using System;
using System.Collections.Generic;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using StellaOps.Concelier.Core.Jobs;

namespace StellaOps.Concelier.WebService.Extensions;

internal static class JobRegistrationExtensions
{
    private sealed record BuiltInJob(
        string Kind,
        string JobType,
        string AssemblyName,
        TimeSpan Timeout,
        TimeSpan LeaseDuration,
        string? CronExpression = null);

    private static readonly IReadOnlyList<BuiltInJob> BaseBuiltInJobs = new List<BuiltInJob>
    {
        new("source:redhat:fetch", "StellaOps.Concelier.Connector.Distro.RedHat.RedHatFetchJob", "StellaOps.Concelier.Connector.Distro.RedHat", TimeSpan.FromMinutes(12), TimeSpan.FromMinutes(6), "0,15,30,45 * * * *"),
        new("source:redhat:parse", "StellaOps.Concelier.Connector.Distro.RedHat.RedHatParseJob", "StellaOps.Concelier.Connector.Distro.RedHat", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(6), "5,20,35,50 * * * *"),
        new("source:redhat:map", "StellaOps.Concelier.Connector.Distro.RedHat.RedHatMapJob", "StellaOps.Concelier.Connector.Distro.RedHat", TimeSpan.FromMinutes(20), TimeSpan.FromMinutes(6), "10,25,40,55 * * * *"),

        new("source:cert-in:fetch", "StellaOps.Concelier.Connector.CertIn.CertInFetchJob", "StellaOps.Concelier.Connector.CertIn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:cert-in:parse", "StellaOps.Concelier.Connector.CertIn.CertInParseJob", "StellaOps.Concelier.Connector.CertIn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:cert-in:map", "StellaOps.Concelier.Connector.CertIn.CertInMapJob", "StellaOps.Concelier.Connector.CertIn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:cert-fr:fetch", "StellaOps.Concelier.Connector.CertFr.CertFrFetchJob", "StellaOps.Concelier.Connector.CertFr", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:cert-fr:parse", "StellaOps.Concelier.Connector.CertFr.CertFrParseJob", "StellaOps.Concelier.Connector.CertFr", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:cert-fr:map", "StellaOps.Concelier.Connector.CertFr.CertFrMapJob", "StellaOps.Concelier.Connector.CertFr", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:jvn:fetch", "StellaOps.Concelier.Connector.Jvn.JvnFetchJob", "StellaOps.Concelier.Connector.Jvn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:jvn:parse", "StellaOps.Concelier.Connector.Jvn.JvnParseJob", "StellaOps.Concelier.Connector.Jvn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:jvn:map", "StellaOps.Concelier.Connector.Jvn.JvnMapJob", "StellaOps.Concelier.Connector.Jvn", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:ics-kaspersky:fetch", "StellaOps.Concelier.Connector.Ics.Kaspersky.KasperskyFetchJob", "StellaOps.Concelier.Connector.Ics.Kaspersky", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:ics-kaspersky:parse", "StellaOps.Concelier.Connector.Ics.Kaspersky.KasperskyParseJob", "StellaOps.Concelier.Connector.Ics.Kaspersky", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:ics-kaspersky:map", "StellaOps.Concelier.Connector.Ics.Kaspersky.KasperskyMapJob", "StellaOps.Concelier.Connector.Ics.Kaspersky", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:osv:fetch", "StellaOps.Concelier.Connector.Osv.OsvFetchJob", "StellaOps.Concelier.Connector.Osv", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:osv:parse", "StellaOps.Concelier.Connector.Osv.OsvParseJob", "StellaOps.Concelier.Connector.Osv", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:osv:map", "StellaOps.Concelier.Connector.Osv.OsvMapJob", "StellaOps.Concelier.Connector.Osv", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:vmware:fetch", "StellaOps.Concelier.Connector.Vndr.Vmware.VmwareFetchJob", "StellaOps.Concelier.Connector.Vndr.Vmware", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:vmware:parse", "StellaOps.Concelier.Connector.Vndr.Vmware.VmwareParseJob", "StellaOps.Concelier.Connector.Vndr.Vmware", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:vmware:map", "StellaOps.Concelier.Connector.Vndr.Vmware.VmwareMapJob", "StellaOps.Concelier.Connector.Vndr.Vmware", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("source:vndr-oracle:fetch", "StellaOps.Concelier.Connector.Vndr.Oracle.OracleFetchJob", "StellaOps.Concelier.Connector.Vndr.Oracle", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:vndr-oracle:parse", "StellaOps.Concelier.Connector.Vndr.Oracle.OracleParseJob", "StellaOps.Concelier.Connector.Vndr.Oracle", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),
        new("source:vndr-oracle:map", "StellaOps.Concelier.Connector.Vndr.Oracle.OracleMapJob", "StellaOps.Concelier.Connector.Vndr.Oracle", TimeSpan.FromMinutes(15), TimeSpan.FromMinutes(5)),

        new("export:json", "StellaOps.Concelier.Exporter.Json.JsonExportJob", "StellaOps.Concelier.Exporter.Json", TimeSpan.FromMinutes(10), TimeSpan.FromMinutes(5)),
        new("export:trivy-db", "StellaOps.Concelier.Exporter.TrivyDb.TrivyDbExportJob", "StellaOps.Concelier.Exporter.TrivyDb", TimeSpan.FromMinutes(20), TimeSpan.FromMinutes(10))
    };

    private static readonly BuiltInJob MergeReconcileBuiltInJob = new(
        "merge:reconcile",
        "StellaOps.Concelier.Merge.Jobs.MergeReconcileJob",
        "StellaOps.Concelier.Merge",
        TimeSpan.FromMinutes(15),
        TimeSpan.FromMinutes(5));

    public static IServiceCollection AddBuiltInConcelierJobs(this IServiceCollection services)
    {
        ArgumentNullException.ThrowIfNull(services);

        services.AddOptions<JobSchedulerOptions>()
            .Configure<IConfiguration>((options, configuration) =>
            {
                foreach (var registration in BaseBuiltInJobs)
                {
                    AddJobIfMissing(options, registration);
                }

                ConfigureMergeJob(options, configuration);
            });

        return services;
    }

    private static void AddJobIfMissing(JobSchedulerOptions options, BuiltInJob registration)
    {
        if (options.Definitions.ContainsKey(registration.Kind))
        {
            return;
        }

        var jobType = Type.GetType(
            $"{registration.JobType}, {registration.AssemblyName}",
            throwOnError: false,
            ignoreCase: false);

        if (jobType is null)
        {
            return;
        }

        var timeout = registration.Timeout > TimeSpan.Zero ? registration.Timeout : options.DefaultTimeout;
        var lease = registration.LeaseDuration > TimeSpan.Zero ? registration.LeaseDuration : options.DefaultLeaseDuration;

        options.Definitions[registration.Kind] = new JobDefinition(
            registration.Kind,
            jobType,
            timeout,
            lease,
            registration.CronExpression,
            Enabled: true);
    }

    private static void ConfigureMergeJob(JobSchedulerOptions options, IConfiguration configuration)
    {
        var noMergeEnabled = configuration.GetValue<bool?>("concelier:features:noMergeEnabled")
            ?? configuration.GetValue<bool?>("features:noMergeEnabled")
            ?? true;
        if (noMergeEnabled)
        {
            options.Definitions.Remove(MergeReconcileBuiltInJob.Kind);
            return;
        }

        var allowlist = configuration.GetSection("concelier:jobs:merge:allowlist").Get<string[]>()
            ?? configuration.GetSection("jobs:merge:allowlist").Get<string[]>();
        if (allowlist is { Length: > 0 })
        {
            var allowlistSet = new HashSet<string>(allowlist, StringComparer.OrdinalIgnoreCase);
            if (!allowlistSet.Contains(MergeReconcileBuiltInJob.Kind))
            {
                options.Definitions.Remove(MergeReconcileBuiltInJob.Kind);
                return;
            }
        }

        AddJobIfMissing(options, MergeReconcileBuiltInJob);
    }
}