// Copyright (c) 2025 Tudor Stanciu

using Bitip.Client.Models;
using Bitip.Client.Tests.Helpers;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Xunit;

namespace Bitip.Client.Tests
{
    /// <summary>
    /// Unit tests for IBitipClient.GetBatchIpLocation method (batch lookup).
    /// </summary>
    public class GetBatchIpLocationTests
    {
        [Fact]
        public async Task GetBatchIpLocation_WithValidIps_ReturnsSucceeded()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8", "1.1.1.1" };
            var expectedResponse = new BatchIpLookupResponse
            {
                Succeeded = new List<IpLocation>
                {
                    new IpLocation
                    {
                        Ip = "8.8.8.8",
                        Country = "United States",
                        CountryCode = "US",
                        IsInEuropeanUnion = false,
                        Region = "California",
                        City = "Mountain View",
                        Latitude = 37.4056,
                        Longitude = -122.0775,
                        Timezone = "America/Los_Angeles"
                    },
                    new IpLocation
                    {
                        Ip = "1.1.1.1",
                        Country = "Australia",
                        CountryCode = "AU",
                        IsInEuropeanUnion = false,
                        Region = "Queensland",
                        City = "Brisbane",
                        Latitude = -27.4679,
                        Longitude = 153.0281,
                        Timezone = "Australia/Brisbane"
                    }
                },
                Failed = new List<BatchIpLookupError>()
            };

            var client = BitipClientTestFixture.CreateMockedClientWithResponse(expectedResponse, "lookup/batch", HttpMethod.Post);

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            var succeededList = result.Succeeded.ToList();
            var failedList = result.Failed.ToList();
            
            Assert.Equal(2, succeededList.Count);
            Assert.Empty(failedList);
            
            Assert.Equal("8.8.8.8", succeededList[0].Ip);
            Assert.Equal("United States", succeededList[0].Country);
            Assert.Equal("1.1.1.1", succeededList[1].Ip);
            Assert.Equal("Australia", succeededList[1].Country);
        }

        [Fact]
        public async Task GetBatchIpLocation_WithMixedSuccessAndErrors_ReturnsBoth()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8", "192.168.1.1" };
            var expectedResponse = new BatchIpLookupResponse
            {
                Succeeded = new List<IpLocation>
                {
                    new IpLocation
                    {
                        Ip = "8.8.8.8",
                        Country = "United States",
                        CountryCode = "US",
                        IsInEuropeanUnion = false,
                        Region = "California",
                        City = "Mountain View"
                    }
                },
                Failed = new List<BatchIpLookupError>
                {
                    new BatchIpLookupError
                    {
                        Ip = "192.168.1.1",
                        Error = "Private IP addresses are not supported"
                    }
                }
            };

            var client = BitipClientTestFixture.CreateMockedClientWithResponse(expectedResponse, "lookup/batch", HttpMethod.Post);

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            var succeededList = result.Succeeded.ToList();
            var failedList = result.Failed.ToList();
            
            Assert.Single(succeededList);
            Assert.Single(failedList);
            
            Assert.Equal("United States", succeededList[0].Country);
            Assert.Contains("Private IP", failedList[0].Error);
        }

        [Fact]
        public async Task GetBatchIpLocation_WithNullList_ThrowsArgumentNullException()
        {
            // Arrange
            var client = BitipClientTestFixture.CreateMockedClient(mock => { });

            // Act & Assert
            await Assert.ThrowsAsync<ArgumentNullException>(async () =>
                await client.GetBatchIpLocation(null!));
        }

        [Fact]
        public async Task GetBatchIpLocation_WithEmptyList_ThrowsArgumentException()
        {
            // Arrange
            var client = BitipClientTestFixture.CreateMockedClient(mock => { });

            // Act & Assert
            await Assert.ThrowsAsync<ArgumentException>(async () =>
                await client.GetBatchIpLocation(new List<string>()));
        }

        [Fact]
        public async Task GetBatchIpLocation_WithInvalidIp_ReturnsInFailed()
        {
            // Arrange - Mix of valid and invalid IPs
            var ips = new List<string> { "8.8.8.8", "invalid-ip", "1.1.1.1" };
            
            // Mock response for the valid IPs only (invalid ones handled client-side)
            var expectedResponse = new BatchIpLookupResponse
            {
                Succeeded = new List<IpLocation>
                {
                    new IpLocation
                    {
                        Ip = "8.8.8.8",
                        Country = "United States",
                        CountryCode = "US",
                        IsInEuropeanUnion = false,
                        Region = "California",
                        City = "Mountain View"
                    },
                    new IpLocation
                    {
                        Ip = "1.1.1.1",
                        Country = "Australia",
                        CountryCode = "AU",
                        IsInEuropeanUnion = false,
                        Region = "Queensland",
                        City = "Brisbane"
                    }
                },
                Failed = new List<BatchIpLookupError>()
            };

            var client = BitipClientTestFixture.CreateMockedClientWithResponse(expectedResponse, "lookup/batch", HttpMethod.Post);

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            var succeededList = result.Succeeded.ToList();
            var failedList = result.Failed.ToList();
            
            Assert.Equal(2, succeededList.Count); // Valid IPs
            Assert.Single(failedList); // Invalid IP

            // Check valid IPs succeeded
            Assert.Equal("8.8.8.8", succeededList[0].Ip);
            Assert.Equal("1.1.1.1", succeededList[1].Ip);

            // Check invalid IP has error
            Assert.Equal("invalid-ip", failedList[0].Ip);
            Assert.Contains("Invalid IP", failedList[0].Error);
        }

        [Fact]
        public async Task GetBatchIpLocation_WithCancellation_ThrowsTaskCanceledException()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8", "1.1.1.1" };
            var client = BitipClientTestFixture.CreateCancelledClient();
            var cts = new CancellationTokenSource();
            cts.Cancel();

            // Act & Assert
            await Assert.ThrowsAsync<TaskCanceledException>(async () =>
                await client.GetBatchIpLocation(ips, cts.Token));
        }

        [Fact]
        public async Task GetBatchIpLocation_WithServerError_ThrowsHttpRequestException()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8" };
            var client = BitipClientTestFixture.CreateClientWithError(
                HttpStatusCode.InternalServerError,
                "Internal Server Error",
                "Failed to process batch lookup");

            // Act & Assert
            await Assert.ThrowsAsync<HttpRequestException>(async () =>
                await client.GetBatchIpLocation(ips));
        }

        [Fact]
        public async Task GetBatchIpLocation_WithSingleIp_ReturnsResult()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8" };
            var expectedResponse = new BatchIpLookupResponse
            {
                Succeeded = new List<IpLocation>
                {
                    new IpLocation
                    {
                        Ip = "8.8.8.8",
                        Country = "United States",
                        CountryCode = "US",
                        IsInEuropeanUnion = false,
                        Region = "California",
                        City = "Mountain View"
                    }
                },
                Failed = new List<BatchIpLookupError>()
            };

            var client = BitipClientTestFixture.CreateMockedClientWithResponse(expectedResponse, "lookup/batch", HttpMethod.Post);

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            var succeededList = result.Succeeded.ToList();
            Assert.Single(succeededList);
            Assert.Empty(result.Failed);
            Assert.Equal("8.8.8.8", succeededList[0].Ip);
        }

        [Fact]
        public async Task GetBatchIpLocation_WithMultipleIps_ReturnsAllResults()
        {
            // Arrange
            var ips = new List<string> { "8.8.8.8", "1.1.1.1", "9.9.9.9" };
            var expectedResponse = new BatchIpLookupResponse
            {
                Succeeded = new List<IpLocation>
                {
                    new IpLocation { Ip = "8.8.8.8", Country = "United States", CountryCode = "US", IsInEuropeanUnion = false, Region = "California", City = "Mountain View" },
                    new IpLocation { Ip = "1.1.1.1", Country = "Australia", CountryCode = "AU", IsInEuropeanUnion = false, Region = "Queensland", City = "Brisbane" },
                    new IpLocation { Ip = "9.9.9.9", Country = "United States", CountryCode = "US", IsInEuropeanUnion = false, Region = "California", City = "Oakland" }
                },
                Failed = new List<BatchIpLookupError>()
            };

            var client = BitipClientTestFixture.CreateMockedClientWithResponse(expectedResponse, "lookup/batch", HttpMethod.Post);

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            var succeededList = result.Succeeded.ToList();
            Assert.Equal(3, succeededList.Count);
            Assert.Empty(result.Failed);
            Assert.All(succeededList, r => Assert.NotNull(r.Ip));
        }

        [Fact]
        public async Task GetBatchIpLocation_WithOnlyInvalidIps_ReturnsAllInFailed()
        {
            // Arrange - Only invalid IPs (no API call should be made)
            var ips = new List<string> { "invalid-ip", "not-an-ip", "xyz" };
            var client = BitipClientTestFixture.CreateMockedClient(mock => { });

            // Act
            var result = await client.GetBatchIpLocation(ips);

            // Assert
            Assert.NotNull(result);
            Assert.Empty(result.Succeeded);
            
            var failedList = result.Failed.ToList();
            Assert.Equal(3, failedList.Count);
            Assert.All(failedList, r =>
            {
                Assert.NotNull(r.Error);
                Assert.Contains("Invalid IP", r.Error);
            });
        }
    }
}