using Microsoft.AspNetCore.Mvc;
using StellaOps.Notifier.Worker.Correlation;

namespace StellaOps.Notifier.WebService.Endpoints;

/// <summary>
/// API endpoints for quiet hours calendar management.
/// </summary>
public static class QuietHoursEndpoints
{
    /// <summary>
    /// Maps quiet hours endpoints.
    /// </summary>
    public static IEndpointRouteBuilder MapQuietHoursEndpoints(this IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api/v2/quiet-hours")
            .WithTags("QuietHours")
            .WithOpenApi();

        group.MapGet("/calendars", ListCalendarsAsync)
            .WithName("ListQuietHoursCalendars")
            .WithSummary("List all quiet hours calendars")
            .WithDescription("Returns all quiet hours calendars for the tenant.");

        group.MapGet("/calendars/{calendarId}", GetCalendarAsync)
            .WithName("GetQuietHoursCalendar")
            .WithSummary("Get a quiet hours calendar")
            .WithDescription("Returns a specific quiet hours calendar by ID.");

        group.MapPost("/calendars", CreateCalendarAsync)
            .WithName("CreateQuietHoursCalendar")
            .WithSummary("Create a quiet hours calendar")
            .WithDescription("Creates a new quiet hours calendar with schedules.");

        group.MapPut("/calendars/{calendarId}", UpdateCalendarAsync)
            .WithName("UpdateQuietHoursCalendar")
            .WithSummary("Update a quiet hours calendar")
            .WithDescription("Updates an existing quiet hours calendar.");

        group.MapDelete("/calendars/{calendarId}", DeleteCalendarAsync)
            .WithName("DeleteQuietHoursCalendar")
            .WithSummary("Delete a quiet hours calendar")
            .WithDescription("Deletes a quiet hours calendar.");

        group.MapPost("/evaluate", EvaluateAsync)
            .WithName("EvaluateQuietHours")
            .WithSummary("Evaluate quiet hours")
            .WithDescription("Checks if quiet hours are currently active for an event kind.");

        return app;
    }

    private static async Task<IResult> ListCalendarsAsync(
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "X-Tenant-Id header is required." });
        }

        var calendars = await calendarService.ListCalendarsAsync(tenantId, cancellationToken);

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

    private static async Task<IResult> GetCalendarAsync(
        string calendarId,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "X-Tenant-Id header is required." });
        }

        var calendar = await calendarService.GetCalendarAsync(tenantId, calendarId, cancellationToken);

        if (calendar is null)
        {
            return Results.NotFound(new { error = $"Calendar '{calendarId}' not found." });
        }

        return Results.Ok(MapToApiResponse(calendar));
    }

    private static async Task<IResult> CreateCalendarAsync(
        [FromBody] QuietHoursCalendarApiRequest request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantIdHeader,
        [FromHeader(Name = "X-Actor")] string? actor,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        var tenantId = request.TenantId ?? tenantIdHeader;
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "Tenant ID is required via X-Tenant-Id header or request body." });
        }

        if (string.IsNullOrWhiteSpace(request.Name))
        {
            return Results.BadRequest(new { error = "Calendar name is required." });
        }

        if (request.Schedules is null || request.Schedules.Count == 0)
        {
            return Results.BadRequest(new { error = "At least one schedule is required." });
        }

        var calendarId = request.CalendarId ?? Guid.NewGuid().ToString("N")[..16];

        var calendar = new QuietHoursCalendar
        {
            CalendarId = calendarId,
            TenantId = tenantId,
            Name = request.Name,
            Description = request.Description,
            Enabled = request.Enabled ?? true,
            Priority = request.Priority ?? 100,
            Schedules = request.Schedules.Select(MapToScheduleEntry).ToList(),
            ExcludedEventKinds = request.ExcludedEventKinds,
            IncludedEventKinds = request.IncludedEventKinds
        };

        var created = await calendarService.UpsertCalendarAsync(calendar, actor, cancellationToken);

        return Results.Created($"/api/v2/quiet-hours/calendars/{created.CalendarId}", MapToApiResponse(created));
    }

    private static async Task<IResult> UpdateCalendarAsync(
        string calendarId,
        [FromBody] QuietHoursCalendarApiRequest request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantIdHeader,
        [FromHeader(Name = "X-Actor")] string? actor,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        var tenantId = request.TenantId ?? tenantIdHeader;
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "Tenant ID is required via X-Tenant-Id header or request body." });
        }

        var existing = await calendarService.GetCalendarAsync(tenantId, calendarId, cancellationToken);
        if (existing is null)
        {
            return Results.NotFound(new { error = $"Calendar '{calendarId}' not found." });
        }

        var calendar = new QuietHoursCalendar
        {
            CalendarId = calendarId,
            TenantId = tenantId,
            Name = request.Name ?? existing.Name,
            Description = request.Description ?? existing.Description,
            Enabled = request.Enabled ?? existing.Enabled,
            Priority = request.Priority ?? existing.Priority,
            Schedules = request.Schedules?.Select(MapToScheduleEntry).ToList() ?? existing.Schedules,
            ExcludedEventKinds = request.ExcludedEventKinds ?? existing.ExcludedEventKinds,
            IncludedEventKinds = request.IncludedEventKinds ?? existing.IncludedEventKinds,
            CreatedAt = existing.CreatedAt,
            CreatedBy = existing.CreatedBy
        };

        var updated = await calendarService.UpsertCalendarAsync(calendar, actor, cancellationToken);

        return Results.Ok(MapToApiResponse(updated));
    }

    private static async Task<IResult> DeleteCalendarAsync(
        string calendarId,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantId,
        [FromHeader(Name = "X-Actor")] string? actor,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "X-Tenant-Id header is required." });
        }

        var deleted = await calendarService.DeleteCalendarAsync(tenantId, calendarId, actor, cancellationToken);

        if (!deleted)
        {
            return Results.NotFound(new { error = $"Calendar '{calendarId}' not found." });
        }

        return Results.NoContent();
    }

    private static async Task<IResult> EvaluateAsync(
        [FromBody] QuietHoursEvaluateApiRequest request,
        [FromHeader(Name = "X-Tenant-Id")] string? tenantIdHeader,
        [FromServices] IQuietHoursCalendarService calendarService,
        CancellationToken cancellationToken)
    {
        var tenantId = request.TenantId ?? tenantIdHeader;
        if (string.IsNullOrWhiteSpace(tenantId))
        {
            return Results.BadRequest(new { error = "Tenant ID is required via X-Tenant-Id header or request body." });
        }

        if (string.IsNullOrWhiteSpace(request.EventKind))
        {
            return Results.BadRequest(new { error = "Event kind is required." });
        }

        var result = await calendarService.EvaluateAsync(
            tenantId,
            request.EventKind,
            request.EvaluationTime,
            cancellationToken);

        return Results.Ok(new QuietHoursEvaluateApiResponse
        {
            IsActive = result.IsActive,
            MatchedCalendarId = result.MatchedCalendarId,
            MatchedCalendarName = result.MatchedCalendarName,
            MatchedScheduleName = result.MatchedScheduleName,
            EndsAt = result.EndsAt,
            Reason = result.Reason
        });
    }

    private static QuietHoursScheduleEntry MapToScheduleEntry(QuietHoursScheduleApiRequest request) => new()
    {
        Name = request.Name ?? "Unnamed Schedule",
        StartTime = request.StartTime ?? "00:00",
        EndTime = request.EndTime ?? "00:00",
        DaysOfWeek = request.DaysOfWeek,
        Timezone = request.Timezone,
        Enabled = request.Enabled ?? true
    };

    private static QuietHoursCalendarApiResponse MapToApiResponse(QuietHoursCalendar calendar) => new()
    {
        CalendarId = calendar.CalendarId,
        TenantId = calendar.TenantId,
        Name = calendar.Name,
        Description = calendar.Description,
        Enabled = calendar.Enabled,
        Priority = calendar.Priority,
        Schedules = calendar.Schedules.Select(s => new QuietHoursScheduleApiResponse
        {
            Name = s.Name,
            StartTime = s.StartTime,
            EndTime = s.EndTime,
            DaysOfWeek = s.DaysOfWeek?.ToList(),
            Timezone = s.Timezone,
            Enabled = s.Enabled
        }).ToList(),
        ExcludedEventKinds = calendar.ExcludedEventKinds?.ToList(),
        IncludedEventKinds = calendar.IncludedEventKinds?.ToList(),
        CreatedAt = calendar.CreatedAt,
        CreatedBy = calendar.CreatedBy,
        UpdatedAt = calendar.UpdatedAt,
        UpdatedBy = calendar.UpdatedBy
    };
}

#region API Request/Response Models

/// <summary>
/// Request to create or update a quiet hours calendar.
/// </summary>
public sealed class QuietHoursCalendarApiRequest
{
    public string? CalendarId { get; set; }
    public string? TenantId { get; set; }
    public string? Name { get; set; }
    public string? Description { get; set; }
    public bool? Enabled { get; set; }
    public int? Priority { get; set; }
    public List<QuietHoursScheduleApiRequest>? Schedules { get; set; }
    public List<string>? ExcludedEventKinds { get; set; }
    public List<string>? IncludedEventKinds { get; set; }
}

/// <summary>
/// Schedule entry in a quiet hours calendar request.
/// </summary>
public sealed class QuietHoursScheduleApiRequest
{
    public string? Name { get; set; }
    public string? StartTime { get; set; }
    public string? EndTime { get; set; }
    public List<int>? DaysOfWeek { get; set; }
    public string? Timezone { get; set; }
    public bool? Enabled { get; set; }
}

/// <summary>
/// Request to evaluate quiet hours.
/// </summary>
public sealed class QuietHoursEvaluateApiRequest
{
    public string? TenantId { get; set; }
    public string? EventKind { get; set; }
    public DateTimeOffset? EvaluationTime { get; set; }
}

/// <summary>
/// Response for a quiet hours calendar.
/// </summary>
public sealed class QuietHoursCalendarApiResponse
{
    public required string CalendarId { get; set; }
    public required string TenantId { get; set; }
    public required string Name { get; set; }
    public string? Description { get; set; }
    public required bool Enabled { get; set; }
    public required int Priority { get; set; }
    public required List<QuietHoursScheduleApiResponse> Schedules { get; set; }
    public List<string>? ExcludedEventKinds { get; set; }
    public List<string>? IncludedEventKinds { get; set; }
    public DateTimeOffset CreatedAt { get; set; }
    public string? CreatedBy { get; set; }
    public DateTimeOffset UpdatedAt { get; set; }
    public string? UpdatedBy { get; set; }
}

/// <summary>
/// Schedule entry in a quiet hours calendar response.
/// </summary>
public sealed class QuietHoursScheduleApiResponse
{
    public required string Name { get; set; }
    public required string StartTime { get; set; }
    public required string EndTime { get; set; }
    public List<int>? DaysOfWeek { get; set; }
    public string? Timezone { get; set; }
    public required bool Enabled { get; set; }
}

/// <summary>
/// Response for quiet hours evaluation.
/// </summary>
public sealed class QuietHoursEvaluateApiResponse
{
    public required bool IsActive { get; set; }
    public string? MatchedCalendarId { get; set; }
    public string? MatchedCalendarName { get; set; }
    public string? MatchedScheduleName { get; set; }
    public DateTimeOffset? EndsAt { get; set; }
    public string? Reason { get; set; }
}

#endregion