using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using FrameworkBLL.GOP;
using FrameworkBLL.Promotion;
using GB5Shared.Deployment;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.DTO.GOP;
using Microsoft.Extensions.Logging.Abstractions;
using Moq;
using Xunit;

namespace FrameworkTests;

/// <summary>
/// PromotionFlowProvisioningBLL authors the real "PromotionIngest" GOP flow (Ingest -> Approval ->
/// Import) via IGopFlowBLL's design-time API rather than hand-inserted snapshot rows, so
/// GopPublishService's own DAG/Approval-role validation actually runs. Covers idempotency (the
/// common re-run case) and the happy-path shape of what gets authored (3 steps, 2 edges, the
/// Approval step's required AssignedRole, and that PublishGopFlow/SaveGopSourceBinding both use the
/// FlowId that SaveGopFlow assigned).
/// </summary>
public class PromotionFlowProvisioningBLLTests
{
    private static LoginDTO Login() => new() { ClientId = -1, UserId = 7 };

    private static IGB5Environment DevEnvironment() => Mock.Of<IGB5Environment>(e => e.GopEnvironmentCode == "DEV");

    [Fact]
    public async Task AlreadyProvisioned_IsANoOp()
    {
        var gopFlowBLL = new Mock<IGopFlowBLL>(MockBehavior.Strict);
        gopFlowBLL.Setup(b => b.GetAllSourceBindings(It.IsAny<LoginDTO>()))
            .ReturnsAsync(new List<GopSourceBindingDTO>
            {
                new() { SourceCode = "PromotionIngest", IsActive = true, FlowId = 501, SnapshotVersion = "v1" }
            });

        var bll = new PromotionFlowProvisioningBLL(
            gopFlowBLL.Object, DevEnvironment(), NullLogger<PromotionFlowProvisioningBLL>.Instance);

        var result = await bll.EnsureIngestFlowProvisionedAsync(Login(), CancellationToken.None);

        Assert.Contains("501", result);
        // Strict mock with only GetAllSourceBindings set up — reaching GetGopFlowList/SaveGopFlow/etc.
        // would have thrown a MockException instead, proving this really is a no-op.
    }

    [Fact]
    public async Task NotYetProvisioned_CreatesFlowStepsEdgesPublishesAndBinds()
    {
        var gopFlowBLL = new Mock<IGopFlowBLL>();
        gopFlowBLL.Setup(b => b.GetAllSourceBindings(It.IsAny<LoginDTO>()))
            .ReturnsAsync(new List<GopSourceBindingDTO>());
        gopFlowBLL.Setup(b => b.GetGopFlowList(It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<GopFlowDTO>());

        gopFlowBLL.Setup(b => b.SaveGopFlow(It.IsAny<GopFlowDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopFlowDTO, LoginDTO, CancellationToken>((dto, _, _) => dto.FlowId = 501)
            .ReturnsAsync("Saved 501");

        gopFlowBLL.Setup(b => b.GetGopFlowGraph(501, It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GopFlowGraphDTO()); // empty — no steps yet

        var stepIdCounter = 1000;
        gopFlowBLL.Setup(b => b.SaveGopFlowStep(It.IsAny<GopFlowStepDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopFlowStepDTO, LoginDTO, CancellationToken>((dto, _, _) => dto.FlowStepId = ++stepIdCounter)
            .ReturnsAsync("Saved step");

        var savedEdges = new List<GopFlowStepEdgeDTO>();
        gopFlowBLL.Setup(b => b.SaveGopFlowStepEdge(It.IsAny<GopFlowStepEdgeDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopFlowStepEdgeDTO, LoginDTO, CancellationToken>((dto, _, _) => savedEdges.Add(dto))
            .ReturnsAsync("Saved edge");

        gopFlowBLL.Setup(b => b.PublishGopFlow(501, "v1", It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(GopPublishResultDTO.Ok(9001, "v1"));

        GopSourceBindingDTO? capturedBinding = null;
        gopFlowBLL.Setup(b => b.SaveGopSourceBinding(It.IsAny<GopSourceBindingDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopSourceBindingDTO, LoginDTO, CancellationToken>((dto, _, _) => capturedBinding = dto)
            .ReturnsAsync("Saved binding");

        var bll = new PromotionFlowProvisioningBLL(
            gopFlowBLL.Object, DevEnvironment(), NullLogger<PromotionFlowProvisioningBLL>.Instance);

        var result = await bll.EnsureIngestFlowProvisionedAsync(Login(), CancellationToken.None);

        Assert.Contains("501", result);
        Assert.Contains("v1", result);

        gopFlowBLL.Verify(b => b.SaveGopFlowStep(
            It.Is<GopFlowStepDTO>(s => s.NodeType == "PromotionIngest" && s.FlowId == 501),
            It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()), Times.Once);
        gopFlowBLL.Verify(b => b.SaveGopFlowStep(
            It.Is<GopFlowStepDTO>(s => s.NodeType == "Approval" && !string.IsNullOrWhiteSpace(s.AssignedRole)),
            It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()), Times.Once);
        gopFlowBLL.Verify(b => b.SaveGopFlowStep(
            It.Is<GopFlowStepDTO>(s => s.NodeType == "PromotionImport"),
            It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()), Times.Once);

        Assert.Equal(2, savedEdges.Count);
        Assert.All(savedEdges, e => Assert.Equal("OnSuccess", e.EdgeCondition));

        Assert.NotNull(capturedBinding);
        Assert.Equal("PromotionIngest", capturedBinding!.SourceCode);
        Assert.Equal(501, capturedBinding.FlowId);
        Assert.Equal("v1", capturedBinding.SnapshotVersion);
    }

    [Fact]
    public async Task ExistingFlowWithNoSteps_ReusesFlowIdRatherThanCreatingANewFlow()
    {
        var gopFlowBLL = new Mock<IGopFlowBLL>();
        gopFlowBLL.Setup(b => b.GetAllSourceBindings(It.IsAny<LoginDTO>()))
            .ReturnsAsync(new List<GopSourceBindingDTO>());
        gopFlowBLL.Setup(b => b.GetGopFlowList(It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<GopFlowDTO> { new() { FlowId = 777, FlowCode = "PromotionIngest" } });
        gopFlowBLL.Setup(b => b.GetGopFlowGraph(777, It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GopFlowGraphDTO());

        var stepIdCounter = 2000;
        gopFlowBLL.Setup(b => b.SaveGopFlowStep(It.IsAny<GopFlowStepDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopFlowStepDTO, LoginDTO, CancellationToken>((dto, _, _) => dto.FlowStepId = ++stepIdCounter)
            .ReturnsAsync("Saved step");
        gopFlowBLL.Setup(b => b.SaveGopFlowStepEdge(It.IsAny<GopFlowStepEdgeDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync("Saved edge");
        gopFlowBLL.Setup(b => b.PublishGopFlow(777, "v1", It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(GopPublishResultDTO.Ok(9002, "v1"));
        gopFlowBLL.Setup(b => b.SaveGopSourceBinding(It.IsAny<GopSourceBindingDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync("Saved binding");

        var bll = new PromotionFlowProvisioningBLL(
            gopFlowBLL.Object, DevEnvironment(), NullLogger<PromotionFlowProvisioningBLL>.Instance);

        var result = await bll.EnsureIngestFlowProvisionedAsync(Login(), CancellationToken.None);

        Assert.Contains("777", result);
        gopFlowBLL.Verify(b => b.SaveGopFlow(It.IsAny<GopFlowDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()), Times.Never);
    }

    [Fact]
    public async Task PublishFailure_ThrowsWithTheValidationErrors()
    {
        var gopFlowBLL = new Mock<IGopFlowBLL>();
        gopFlowBLL.Setup(b => b.GetAllSourceBindings(It.IsAny<LoginDTO>()))
            .ReturnsAsync(new List<GopSourceBindingDTO>());
        gopFlowBLL.Setup(b => b.GetGopFlowList(It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new List<GopFlowDTO>());
        gopFlowBLL.Setup(b => b.SaveGopFlow(It.IsAny<GopFlowDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .Callback<GopFlowDTO, LoginDTO, CancellationToken>((dto, _, _) => dto.FlowId = 501)
            .ReturnsAsync("Saved");
        gopFlowBLL.Setup(b => b.GetGopFlowGraph(501, It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new GopFlowGraphDTO());
        gopFlowBLL.Setup(b => b.SaveGopFlowStep(It.IsAny<GopFlowStepDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync("Saved step");
        gopFlowBLL.Setup(b => b.SaveGopFlowStepEdge(It.IsAny<GopFlowStepEdgeDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync("Saved edge");
        gopFlowBLL.Setup(b => b.PublishGopFlow(501, "v1", It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(GopPublishResultDTO.Failure(new List<string> { "Approval step 'approve' requires an AssignedRole" }));

        var bll = new PromotionFlowProvisioningBLL(
            gopFlowBLL.Object, DevEnvironment(), NullLogger<PromotionFlowProvisioningBLL>.Instance);

        var ex = await Assert.ThrowsAsync<System.InvalidOperationException>(
            () => bll.EnsureIngestFlowProvisionedAsync(Login(), CancellationToken.None));
        Assert.Contains("AssignedRole", ex.Message);

        gopFlowBLL.Verify(b => b.SaveGopSourceBinding(
            It.IsAny<GopSourceBindingDTO>(), It.IsAny<LoginDTO>(), It.IsAny<CancellationToken>()), Times.Never);
    }
}