using System.Text.Json.Nodes;
using StellaOps.Scheduler.Models;

using StellaOps.TestKit;
namespace StellaOps.Scheduler.Models.Tests;

public sealed class SchedulerSchemaMigrationTests
{
    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeSchedule_DefaultsSchemaVersionWhenMissing()
    {
        var schedule = new Schedule(
            id: "sch-01",
            tenantId: "tenant-alpha",
            name: "Nightly",
            enabled: true,
            cronExpression: "0 2 * * *",
            timezone: "UTC",
            mode: ScheduleMode.AnalysisOnly,
            selection: new Selector(SelectorScope.AllImages, tenantId: "tenant-alpha"),
            onlyIf: null,
            notify: null,
            limits: null,
            createdAt: DateTimeOffset.Parse("2025-10-18T00:00:00Z"),
            createdBy: "svc-scheduler",
            updatedAt: DateTimeOffset.Parse("2025-10-18T00:00:00Z"),
            updatedBy: "svc-scheduler");

        var json = JsonNode.Parse(CanonicalJsonSerializer.Serialize(schedule))!.AsObject();
        json.Remove("schemaVersion");

        var result = SchedulerSchemaMigration.UpgradeSchedule(json);

        Assert.Equal(SchedulerSchemaVersions.Schedule, result.Value.SchemaVersion);
        Assert.Equal(SchedulerSchemaVersions.Schedule, result.ToVersion);
        Assert.Empty(result.Warnings);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeRun_StrictModeRemovesUnknownProperties()
    {
        var run = new Run(
            id: "run-01",
            tenantId: "tenant-alpha",
            trigger: RunTrigger.Manual,
            state: RunState.Queued,
            stats: RunStats.Empty,
            createdAt: DateTimeOffset.Parse("2025-10-18T01:10:00Z"));

        var json = JsonNode.Parse(CanonicalJsonSerializer.Serialize(run))!.AsObject();
        json["extraField"] = "to-be-removed";

        var result = SchedulerSchemaMigration.UpgradeRun(json, strict: true);

        Assert.Contains(result.Warnings, warning => warning.Contains("extraField", StringComparison.Ordinal));
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeImpactSet_ThrowsForUnsupportedVersion()
    {
        var impactSet = new ImpactSet(
            selector: new Selector(SelectorScope.AllImages, "tenant-alpha"),
            images: Array.Empty<ImpactImage>(),
            usageOnly: false,
            generatedAt: DateTimeOffset.Parse("2025-10-18T02:00:00Z"));

        var json = JsonNode.Parse(CanonicalJsonSerializer.Serialize(impactSet))!.AsObject();
        json["schemaVersion"] = "scheduler.impact-set@99";

        var ex = Assert.Throws<NotSupportedException>(() => SchedulerSchemaMigration.UpgradeImpactSet(json));
        Assert.Contains("Unsupported scheduler schema version", ex.Message, StringComparison.Ordinal);
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeSchedule_Legacy0_UpgradesToLatestVersion()
    {
        var legacy = new JsonObject
        {
            ["schemaVersion"] = SchedulerSchemaVersions.ScheduleLegacy0,
            ["id"] = "sch-legacy",
            ["tenantId"] = "tenant-alpha",
            ["name"] = "Legacy Nightly",
            ["enabled"] = true,
            ["cronExpression"] = "0 2 * * *",
            ["timezone"] = "UTC",
            ["mode"] = "analysis-only",
            ["selection"] = new JsonObject
            {
                ["scope"] = "all-images",
                ["tenantId"] = "tenant-alpha",
            },
            ["notify"] = new JsonObject
            {
                ["onNewFindings"] = "true",
                ["minSeverity"] = "HIGH",
            },
            ["limits"] = new JsonObject
            {
                ["maxJobs"] = "5",
                ["parallelism"] = -2,
            },
            ["subscribers"] = "ops-team",
            ["createdAt"] = "2025-10-10T00:00:00Z",
            ["createdBy"] = "system",
            ["updatedAt"] = "2025-10-10T01:00:00Z",
            ["updatedBy"] = "system",
        };

        var result = SchedulerSchemaMigration.UpgradeSchedule(legacy, strict: true);

        Assert.Equal(SchedulerSchemaVersions.ScheduleLegacy0, result.FromVersion);
        Assert.Equal(SchedulerSchemaVersions.Schedule, result.ToVersion);
        Assert.Equal(SchedulerSchemaVersions.Schedule, result.Value.SchemaVersion);
        Assert.True(result.Value.Notify.IncludeKev);
        Assert.Empty(result.Value.Subscribers);
        Assert.Contains(result.Warnings, warning => warning.Contains("schedule.limits.parallelism", StringComparison.Ordinal));
        Assert.Contains(result.Warnings, warning => warning.Contains("schedule.subscribers", StringComparison.Ordinal));
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeRun_Legacy0_BackfillsMissingStats()
    {
        var legacy = new JsonObject
        {
            ["schemaVersion"] = SchedulerSchemaVersions.RunLegacy0,
            ["id"] = "run-legacy",
            ["tenantId"] = "tenant-alpha",
            ["trigger"] = "manual",
            ["state"] = "queued",
            ["stats"] = new JsonObject
            {
                ["candidates"] = "4",
                ["queued"] = 2,
            },
            ["createdAt"] = "2025-10-10T02:00:00Z",
        };

        var result = SchedulerSchemaMigration.UpgradeRun(legacy, strict: true);

        Assert.Equal(SchedulerSchemaVersions.RunLegacy0, result.FromVersion);
        Assert.Equal(SchedulerSchemaVersions.Run, result.ToVersion);
        Assert.Equal(SchedulerSchemaVersions.Run, result.Value.SchemaVersion);
        Assert.Equal(4, result.Value.Stats.Candidates);
        Assert.Equal(0, result.Value.Stats.NewMedium);
        Assert.Equal(RunState.Queued, result.Value.State);
        Assert.Empty(result.Value.Deltas);
        Assert.Contains(result.Warnings, warning => warning.Contains("run.stats.newMedium", StringComparison.Ordinal));
    }

    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public void UpgradeImpactSet_Legacy0_ComputesTotal()
    {
        var legacy = new JsonObject
        {
            ["schemaVersion"] = SchedulerSchemaVersions.ImpactSetLegacy0,
            ["selector"] = JsonNode.Parse("""{"scope":"all-images","tenantId":"tenant-alpha"}"""),
            ["images"] = new JsonArray(
                JsonNode.Parse("""{"imageDigest":"sha256:1111111111111111111111111111111111111111111111111111111111111111","registry":"docker.io","repository":"library/nginx"}"""),
                JsonNode.Parse("""{"imageDigest":"sha256:2222222222222222222222222222222222222222222222222222222222222222","registry":"docker.io","repository":"library/httpd"}""")),
            ["usageOnly"] = "false",
            ["generatedAt"] = "2025-10-10T03:00:00Z",
        };

        var result = SchedulerSchemaMigration.UpgradeImpactSet(legacy, strict: true);

        Assert.Equal(SchedulerSchemaVersions.ImpactSetLegacy0, result.FromVersion);
        Assert.Equal(SchedulerSchemaVersions.ImpactSet, result.ToVersion);
        Assert.Equal(2, result.Value.Total);
        Assert.Equal(2, result.Value.Images.Length);
        Assert.Contains(result.Warnings, warning => warning.Contains("impact set total", StringComparison.OrdinalIgnoreCase));
    }
}