using ControlPlane.Core.Config;
using ControlPlane.Core.Interfaces;
using ControlPlane.Core.Messages;
using ControlPlane.Core.Models;
using ControlPlane.Core.Services;
using MassTransit;
using Microsoft.Extensions.Options;

namespace ControlPlane.Worker;

/// <summary>
/// MassTransit consumer. Triggered by ProvisionClientCommand off RabbitMQ.
/// Runs the saga and publishes ProvisioningProgressEvent for each step transition.
/// </summary>
public sealed class ProvisioningConsumer(
    IEnumerable<ISagaStep> steps,
    IPublishEndpoint bus,
    IConfiguration config,
    IOptions<ClarityInfraOptions> infraOptions,
    TenantRegistryService registry,
    ILogger<ProvisioningConsumer> logger) : IConsumer<ProvisionClientCommand>
{
    public async Task Consume(ConsumeContext<ProvisionClientCommand> context)
    {
        var cmd = context.Message;
        var job = new ProvisioningJob
        {
            Id          = cmd.JobId,
            ClientName  = cmd.ClientName,
            StateCode   = cmd.StateCode,
            Subdomain   = cmd.Subdomain,
            AdminEmail  = cmd.AdminEmail,
            SiteCode    = cmd.SiteCode,
            Environment = cmd.Environment,
            Status      = ProvisioningStatus.Running
        };

        logger.LogInformation("Starting provisioning saga for job {JobId} ({Client})", job.Id, job.ClientName);
        await RunSagaAsync(job, context.CancellationToken);
    }

    private async Task RunSagaAsync(ProvisioningJob job, CancellationToken cancellationToken)
    {
        var sagaContext  = new SagaContext { Job = job };
        var executedSteps = new Stack<ISagaStep>();

        foreach (var step in steps)
        {
            try
            {
                await Publish(job.Id, "step_started", step.StepName, $"Starting: {step.StepName}");
                logger.LogInformation("[{JobId}] Executing: {Step}", job.Id, step.StepName);

                await step.ExecuteAsync(sagaContext, cancellationToken);
                executedSteps.Push(step);

                await Publish(job.Id, "step_complete", step.StepName, $"Completed: {step.StepName}");
            }
            catch (Exception ex)
            {
                logger.LogError(ex, "[{JobId}] Step {Step} failed", job.Id, step.StepName);
                await Publish(job.Id, "step_failed",  step.StepName, $"Failed: {step.StepName} - {ex.Message}");
                await PublishDiagnostic(job.Id, step.StepName, ex);

                job.Status = ProvisioningStatus.Compensating;
                job.FailureReason = $"{step.StepName}: {ex.Message}";

                await CompensateAsync(sagaContext, executedSteps, cancellationToken);

                job.Status = ProvisioningStatus.Failed;
                await Publish(job.Id, "job_failed", null, job.FailureReason);
                return;
            }
        }

        job.Status     = ProvisioningStatus.Completed;
        job.CompletedAt = DateTimeOffset.UtcNow;
        await Publish(job.Id, "job_complete", null, "All steps completed successfully.");

        var infra = infraOptions.Value;
        var apiBaseUrl = sagaContext.TenantApiBaseUrl
                         ?? infra.TenantPublicUrl(job.Subdomain);

        // Persist to ClientAssets/{subdomain}.xml
        var nginxConfPath = config["Nginx:ConfDPath"] is { } p
            ? Path.Combine(p, $"{job.Subdomain}.conf")
            : null;

        var record = new TenantRecord
        {
            JobId              = job.Id.ToString(),
            Subdomain          = job.Subdomain,
            ClientName         = job.ClientName,
            StateCode          = job.StateCode,
            AdminEmail         = job.AdminEmail,
            SiteCode           = job.SiteCode,
            Environment        = job.Environment,
            Tier               = job.Tier.ToString(),
            ApiBaseUrl         = apiBaseUrl,
            Status             = "Provisioned",
            ProvisionedAt      = job.CompletedAt!.Value.ToString("o"),
            ContainerName      = sagaContext.ContainerName,
            ContainerPort      = null,
            ContainerImage     = config["Docker:ClarityServerImage"] ?? "clarity-server:latest",
            ContainerNetwork   = infra.Network,
            NginxConfPath      = nginxConfPath,
            PublicUrl          = infra.TenantPublicUrl(job.Subdomain),
            LastProvisioningStep = "LaunchStep",
            ProvisioningNotes  = $"Provisioned at {job.CompletedAt:o}. All {job.CompletedSteps} steps completed.",
        };

        // AppSettings — enriched by each step via SagaContext
        record.SetAppSetting("Keycloak:Realm", $"clarity-{job.Subdomain.ToLowerInvariant()}");
        record.SetAppSetting("Keycloak:BaseUrl", infra.KeycloakPublicUrl);
        record.SetAppSetting("Keycloak:InternalUrl", infra.KeycloakInternalUrl);

        if (!string.IsNullOrWhiteSpace(sagaContext.TenantStackName))
            record.SetAppSetting("Pulumi:StackName", sagaContext.TenantStackName);

        // ConnectionStrings — written by MigrationStep once DB is provisioned
        if (!string.IsNullOrWhiteSpace(sagaContext.TenantConnectionString))
            record.SetConnectionString("TenantDb", sagaContext.TenantConnectionString);

        registry.Save(record);

        logger.LogInformation("[{JobId}] Provisioning completed. Tenant record saved.", job.Id);
    }

    private async Task CompensateAsync(SagaContext sagaContext, Stack<ISagaStep> executedSteps, CancellationToken cancellationToken)
    {
        while (executedSteps.TryPop(out var step))
        {
            try
            {
                logger.LogInformation("[{JobId}] Compensating: {Step}", sagaContext.Job.Id, step.StepName);
                await Publish(sagaContext.Job.Id, "compensation_started", step.StepName, $"Rolling back: {step.StepName}");
                await step.CompensateAsync(sagaContext, cancellationToken);
                await Publish(sagaContext.Job.Id, "compensation_complete", step.StepName, $"Rolled back: {step.StepName}");
            }
            catch (Exception ex)
            {
                logger.LogError(ex, "[{JobId}] Compensation failed for {Step} - manual intervention required", sagaContext.Job.Id, step.StepName);
                await PublishDiagnostic(sagaContext.Job.Id, $"{step.StepName} (compensation)", ex);
            }
        }
    }

    private Task Publish(Guid jobId, string type, string? step, string? message) =>
        bus.Publish(new ProvisioningProgressEvent
        {
            JobId   = jobId,
            Type    = type,
            Step    = step,
            Message = message
        });

    private Task PublishDiagnostic(Guid jobId, string? step, Exception ex) =>
        bus.Publish(new ProvisioningProgressEvent
        {
            JobId   = jobId,
            Type    = "diagnostic",
            Step    = step,
            Message = ex.Message,
            Detail  = ex.ToString()
        });
}