using System;
using System.Linq;
using System.Text.Json.Nodes;
using StellaOps.AirGap.Policy;
using StellaOps.TaskRunner.Core.Planning;

namespace StellaOps.TaskRunner.Tests;

public sealed class TaskPackPlannerTests
{
    [Fact]
    public void Plan_WithSequentialSteps_ComputesDeterministicHash()
    {
        var manifest = TestManifests.Load(TestManifests.Sample);
        var planner = new TaskPackPlanner();

        var inputs = new Dictionary<string, JsonNode?>
        {
            ["dryRun"] = JsonValue.Create(false)
        };

        var resultA = planner.Plan(manifest, inputs);
        Assert.True(resultA.Success);
        var plan = resultA.Plan!;
        Assert.Equal(3, plan.Steps.Count);
        Assert.Equal("plan-step", plan.Steps[0].Id);
        Assert.Equal("plan-step", plan.Steps[0].TemplateId);
        Assert.Equal("run", plan.Steps[0].Type);
        Assert.Equal("gate.approval", plan.Steps[1].Type);
        Assert.Equal("security-review", plan.Steps[1].ApprovalId);
        Assert.Equal("run", plan.Steps[2].Type);
        Assert.True(plan.Steps[2].Enabled);
        Assert.Single(plan.Approvals);
        Assert.Equal("security-review", plan.Approvals[0].Id);
        Assert.False(string.IsNullOrWhiteSpace(plan.Hash));

        var resultB = planner.Plan(manifest, inputs);
        Assert.True(resultB.Success);
        Assert.Equal(plan.Hash, resultB.Plan!.Hash);
    }

    [Fact]
    public void PlanHash_IsPrefixedSha256Digest()
    {
        var manifest = TestManifests.Load(TestManifests.Sample);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.True(result.Success);
        var hash = result.Plan!.Hash;
        Assert.StartsWith("sha256:", hash, StringComparison.Ordinal);
        Assert.Equal(71, hash.Length); // "sha256:" + 64 hex characters
        var hex = hash.Substring("sha256:".Length);
        Assert.True(hex.All(c => Uri.IsHexDigit(c)), "Hash contains non-hex characters.");
    }

    [Fact]
    public void Plan_WhenConditionEvaluatesFalse_DisablesStep()
    {
        var manifest = TestManifests.Load(TestManifests.Sample);
        var planner = new TaskPackPlanner();

        var inputs = new Dictionary<string, JsonNode?>
        {
            ["dryRun"] = JsonValue.Create(true)
        };

        var result = planner.Plan(manifest, inputs);
        Assert.True(result.Success);
        Assert.False(result.Plan!.Steps[2].Enabled);
    }

    [Fact]
    public void Plan_WithStepReferences_MarksParametersAsRuntime()
    {
        var manifest = TestManifests.Load(TestManifests.StepReference);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.True(result.Success);
        var plan = result.Plan!;
        Assert.Equal(2, plan.Steps.Count);
        var referenceParameters = plan.Steps[1].Parameters!;
        Assert.True(referenceParameters["sourceSummary"].RequiresRuntimeValue);
        Assert.Equal("steps.prepare.outputs.summary", referenceParameters["sourceSummary"].Expression);
    }

    [Fact]
    public void Plan_WithMapStep_ExpandsIterations()
    {
        var manifest = TestManifests.Load(TestManifests.Map);
        var planner = new TaskPackPlanner();

        var inputs = new Dictionary<string, JsonNode?>
        {
            ["targets"] = new JsonArray("alpha", "beta", "gamma")
        };

        var result = planner.Plan(manifest, inputs);
        Assert.True(result.Success);
        var plan = result.Plan!;
        var mapStep = plan.Steps.Single(s => s.Type == "map");
        Assert.Equal(3, mapStep.Children!.Count);
        Assert.All(mapStep.Children!, child => Assert.Equal("echo-step", child.TemplateId));
        Assert.Equal(3, mapStep.Parameters!["iterationCount"].Value!.GetValue<int>());
        Assert.Equal("alpha", mapStep.Children![0].Parameters!["item"].Value!.GetValue<string>());
    }

    [Fact]
    public void CollectApprovalRequirements_GroupsGates()
    {
        var manifest = TestManifests.Load(TestManifests.Sample);
        var planner = new TaskPackPlanner();

        var plan = planner.Plan(manifest).Plan!;
        var requirements = TaskPackPlanInsights.CollectApprovalRequirements(plan);
        Assert.Single(requirements);
        var requirement = requirements[0];
        Assert.Equal("security-review", requirement.ApprovalId);
        Assert.Contains("Packs.Approve", requirement.Grants);
        Assert.Equal(plan.Steps[1].Id, requirement.StepIds.Single());

        var notifications = TaskPackPlanInsights.CollectNotificationHints(plan);
        Assert.Contains(notifications, hint => hint.Type == "approval-request" && hint.StepId == plan.Steps[1].Id);
    }

    [Fact]
    public void Plan_WithSecretReference_RecordsSecretMetadata()
    {
        var manifest = TestManifests.Load(TestManifests.Secret);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.True(result.Success);
        var plan = result.Plan!;
        Assert.Single(plan.Secrets);
        Assert.Equal("apiKey", plan.Secrets[0].Name);
        var param = plan.Steps[0].Parameters!["token"];
        Assert.True(param.RequiresRuntimeValue);
        Assert.Equal("secrets.apiKey", param.Expression);
    }

    [Fact]
    public void Plan_WithOutputs_ProjectsResolvedValues()
    {
        var manifest = TestManifests.Load(TestManifests.Output);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.True(result.Success);
        var plan = result.Plan!;
        Assert.Equal(2, plan.Outputs.Count);

        var bundle = plan.Outputs.First(o => o.Name == "bundlePath");
        Assert.NotNull(bundle.Path);
        Assert.False(bundle.Path!.RequiresRuntimeValue);
        Assert.Equal("artifacts/report.txt", bundle.Path.Value!.GetValue<string>());

        var evidence = plan.Outputs.First(o => o.Name == "evidenceModel");
        Assert.NotNull(evidence.Expression);
        Assert.True(evidence.Expression!.RequiresRuntimeValue);
        Assert.Equal("steps.generate.outputs.evidence", evidence.Expression.Expression);
    }

    [Fact]
    public void Plan_WithFailurePolicy_PopulatesPlanFailure()
    {
        var manifest = TestManifests.Load(TestManifests.FailurePolicy);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.True(result.Success);
        var plan = result.Plan!;
        Assert.NotNull(plan.FailurePolicy);
        Assert.Equal(4, plan.FailurePolicy!.MaxAttempts);
        Assert.Equal(30, plan.FailurePolicy.BackoffSeconds);
        Assert.False(plan.FailurePolicy.ContinueOnError);
    }

    [Fact]
    public void PolicyGateHints_IncludeRuntimeMetadata()
    {
        var manifest = TestManifests.Load(TestManifests.PolicyGate);
        var planner = new TaskPackPlanner();

        var plan = planner.Plan(manifest).Plan!;
        var hints = TaskPackPlanInsights.CollectPolicyGateHints(plan);
        Assert.Single(hints);
        var hint = hints[0];
        Assert.Equal("policy-check", hint.StepId);
        var threshold = hint.Parameters.Single(p => p.Name == "threshold");
        Assert.False(threshold.RequiresRuntimeValue);
        Assert.Null(threshold.Expression);
        var evidence = hint.Parameters.Single(p => p.Name == "evidenceRef");
        Assert.True(evidence.RequiresRuntimeValue);
        Assert.Equal("steps.prepare.outputs.evidence", evidence.Expression);
    }

    [Fact]
    public void Plan_SealedMode_BlocksUndeclaredEgress()
    {
        var manifest = TestManifests.Load(TestManifests.EgressBlocked);
        var options = new EgressPolicyOptions
        {
            Mode = EgressPolicyMode.Sealed
        };
        var planner = new TaskPackPlanner(new EgressPolicy(options));

        var result = planner.Plan(manifest);

        Assert.False(result.Success);
        Assert.Contains(result.Errors, error => error.Message.Contains("example.com", StringComparison.OrdinalIgnoreCase));
    }

    [Fact]
    public void Plan_WhenRequiredInputMissing_ReturnsError()
    {
        var manifest = TestManifests.Load(TestManifests.RequiredInput);
        var planner = new TaskPackPlanner();

        var result = planner.Plan(manifest);
        Assert.False(result.Success);
        Assert.NotEmpty(result.Errors);
    }

    [Fact]
    public void Plan_SealedMode_AllowsDeclaredEgress()
    {
        var manifest = TestManifests.Load(TestManifests.EgressAllowed);
        var options = new EgressPolicyOptions
        {
            Mode = EgressPolicyMode.Sealed
        };
        options.AddAllowRule("mirror.internal", 443, EgressTransport.Https);

        var planner = new TaskPackPlanner(new EgressPolicy(options));

        var result = planner.Plan(manifest);

        Assert.True(result.Success);
    }

    [Fact]
    public void Plan_SealedMode_RuntimeUrlWithoutDeclaration_ReturnsError()
    {
        var manifest = TestManifests.Load(TestManifests.EgressRuntime);
        var options = new EgressPolicyOptions
        {
            Mode = EgressPolicyMode.Sealed
        };
        var planner = new TaskPackPlanner(new EgressPolicy(options));

        var result = planner.Plan(manifest);

        Assert.False(result.Success);
        Assert.Contains(result.Errors, error => error.Path.StartsWith("spec.steps[0]", StringComparison.Ordinal));
    }
}