using System.Text.Json.Nodes;
using Microsoft.Extensions.Configuration;
using w4c_workflows.Models.Nodes;
using w4c_workflows.Services;
using w4c_workflows.Services.Execution;
using w4c_workflows.Services.Nodes;
using w4c_workflows.Services.Nodes.Executors;
using Xunit;

namespace w4c_workflows.Tests;

/// <summary>
/// The <c>core.code</c> node bridges the node kernel to the language runtimes:
/// input items go in as JSON, the script's JSON output comes back as items.
/// </summary>
public class CodeNodeExecutorTests
{
    private static CodeNodeExecutor Executor()
    {
        var config = new ConfigurationBuilder()
            .AddInMemoryCollection(new Dictionary<string, string?>
            {
                ["Workflows:TaskTimeoutSeconds"] = "60",
            })
            .Build();
        var runtimes = new RuntimeRegistry(
            new LanguageRegistry(),
            new IScriptExecutor[] { new SubprocessScriptExecutor("shell", "sh", config) });
        return new CodeNodeExecutor(runtimes);
    }

    private static NodeExecutionContext Context(
        string? language,
        string? entryFile,
        IReadOnlyList<FlowItem> input,
        string? workingDirectory)
        => new()
        {
            Blueprint = NodeTestData.CoreCatalog().Get("core.code")!,
            Parameters = new JsonObject
            {
                ["language"] = language,
                ["entryFile"] = entryFile,
            },
            Inputs = new IReadOnlyList<FlowItem>[] { input },
            WorkingDirectory = workingDirectory,
            TenantId = "tenant-1",
            RunId = "run-1",
            TaskId = "task-1",
            NodeName = "code",
        };

    private static FlowItem Item(string json) => FlowItem.FromJson(JsonNode.Parse(json)!.AsObject());

    [Fact]
    public async Task Runs_a_shell_script_and_maps_its_json_output_to_items()
    {
        using var dir = new TempDir();
        dir.Write("task.sh", "#!/bin/sh\nread input\necho '{\"ok\":true,\"seen\":\"input\"}'\n");

        var outcome = await Executor().RunAsync(
            Context("shell", "task.sh", new[] { Item("""{"x":1}""") }, dir.Path), default);

        Assert.True(outcome.Succeeded, outcome.Failure?.Message);
        var item = Assert.Single(outcome.Outputs[0]);
        Assert.True(item.Json["ok"]!.GetValue<bool>());
    }

    [Fact]
    public async Task Missing_language_fails_with_an_invalid_parameter_code()
    {
        var outcome = await Executor().RunAsync(
            Context(null, "task.sh", Array.Empty<FlowItem>(), null), default);

        Assert.False(outcome.Succeeded);
        Assert.Equal("invalid_parameter", outcome.Failure!.Code);
    }

    [Fact]
    public async Task Unknown_language_fails_with_a_clear_code()
    {
        var outcome = await Executor().RunAsync(
            Context("cobol", "task.cob", Array.Empty<FlowItem>(), null), default);

        Assert.False(outcome.Succeeded);
        Assert.Equal("unknown_language", outcome.Failure!.Code);
    }

    [Fact]
    public async Task A_non_zero_exit_fails_the_node()
    {
        using var dir = new TempDir();
        dir.Write("task.sh", "#!/bin/sh\necho boom 1>&2\nexit 2\n");

        var outcome = await Executor().RunAsync(
            Context("shell", "task.sh", Array.Empty<FlowItem>(), dir.Path), default);

        Assert.False(outcome.Succeeded);
        Assert.Equal("script_failed", outcome.Failure!.Code);
        Assert.Contains("boom", outcome.Failure.Message);
    }
}