using System;
using System.Collections.Immutable;
using System.Text.Json;

namespace StellaOps.Scheduler.Models.Tests;

public sealed class SamplePayloadTests
{
    private static readonly string SamplesRoot = LocateSamplesRoot();

    [Fact]
    public void ScheduleSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("schedule.json");
        var schedule = CanonicalJsonSerializer.Deserialize<Schedule>(json);

        Assert.Equal("sch_20251018a", schedule.Id);
        Assert.Equal("tenant-alpha", schedule.TenantId);

        var canonical = CanonicalJsonSerializer.Serialize(schedule);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void RunSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("run.json");
        var run = CanonicalJsonSerializer.Deserialize<Run>(json);

        Assert.Equal(RunState.Running, run.State);
        Assert.Equal(42, run.Stats.Deltas);

        var canonical = CanonicalJsonSerializer.Serialize(run);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void ImpactSetSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("impact-set.json");
        var impact = CanonicalJsonSerializer.Deserialize<ImpactSet>(json);

        Assert.True(impact.UsageOnly);
        Assert.Single(impact.Images);

        var canonical = CanonicalJsonSerializer.Serialize(impact);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void AuditSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("audit.json");
        var audit = CanonicalJsonSerializer.Deserialize<AuditRecord>(json);

        Assert.Equal("scheduler", audit.Category);
        Assert.Equal("pause", audit.Action);

        var canonical = CanonicalJsonSerializer.Serialize(audit);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void GraphBuildJobSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("graph-build-job.json");
        var job = CanonicalJsonSerializer.Deserialize<GraphBuildJob>(json);

        Assert.Equal(GraphJobStatus.Running, job.Status);
        Assert.Equal(GraphBuildJobTrigger.SbomVersion, job.Trigger);

        var canonical = CanonicalJsonSerializer.Serialize(job);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void GraphOverlayJobSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("graph-overlay-job.json");
        var job = CanonicalJsonSerializer.Deserialize<GraphOverlayJob>(json);

        Assert.Equal(GraphJobStatus.Queued, job.Status);
        Assert.Equal(GraphOverlayJobTrigger.Policy, job.Trigger);
        Assert.Equal(GraphOverlayKind.Policy, job.OverlayKind);

        var canonical = CanonicalJsonSerializer.Serialize(job);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void PolicyRunRequestSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("policy-run-request.json");
        var request = CanonicalJsonSerializer.Deserialize<PolicyRunRequest>(json);

        Assert.Equal("default", request.TenantId);
        Assert.Equal(PolicyRunMode.Incremental, request.Mode);
        Assert.Equal("run:P-7:2025-10-26:auto", request.RunId);
        Assert.True(request.Inputs.CaptureExplain);
        Assert.Equal(2, request.Inputs.SbomSet.Length);

        var canonical = CanonicalJsonSerializer.Serialize(request);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void PolicyRunStatusSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("policy-run-status.json");
        var status = CanonicalJsonSerializer.Deserialize<PolicyRunStatus>(json);

        Assert.Equal(PolicyRunExecutionStatus.Succeeded, status.Status);
        Assert.Equal(1742, status.Stats.Components);
        Assert.Equal("scheduler", status.Metadata["orchestrator"]);

        var canonical = CanonicalJsonSerializer.Serialize(status);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void PolicyDiffSummarySample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("policy-diff-summary.json");
        var summary = CanonicalJsonSerializer.Deserialize<PolicyDiffSummary>(json);

        Assert.Equal(12, summary.Added);
        Assert.Contains(summary.BySeverity.Keys, key => string.Equals(key, "critical", StringComparison.OrdinalIgnoreCase));
        Assert.Equal(2, summary.RuleHits.Length);

        var canonical = CanonicalJsonSerializer.Serialize(summary);
        AssertJsonEquivalent(json, canonical);
    }

    [Fact]
    public void PolicyExplainTraceSample_RoundtripsThroughCanonicalSerializer()
    {
        var json = ReadSample("policy-explain-trace.json");
        var trace = CanonicalJsonSerializer.Deserialize<PolicyExplainTrace>(json);

        Assert.Equal("finding:sbom:S-42/pkg:npm/lodash@4.17.21", trace.FindingId);
        Assert.Equal(PolicyVerdictStatus.Blocked, trace.Verdict.Status);
        Assert.Equal(2, trace.RuleChain.Length);
        Assert.Equal(2, trace.Evidence.Length);

        var canonical = CanonicalJsonSerializer.Serialize(trace);
        AssertJsonEquivalent(json, canonical);
    }
    [Fact]
    public void PolicyRunJob_RoundtripsThroughCanonicalSerializer()
    {
        var metadata = ImmutableSortedDictionary.CreateBuilder<string, string>(StringComparer.Ordinal);
        metadata["source"] = "cli";
        metadata["trigger"] = "manual";

        var job = new PolicyRunJob(
            SchemaVersion: SchedulerSchemaVersions.PolicyRunJob,
            Id: "job_20251026T140500Z",
            TenantId: "tenant-alpha",
            PolicyId: "P-7",
            PolicyVersion: 4,
            Mode: PolicyRunMode.Incremental,
            Priority: PolicyRunPriority.High,
            PriorityRank: -1,
            RunId: "run:P-7:2025-10-26:auto",
            RequestedBy: "user:cli",
            CorrelationId: "req-20251026T140500Z",
            Metadata: metadata.ToImmutable(),
            Inputs: new PolicyRunInputs(
                sbomSet: new[] { "sbom:S-42", "sbom:S-318" },
                advisoryCursor: DateTimeOffset.Parse("2025-10-26T13:59:00Z"),
                captureExplain: true),
            QueuedAt: DateTimeOffset.Parse("2025-10-26T14:05:00Z"),
            Status: PolicyRunJobStatus.Pending,
            AttemptCount: 1,
            LastAttemptAt: DateTimeOffset.Parse("2025-10-26T14:05:30Z"),
            LastError: "transient network error",
            CreatedAt: DateTimeOffset.Parse("2025-10-26T14:04:50Z"),
            UpdatedAt: DateTimeOffset.Parse("2025-10-26T14:05:10Z"),
            AvailableAt: DateTimeOffset.Parse("2025-10-26T14:05:20Z"),
            SubmittedAt: null,
            CompletedAt: null,
            LeaseOwner: "worker-01",
            LeaseExpiresAt: DateTimeOffset.Parse("2025-10-26T14:06:30Z"),
            CancellationRequested: false,
            CancellationRequestedAt: null,
            CancellationReason: null,
            CancelledAt: null);

        var canonical = CanonicalJsonSerializer.Serialize(job);
        var roundtrip = CanonicalJsonSerializer.Deserialize<PolicyRunJob>(canonical);

        Assert.Equal(job.TenantId, roundtrip.TenantId);
        Assert.Equal(job.PolicyId, roundtrip.PolicyId);
        Assert.Equal(job.Priority, roundtrip.Priority);
        Assert.Equal(job.Status, roundtrip.Status);
        Assert.Equal(job.RunId, roundtrip.RunId);
        Assert.Equal("cli", roundtrip.Metadata!["source"]);
    }


    private static string ReadSample(string fileName)
    {
        var path = Path.Combine(SamplesRoot, fileName);
        return File.ReadAllText(path);
    }

    private static string LocateSamplesRoot()
    {
        var current = AppContext.BaseDirectory;
        while (!string.IsNullOrEmpty(current))
        {
            var candidate = Path.Combine(current, "samples", "api", "scheduler");
            if (Directory.Exists(candidate))
            {
                return candidate;
            }

            var parent = Path.GetDirectoryName(current.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar));
            if (string.Equals(parent, current, StringComparison.Ordinal))
            {
                break;
            }

            current = parent;
        }

        throw new DirectoryNotFoundException("Unable to locate samples/api/scheduler in repository tree.");
    }

    private static void AssertJsonEquivalent(string expected, string actual)
    {
        var normalizedExpected = NormalizeJson(expected);
        var normalizedActual = NormalizeJson(actual);
        Assert.Equal(normalizedExpected, normalizedActual);
    }

    private static string NormalizeJson(string json)
    {
        using var document = JsonDocument.Parse(json);
        return JsonSerializer.Serialize(document.RootElement, new JsonSerializerOptions
        {
            WriteIndented = false
        });
    }
}