using NSubstitute;
using Octokit;
using Octokit.Internal;
using Octokit.Reactive;
using Octokit.Tests.Helpers;
using System;
using System.Collections.Generic;
using System.Reactive.Linq;
using System.Threading.Tasks;
using Xunit;

public class ObservableIssuesClientTests
{
    public class TheGetMethod
    {
        [Fact]
        public void GetsFromClientIssueIssue()
        {
            var gitHubClient = Substitute.For<IGitHubClient>();
            var client = new ObservableIssuesClient(gitHubClient);

            client.Get("fake", "repo", 42);

            gitHubClient.Issue.Received().Get("fake", "repo", 42);
        }

        [Fact]
        public async Task EnsuresNonNullArguments()
        {
            var client = new ObservableIssuesClient(Substitute.For<IGitHubClient>());

            await AssertEx.Throws<ArgumentNullException>(async () => await client.Get(null, "name", 1));
            await AssertEx.Throws<ArgumentNullException>(async () => await client.Get("owner", null, 1));
            await AssertEx.Throws<ArgumentException>(async () => await client.Get(null, "", 1));
            await AssertEx.Throws<ArgumentException>(async () => await client.Get("", null, 1));
        }
    }

    public class TheGetForRepositoryMethod
    {
        [Fact]
        public async Task ReturnsEveryPageOfIssues()
        {
            var firstPageUrl = new Uri("repos/fake/repo/issues", UriKind.Relative);
            var secondPageUrl = new Uri("https://example.com/page/2");
            var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
            var firstPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(1),
                    CreateIssue(2),
                    CreateIssue(3)
                },
                ApiInfo = CreateApiInfo(firstPageLinks)
            };
            var thirdPageUrl = new Uri("https://example.com/page/3");
            var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
            var secondPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(4),
                    CreateIssue(5),
                    CreateIssue(6)
                },
                ApiInfo = CreateApiInfo(secondPageLinks)
            };
            var lastPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(7),
                },
                ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
            };
            var gitHubClient = Substitute.For<IGitHubClient>();
            gitHubClient.Connection.Get<List<Issue>>(Arg.Is(firstPageUrl),
                Arg.Is<Dictionary<string, string>>(d => d.Count == 4
                    && d["direction"] == "desc"
                    && d["state"] == "open"
                    && d["sort"] == "created"
                    && d["filter"] == "assigned"), Arg.Any<string>())
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(secondPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(thirdPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
            var client = new ObservableIssuesClient(gitHubClient);

            var results = await client.GetForRepository("fake", "repo").ToArray();

            Assert.Equal(7, results.Length);
            Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
            Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
            Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
        }
    }

    public class TheGetAllForOwnedAndMemberRepositoriesMethod
    {
        [Fact]
        public async Task ReturnsEveryPageOfIssues()
        {
            var firstPageUrl = new Uri("user/issues", UriKind.Relative);
            var secondPageUrl = new Uri("https://example.com/page/2");
            var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
            var firstPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(1),
                    CreateIssue(2),
                    CreateIssue(3)                    },
                ApiInfo = CreateApiInfo(firstPageLinks)
            };
            var thirdPageUrl = new Uri("https://example.com/page/3");
            var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
            var secondPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(4),
                    CreateIssue(5),
                    CreateIssue(6)
                },
                ApiInfo = CreateApiInfo(secondPageLinks)
            };
            var lastPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(7)
                },
                ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
            };
            var gitHubClient = Substitute.For<IGitHubClient>();
            gitHubClient.Connection.Get<List<Issue>>(Arg.Is(firstPageUrl),
                Arg.Is<Dictionary<string, string>>(d => d.Count == 4
                    && d["direction"] == "desc"
                    && d["state"] == "open"
                    && d["sort"] == "created"
                    && d["filter"] == "assigned"), Arg.Any<string>())
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(secondPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(thirdPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
            var client = new ObservableIssuesClient(gitHubClient);

            var results = await client.GetAllForOwnedAndMemberRepositories().ToArray();

            Assert.Equal(7, results.Length);
            Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
            Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
            Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
        }
    }

    public class TheGetAllForOrganizationMethod
    {
        [Fact]
        public async Task ReturnsEveryPageOfIssues()
        {
            var firstPageUrl = new Uri("orgs/test/issues", UriKind.Relative);
            var secondPageUrl = new Uri("https://example.com/page/2");
            var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
            var firstPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(1),
                    CreateIssue(2),
                    CreateIssue(3)
                },
                ApiInfo = CreateApiInfo(firstPageLinks)
            };
            var thirdPageUrl = new Uri("https://example.com/page/3");
            var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
            var secondPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(4),
                    CreateIssue(5),
                    CreateIssue(6)
                },
                ApiInfo = CreateApiInfo(secondPageLinks)
            };
            var lastPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(7)
                },
                ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
            };
            var gitHubClient = Substitute.For<IGitHubClient>();
            gitHubClient.Connection.Get<List<Issue>>(Arg.Is(firstPageUrl),
                Arg.Is<Dictionary<string, string>>(d => d.Count == 4
                    && d["direction"] == "desc"
                    && d["state"] == "open"
                    && d["sort"] == "created"
                    && d["filter"] == "assigned"), Arg.Any<string>())
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(secondPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(thirdPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
            var client = new ObservableIssuesClient(gitHubClient);

            var results = await client.GetAllForOrganization("test").ToArray();

            Assert.Equal(7, results.Length);
            Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
            Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
            Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
        }
    }

    public class TheGetAllForCurrentMethod
    {
        [Fact]
        public async Task ReturnsEveryPageOfIssues()
        {
            var firstPageUrl = new Uri("issues", UriKind.Relative);
            var secondPageUrl = new Uri("https://example.com/page/2");
            var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
            var firstPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(1),
                    CreateIssue(2),
                    CreateIssue(3)
                },
                ApiInfo = CreateApiInfo(firstPageLinks)
            };
            var thirdPageUrl = new Uri("https://example.com/page/3");
            var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
            var secondPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(4),
                    CreateIssue(5),
                    CreateIssue(6)
                },
                ApiInfo = CreateApiInfo(secondPageLinks)
            };
            var lastPageResponse = new ApiResponse<List<Issue>>
            {
                BodyAsObject = new List<Issue>
                {
                    CreateIssue(7)
                },
                ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
            };
            var gitHubClient = Substitute.For<IGitHubClient>();
            gitHubClient.Connection.Get<List<Issue>>(Arg.Is(firstPageUrl),
                Arg.Is<Dictionary<string, string>>(d => d.Count == 4
                    && d["direction"] == "desc"
                    && d["state"] == "open"
                    && d["sort"] == "created"
                    && d["filter"] == "assigned"), Arg.Any<string>())
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(secondPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
            gitHubClient.Connection.Get<List<Issue>>(thirdPageUrl, null, null)
                .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
            var client = new ObservableIssuesClient(gitHubClient);

            var results = await client.GetAllForCurrent().ToArray();

            Assert.Equal(7, results.Length);
            Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
            Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
            Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
        }
    }

    public class TheCreateMethod
    {
        [Fact]
        public void CreatesFromClientIssueIssue()
        {
            var newIssue = new NewIssue("some title");
            var gitHubClient = Substitute.For<IGitHubClient>();
            var client = new ObservableIssuesClient(gitHubClient);

            client.Create("fake", "repo", newIssue);

            gitHubClient.Issue.Received().Create("fake", "repo", newIssue);
        }

        [Fact]
        public void EnsuresArgumentsNotNull()
        {
            var gitHubClient = Substitute.For<IGitHubClient>();
            var client = new ObservableIssuesClient(gitHubClient);

            Assert.Throws<ArgumentNullException>(() => client.Create(null, "name", new NewIssue("title")));
            Assert.Throws<ArgumentException>(() => client.Create("", "name", new NewIssue("x")));
            Assert.Throws<ArgumentNullException>(() => client.Create("owner", null, new NewIssue("x")));
            Assert.Throws<ArgumentException>(() => client.Create("owner", "", new NewIssue("x")));
            Assert.Throws<ArgumentNullException>(() => client.Create("owner", "name", null));
        }
    }

    public class TheUpdateMethod
    {
        [Fact]
        public void UpdatesClientIssueIssue()
        {
            var issueUpdate = new IssueUpdate();
            var gitHubClient = Substitute.For<IGitHubClient>();
            var client = new ObservableIssuesClient(gitHubClient);

            client.Update("fake", "repo", 42, issueUpdate);

            gitHubClient.Issue.Received().Update("fake", "repo", 42, issueUpdate);
        }

        [Fact]
        public void EnsuresArgumentsNotNull()
        {
            var gitHubClient = Substitute.For<IGitHubClient>();
            var client = new ObservableIssuesClient(gitHubClient);

            Assert.Throws<ArgumentNullException>(() => client.Create(null, "name", new NewIssue("title")));
            Assert.Throws<ArgumentException>(() => client.Create("", "name", new NewIssue("x")));
            Assert.Throws<ArgumentNullException>(() => client.Create("owner", null, new NewIssue("x")));
            Assert.Throws<ArgumentException>(() => client.Create("owner", "", new NewIssue("x")));
            Assert.Throws<ArgumentNullException>(() => client.Create("owner", "name", null));
        }
    }

    public class TheCtor
    {
        [Fact]
        public void EnsuresArgument()
        {
            Assert.Throws<ArgumentNullException>(() => new IssuesClient(null));
        }
    }

    static ApiInfo CreateApiInfo(IDictionary<string, Uri> links)
    {
        return new ApiInfo(links, new List<string>(), new List<string>(), "etag", new RateLimit(new Dictionary<string, string>()));
    }

    static Issue CreateIssue(int issueNumber)
    {
        var serializer = new SimpleJsonSerializer();
        return serializer.Deserialize<Issue>(@"{""number"": """ + issueNumber + @"""}");
    }
}