using Microsoft.AspNetCore.Mvc;
using StellaOps.Auth.ServerIntegration.Tenancy;
using StellaOps.Notify.WebService.Constants;
using StellaOps.Notify.WebService.Extensions;
using StellaOps.Notifier.Worker.Correlation;
using static StellaOps.Localization.T;

namespace StellaOps.Notify.WebService.Endpoints;

/// <summary>
/// API endpoints for operator override management.
/// </summary>
public static class OperatorOverrideEndpoints
{
    /// <summary>
    /// Maps operator override endpoints.
    /// </summary>
    public static IEndpointRouteBuilder MapOperatorOverrideEndpoints(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/v2/overrides")
            .WithTags("Overrides")
            .WithOpenApi()
            .RequireAuthorization(NotifierPolicies.NotifyViewer)
            .RequireTenant();

        group.MapGet("/", ListOverridesAsync)
            .WithName("ListOperatorOverrides")
            .WithSummary("List active operator overrides")
            .WithDescription(_t("notifier.override.list_description"));

        group.MapGet("/{overrideId}", GetOverrideAsync)
            .WithName("GetOperatorOverride")
            .WithSummary("Get an operator override")
            .WithDescription(_t("notifier.override.get_description"));

        group.MapPost("/", CreateOverrideAsync)
            .WithName("CreateOperatorOverride")
            .WithSummary("Create an operator override")
            .WithDescription(_t("notifier.override.create_description"))
            .RequireAuthorization(NotifierPolicies.NotifyOperator);

        group.MapPost("/{overrideId}/revoke", RevokeOverrideAsync)
            .WithName("RevokeOperatorOverride")
            .WithSummary("Revoke an operator override")
            .WithDescription(_t("notifier.override.revoke_description"))
            .RequireAuthorization(NotifierPolicies.NotifyOperator);

        group.MapPost("/check", CheckOverrideAsync)
            .WithName("CheckOperatorOverride")
            .WithSummary("Check for applicable override")
            .WithDescription(_t("notifier.override.check_description"));

        return app;
    }

    private static async Task<IResult> ListOverridesAsync(
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromServices] IOperatorOverrideService overrideService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = _t("notifier.error.tenant_id_missing") });
        }

        var overrides = await overrideService.ListActiveOverridesAsync(tenantId, cancellationToken);

        return Results.Ok(overrides.Select(MapToApiResponse));
    }

    private static async Task<IResult> GetOverrideAsync(
        string overrideId,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromServices] IOperatorOverrideService overrideService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = _t("notifier.error.tenant_id_missing") });
        }

        var @override = await overrideService.GetOverrideAsync(tenantId, overrideId, cancellationToken);

        if (@override is null)
        {
            return Results.NotFound(new { error = _t("notifier.error.override_not_found", overrideId) });
        }

        return Results.Ok(MapToApiResponse(@override));
    }

    private static async Task<IResult> CreateOverrideAsync(
        [FromBody] OperatorOverrideApiRequest request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantIdHeader,
        [FromHeader(Name = "X-Actor")] string? actorHeader,
        [FromServices] IOperatorOverrideService overrideService,
        CancellationToken cancellationToken)
    {
        var tenantId = request.TenantId ?? tenantIdHeader;
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = _t("notifier.error.tenant_required") });
        }

        var actor = request.Actor ?? actorHeader;
        if (string.IsNullOrWhiteSpace(actor))
        {
            return Results.BadRequest(new { error = _t("notifier.error.actor_required") });
        }

        if (string.IsNullOrWhiteSpace(request.Reason))
        {
            return Results.BadRequest(new { error = _t("notifier.error.reason_required") });
        }

        if (request.DurationMinutes is null or <= 0)
        {
            return Results.BadRequest(new { error = _t("notifier.error.duration_required") });
        }

        var createRequest = new OperatorOverrideCreate
        {
            Type = MapOverrideType(request.Type),
            Reason = request.Reason,
            Duration = TimeSpan.FromMinutes(request.DurationMinutes.Value),
            EffectiveFrom = request.EffectiveFrom,
            EventKinds = request.EventKinds,
            CorrelationKeys = request.CorrelationKeys,
            MaxUsageCount = request.MaxUsageCount
        };

        try
        {
            var created = await overrideService.CreateOverrideAsync(tenantId, createRequest, actor, cancellationToken);
            return Results.Created($"/api/v2/overrides/{created.OverrideId}", MapToApiResponse(created));
        }
        catch (ArgumentException ex)
        {
            return Results.BadRequest(new { error = ex.Message });
        }
        catch (InvalidOperationException ex)
        {
            return Results.Conflict(new { error = ex.Message });
        }
    }

    private static async Task<IResult> RevokeOverrideAsync(
        string overrideId,
        [FromBody] RevokeOverrideApiRequest? request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromHeader(Name = "X-Actor")] string? actorHeader,
        [FromServices] IOperatorOverrideService overrideService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = _t("notifier.error.tenant_id_missing") });
        }

        var actor = request?.Actor ?? actorHeader;
        if (string.IsNullOrWhiteSpace(actor))
        {
            return Results.BadRequest(new { error = _t("notifier.error.actor_required") });
        }

        var revoked = await overrideService.RevokeOverrideAsync(
            tenantId,
            overrideId,
            actor,
            request?.Reason,
            cancellationToken);

        if (!revoked)
        {
            return Results.NotFound(new { error = _t("notifier.error.override_not_found_or_inactive", overrideId) });
        }

        return Results.NoContent();
    }

    private static async Task<IResult> CheckOverrideAsync(
        [FromBody] CheckOverrideApiRequest request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantIdHeader,
        [FromServices] IOperatorOverrideService overrideService,
        CancellationToken cancellationToken)
    {
        var tenantId = request.TenantId ?? tenantIdHeader;
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = _t("notifier.error.tenant_required") });
        }

        if (string.IsNullOrWhiteSpace(request.EventKind))
        {
            return Results.BadRequest(new { error = _t("notifier.error.event_kind_required") });
        }

        var result = await overrideService.CheckOverrideAsync(
            tenantId,
            request.EventKind,
            request.CorrelationKey,
            cancellationToken);

        return Results.Ok(new CheckOverrideApiResponse
        {
            HasOverride = result.HasOverride,
            BypassedTypes = MapOverrideTypeToStrings(result.BypassedTypes),
            Override = result.Override is not null ? MapToApiResponse(result.Override) : null
        });
    }

    private static OverrideType MapOverrideType(string? type) => type?.ToLowerInvariant() switch
    {
        "quiethours" or "quiet_hours" => OverrideType.QuietHours,
        "throttle" => OverrideType.Throttle,
        "maintenance" => OverrideType.Maintenance,
        "all" or _ => OverrideType.All
    };

    private static List<string> MapOverrideTypeToStrings(OverrideType type)
    {
        var result = new List<string>();
        if (type.HasFlag(OverrideType.QuietHours)) result.Add("quiet_hours");
        if (type.HasFlag(OverrideType.Throttle)) result.Add("throttle");
        if (type.HasFlag(OverrideType.Maintenance)) result.Add("maintenance");
        return result;
    }

    private static OperatorOverrideApiResponse MapToApiResponse(OperatorOverride @override) => new()
    {
        OverrideId = @override.OverrideId,
        TenantId = @override.TenantId,
        Type = MapOverrideTypeToStrings(@override.Type),
        Reason = @override.Reason,
        EffectiveFrom = @override.EffectiveFrom,
        ExpiresAt = @override.ExpiresAt,
        EventKinds = @override.EventKinds.ToList(),
        CorrelationKeys = @override.CorrelationKeys.ToList(),
        MaxUsageCount = @override.MaxUsageCount,
        UsageCount = @override.UsageCount,
        Status = @override.Status.ToString().ToLowerInvariant(),
        CreatedBy = @override.CreatedBy,
        CreatedAt = @override.CreatedAt,
        RevokedBy = @override.RevokedBy,
        RevokedAt = @override.RevokedAt,
        RevocationReason = @override.RevocationReason
    };
}

#region API Request/Response Models

/// <summary>
/// Request to create an operator override.
/// </summary>
public sealed class OperatorOverrideApiRequest
{
    public string? TenantId { get; set; }
    public string? Actor { get; set; }
    public string? Type { get; set; }
    public string? Reason { get; set; }
    public int? DurationMinutes { get; set; }
    public DateTimeOffset? EffectiveFrom { get; set; }
    public List<string>? EventKinds { get; set; }
    public List<string>? CorrelationKeys { get; set; }
    public int? MaxUsageCount { get; set; }
}

/// <summary>
/// Request to revoke an operator override.
/// </summary>
public sealed class RevokeOverrideApiRequest
{
    public string? Actor { get; set; }
    public string? Reason { get; set; }
}

/// <summary>
/// Request to check for applicable override.
/// </summary>
public sealed class CheckOverrideApiRequest
{
    public string? TenantId { get; set; }
    public string? EventKind { get; set; }
    public string? CorrelationKey { get; set; }
}

/// <summary>
/// Response for an operator override.
/// </summary>
public sealed class OperatorOverrideApiResponse
{
    public required string OverrideId { get; set; }
    public required string TenantId { get; set; }
    public required List<string> Type { get; set; }
    public required string Reason { get; set; }
    public required DateTimeOffset EffectiveFrom { get; set; }
    public required DateTimeOffset ExpiresAt { get; set; }
    public required List<string> EventKinds { get; set; }
    public required List<string> CorrelationKeys { get; set; }
    public int? MaxUsageCount { get; set; }
    public required int UsageCount { get; set; }
    public required string Status { get; set; }
    public required string CreatedBy { get; set; }
    public required DateTimeOffset CreatedAt { get; set; }
    public string? RevokedBy { get; set; }
    public DateTimeOffset? RevokedAt { get; set; }
    public string? RevocationReason { get; set; }
}

/// <summary>
/// Response for override check.
/// </summary>
public sealed class CheckOverrideApiResponse
{
    public required bool HasOverride { get; set; }
    public required List<string> BypassedTypes { get; set; }
    public OperatorOverrideApiResponse? Override { get; set; }
}

#endregion