using Elsa.Workflows.Runtime.Features;
using Medallion.Threading.Redis;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using StackExchange.Redis;

namespace Caspian.WorkflowFramework.Config;

internal static class WorkflowRuntimeFeatureExtensions
{
    internal static void UseConfiguredDistributedLocking(this WorkflowRuntimeFeature runtime, IConfiguration configuration)
    {
        var legacySettings = configuration.GetSection("Runtime:DistributedLocking");
        var settings = configuration.GetSection("Workflow:Runtime:DistributedLocking");
        runtime.DistributedLockingOptions = options =>
        {
            legacySettings.Bind(options);
            settings.Bind(options);
        };

        var providerName = settings["Provider"] ?? legacySettings["Provider"];
        switch (providerName?.ToUpperInvariant())
        {
            case "REDIS":
            {
                var database = settings.GetValue<int?>("Database")
                    ?? legacySettings.GetValue<int?>("Database")
                    ?? configuration.GetValue<int?>("Redis:Database") ?? -1;
                var prefix = settings["KeyPrefix"] ?? legacySettings["KeyPrefix"] ?? "nextbank:workflow:locks:";
                if (database < -1) throw new InvalidOperationException("Workflow lock database must be -1 or a non-negative number.");
                if (string.IsNullOrWhiteSpace(prefix)) throw new InvalidOperationException("Workflow lock KeyPrefix must not be empty.");
                runtime.DistributedLockProvider = sp => new PrefixedDistributedLockProvider(
                    new RedisDistributedSynchronizationProvider(sp.GetRequiredService<IConnectionMultiplexer>().GetDatabase(database)), prefix);
                break;
            }
            case null:
            case "":
            case "FILE":
                break;
            default:
                throw new InvalidOperationException($"Unsupported workflow lock provider '{providerName}'. Configure File or Redis.");
        }
    }
}