo/bar/baz", "(.*)/(.*)/(.*)");
            return new BackReferenceCollection(match.Groups);
        }

        private MatchResults CreateRewriteMapRuleMatch(string input)
        {
            var match = Regex.Match(input, "([^/]*)/?(.*)");
            return new MatchResults { BackReferences = new BackReferenceCollection(match.Groups), Success = match.Success };
        }

        private MatchResults CreateRewriteMapConditionMatch(string input)
        {
            var match = Regex.Match(input, "(.+)");
            return new MatchResults { BackReferences = new BackReferenceCollection(match.Groups), Success = match.Success };
        }
    }
}