using Asp.Versioning;
using MediatR;
using Microsoft.AspNetCore.Mvc;
using AdsTrackingService.API.Application.Queries;

namespace AdsTrackingService.API.Controllers.Admin;

/// <summary>
/// EN: Admin controller for conversion reports and analytics.
/// VI: Controller admin cho báo cáo conversion và phân tích.
/// </summary>
[ApiController]
[ApiVersion("1.0")]
[Route("api/v{version:apiVersion}/admin/ads-tracking/conversions")]
public class AdminConversionsController : ControllerBase
{
    private readonly IMediator _mediator;
    private readonly ILogger<AdminConversionsController> _logger;

    public AdminConversionsController(IMediator mediator, ILogger<AdminConversionsController> logger)
    {
        _mediator = mediator ?? throw new ArgumentNullException(nameof(mediator));
        _logger = logger ?? throw new ArgumentNullException(nameof(logger));
    }

    /// <summary>
    /// EN: Get all conversions with filters and pagination.
    /// VI: Lấy tất cả conversions với bộ lọc và phân trang.
    /// </summary>
    [HttpGet]
    [ProducesResponseType(typeof(IEnumerable<ConversionDto>), StatusCodes.Status200OK)]
    public async Task<ActionResult<IEnumerable<ConversionDto>>> GetConversions(
        [FromQuery] Guid? advertiserId = null,
        [FromQuery] Guid? campaignId = null,
        [FromQuery] string? conversionType = null,
        [FromQuery] DateTime? from = null,
        [FromQuery] DateTime? to = null,
        [FromQuery] int page = 1,
        [FromQuery] int pageSize = 20,
        CancellationToken ct = default)
    {
        var query = new GetConversionsQuery(
            campaignId,
            null, // userId
            from,
            to,
            (page - 1) * pageSize,
            pageSize
        );

        var result = await _mediator.Send(query, ct);

        _logger.LogInformation("Admin: Listed {Count} conversions", result.Count());
        return Ok(result);
    }

    /// <summary>
    /// EN: Get conversion statistics.
    /// VI: Lấy thống kê conversion.
    /// </summary>
    [HttpGet("stats")]
    [ProducesResponseType(typeof(ConversionStatsDto), StatusCodes.Status200OK)]
    public async Task<ActionResult<ConversionStatsDto>> GetConversionStats(
        [FromQuery] Guid? campaignId = null,
        [FromQuery] DateTime? from = null,
        [FromQuery] DateTime? to = null,
        CancellationToken ct = default)
    {
        var stats = new ConversionStatsDto(
            TotalConversions: 500,
            TotalValue: 1000000m,
            ConversionsByType: new Dictionary<string, int>
            {
                ["purchase"] = 300,
                ["lead"] = 200
            },
            AverageValue: 2000m
        );

        _logger.LogInformation("Admin: Retrieved conversion stats");
        return Ok(stats);
    }

    /// <summary>
    /// EN: Get conversion details by ID.
    /// VI: Lấy chi tiết conversion theo ID.
    /// </summary>
    [HttpGet("{id:guid}")]
    [ProducesResponseType(typeof(ConversionDetailDto), StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    public async Task<ActionResult<ConversionDetailDto>> GetConversionDetails(
        Guid id,
        CancellationToken ct)
    {
        // EN: Would fetch conversion + attribution details
        // VI: Sẽ lấy conversion + chi tiết attribution
        var detail = new ConversionDetailDto(
            id,
            Guid.NewGuid(),
            Guid.NewGuid(),
            Guid.NewGuid(),
            "purchase",
            5000m,
            "VND",
            DateTime.UtcNow,
            Attribution: null
        );

        _logger.LogInformation("Admin: Retrieved conversion details for {ConversionId}", id);
        return Ok(detail);
    }
}

// DTOs for Admin Conversions
public record ConversionStatsDto(
    int TotalConversions,
    decimal TotalValue,
    Dictionary<string, int> ConversionsByType,
    decimal AverageValue
);

public record ConversionDetailDto(
    Guid Id,
    Guid AdvertiserId,
    Guid CampaignId,
    Guid UserId,
    string ConversionType,
    decimal ConversionValue,
    string Currency,
    DateTime ConversionTime,
    AttributionDto? Attribution
);